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WIGGLING 'LITE' IN GUEST MODE

BUILD THREAD: 266-style PCBs
MUFF WIGGLER Forum Index -> Music Tech DIY  
Author BUILD THREAD: 266-style PCBs
roman_f
this is gonna be a 266 clone build-thread, i will update 5 following comments as i have new information.

Some general knowledge:

Buchla and 5U format PCBs work only on 15V, bot has pads for Eurorack IDC-10 (Cwejman-style), mta-100 dotcom, mta-156 MOTM and MODCAN power connectors.

Eurorack format is for 12V operation, but can work on 15V as well - just do not install 12V-to-15V transformer parts and put 2 links/wires instead - i'll show it a bit later. It has Eurorack IDC-10 (Cwejman-style) power connector only.

Do not solder jacks/leds/pots before you solder voltage shifts parts.
Also do not solder jacks before you fit them into panel.

1) put jacks into pads on the PCB, but to not solder them
2) fit the panel on jacks
3) turn it all upside down and then solder the jacks
4) after that fit the pots and LEDs

Do not forget to connect 2 PCBs with 3 THRU pads
this brings power to the 2nd PCB

one more thing to say

i have also experienced an issue with ribbon-cables - a few of them look good, but do not function well, a couple had wrong key position

so:
1) take a look at your ribbon cables.



2) 5U & Buchla ones should have "keys" looking outside and EURO's "keys" are looking inside on both sides on the cable

3) check that "arrows" are located at the same side as the red line on the cable

4) ring all the connections with a multi-meter so be sure that nothing is shorting inside of the cable. holes are too small to put the test-leads inside of them, so you may put the other part of the connector and have an access to pins.

i do not think that many people would have such a problem, but anyway - please check it.
roman_f
5U





The only issue with 5U PCBs are swapped SRV1 and SRV2 outputs
you may cut 2 traces and wire in a proper order or leave it as it is

what's the difference between SRV1 & SRV2?
well, SRV is fixed flat Stored Random Voltages
SRV2 is kinda bell which is moved thru the SRV1 area, it selects the voltages range from low to high.

DO NOT install R16 & R35 - this will allow the S&H to work with 5V pulses, originally it's for 15Vs
roman_f
EURORACK




EURO version still has an issue with power, please give me a couple days for fixing it.
at end you'll just need to skip some parts and install 2 jumpers
sorry for that issue and please wait a bit
roman_f
BUCHLA






banana color code:

black - cv in
blue - cv out
violet - alt cv out
orange - pulse in
red - pulse out
roman_f
RARE PARTS & REPLACEMENTS:

2x VTL5C3 Vactrols
2x VTL5C3/2 Vactrols

PCB has pads for single Silonex NSL-32SR3 optopairs, but i could not manage them working properly with 266. so please use vactrols.

the noise chip - MM5837 can be purchased from Kevin Keinert, $19 each, if you buy only 1.
he also sells same chip with a different marking for $10.
Bleeps is currently making a group-buy of them.

1x CA3080 OTA - good chinese ebay seller or Bridechamber

1N457 diodes can be replaced with 1N4148.
RC4558 dual opamps can be replaced with TL072 (offset may change a bit)
LF356 single opamps can be replaced with TL071 (offset may change a bit)
2N1711 transistors can be replaced with a generic 2N3904 (or similar). They are used for driving LEDs only.
CD4030 CMOS Quad Exclusive-OR Gate can be replaced with CD4070
CD4006 can be replaced with HEF4006
roman_f
PANELS

Rod Serling Fan Club is currently taking orders for Buchla-format panels.
https://www.muffwiggler.com/forum/viewtopic.php?t=57931

5U and Euro offers to come very soon
MechaSeb
I have a 10x VTL5C3 set i bought a while ago for another project which never saw the light.
Is it possible to replace the two listed VTL5C3/2 by two VTL5C3 ? I guess yes as their proprieties are pretty similar but... preferred to ask before anything.
roman_f
MechaSeb wrote:
I have a 10x VTL5C3 set i bought a while ago for another project which never saw the light.
Is it possible to replace the two listed VTL5C3/2 by two VTL5C3 ? I guess yes as their proprieties are pretty similar but... preferred to ask before anything.


probably, but i can not confirm it
+ you would have problems with the depth of the module - standoffs would have to be extended (vactrol are big guys)
blue_lu
so, is there anyone planning to do pannels - for the buchla format especially?
roman_f
blue_lu wrote:
so, is there anyone planning to do pannels - for the buchla format especially?

Rod Serling Fan Club
julian
I would, of course, be happy to work out some costing for whatever RSFC isnt taking care of.

- meening i dont know if he is doing all the formats, or otherwise, but im sure either way panels will be availible : )
Rod Serling Fan Club
I just plan on doing buchla format panels that are similar to the others I am doing in this thread.
sinequanon
julian wrote:
I would, of course, be happy to work out some costing for whatever RSFC isnt taking care of.

- meening i dont know if he is doing all the formats, or otherwise, but im sure either way panels will be availible : )


Well , I'd be interested in knowing the cost of a 5U panel, I usually make my own front panels out of wood but never used pcb mounted jacks and pots, that project would be tricky for me as i don't have precision woodworking tools and there will be a ton of panel components...

awesome project..
roman_f
sinequanon wrote:
julian wrote:
I would, of course, be happy to work out some costing for whatever RSFC isnt taking care of.

- meening i dont know if he is doing all the formats, or otherwise, but im sure either way panels will be availible : )


Well , I'd be interested in knowing the cost of a 5U panel, I usually make my own front panels out of wood but never used pcb mounted jacks and pots, that project would be tricky for me as i don't have precision woodworking tools and there will be a ton of panel components...

awesome project..


5U panels would be done by ben @ re:synthesis
and you can always solders jacks/pots not directly to the pcb, but with a wires to the proper pads
fluxmonkey
roman, if you could send me the board dimensions & coordinates of th board-mounted components, euro format, id be willing to try my hand at a frac-format panel in FPD

b
bleeps
Would anyone be interested in a group buy of the noise chip (generic version)? I placed a query with the vendor to see if we could get a larger discount with a larger quantity. Keep in mind I haven't organized one of these before but I have the time and the means to do one at the moment and I think it would be nice a nice way to contribute to a community I am learning so much from.

If you want in, PM me and I'll start a separate thread with info and costs if there is enough interest.

EDIT: Group Buy thread has been started.
roman_f
bleeps wrote:
Would anyone be interested in a group buy of the noise chip (generic version)? I placed a query with the vendor to see if we could get a larger discount with a larger quantity. Keep in mind I haven't organized one of these before but I have the time and the means to do one at the moment and I think it would be nice a nice way to contribute to a community I am learning so much from.

If you want in, PM me and I'll start a separate thread with info and costs if there is enough interest.


kevin has told me he can get the replacement chips (same chips with the different marking on them) for $8.75 if someone buys 20+
original chips are $18.95 now (or $15.95 for 10+)
roman_f
fluxmonkey wrote:
roman, if you could send me the board dimensions & coordinates of th board-mounted components, euro format, id be willing to try my hand at a frac-format panel in FPD

b


gonna do that tomorrow, i have to double-check everything
bleeps
roman_f wrote:
kevin has told me he can get the replacement chips (same chips with the different marking on them) for $8.75 if someone buys 20+
original chips are $18.95 now (or $15.95 for 10+)

Perfect!
julian
roman_f wrote:
sinequanon wrote:
julian wrote:
I would, of course, be happy to work out some costing for whatever RSFC isnt taking care of.

- meening i dont know if he is doing all the formats, or otherwise, but im sure either way panels will be availible : )


Well , I'd be interested in knowing the cost of a 5U panel, I usually make my own front panels out of wood but never used pcb mounted jacks and pots, that project would be tricky for me as i don't have precision woodworking tools and there will be a ton of panel components...

awesome project..


5U panels would be done by ben @ re:synthesis
and you can always solders jacks/pots not directly to the pcb, but with a wires to the proper pads



/confused/

Ben makes etched panels, i do cnc panels - they're very different finishes...
I would assume people would enjoy different options??

Either way though, im easy - it was just an offer!
akrylik
Do you think it would be possible to do a euro panel like sduck did for his corgasmatron?

http://www.flickr.com/photos/sduck409/6900025462/

That look is just so inviting to me.
emdot_ambient
Julian, I'd be interested in seeing what you come up with for a 5U design on this. I'm using MOTM panel sizes at the moment.
emdot_ambient
bleeps wrote:
Would anyone be interested in a group buy of the noise chip (generic version)?

I'd be in for that (1)!
emdot_ambient
roman_f wrote:
the noise chip - MM5837 can be purchased from Kevin Keinert, $16.69 each, if you buy only 1.

An FYI on this...I just looked on vintageplanet.nl and they're referencing the MM5437N as a replacement for the MM5837. Don't know if that's available anywhere cheaper (vintageplanet has them but they're more expensive than the US guy in the link above).
E.A.S.
emdot_ambient wrote:
roman_f wrote:
the noise chip - MM5837 can be purchased from Kevin Keinert, $16.69 each, if you buy only 1.

An FYI on this...I just looked on vintageplanet.nl and they're referencing the MM5437N as a replacement for the MM5837. Don't know if that's available anywhere cheaper (vintageplanet has them but they're more expensive than the US guy in the link above).


Just checked out the data sheet for both the mm5837 and the mm5437 and they are not plug and play compatible.

The first thing I notice is, that they have different pinouts completely.
Second the 5837 has only pins for power and output, also it uses a 17 bit shift shift register.

On the 5437 there is a 23 bit shift register. It can be clocked externally and has a data in pin.

So, they both could be made to work. but its certainly not just as simple as a chip-swap as one might first think when seeing the word "replacement".

-Mike
roman_f
emdot_ambient wrote:
roman_f wrote:
the noise chip - MM5837 can be purchased from Kevin Keinert, $16.69 each, if you buy only 1.

An FYI on this...I just looked on vintageplanet.nl and they're referencing the MM5437N as a replacement for the MM5837. Don't know if that's available anywhere cheaper (vintageplanet has them but they're more expensive than the US guy in the link above).


i would recommend buying the replacement for $10 from Kevin

"I can get these parts with a different part number printed on them. They are New Old Stock MM5837N parts, but they were made by National Semiconductor as a special order for another company. This company had National Semi place a unique part number on them. So they are not marked as MM5837N, but they really are the correct original parts made by National Semi."
roman_f
julian wrote:
roman_f wrote:
sinequanon wrote:
julian wrote:
I would, of course, be happy to work out some costing for whatever RSFC isnt taking care of.

- meening i dont know if he is doing all the formats, or otherwise, but im sure either way panels will be availible : )


Well , I'd be interested in knowing the cost of a 5U panel, I usually make my own front panels out of wood but never used pcb mounted jacks and pots, that project would be tricky for me as i don't have precision woodworking tools and there will be a ton of panel components...

awesome project..


5U panels would be done by ben @ re:synthesis
and you can always solders jacks/pots not directly to the pcb, but with a wires to the proper pads



/confused/

Ben makes etched panels, i do cnc panels - they're very different finishes...
I would assume people would enjoy different options??

Either way though, im easy - it was just an offer!


Ben is into MU on this, but anyone can make and sell his own panels
MOTM version is 4U and looks like this



if anyone thinks that this is not the MOTM-style - you can make the regular/smaller version with pcbs perpendicular to the panel

i will provide the drilling vector file as well
as i said above ben is mentioned as soon as he makes the MU-panels and i've had good experience with him before. if anyone wants to make a run of MOTMs - he is very welcomed
numbertalk
Roman, do you have a fpd file for this MOTM version? Also, there are board-mounted pots and jacks for that version too, right?

roman_f wrote:
julian wrote:
roman_f wrote:
sinequanon wrote:
julian wrote:
I would, of course, be happy to work out some costing for whatever RSFC isnt taking care of.

- meening i dont know if he is doing all the formats, or otherwise, but im sure either way panels will be availible : )


Well , I'd be interested in knowing the cost of a 5U panel, I usually make my own front panels out of wood but never used pcb mounted jacks and pots, that project would be tricky for me as i don't have precision woodworking tools and there will be a ton of panel components...

awesome project..


5U panels would be done by ben @ re:synthesis
and you can always solders jacks/pots not directly to the pcb, but with a wires to the proper pads



/confused/

Ben makes etched panels, i do cnc panels - they're very different finishes...
I would assume people would enjoy different options??

Either way though, im easy - it was just an offer!


Ben is into MU on this, but anyone can make and sell his own panels
MOTM version is 4U and looks like this



if anyone thinks that this is not the MOTM-style - you can make the regular/smaller version with pcbs perpendicular to the panel

i will provide the drilling vector file as well
as i said above ben is mentioned as soon as he makes the MU-panels and i've had good experience with him before. if anyone wants to make a run of MOTMs - he is very welcomed
roman_f
numbertalk wrote:
Roman, do you have a fpd file for this MOTM version? Also, there are board-mounted pots and jacks for that version too, right


jacks are the switchcrafts and pots are those ones:
http://www.smallbearelec.com/Detail.bok?no=710
10K LIN

i do not have the FPD, i will upload the vector file with holes and then someone would make the FPD probably. i've never used that application and do all graphics in Adobe Illustrator.
emdot_ambient
E.A.S. wrote:
emdot_ambient wrote:
roman_f wrote:
the noise chip - MM5837 can be purchased from Kevin Keinert, $16.69 each, if you buy only 1.

An FYI on this...I just looked on vintageplanet.nl and they're referencing the MM5437N as a replacement for the MM5837.

Just checked out the data sheet for both the mm5837 and the mm5437 and they are not plug and play compatible.

The first thing I notice is, that they have different pinouts completely.

Yeah, not good. I hadn't looked at the data sheets (can't read them very well anyway). Just saw the following on vintageplanet's site:

"MM5837N Noise Generator - DIP8 - see: MM5437"

But turns out NOT SO MUCH, huh? My bad. sad banana
julian
roman_f wrote:
numbertalk wrote:
Roman, do you have a fpd file for this MOTM version?


I do not have the FPD, i will upload the vector file with holes and then someone would make the FPD probably.


I cut from vector (dxf) but its also resonably simple to create fpd files from vector formats, via HPLG import.

There is no reason why a cnc cut panel should not look exactly as the vector design provided by Roman.
roman_f
julian wrote:
roman_f wrote:
numbertalk wrote:
Roman, do you have a fpd file for this MOTM version?


I do not have the FPD, i will upload the vector file with holes and then someone would make the FPD probably.


I cut from vector (dxf) but its also resonably simple to create fpd files from vector formats, via HPLG import.

There is no reason why a cnc cut panel should not look exactly as the vector design provided by Roman.


i've added a pdf with holes for MOTM
numbertalk
Thanks! Where did you add it? Is there a link I missed with documentation?

roman_f wrote:
julian wrote:
roman_f wrote:
numbertalk wrote:
Roman, do you have a fpd file for this MOTM version?


I do not have the FPD, i will upload the vector file with holes and then someone would make the FPD probably.


I cut from vector (dxf) but its also resonably simple to create fpd files from vector formats, via HPLG import.

There is no reason why a cnc cut panel should not look exactly as the vector design provided by Roman.


i've added a pdf with holes for MOTM
roman_f
numbertalk wrote:
Thanks! Where did you add it? Is there a link I missed with documentation?

roman_f wrote:
julian wrote:
roman_f wrote:
numbertalk wrote:
Roman, do you have a fpd file for this MOTM version?


I do not have the FPD, i will upload the vector file with holes and then someone would make the FPD probably.


I cut from vector (dxf) but its also resonably simple to create fpd files from vector formats, via HPLG import.

There is no reason why a cnc cut panel should not look exactly as the vector design provided by Roman.


i've added a pdf with holes for MOTM


1st 5 comments are updated on a progress
numbertalk
Ah I see thanks!
blue_lu
edit: nevermind
Pfurmel
Just cross-posting from the other thread:

I sourced some noise chips from Neil Johnson a while ago, he is sold out at the moment but I think he is getting more delivered.
http://www.njohnson.co.uk/
roman_f
Pfurmel wrote:
Just cross-posting from the other thread:

I sourced some noise chips from Neil Johnson a while ago, he is sold out at the moment but I think he is getting more delivered.
http://www.njohnson.co.uk/


how much did they cost to you?
Monobass
I've never built a single module this complex, Is it possible to build and test in sections or is that more complex than just building the whole thing in one shot?

I've always managed to get every board I've made working so far... I'm just looking at the price and complexity of this one and wondering smile
roman_f
Monobass wrote:
I've never built a single module this complex, Is it possible to build and test in sections or is that more complex than just building the whole thing in one shot?

I've always managed to get every board I've made working so far... I'm just looking at the price and complexity of this one and wondering smile


sure, there would be a schematic for every section and could can build it one after another
julian
roman_f wrote:

MOTM version is 4U and looks like this





Could you post a vector format file of the above design?

Id like to be able to translate it as directly as possible for a cutting simulation.

Thank you,
Julian
sinequanon
akrylik wrote:
Do you think it would be possible to do a euro panel like sduck did for his corgasmatron?

http://www.flickr.com/photos/sduck409/6900025462/

That look is just so inviting to me.


that is beautiful.. I like the colored text.

I'm not so particular on finishes and width and knob spacing.. As long as it's 5U high, I'll fit it in a case. It would be my first time buying a panel so I,m not up to stuff on all the particulars.

I would buy 2 noise chips from the group buy.[/s]
sinequanon
[quote="julian"][quote="roman_f"]
MOTM version is 4U and looks like this



tasty, I would definately buy this.. what price range would we be looking at?
Pfurmel
roman_f wrote:
Pfurmel wrote:
Just cross-posting from the other thread:

I sourced some noise chips from Neil Johnson a while ago, he is sold out at the moment but I think he is getting more delivered.
http://www.njohnson.co.uk/


how much did they cost to you?


£10GBP each
roman_f
that's how MU looks like


i do not share the drawing, sorry - only the drilling, you have to draw your own (that's kinda easy since you have the drilling and the example)
numbertalk
Would you mind at least sharing drawing of the images for "distribution" and the 2n and n+1 states?
julian
numbertalk wrote:
Would you mind at least sharing drawing of the images for "distribution" and the 2n and n+1 states?


If you like, in the next couple of days, i will post a vector of the MOTM format panel laid out with DIN 1451 (for rotatry cnc engraving). This will have the panel graphics in vector format also.
roman_f
numbertalk wrote:
Would you mind at least sharing drawing of the images for "distribution" and the 2n and n+1 states?


the redraw is not mine, sorry
numbertalk
julian wrote:
numbertalk wrote:
Would you mind at least sharing drawing of the images for "distribution" and the 2n and n+1 states?


If you like, in the next couple of days, i will post a vector of the MOTM format panel laid out with DIN 1451 (for rotatry cnc engraving). This will have the panel graphics in vector format also.


Yes please. Thanks!
L-1
Quote:
Would you mind at least sharing drawing of the images for "distribution" and the 2n and n+1 states?

I have made SOU with home etched boards last year and have panel drawing. See Corel Draw file below.
roman_f
I got a quote from Ben for MU/dotcom panels - 40UKP

he also mentioned that he can reduce the price if there would be multiple orders

4U MOTM panel costs the same
magneticweb
if anyone comes up with a panel design for MOTM, i sure could use it! thanks
schmidtc
magneticweb wrote:
if anyone comes up with a panel design for MOTM, i sure could use it! thanks


Second that. I'm really only interested in building stuff that has a classic MOTM panel available. Then I'll take 3. Scott, are you reading?
julian
As above, im happy to do CNC engraved motm panels.

I wont have a price untill i can run a simulation to work out the machine time, but im generally about 20-25% cheaper than FPD.

Ill sort out a panel, but ive just been sucked into other things in the past few days, and i dont think anyone's going to want the panel before the pcbs anyhow? : )
beautyofdecay_
Hi Roman,

Is there an easy way to get 5V from somewhere on the PCB's?
I'm planning on using Electric Druid's White Noise Source as a replacement for the MM5837 (no cyclic noise behavior wink): (http://www.electricdruid.net/index.php?page=projects.noisegen)

If not I'll design a little piggyback PCB which plugs into the original MM5837 IC socket.
roman_f
beautyofdecay_ wrote:
Hi Roman,

Is there an easy way to get 5V from somewhere on the PCB's?
I'm planning on using Electric Druid's White Noise Source as a replacement for the MM5837 (no cyclic noise behavior wink): (http://www.electricdruid.net/index.php?page=projects.noisegen)

If not I'll design a little piggyback PCB which plugs into the original MM5837 IC socket.


there's only 10V source + original voltages
why not using the original chip? it's not cheap, but cheaper than a vactrol
beautyofdecay_
roman_f wrote:
why not using the original chip? it's not cheap, but cheaper than a vactrol

As I understand the noise pattern of the MM5837 repeats itself every 3 or 4 seconds ("steam train sound") and the Electric Druid chip doesn't have that problem.
I would like to have a real random noise source.
roman_f
beautyofdecay_ wrote:
roman_f wrote:
why not using the original chip? it's not cheap, but cheaper than a vactrol

As I understand the noise pattern of the MM5837 repeats itself every 3 or 4 seconds ("stream train sound") and the Electric Druid chip doesn't have that problem.
I would like to have a real random noise source.


that is interesting remark, but i'm not sure that FRV will work same way as it works originally then smile
blue_lu
does anybody have a eu located source for these banana jacks? the ones at banzai look a bit funky and different from the mouser ones. I'd really like to stay within the eu for this though (even within germany, if possible)...
numbertalk
roman_f wrote:
5U

Hardware:

27x of Switchcraft 112 jacks:
original
clones


Sorry if I am confused but does this mean for the 5U version the jacks are not directly mounted to the board? Thought there would be no wiring.

Thanks.
ultrashock
beautyofdecay_ wrote:
As I understand the noise pattern of the MM5837 repeats itself every 3 or 4 seconds ("steam train sound") and the Electric Druid chip doesn't have that problem.
I would like to have a real random noise source.
in 265 selected 6V zener was used and nobody cared about the flatness the noise spectrum smile 266e states, that fluctuating random voltages are continuously variable so where is the truth? hihi
in fact, it's easy to breadboard, FRV is pretty straightforward - first part are active RC filters for various noise distributions and second is a bit more complicated vactrol based lo-pass filter with internal s&h circuits (ne556 timer + 4016 switch) - that goes twice.
roman_f
numbertalk wrote:
roman_f wrote:
5U

Hardware:

27x of Switchcraft 112 jacks:
original
clones


Sorry if I am confused but does this mean for the 5U version the jacks are not directly mounted to the board? Thought there would be no wiring.

Thanks.


jacks are directly mounted on the pcb
roman_f
i have updated the rare parts list

i do not like the vactrol integrator from 208 after all, the cv is inversed and the linearity is awful

since i have made the original 266 integrator running i'll replace this section in the main run of the pcbs
so only 2 single vactrols are required, not 3

but you need a CA3080 OTA

i buy all 3080s here ($2.50 with free delivery) and never had a faulty or fake one
thanatronique
Do you have the bom up somewhere? Would like to see what I have to get regarding usual parts that I might not have on hand.

Thanks
roman_f
i will post full boms for each format after i receive the test-boards
first test boards had some mistakes + i've changed the integrator

next week i receive the new pcbs and after all tests i order the main run and upload BOMs for you
thanatronique
Cool thanks
batchas
roman_f wrote:
5x of those 10K LIN pots:
http://www.smallbearelec.com/Detail.bok?no=1139

The link seems broken.
Thank you very much for all infos Roman!
roman_f
batchas wrote:
roman_f wrote:
5x of those 10K LIN pots:
http://www.smallbearelec.com/Detail.bok?no=1139

The link seems broken.
Thank you very much for all infos Roman!


it seems they have new paths
i update the links
http://www.smallbearelec.com/servlet/Detail?no=1139
E.A.S.
roman_f wrote:

9x RC4136 quad opamps


Something to keep in mind, the 4136 quad op-amp has a different pin-out than most modern op-amps, so if any of you plan on making any substitutions on this one, be VERY careful to check the data sheets.

-Mike
roman_f
so, i've made pads which allow using either VTL5C3/2 or 2 Silonex NSL-32SR3's.



every Vactrol in 266 has 10M resistor in parallel.

my guess is that changing it to 6.25M resistor gives the possibility to use NSL-32SR3 with probably the same effect. i'll make tests as i'll get Silonex's.

ps: yes - you can use two single vactrols as well (without any resistor changes)
raisinbag
Anyone doing a euro panel yet?
roman_f
raisinbag wrote:
Anyone doing a euro panel yet?


bleeps will do after i give him the holes layout
just in a few days
L-1
I really sure VCTL-prices crisis is temporary.
roman_f
i have started with BOMs

1) i would be thankful if someone would help me with proper Mouser part #s for some hardware

- regular 5mm red leds
- regular 3mm red leds
- 5/16" 4-40 screws
- standoffs with M3 thread
- M3 screws (for standoffs)
- 10pin IDC connector (on panel)

2) what power socket does FRAC use?
3) would anyone help me with Farnell's BOM if i provide Mouser's?
roman_f
i have added BOMs and schematics for Buchla-format
resistor mouser #s and BOMs/schematics for 5U and EURO to come soon
roman_f
Buchla BOMs are corrected and updated
terjewinther
Hi,
I have just discovered this thread.
Am I way too late, or is it still possible to get PCBs and/or front panels for this project?
roman_f
you have a day to preorder PCBs
https://www.muffwiggler.com/forum/viewtopic.php?t=56727
diophantine
roman_f wrote:


banana color code:

black - cv in
blue - cv out
violet - alt cv out
orange - pulse in
red - pulse out


Hey Roman, I'm somewhat colourblind & can't differentiate the blue vs violet and red vs orange in the picture. sad Could you perhaps add crosshatching or something to the pics, or describe which go where? Sorry! smile (and yes, reading resistor color codes sucks!!)

The BOMs and schematics look great thus far. My only request, if it wouldn't be difficult, is if the PCB silkscreen pics in the PDFs could also be done with the part values, rather than just RX, especially for all the resistors? It would really come in handy while building! thumbs up

Thanks so much for doing this!
roman_f
diophantine wrote:


Hey Roman, I'm somewhat colourblind & can't differentiate the blue vs violet and red vs orange in the picture. sad Could you perhaps add crosshatching or something to the pics, or describe which go where? Sorry! smile (and yes, reading resistor color codes sucks!!)

The BOMs and schematics look great thus far. My only request, if it wouldn't be difficult, is if the PCB silkscreen pics in the PDFs could also be done with the part values, rather than just RX, especially for all the resistors? It would really come in handy while building! thumbs up

Thanks so much for doing this!




alt outs means these are alternative output which divide the main output to odd and even steps
roman_f


3rd pcb for eurorack
holds jacks, pots and leds

+6 opamps, 2 capacitors and a bunch of resistors for voltage shifts
raisinbag
Ya!!!!!!!!! That looks so cool. Maybe I should make a clear panel!!!!!!!
julian
roman,

can i ask when you expect to add the euro panel hole locations to the thread?

thank you
julian
Im looking at the pdf file for the motm format panel also.

The page size is 6.11 inches x 8.75 inches.

One rack unit is 1.75 inches, so 4u (width) is 7 inches -

I would like to check that your design should be placed in the center of the panel - ie that the pcb behind does not stretch wider on one side than the other?
roman_f
julian wrote:
roman,

can i ask when you expect to add the euro panel hole locations to the thread?

thank you


here it is
roman_f
julian wrote:
Im looking at the pdf file for the motm format panel also.

The page size is 6.11 inches x 8.75 inches.

One rack unit is 1.75 inches, so 4u (width) is 7 inches -

I would like to check that your design should be placed in the center of the panel - ie that the pcb behind does not stretch wider on one side than the other?


it's exactly 7" in this file:
julian
edit - cant see the wood for the trees....
roman_f
i have updated the file, hope now it is clear
madcap
maybe showing my noobs but,

I don't see a BOM for any format other than buchla. I want to start buying parts...specially the rare ones listed in the er.. rare parts list. I just want to be sure that the quantities are the same in the buchla parts list.

I imagine the rare parts are the same, but there may be other parts in the buchla BOM that are no the same for other formats... in my case: euro

do I just work off the buchla BOM?

thank you
roman_f
madcap wrote:
maybe showing my noobs but,

I don't see a BOM for any format other than buchla. I want to start buying parts...specially the rare ones listed in the er.. rare parts list. I just want to be sure that the quantities are the same in the buchla parts list.

I imagine the rare parts are the same, but there may be other parts in the buchla BOM that are no the same for other formats... in my case: euro

do I just work off the buchla BOM?

thank you


i will upload 5U and EURO BOMs shortly as i find some time to make them

here's the scans of the properly assembled buchla-format pcbs
hi-rez version are attached to the buchla-build comment


julian
I have been working on a panel for my own euro build. Im aware that there is a group buy for euro panels, but i want to make the panel in the same style as the klee panel i cut for jooks/erik some time ago (the infill colour on the euro panel will be identical to jooks' klee panel)




The panel is not yet finished, but Ive tried to get it as close to the buchla design as possible. So far as im aware, the only things currently missing are the dots arround the knobs. Oh, and the (i think) arrows.

Roman has hinted above that the some of the positions may change on the euro panel, so im not going to cut anything prior to that.

The klee, in buchla style, mentioned above -




For my 4u 266 build, i have purchased a panel from RSFC's group buy.
roman_f
1) positions are final, i do confirm it
2) i would like anyone who makes a panel not to put "b&a" name on the bottom, hope you understand
3) klee panel is very cool, is is still possible to buy one? i remember zthee made a 2U buchla panel for klee, but i have never seen it IRL
julian
roman_f wrote:
1) positions are final, i do confirm it


Thank you.

Quote:
2) i would like anyone who makes a panel not to put "b&a" name on the bottom, hope you understand


I do understand. I would feel uneasy running a 'group buy' of such a panel, but the panel above is for me. Ie a 1-off for private use only.

Quote:
3) klee panel is very cool, is is still possible to buy one? i remember zthee made a 2U buchla panel for klee, but i have never seen it IRL


Im about to cut another two panels in the 4u klee format. One is for me, and the other is for a builder in Sweeden.

We are just waiting for some comments back from Erik (the panel author) before cutting.
zoot horn rollo
In the buchla BOM # 1 the mouser part number for the 33K resistors should be 271-33K-RC rather than 271-22K-RC as stated.

Just thought i'd point this out for others because I almost ordered the wrong ones without checking.
batchas
Does anyone have more infos (length, diameter) or even better mouser references for:

Male-Female Standoffs
Female-Female Standoffs
Machine Screws
Red LEDs
LED standoffs

I need these for the Buchla build. They are listed in the BOM without refs and I have no idea which screw, which standoff length, 3mm or 5mm for LEDs (I read it needs both somewhere, on the BOM only 3mm) etc etc.

THANX A LOT!!!!!
roman_f
batchas wrote:
Does anyone have more infos (length, diameter) or even better mouser references for:

Male-Female Standoffs
Female-Female Standoffs
Machine Screws
Red LEDs
LED standoffs

I need these for the Buchla build. They are listed in the BOM without refs and I have no idea which screw, which standoff length, 3mm or 5mm for LEDs (I read it needs both somewhere, on the BOM only 3mm) etc etc.

THANX A LOT!!!!!


i will upload final boms for all 3 systems today
batchas
roman_f wrote:
batchas wrote:
Does anyone have more infos (length, diameter) or even better mouser references for:

Male-Female Standoffs
Female-Female Standoffs
Machine Screws
Red LEDs
LED standoffs

I need these for the Buchla build. They are listed in the BOM without refs and I have no idea which screw, which standoff length, 3mm or 5mm for LEDs (I read it needs both somewhere, on the BOM only 3mm) etc etc.

THANX A LOT!!!!!


i will upload final boms for all 3 systems today
roman_f
i have added BOMs for 5U, EURO and Buchla formats

EURO may be powered with 12V or 15V (see notes)
5U & Buchla may be powered only with 15V
bananeurysm
Could someone explain the 'voltage shifts'?

I'd like to put this project in a 15V system, I'd like to keep all my i/o banana, and fitting into a sergey bud boat would be nice - but not necessary.

Are any of the 1/8" jacks switching? Buchla format sounds like it'll work for me right?
roman_f
bananeurysm wrote:
Could someone explain the 'voltage shifts'?

I'd like to put this project in a 15V system, I'd like to keep all my i/o banana, and fitting into a sergey bud boat would be nice - but not necessary.

Are any of the 1/8" jacks switching? Buchla format sounds like it'll work for me right?


Buchla uses 0/+10V for CV and 1.2V/Oct for pitch
regular modular systems use -5V/+5V for CV and 1V/Oct for pitch

if you buy a Buchla-set - using it in a regular system would be a bit strange
if you power in from 15V - both EURO and 5U kits are possible
only a EURO kit can do 12V operation

hope it helps
JCM
Is a Buchla PCB set with 5U BOM possible? I do 5U w/ Banana's and the Buchla set seemed to be best for my panel needs, but I use a 15V PSU and need 1/V Oct.
roman_f
JCM wrote:
Is a Buchla PCB set with 5U BOM possible? I do 5U w/ Banana's and the Buchla set seemed to be best for my panel needs, but I use a 15V PSU and need 1/V Oct.


no, since buchla PCBs do not hold voltage shifts parts, it was designed as the pure 266 module

you should get 5U version and wire bananas to the input pads of jacks, that's it
JCM
roman_f wrote:
JCM wrote:
Is a Buchla PCB set with 5U BOM possible? I do 5U w/ Banana's and the Buchla set seemed to be best for my panel needs, but I use a 15V PSU and need 1/V Oct.


no, since buchla PCBs do not hold voltage shifts parts, it was designed as the pure 266 module

you should get 5U version and wire bananas to the input pads of jacks, that's it


Hmm, I'll have to send you a PM then. I think I may actually need the Euro version because my panel is only 3U wide compared to the 4U of your PCB.
bananeurysm
roman_f wrote:


Buchla uses 0/+10V for CV and 1.2V/Oct for pitch
regular modular systems use -5V/+5V for CV and 1V/Oct for pitch

if you buy a Buchla-set - using it in a regular system would be a bit strange
if you power in from 15V - both EURO and 5U kits are possible
only a EURO kit can do 12V operation

hope it helps


Thanks - that totally clears it up!
roman_f
got the PCBs


5U



EURO


BUCHLA



EURORACK & 5U are tight to edges, but fit in the cases without any problem




nickster
Great, thanks for uploading these photos! Looking forward to building this.
djangosfire
THIS is going to be awesome!! Thanks Roman - can't wait Guinness ftw!
roman_f
i've added some info to the first comments, feel free to ask me if you have any questions

i'll make some fotos with examples very soon (how to fit the connectors, how to make jumpers for 15V operation on EURORACK etc)
Willzyx
Watch out for fake MM5837N's

Just spotted a seller on ebay selling fakes:
http://www.ebay.com/itm/NS-MM5837N-NS-Digital-Noise-Source-/2610536594 47?pt=LH_DefaultDomain_0&hash=item3cc802b937#ht_1794wt_1130

The chip is obviously black topped. It might still be legit, maybe changed the date code to fake RoHS but I would stay away.
fluxmonkey
does anybody have HPGL files for the Quantized and Stored Random Voltage graphics that they'd be willing to share w/ me? i'm planning to do a FPD panel in sergish style, but keep the traditional elegant visual queues for those 4 outs. would be greatly appreciated!

bbob
Peake
Willzyx wrote:
Watch out for fake MM5837N's

Just spotted a seller on ebay selling fakes:
http://www.ebay.com/itm/NS-MM5837N-NS-Digital-Noise-Source-/2610536594 47?pt=LH_DefaultDomain_0&hash=item3cc802b937#ht_1794wt_1130

The chip is obviously black topped. It might still be legit, maybe changed the date code to fake RoHS but I would stay away.


I purchased a couple from Unicorn Electronics a while back and they work fine, if anyone is still looking for some. Thanks for the heads-up. Used to be able to buy these at Rat Shack for a couple of dollars...!
cleaninglady
HI Roman , thanks it looks great !

I just wanted to ask about the 3.5mm sockets shown.

Will i have to get Erthenvar sockets ? Mine are a bit different...
Dead Banana
blinosynth
how much for a euro finished module ?
roman_f
cleaninglady wrote:
HI Roman , thanks it looks great !

I just wanted to ask about the 3.5mm sockets shown.

Will i have to get Erthenvar sockets ? Mine are a bit different...
Dead Banana


yes, you have to
rowman
cleaninglady wrote:
HI Roman , thanks it looks great !

I just wanted to ask about the 3.5mm sockets shown.

Will i have to get Erthenvar sockets ? Mine are a bit different...
Dead Banana


I bought a stack of Kobiconns from the group buy which are supposed to fit like erthenvars. You can grab some out of my order if you want, I should have them in about a month.
terjewinther
Hi,
I am preparing to build these in 5U format, really looking forward to that.
I have found the 5U BOMs and other details, but the schematics seems to be for the Buchla version only, or am I missing something?
roman_f
terjewinther wrote:
Hi,
I am preparing to build these in 5U format, really looking forward to that.
I have found the 5U BOMs and other details, but the schematics seems to be for the Buchla version only, or am I missing something?


i will update all the boms & schematics on the weekend
just hold on 2 days please and after that start with assembly
terjewinther
Great - thanks!
The boards arrived at the post office here in Norway today.

Terje

roman_f wrote:
i will update all the boms & schematics on the weekend
just hold on 2 days please and after that start with assembly
roman_f
i've added the revisited BOMs and Schematics for 5U
feel free to start the assembly

do not solder the jacks before you put the panel on
the best way is to:

1) insert jacks into sockets on the PCB
2) put the panel on the jacks (no need to screw the nuts)
3) turn this construction upside down and solder the jacks


DO NOT start with soldering EURORACK before my confirmation - just give me a day or two to double-check everything. This is too advanced module.


one more thing - i had a couple of faulty ribbon cables when i was making my batch of 266s
they look just as they should look, but do not work properly

try to "ring" all the connections on the both sides of the cable if something doesn't work
Minimoog56
Thanks for sharing Roman!
terjewinther
Thanks for the update.
ATOM
Pcb´s are coming.

5U panel?

ATOM
thebot
ATOM wrote:
Pcb´s are coming.

5U panel?

ATOM


Also interested, cheers.
roman_f
ATOM wrote:
Pcb´s are coming.

5U panel?

ATOM


what do you mean?
ATOM
roman_f wrote:
ATOM wrote:
Pcb´s are coming.

5U panel?

ATOM


what do you mean?


It´s a short and confusing message. Sorry.

There was talk about a 5U panel from someone.
Sorry I think I posted in the wrong. Thread. very frustrating

ATOM
roman_f
panels can be ordered from ben @ re:synthesis
drilling template may be found in the "panels" comment in the beginning of this thread
thanatronique
Received my euro set, thanks Roman.
roman_f
i've updated BOMs & schematics for buchla format
those are final, tested and confirmed
janvanvolt
Any news on the eurorack ? can we start soldering ?
What i noticed (will update more finds in here):

(1) on PCB2, some of the 0.1uf (3 to be exact) i didn't find
(2) on PCB1, the 100pf are not 2.5mm, they are larger.
roman_f
janvanvolt wrote:
Any news on the eurorack ? can we start soldering ?
What i noticed (will update more finds in here):

(1) on PCB2, some of the 0.1uf (3 to be exact) i didn't find
(2) on PCB1, the 100pf are not 2.5mm, they are larger.


not yet, only PCB2
i mean you can start with soldering PCB2

PCB1 - will report on monday
there's an issue with the power converter
it was made as written in the datasheet, but doesn't work properly
i've made it working now on a proto-board and now i need to make a picture describing what traces should be cut
DO NOT solder PCB1 @ euro before my instruction

3 missing caps are ok, those are just for decoupling
original buchla pcbs didn't have them at all

i will also upload the mainboard/hardware pcb with an instruction (2 resistors should be skipped there)
fluxmonkey
bump... anybody? would trade some goodies if someone would help me out....


fluxmonkey wrote:
does anybody have HPGL files for the Quantized and Stored Random Voltage graphics that they'd be willing to share w/ me? i'm planning to do a FPD panel in sergish style, but keep the traditional elegant visual queues for those 4 outs. would be greatly appreciated!

bbob
roman_f
fluxmonkey wrote:
bump... anybody? would trade some goodies if someone would help me out....


fluxmonkey wrote:
does anybody have HPGL files for the Quantized and Stored Random Voltage graphics that they'd be willing to share w/ me? i'm planning to do a FPD panel in sergish style, but keep the traditional elegant visual queues for those 4 outs. would be greatly appreciated!

bbob


i can do EPS/PDF only
roman_f
going to ship all the remaining orders in 9 hours

after counting all missed orders and PCBs it seems that i still have for sale:

1) 4 Buchla sets
2) 5 euro sets
3) 1 5U set (this one is on hold)

once again - if you're not in 3 shipped lists - please PM me, i could probably miss you in my mailbox (though i've double-checked everything today)

all my future orders would be done to a special email, so it would be easier to find people.
janvanvolt
Hi, any news on the Euro PCB1 ? I finished PCB2 and PCB3 now :-)
roman_f
janvanvolt wrote:
Hi, any news on the Euro PCB1 ? I finished PCB2 and PCB3 now :-)


will upload the instruction today
roman_f
i've uploaded the building docs for EURO
please read them carefully, the module would not work without the described modifications
raisinbag
Cool, well I had a little look at what you uploaded and was wondering: Would it just be better to make this run on 15v instead of 12v.?? I do not HAVE to stick to 12v and can just run with my Frac stuff. If you get a chance when you are back from your travels can you walk me through what I should do if I want to run off 15v instead of 12v?

Thanks
roman_f
raisinbag wrote:
Cool, well I had a little look at what you uploaded and was wondering: Would it just be better to make this run on 15v instead of 12v.?? I do not HAVE to stick to 12v and can just run with my Frac stuff. If you get a chance when you are back from your travels can you walk me through what I should do if I want to run off 15v instead of 12v?

Thanks


for powering with 15Vs - solder С35, С36, С37, С38, L1, L2
do not solder C14, C40, C41, IC14, IC15, L3, L4, R44, D12, D13
install 2 shorting jumpers



check the voltages on THRU pads (+15/0/-15)
solder all the remaining parts on the PCB (excl. C14, C40, C41, IC14, IC15, L3, L4, R44, D12, D13)
raisinbag
thats it? no cutting traces etc, cool maybe it will be my frac/ euro module now!

Thanks.
roman_f
raisinbag wrote:
thats it? no cutting traces etc, cool maybe it will be my frac/ euro module now!

Thanks.

yes, cutting traces is for 12V operation only
for 12-to-15V conversion i've used the schematic from the datasheet of those voltage regulator ICs, but it didn't work correctly, so now after cutting the traces and removing come components and replacing the others - it works fine.
it uses only +12V rail to make +/-15Vs
janvanvolt
Okay, stuff cut. Will solder parts tomorrow and then also report if this works or not :-)
roman_f
5U building docs are updated - i've added picture showing how to swap mixed SRV1 & SRV2 outputs



303monkey
Boards arrived this morming. spinning

Boba Fett
raisinbag
Hey, for the ceramic caps, can we use the usual cerami disks? Or do they. Red to be a little better than the disk type.
e-grad
raisinbag wrote:
Hey, for the ceramic caps, can we use the usual cerami disks? Or do they. Red to be a little better than the disk type.


Ceramic disks are a variety of ceramic caps. You can use them unless 'low k' or C0G/NPO are specified.
raisinbag
Cool, basically I have lots of "random" disk caps, not sure about their specs. (got from parts bins at stores, and lots from Tayda, etc.... no specs, just labeled "ceramic disk")

I'll look again at the BOM, but I don't remember anything about Cog/Npo in the BOM. I'd love to use whats on hand, but if they are shitty, I'll get some better ones.

Thanks.
thebot
Roman,

I know the panel is designed to look like the original unit but would an easier option not be to just change the panel so the outputs are swapped on the panel rather than any adjustment on wiring? Or are the LEDs the right way round?

Edit: I'm talking about the 5U version here by the way.
janvanvolt
Roman,

i tried to build it as you proposed, but i am getting a short between the - and the GND rail.

thoughts ?

Also i noticed:
- L3 and L4 have different uH values in the schematics
- C41 is 470uf vs. 100uf as in the different BOM Versions
radiokoala
Okay, so to make everyone's life easier I created shared shopping carts at mouser. Now you don't need to add 100+ parts manually by copy-pasting their #'s, because I did it for you. Guinness ftw! Including all parts as listed in corresponding PDF files; eurorack.

266c-EURO-1 v1.1 - EURORACK FORMAT - INTEGRATOR - SRV - S&H

== order parts ==

Please note that the part # 667-ECQ-V1H184JL3 is not currently in stock at Mouser. You can wait approximately until 8/17 or simply remove it from the cart and order later. Other than that, it is all parts as mentioned in 266c-eurorack-1-bom-v1.1.pdf, except for CA3080, which is to be ordered from ebay or bridechamber.

266c-EURO-2 v1.1 - EURORACK FORMAT - FRV - QRV

== order parts ==

All parts but a few ordered separately. See 266c-eurorack-1-bom-v1.1.pdf.

266c-EURO-3 v1.1 - EURORACK FORMAT - JACKS, POTS, LEDS, VOLTAGE SHIFTS
+
266c-EURO-4 v1.1 - EURORACK FORMAT - MISC


== order parts ==

266c-eurorack-3-bom-v1.1.pdf & 266c-eurorack-1-bom-v1.1.pdf. All parts but minijacks and potentiometers – refer to the former file for the ordering links.

Have a fun build screaming goo yo w00t
ringstone
radiokoala wrote:
Please note that the part # 667-ECQ-V1H184JL3 is not currently in stock at Mouser. You can wait approximately until 8/17 or simply remove it from the cart and order later.


Actually this part:

http://au.mouser.com/ProductDetail/Panasonic-Electronic-Components/ECQ -V1H184JL/?qs=Y%2fBAFGi0CNpejMU%252bxEnUCyqKElmqkH1s2Lthd0lcx%252bI%3d

looks identical to me apart from packaging, you should be able to substitute.

Cheers
Blair
roman_f
janvanvolt wrote:
Roman,

i tried to build it as you proposed, but i am getting a short between the - and the GND rail.

thoughts ?

Also i noticed:
- L3 and L4 have different uH values in the schematics
- C41 is 470uf vs. 100uf as in the different BOM Versions


i've out the city, but i ask my friend to check the pcbs and report shortly. i've done 5 of them working correctly this way, let me double check. sorry for that powering issue.
roman_f
my fault - 1 more trace should be cut
d'oh!
updated docs, should work now
raisinbag
HEY THANKS Radiokoalal! Is there a way to MERGE the carts together? I looked around but it isn't obvious. Thanks so much. I have many of the parts, but need a bunch of funky ones from each BOM.

Also if anyone is building with a Bleeps Euro panel, will the Davies 1900h knobs work?
roman_f
thebot wrote:
Roman,

I know the panel is designed to look like the original unit but would an easier option not be to just change the panel so the outputs are swapped on the panel rather than any adjustment on wiring? Or are the LEDs the right way round?

Edit: I'm talking about the 5U version here by the way.


1) leds are not swapped
2) cutting 2 traces / wiring other 2 is super easy, this mod is done in 2 minutes
decaying.sine
raisinbag wrote:
HEY THANKS Radiokoalal! Is there a way to MERGE the carts together? I looked around but it isn't obvious. Thanks so much. I have many of the parts, but need a bunch of funky ones from each BOM.

Also if anyone is building with a Bleeps Euro panel, will the Davies 1900h knobs work?


You can merge carts. I have done this and it has worked for me. BTW, I'll PM you tonight raisins Hug

From Mouser...
Combining Multiple Projects

Log in. Select the "View basket tab to ensure you do not have parts in your shopping basket that you do not wish to be added to this order. (Clear your shopping basket, if necessary.) Click on the "Project Manager" link.

Click on the "Edit" link next to one of the projects that you wish to combine. In the bottom right hand corner under the merchandise total, click on the "Order Project" button. This will add the parts to your basket.

Then go into the next project and follow the same steps, which will add each project to your basket and add together any quantities for any duplicate products.

Once all the projects that you wish to combine are in your shopping basket, save your shopping basket as a new project.
rico loverde
you are awesome radiokoala!!! thank you very much for that.
raisinbag
hey Roman while you are there, I notice from your picture of PCB that some of your resistors are Carbon 5% ones. Are there any resistors that I can be Lazy with? Or should they all HAVE to be 1%? I was stuffing resistors last night and measured my 10M ones and they are closer to 9.4M. Will this mess things up? I can order some 1% for everything if need be. Thanks
raisinbag
Oh missed your response above, thanks Brian, I'll go do that once I pour some concrete w00t

And I thought you didn't love me anymore love love love love love love love love
roman_f
raisinbag wrote:
hey Roman while you are there, I notice from your picture of PCB that some of your resistors are Carbon 5% ones. Are there any resistors that I can be Lazy with? Or should they all HAVE to be 1%? I was stuffing resistors last night and measured my 10M ones and they are closer to 9.4M. Will this mess things up? I can order some 1% for everything if need be. Thanks


10Ms can be 5%
i would not recommend using 5% in most of QRV part, in voltages shifts (you'll even need 0.1% somewhere)
roman_f
roman_f wrote:
raisinbag wrote:
hey Roman while you are there, I notice from your picture of PCB that some of your resistors are Carbon 5% ones. Are there any resistors that I can be Lazy with? Or should they all HAVE to be 1%? I was stuffing resistors last night and measured my 10M ones and they are closer to 9.4M. Will this mess things up? I can order some 1% for everything if need be. Thanks


10Ms can be 5%
i would not recommend using 5% in most of QRV part, in voltages shifts (you'll even need 0.1% somewhere)


i use 1% mostly everywhere since they do cost the same on mouser as 5%
+ i buy batches of them, so it's better to buy 200 1%s than 100 5%s + 100 1%s.
raisinbag
OK cool, ya I mainly use 1% as well, just have some 5% for certain values for some reason. Oh thanks, I hadn't noticed the .1% ones. I need a few of those 2ks for something else as well, so goo excuse to grab a few more.

Thanks again.
xpander
radiokoala wrote:
Okay, so to make everyone's life easier I created shared shopping carts at mouser. Now you don't need to add 100+ parts manually by copy-pasting their #'s ...

wait- you didn't manually enter every number in did you? you can import the .xls BOMs as they are. create a project (mine is '266r') and then import a BOM, resolve the obsolete parts & send it to your project. it's a little tricky at first (particularly the unnecessary "export" step) but once you got it down, you'll be a happy wiggler.
radiokoala
xpander wrote:
radiokoala wrote:
Okay, so to make everyone's life easier I created shared shopping carts at mouser. Now you don't need to add 100+ parts manually by copy-pasting their #'s ...

wait- you didn't manually enter every number in did you? you can import the .xls BOMs as they are. create a project (mine is '266r') and then import a BOM, resolve the obsolete parts & send it to your project. it's a little tricky at first (particularly the unnecessary "export" step) but once you got it down, you'll be a happy wiggler.

I did, mate.
Eurorack BOMs are PDF, hence ain't supported Dead Banana

If for your format they were XLS, lucky you then!

upd. ...I like how our avatars go together. same colors! w00t
roman_f
one more thing to say

i have also experienced an issue with ribbon-cables - a few of them look good, but do not function well, a couple had wrong key position

so:
1) take a look at your ribbon cables.



2) 5U & Buchla ones should have "keys" looking outside and EURO's "keys" are looking inside on both sides on the cable

3) check that "arrows" are located at the same side as the red line on the cable

4) ring all the connections with a multi-meter so be sure that nothing is shorting inside of the cable. holes are too small to put the test-leads inside of them, so you may put the other part of the connector and have an access to pins.

i do not think that many people would have such a problem, but anyway - please check it.
xpander
radiokoala wrote:
upd. ...I like how our avatars go together. same colors! w00t

hihi
xpander
roman- i don't know if this was answered earlier but is the 1st Buchla-format BOM correct? when you open both 266c-buchla-1-bom.pdf and 266c-buchla-1-bom.xls, they have "5U Format" on the top of the page. all of the others are labelled correctly.
roman_f
xpander wrote:
roman- i don't know if this was answered earlier but is the 1st Buchla-format BOM correct? when you open both 266c-buchla-1-bom.pdf and 266c-buchla-1-bom.xls, they have "5U Format" on the top of the page. all of the others are labelled correctly.


you probably have the older version of BOM
please download the latest one
the archive also features the updated schematics
thebot
roman_f wrote:
thebot wrote:
Roman,

I know the panel is designed to look like the original unit but would an easier option not be to just change the panel so the outputs are swapped on the panel rather than any adjustment on wiring? Or are the LEDs the right way round?

Edit: I'm talking about the 5U version here by the way.


1) leds are not swapped
2) cutting 2 traces / wiring other 2 is super easy, this mod is done in 2 minutes


Great, thanks.

Scott.
Luka
i was tuning up my QRV and SRV last night and I found these great videos which explain the funcionality of the doepfer version. might help some people with the build.

qrv



srv

xpander
quick question before i sink money into small bear for pots- i should be ordering the linear ones, right?
roman_f
xpander wrote:
quick question before i sink money into small bear for pots- i should be ordering the linear ones, right?

sure - B10K
B means linear, A - log, C - reverse log
janvanvolt
Unfortunately, after the other fix - still does not work as expected. i am getting a "huge" load on the neg tail ( test is a a-100 miniature board which usually works fine.

on the THRU pad i am getting:
(Pin1 being leftmost, squared), Voltmeter COM = Pin 1 or 2, Plus Pin either Pin 2 or 3)

Pin 1-2 - 0.69V
Pin 2-3 - (-) 1.82V
Pin 1-3 - (-) 1.12V

I made HD photos of the PCB, maybe you'd be able to find the culprit:

http://www.flickr.com/photos/jczmok/sets/72157630796094288/

Usually only 1 out of 40 projects fail here, so i am wondering what it might be.

If i can't fix it, how much would you take for one PCB with PSU parts and the fixed issues ? Other PCBs seem fine (so far).
roman_f
janvanvolt wrote:
Unfortunately, after the other fix - still does not work as expected. i am getting a "huge" load on the neg tail ( test is a a-100 miniature board which usually works fine.

on the THRU pad i am getting:
(Pin1 being leftmost, squared), Voltmeter COM = Pin 1 or 2, Plus Pin either Pin 2 or 3)

Pin 1-2 - 0.69V
Pin 2-3 - (-) 1.82V
Pin 1-3 - (-) 1.12V

I made HD photos of the PCB, maybe you'd be able to find the culprit:

http://www.flickr.com/photos/jczmok/sets/72157630796094288/

Usually only 1 out of 40 projects fail here, so i am wondering what it might be.

If i can't fix it, how much would you take for one PCB with PSU parts and the fixed issues ? Other PCBs seem fine (so far).


i will return back home monday and will test/measure everything, will upload the fotos/videos as well. i didn't make this fix by myself - it was done by my friend engineer, but he has corrected 5 PCBs for me and all seem to be good.

i would prefer if people would wait till monday before they assemble that PCB.

what power source do you use?
roman_f
janvanvolt wrote:
Unfortunately, after the other fix - still does not work as expected. i am getting a "huge" load on the neg tail ( test is a a-100 miniature board which usually works fine.

on the THRU pad i am getting:
(Pin1 being leftmost, squared), Voltmeter COM = Pin 1 or 2, Plus Pin either Pin 2 or 3)

Pin 1-2 - 0.69V
Pin 2-3 - (-) 1.82V
Pin 1-3 - (-) 1.12V

I made HD photos of the PCB, maybe you'd be able to find the culprit:

http://www.flickr.com/photos/jczmok/sets/72157630796094288/

Usually only 1 out of 40 projects fail here, so i am wondering what it might be.

If i can't fix it, how much would you take for one PCB with PSU parts and the fixed issues ? Other PCBs seem fine (so far).


do you have +15 if you disconnect a wire from pin1?
it should be there, since those cuts/wires are related only to +12->-15 transformations
janvanvolt
Let be more specific: I am feeding it via a 9V AC/AC Adapter to an A-100 Busboard (the "small" one which can feed +4 modules). It is working fine for testing.
On the +12V rail on the busboard light is normally lit.
On the -12V rail on the busboard the light is very dim, e.g. either a high load or a near-short.

The measurements i took are from the THRU pad, e.g. i am not getting the voltages (15/-15V) out.
roman_f
Quote:
I am feeding it via a 9V AC/AC Adapter to an A-100 Busboard (the "small" one which can feed +4 modules). It is working fine for testing.


this transformer need some normal PSU with high current

Quote:
On the -12V rail on the busboard the light is very dim, e.g. either a high load or a near-short.


this is strange, since the -12Vs rail is not used at all if L2 is not soldered

have you tried disconnecting a wire from pad 1 and measuring +15Vs?
roman_f
janvanvolt wrote:
Let be more specific: I am feeding it via a 9V AC/AC Adapter to an A-100 Busboard (the "small" one which can feed +4 modules). It is working fine for testing.
On the +12V rail on the busboard light is normally lit.
On the -12V rail on the busboard the light is very dim, e.g. either a high load or a near-short.

The measurements i took are from the THRU pad, e.g. i am not getting the voltages (15/-15V) out.


my engineer friend reports that you should use L3/L4 inductors from the BOM, the ones you're using won't work with such current level
zoot horn rollo
Hi Roman,

I'd like to build my buchla format pcbs to be 1v/oct rather than 1.2v/oct.

Is this as easy as changing a few resistor values? If so, do you think you could let me know which resistors? (I assume that I can then change these resistors to the values in the 5U bom).

Thanks It's peanut butter jelly time!
roman_f
zoot horn rollo wrote:
Hi Roman,

I'd like to build my buchla format pcbs to be 1v/oct rather than 1.2v/oct.

Is this as easy as changing a few resistor values? If so, do you think you could let me know which resistors? (I assume that I can then change these resistors to the values in the 5U bom).

Thanks It's peanut butter jelly time!


use 2K 0.1% resistor to connect the outputting banana with the related pad on the PCB (instead of wire), connect same banana with a ground with 10K 0.1% resistor

you should do this after you have the PCB attached to a front-panel
ground may be found nearby if you remove the mask off the ground-fill area, or on one leg of pots
zoot horn rollo
Thanks Roman!
janvanvolt
Roman,

just verified your first page - and saw probably my error as i am trying to feed the power -12V instead of +12V...

--jan
roman_f
janvanvolt wrote:
Roman,

just verified your first page - and saw probably my error as i am trying to feed the power -12V instead of +12V...

--jan


please report me on you progress, i would be happy to know if you fixes this
roman_f
i've just tested it again - works great here

1) i need to wait maybe 10 seconds after i power up the system, that's normal.
2) IC15's is pretty hot. you might want to put a heat sink on it



but everything works perfect
synaptech
Just a note on radiokoala's Mouser Projects - it looks like the eurorack 3+4 project lists both types of pin sockets (gold/tin and dual wipe). The gold ones will run you ~$30 so be aware when placing your order! thumbs up

Thanks for throwing that together though radiokoala, saves me the headache of importing BOMs! smile
L-1
I've taken quick look at the Euro BOM. C37 is missed.
roman_f
synaptech wrote:
Just a note on radiokoala's Mouser Projects - it looks like the eurorack 3+4 project lists both types of pin sockets (gold/tin and dual wipe). The gold ones will run you ~$30 so be aware when placing your order! thumbs up

Thanks for throwing that together though radiokoala, saves me the headache of importing BOMs! smile


transistors are missing in this Mouser Project as far as i see
3904, 3906
roman_f
L-1 wrote:
I've taken quick look at the Euro BOM. C37 is missed.


for 12V operation you should skip it, the value is in the schematics
frozenkore
I'm assuming these are these CA3080s will work too but I wanted to verify before I order them with my switches: http://www.smallbearelec.com/servlet/Detail?no=219

Here is more details of it:
IC CA3080AE
8-pin DIP OTA for the Ross/Dynacomp. These are the re-issue parts made by Rochester Electronics from the Intersil masks.
roman_f
frozenkore wrote:
I'm assuming these are these CA3080s will work too but I wanted to verify before I order them with my switches: http://www.smallbearelec.com/servlet/Detail?no=219

Here is more details of it:
IC CA3080AE
8-pin DIP OTA for the Ross/Dynacomp. These are the re-issue parts made by Rochester Electronics from the Intersil masks.


should work
i buy my 3080s in china from the provider in BOM seller, but since you have them @ smallbear and you need only one - do it
frozenkore
Cool, thanks!
janvanvolt
Back to my debugging adventures now:

a) fixed the +/- Doepfer connector, so that the + rail is only used and not the neg one.

Next problems:

a) On Thru Pad, +15V gives 14.97 (well that seems right)
b) On Thru Pad, -15V gives me 0.47V (seems odd...)

and ... some part is getting hot, but need to find out which one, but it seems to be the regulators.

Thougts ?
roman_f
janvanvolt wrote:
Back to my debugging adventures now:

a) fixed the +/- Doepfer connector, so that the + rail is only used and not the neg one.

Next problems:

a) On Thru Pad, +15V gives 14.97 (well that seems right)
b) On Thru Pad, -15V gives me 0.47V (seems odd...)

and ... some part is getting hot, but need to find out which one, but it seems to be the regulators.

Thougts ?


it seems that we have to make it work without a 12-15 transformer on 12Vs

it worked perfect on my bench PSU, but when i fit it to my doepfer case - promlems start
gimme a day or two, i'll recount the resistors for QRV
or probably someone can help me:

QRV - gives 1.2V/pct quantized voltages which are then scaled to 1v/oct using 2 0.1% resistors
it works on 15Vs, but if i power it with 12Vs - the quantization goes down
please check the schematics, it's probably just a couple of resistors to change

roman
roman_f
i've tested the module @ my doepfer case now

installed 2 jumpers
i didn't install:

D12, D13, IC15, IC14, L4, L3, R44, C14, C41, C40

@ 15Vs - everything works perfect
@ 12Vs - everything works, but the quantization of QRV is incorrect

so the only thing is to correct the QRV

camelneck
Roman,
I've recently returned to the forum after being on an extended break from DIY synth building. (I had to undergo back surgery several months ago.)

I must admit that I was surprised to find out about this wonderful project and how quickly it came together. I'm only hoping that I am not too late to partake in this great adventure.

Are any of the PCB sets still available or are they all sold out?

If you are sold out (heaven forbid), is there any chance you might do another run sometime in the future?
janvanvolt
Does not install R16 and R35 also apply to eurorack ? if yes: fine, if no: what are the values ?
spotta
Hi

Is is all good to populate Euro PCB3 yet, I am using the schematic dated 26th July which has the amendments re R6 & R7 and the insulating tape.
mayanspring
this is the third related thread I am going to throw this out in, but lacking time and skill I am hoping someone out there is building an extra Eurorack one or planning to do so that they would sell me.
don't have time or ability to really jump into this on my own, but I think it looks like a great module.

PM me if you think you can help.
ringstone
Any progress on the 12V Euro issues? My current mouser order is on hold for the time being... not having to buy the voltage converters will certainly improve the overall cost for this project!

Cheers
Blair
janvanvolt
Well. I asked some people and waiting also for answers :-) In the meantime the 266 will be finished, except the Panel and the 910pf caps. Does it have to be exact 910pf ? What is so magical about this value ?

... and the 266 works by the first power on after completion :-)
ringstone
janvanvolt wrote:
Well. I asked some people and waiting also for answers :-) In the meantime the 266 will be finished, except the Panel and the 910pf caps. Does it have to be exact 910pf ? What is so magical about this value ?

... and the 266 works by the first power on after completion :-)


Actually the Mouser link in the BOM is for 1000pF (1n) caps, so I guess not THAT important. I just splashed out on some silver micas, they were significantly less expensive than anything Mouser offers in that value (nearly $4 a cap!).

Cheers
Blair
janvanvolt
Okay, 1nf soldered in. Everything as it should be - except the quatization. So another working Source of Uncertainty done :-)

So i'm now waiting for the frontpanel and the correction mods for 12V correct quantizing.
E.A.S.
janvanvolt wrote:
Okay, 1nf soldered in. Everything as it should be - except the quatization. So another working Source of Uncertainty done :-)

So i'm now waiting for the frontpanel and the correction mods for 12V correct quantizing.



To fix quantizer on 12v version, change R46 (on board 2) from 68.1k to 46.4k.

Edit: Also you'd want to change R59 (on board 2) from 60.1k to 75k

I don't have the euro version, so I can't try this out, but I think it should work.

Someone try it out. thumbs up

-Mike
JCM
I got my Buchla version mostly up and running, but I'm getting nothing out of the noise source and S&H. I think I may have a bad noise chip, power and ground seem to be getting to the right pins. Also what is to be expected out of the "noisy triangle"? I'm just getting a steady triangle on the scope.

I suspect the triggers from the DIY topp 281 end outs are not good enough to trigger the S&H. Are there resistors I can change for this? My system is only DIY, so I need a little more forgiveness with what the S&H will accept for triggers/gates.

Also I need to upgrade my power supply, the LED's seem to be effecting the pitch of my VCO's.
JCM
Or maybe I just don't fully understand a Sample & Hold. Do I need a sustained gate signal?
Luka
(editing post for clarity)

the frv works a bit different to the qrv and srv in that it uses the noise and the 555 for the clock and crazyness. if the noise isnt working i dont think much else will.

the qrv and srv need to be triggered to get an event whereas the frv just runs
nickster
Sorry for the confusion but are we good to go now on the Eurorack version? What changes need to be done etc? Or are we still waiting on confirmation from Roman? Can someone kindly clarify this for me, reading previous posts would indicate that the 12v version is not working yet pending some alterations, am I correct in this? sad banana very frustrating
JCM
Luka wrote:
(editing post for clarity)

the frv works a bit different to the qrv and srv in that it uses the noise and the 555 for the clock and crazyness. if the noise isnt working i dont think much else will.

the qrv and srv need to be triggered to get an event whereas the frv just runs


Thanks for that. The FRV is giving me something, but it's not very "fluctuating". It just behaves like an LFO and will seemingly lock up at some settings.

The QRV and SRV behave as expected.

I ordered a new noise chip, we'll see if that does it.

Anyone on the S&H triggers? The end outs on the 281 trigger the QRV and SRV, but I get nothing from the S&H.
JCM
I'll try removing R16 & R35 and see if that helps.
roman_f
JCM wrote:
I'll try removing R16 & R35 and see if that helps.


first of all you should check the NT pad (top right) if there's a noisy triangle
if it doesn't happen - then you should check the noise section
if it is happening - FRV is not ok
roman_f
i'm sorry i was out for a while
will help everyone with their questions
janvanvolt
Hi Roman,

did all the changes to R46 and R59 and it seems now everything is correct.
How can i actually verify ? My assumptions are based on various youtube videos comparing against the behavior and results..
jaidee
Can anyone verify whether Switchcraft 112AX jacks as per the group buy happening on this list will fit the 5U/MOTM PCBs?

These jacks have solder terminals rather than PCB pins, but Roman's PCBs are clearly intended to accommodate a lug rather than a pin!

I've asked the same question on the group order thread, so apologies for the cross-posting.

Alternatively, does anyone have a UK source for a reasonable (in terms of cost and quality) alternative socket?

Unfortunately, the shipping cost of the Bridechamber sockets plus the likelihood of customs charges makes them a less than economic alternative.

My local supplier, ESR. has some dirt cheap sockets, but the quality is shite...

Thanks
ringstone
janvanvolt wrote:
Hi Roman,

did all the changes to R46 and R59 and it seems now everything is correct.
How can i actually verify ? My assumptions are based on various youtube videos comparing against the behavior and results..


I'd be grateful if you could verify for me that you didn't install these components:
D12, D13, IC15, IC14, L4, L3, R44, C14, C41, C40

as well as doing the changes to R46 and R59?

Thanks!
Blair
marvkaye
jaidee wrote:
Can anyone verify whether Switchcraft 112AX jacks as per the group buy happening on this list will fit the 5U/MOTM PCBs?

These jacks have solder terminals rather than PCB pins, but Roman's PCBs are clearly intended to accommodate a lug rather than a pin!

I've asked the same question on the group order thread, so apologies for the cross-posting.

Alternatively, does anyone have a UK source for a reasonable (in terms of cost and quality) alternative socket?

Unfortunately, the shipping cost of the Bridechamber sockets plus the likelihood of customs charges makes them a less than economic alternative.

My local supplier, ESR. has some dirt cheap sockets, but the quality is shite...

Thanks


Question was answered yesterday on the group-buy thread. Go to this page, almost to the bottom. Yes, they fit. Sorry, I don't have an alternate source for you in UK, but I'm sure someone will.

<marv>
thebot
marvkaye wrote:
jaidee wrote:
Can anyone verify whether Switchcraft 112AX jacks as per the group buy happening on this list will fit the 5U/MOTM PCBs?

These jacks have solder terminals rather than PCB pins, but Roman's PCBs are clearly intended to accommodate a lug rather than a pin!

I've asked the same question on the group order thread, so apologies for the cross-posting.

Alternatively, does anyone have a UK source for a reasonable (in terms of cost and quality) alternative socket?

Unfortunately, the shipping cost of the Bridechamber sockets plus the likelihood of customs charges makes them a less than economic alternative.

My local supplier, ESR. has some dirt cheap sockets, but the quality is shite...

Thanks


Question was answered yesterday on the group-buy thread. Go to this page, almost to the bottom. Yes, they fit. Sorry, I don't have an alternate source for you in UK, but I'm sure someone will.

<marv>


Here you go:

http://www.rapidonline.com/Cables-Connectors/2-Pole-Switched-Jack-Sock et-20-1430
E.A.S.
janvanvolt wrote:


did all the changes to R46 and R59 and it seems now everything is correct.


Glad to hear it seems to be working!

A little on what those changes do...

When when looking at the original schematics I saw the reference voltage to the comparators needed to be -5.6v. The voltage divider obtains it reference via a voltage divider hooked between the - rail and ground. Obviously when you change the rail voltage, your reference voltage will be off! When powered from 12v the reference voltage lowers to -4.488. Not gonna work right. With a little simple maths we find the value for R46 needs to be lowered to around 46.4k. (more precisely 46.491k, but the more common value of 46.4k gives -5.606v, still pretty good.)

The next change needed to be changed to bring range of the input back up.

With the quantization knob all the way up, you wouldn't get the full range out of the knob. R59 sets the gain of the quantization input mixer. Because we've lowered the voltage feeding the QRV pot (from +15 rail to +12v), you wont get the full 0 to -6v range you need out of the op-amp output to feed the comparators. So changing R59 to to 75k, gives you the -.5 x gain you need to scale the voltage correctly.

There could be more changes I'm overlooking, but at least these two parts should be changed.


-Mike This is fun!
jaidee
Thanks for ths jacK socket info guys!
janvanvolt
ringstone wrote:
janvanvolt wrote:
Hi Roman,

did all the changes to R46 and R59 and it seems now everything is correct.
How can i actually verify ? My assumptions are based on various youtube videos comparing against the behavior and results..


I'd be grateful if you could verify for me that you didn't install these components:
D12, D13, IC15, IC14, L4, L3, R44, C14, C41, C40

as well as doing the changes to R46 and R59?

Thanks!
Blair


I just followed the instructions for the 15V build, e.g. no PCB cuts,
some jumpers and R46 and R59 changed. Just got the panel today. Module is now fully finished and working here :-)
rowman
Just removed the voltage regulators from my spreadsheet, thanks for figuring this out guys.
ringstone
janvanvolt wrote:
ringstone wrote:
janvanvolt wrote:
Hi Roman,

did all the changes to R46 and R59 and it seems now everything is correct.
How can i actually verify ? My assumptions are based on various youtube videos comparing against the behavior and results..


I'd be grateful if you could verify for me that you didn't install these components:
D12, D13, IC15, IC14, L4, L3, R44, C14, C41, C40

as well as doing the changes to R46 and R59?

Thanks!
Blair


I just followed the instructions for the 15V build, e.g. no PCB cuts,
some jumpers and R46 and R59 changed. Just got the panel today. Module is now fully finished and working here :-)


Thank you! That reduces the BOM cost by about $15 I think w00t

Cheers
Blair
numbertalk
janvanvolt wrote:
I just followed the instructions for the 15V build, e.g. no PCB cuts,
some jumpers and R46 and R59 changed. Just got the panel today. Module is now fully finished and working here :-)


Post some pics!
nickster
So for correct 12v Eurorack to function we actually need to follow the 15 v (eurorack) installation instructions omitting D12, D13, IC15, IC14, L4, L3, R44, C14, C41, C40

And changing R46 to a 46.4k resistor on Board 2,
also changing R59 to a 75K Resistor again on Board 2.

No traces need to be cut.

Can somebody confirm this for me and Roman if possible can you update the build documents.

Thanks very much in advance.
8_)
msprigings
I too would like to get started on this one. Just need the final working build instructions!
L-1
I've almost finished my build but still wait for some parts.
Just fit panel with Kobiconn jacks and Alpha pots - some thin about 0,5mm washers are needed for full happiness.



hellpony
Any word on the euro build corrections? seriously, i just don't get it
nickster
Roman

On your BOM you call for Minijacks from Erthenvar

Can we use Kobiconn jacks or are the ground lugs on the PJ-301B jacks essential for this build?
L-1
If you use alu panel, you can use Kobiconn jacks and connect panel to board ground somewhere once.
nickster
L-1 wrote:
If you use alu panel, you can use Kobiconn jacks and connect panel to board ground somewhere once.


Thanks, any good idea where I should take a ground link from? Or should I just take a wire from one jack ground slot and run this to a jack head which touches the faceplate.
Thanks in advance
L-1
Really better if two groundplanes are connected in one location. For example, Oakley connected their panels ground direct near power source, not even to board. But majority ignore it. It's question how many hi-end you want.
Just connect ground leg of one jack with wire to board ground. Other jacks grounds will be connected between via panel .
Juxwl
nickster wrote:
So for correct 12v Eurorack to function we actually need to follow the 15 v (eurorack) installation instructions omitting D12, D13, IC15, IC14, L4, L3, R44, C14, C41, C40

And changing R46 to a 46.4k resistor on Board 2,
also changing R59 to a 75K Resistor again on Board 2.

No traces need to be cut.

Can somebody confirm this for me and Roman if possible can you update the build documents.

Thanks very much in advance.
8_)


Has anyone verified that these changes work?
numbertalk
Should we find it at all disconcerting Roman isn't replying here to answer questions in a while?
spotta
numbertalk wrote:
Should we find it at all disconcerting Roman isn't replying here to answer questions in a while?

He's been on the missing list before for a week or two and and always returned.
I wouldnt get too worried yet.

Although I really want to get mine built as well!
nickster
Roman was robbed of his laptop just recently so I imagine it will take a while longer before he can get round to answering these questions. Pretty tough luck for him as most of his stuff was on the hard drive.
janvanvolt
As i got asked, here are the summarized items i did to get the 266c (eurorack) running:

- omit D12, D13, IC15, IC14, L4, L3, R44, C14, C41, C40
- do NOT cut any traces
- for R46 use a 46.4k resistor on Board 2,
- for R59 use a 75K Resistor again on Board 2.
- do NOT follow instructions from page 1 on 266c-eurorack-1-schematics-v1.1
- check and apply the fix according to 266c-eurorack-3-schematics-v1.1
nickster
janvanvolt wrote:
As i got asked, here are the summarized items i did to get the 266c (eurorack) running:

- omit D12, D13, IC15, IC14, L4, L3, R44, C14, C41, C40
- do NOT cut any traces
- for R46 use a 46.4k resistor on Board 2,
- for R59 use a 75K Resistor again on Board 2.
- do NOT follow instructions from page 1 on 266c-eurorack-1-schematics-v1.1
- check and apply the fix according to 266c-eurorack-3-schematics-v1.1


Wicked! Eurorack build starts today, finally. Thanks for confirming this.
Jan, you are the man.
nanners nanners It's motherfucking bacon yo
Juxwl
janvanvolt wrote:
As i got asked, here are the summarized items i did to get the 266c (eurorack) running:

- omit D12, D13, IC15, IC14, L4, L3, R44, C14, C41, C40
- do NOT cut any traces
- for R46 use a 46.4k resistor on Board 2,
- for R59 use a 75K Resistor again on Board 2.
- do NOT follow instructions from page 1 on 266c-eurorack-1-schematics-v1.1
- check and apply the fix according to 266c-eurorack-3-schematics-v1.1


Did you install jumpers for any or all of the omitted components?
L-1
Roman, what values are R16 and R35 on 1st board Euro. ?

I can't find them on the schematic and in BOM but they are on the board.
L-1
I've assembled the module but it doesn't work. Euro but 15V version.
+11V instead of -15 on 2nd and 3rd boards. And I don't see any V- out from 1st board connector at all. please advise.
raisinbag
It sounds like jananvolt has it working, maybe send him a PM and find out all the details? It sounds like Roman is quite messed up with robbery and all. I haven't built mine yet as I have been waiting for an official build confirm before I do mine. I don't have enough experience to trouble shoot something so big. I'm like a DIY vulture.
L-1
I've checked with tester - any V- out from 1st board.
raisinbag
Oh sorry you are doing it at 15v. That was my plan, but not sure what I want to do. Seems there is trouble with the builds so I will wait till after I build the tube vca and vocorder and do 266 after. razz

I hope you can figure this one out. What directions did you follow? Seems there are some different versions and it is getting confusing. I'm sure Roman will check in again soon and sort us out.
L-1
Yes, I've placed a wire between V- of boards 1 and 3, and the device started to work. Will check all the functions later but at least LEDs started to blink.

In other words I got V- to board 3.

Tomorrow will make a photo. Very nice module.
ringstone
I think Roman mentioned there might have been an issue with some of the ribbon cables - might be worth checking.

Cheers
Blair
raisinbag
Good call. I hope that it what L1's prob is. Kinda like that broken guitar amp I bought cheap becasue it didnt work and it just had a blown fuse. applause
L-1
These are a photos of my 266. Thanks to Roman for the great project!

10R (bead) resistor at V+ is pretty hot. Will replace this to 0.5W

Smaller knob is needed for integrators pot, too close to jack.

Intergator's pot adjusts amplitude. It is normal?

Other functions work correct.

The V- wire from 1 to 3 board is visible on the fourth photo. I think it is possible to connect V- of 1 and 2 boards with shorter wire, but I made V- IN near bypass caps, as it must be.









raisinbag
What was wrong with your board yesterday, how did you get it to work? Oh also, you are powering it with 15v right, so what do you do in this case to connect a 15v supply to a euro 10 pin header?
L-1
I've connected V- thru pin on 1 board and V- via hole near bypass electrolyth on board 3.
pre55ure
Edited to say "nevermind"
synaptech
Hmm can anyone clarify why R53 (150k) on 266c-EURO-2 v1.1 is in red? Was this an addition from v1.0? I'm assuming I should install it but just wanted to clarify. thumbs up
jbaken
just finished building the euro version. everything seems to be working except the sample and hold. cant seem to get any output from it.. seems like its not responding to my clock input. ive tried running it without R16 and R35 and with 47ks in both spots (based on the buchla schematic). not sure what to try now. thoughts?
jbaken
@L-1
it looks like you didn't connect board 1 to board 2 with the thru connection (next to euro connector). also looks like your ribbon cable is upside down?
L-1
Ribbon cables are correct.
V+ connected via ribbon cable from board1 to board3 and then to board2.
V- connected via ribbon cable between board3 and 2 but not connected to board1 where is power. It is an error. I've connected V- from board1 to 3 via wire, as it must to be.
camelneck
Roman's BOM for the 266 (Buchla & Euro Formats only) lists Small Bear as a parts source for the five B10K potentiometers. They cost $1.95 each.

Has anyone bought and used these pots (or equivalents) from Mouser?
If so, do they fit on the PCB properly?
Can you list (or verify) the Mouser or Alpha part number for these pots?

I'm almost sure that I have found the same Alpha pots (or equivalents) on the Mouser website for $1.11 each, but I'd like to know if someone can verify this for me. (Although I think Small Bear is a great company, buying them from Mouser would save me from having to place a second order and having to pay a 2nd shipping charge. The pots at Mouser are also considerably cheaper than those from Small Bear.)

Here is the part number and other information about these pots from Mouser.

Mouser Part #: 317-2090F-10K
Manufacturer Part #: RV09AF-40-20K-B10K (Alpha)
Type: miniature, vertical mount snap-in
Shaft Diameter: 6 mm
Shaft Length: 12.7 m
Resistance: 10 KOhms (0.1 Watt)
Shaft Type: Knurled / Serrated with 40 teeth
Termination Style: Snap In, Pin
Voltage Rating: 50 Volts
Datasheet: http://www.mouser.com/catalog/specsheets/TW-700167.pdf

I measured the pot pads on the PCB and compared these measurements with the dimensions listed on the datasheet and these pots look like they should fit on the PCB just fine. (This includes the 3 pot pins and the 2 mounting pins).

The only difference I see between these Mouser pots and the one pictured on the Small Bear website is the Small Bear pot appears to have a smooth shaft, whereas the Mouser pot is knurled or serrated. However, there are 40 teeth on the shaft (which is a lot more than most knurled shafts have) so I don't think it will be a major problem if you are using the Buchla-style (Davies) knobs. (Since these knobs have set screws they work best with smooth shafts.)

There were no specs on the Small Bear website except for the description:
Alpha Single-Gang 9mm Right-Angle PC Mount
Otherwise, if they had given the Alpha part number I would know for certain if this is the same pot.
http://www.smallbearelec.com/servlet/Detail?no=1139
ringstone
camelneck wrote:
Roman's BOM for the 266 (Buchla & Euro Formats only) lists Small Bear as a parts source for the five B10K potentiometers. They cost $1.95 each.

Has anyone bought and used these pots (or equivalents) from Mouser?
If so, do they fit on the PCB properly?
Can you list (or verify) the Mouser or Alpha part number for these pots?

I'm almost sure that I have found the same Alpha pots (or equivalents) on the Mouser website for $1.11 each, but I'd like to know if someone can verify this for me. (Although I think Small Bear is a great company, buying them from Mouser would save me from having to place a second order and having to pay a 2nd shipping charge. The pots at Mouser are also considerably cheaper than those from Small Bear.)

Here is the part number and other information about these pots from Mouser.

Mouser Part #: 317-2090F-10K
Manufacturer Part #: RV09AF-40-20K-B10K (Alpha)
Type: miniature, vertical mount snap-in
Shaft Diameter: 6 mm
Shaft Length: 12.7 m
Resistance: 10 KOhms (0.1 Watt)
Shaft Type: Knurled / Serrated with 40 teeth
Termination Style: Snap In, Pin
Voltage Rating: 50 Volts
Datasheet: http://www.mouser.com/catalog/specsheets/TW-700167.pdf

I measured the pot pads on the PCB and compared these measurements with the dimensions listed on the datasheet and these pots look like they should fit on the PCB just fine. (This includes the 3 pot pins and the 2 mounting pins).

The only difference I see between these Mouser pots and the one pictured on the Small Bear website is the Small Bear pot appears to have a smooth shaft, whereas the Mouser pot is knurled or serrated. However, there are 40 teeth on the shaft (which is a lot more than most knurled shafts have) so I don't think it will be a major problem if you are using the Buchla-style (Davies) knobs. (Since these knobs have set screws they work best with smooth shafts.)

There were no specs on the Small Bear website except for the description:
Alpha Single-Gang 9mm Right-Angle PC Mount
Otherwise, if they had given the Alpha part number I would know for certain if this is the same pot.
http://www.smallbearelec.com/servlet/Detail?no=1139


I'm not sure Mouser even carry these pots (specified in the 266 BOM). They do carry the non right-angle version, but at $4.73 each, so over double the cost of Small Bear. Plus they only carry a few of the most common values.

The pot you are looking at on Mouser is probably a plastic shaft pot with no mounting hardware. It may well be fine, but I'd check the specs very carefully.

I find that buying pots for around 10+ projects at a time from Small Bear is the best way to go. You gain more advantage from price breaks that way.

Cheers
Blair

EDIT: Looking at that PDF you posted confirms these have no sleeve for mounting to the panel. I'm pretty sure these are the plastic shafts intended to have no knob, as you can see from the technical drawing there is a tick mark on the end of the shaft itself. In my experience you might have a problem finding a knob to fit on the shaft, even set screw.
camelneck
I have a few questions about LEDs.

1) I still haven't made up my mind whether to use the red LEDs as the older 266 modules used or blue LEDs as the 266e modules use. The red LEDs look more authentic, but personally, I prefer the look of blue LEDs.

Does anybody have a Mouser part number for a 3mm blue LED that they would recommend?

2) All 6 of the 266's LED drivers consists of a 2N1711 transistor and a 100 ohm resistor. The 100 ohm resistor seems a bit low in value (which means the LED current is probably too high) for modern day LED's.

Has anybody experimented with different transistors and/or resistor values as far as the LED driver circuits are concerned?

3) I know this is off-topic, but does anybody know the LED colors for a Buchla 281 (not a 281e)? I'm sure the 4 output LEDs are red, but are the other 4 LEDs, which are lit when the FGs are in Quadrature mode, suppose to be red or orange in color?
camelneck
ringstone wrote:

EDIT: Looking at that PDF you posted confirms these have no sleeve for mounting to the panel. I'm pretty sure these are the plastic shafts intended to have no knob, as you can see from the technical drawing there is a tick mark on the end of the shaft itself. In my experience you might have a problem finding a knob to fit on the shaft, even set screw.


Thanks for the help Blair. You are absolutely right--these pots don't have a sleeve so there is no way to screw them to the front panel. I can't believe that I overlooked that! The shaft might be a little short, also. So scratch that idea!

Do you have the Alpha pot number for these pots?

If Mouser is charging $4.73 for the right-angled (horizontal) pots, the vertical pots are probably about the same price. So I guess it would be cheaper to buy them from Small Bear even if I have to pay a 2nd shipping charge.

Thanks again.
ringstone
camelneck wrote:
ringstone wrote:

EDIT: Looking at that PDF you posted confirms these have no sleeve for mounting to the panel. I'm pretty sure these are the plastic shafts intended to have no knob, as you can see from the technical drawing there is a tick mark on the end of the shaft itself. In my experience you might have a problem finding a knob to fit on the shaft, even set screw.


Thanks for the help Blair. You are absolutely right--these pots don't have a sleeve so there is no way to screw them to the front panel. I can't believe that I overlooked that! The shaft might be a little short, also. So scratch that idea!

Do you have the Alpha pot number for these pots?

If Mouser is charging $4.73 for the right-angled (horizontal) pots, the vertical pots are probably about the same price. So I guess it would be cheaper to buy them from Small Bear even if I have to pay a 2nd shipping charge.

Thanks again.


No problems! I have been down this path myself before... hihi I'm not sure of the part no. of those vertical pots, a trawl through the Alpha web site might turn them up - but I've not found another supplier who actually stocks them with the sleeve for mounting to a panel, that's cheaper than Small Bear. 9mm pots are generally more expensive than their 16mm counterparts I'm afraid.

Cheers
Blair
roman_f
hello guys
did anyone finish the 266 for Buchla or 5U?

i'm going to upload the build docs for Euro next days - just need to make them from scratch, since i have a new laptop
roman_f
jbaken wrote:
just finished building the euro version. everything seems to be working except the sample and hold. cant seem to get any output from it.. seems like its not responding to my clock input. ive tried running it without R16 and R35 and with 47ks in both spots (based on the buchla schematic). not sure what to try now. thoughts?


are you able to make another set of ribbon cables?
due to my experience there's a very high amount of bad cables
i'll never do any more project with ribbons - only with PLDs

i have 1 working unit on my desk and ready to help anyone with scoping
cleaninglady
I've finished the build but this does not fit into a Doepfer box.

I'm not talking about depth here either ; the PCB's actually won't even fit between the rails. Dead Banana

I'm seriously bummed about his. sad banana
nickster
Edit question already answered sorry!
L-1
cleaninglady wrote:
I've finished the build but this does not fit into a Doepfer box.

I'm not talking about depth here either ; the PCB's actually won't even fit between the rails. Dead Banana

I'm seriously bummed about his. sad banana


It's easy to solve:

Don't fit:




Remove about 0.2mm from each side:




Now fit:


cleaninglady
Thanks !! It would have been good to know before i finished the build. very frustrating

Much appreciated , nonetheless... thumbs up
marvkaye
Just curious what folks did for the 910pF capacitors that are called for? Couldn't find them in poly or mylar, decided to attach leads to some SMT 0805 MLCC NP0(C0G) hoping they'll be appropriate. Any thoughts?

<marv>
ringstone
marvkaye wrote:
Just curious what folks did for the 910pF capacitors that are called for? Couldn't find them in poly or mylar, decided to attach leads to some SMT 0805 MLCC NP0(C0G) hoping they'll be appropriate. Any thoughts?

<marv>


The BOM actually substituted 1nF ceramic ML caps.

Cheers
Blair
raisinbag
Is there a different bom than that one I have that calls for 910pf and there is a mouser number for it. I haven't built yet as I'm waiting for an official build doc for the euro. If I can use a 1n that would be easier as I have lots if those.
marvkaye
ringstone wrote:
marvkaye wrote:
Just curious what folks did for the 910pF capacitors that are called for? Couldn't find them in poly or mylar, decided to attach leads to some SMT 0805 MLCC NP0(C0G) hoping they'll be appropriate. Any thoughts?

<marv>


The BOM actually substituted 1nF ceramic ML caps.

Cheers
Blair


Thanx, Blair... the 5U BOM still calls out the 910pF but the Mouser part number that goes with it actually references a 1nF poly. I hadn't noticed that before. I need to pay closer attention to those part lists. d'oh!

<marv>
J3RK
You can get 910pF in styrene from anywhere that sells them. I have them. I can't remember for sure, but I think I got them at Mouser.
J3RK
roman_f wrote:
hello guys
did anyone finish the 266 for Buchla or 5U?

i'm going to upload the build docs for Euro next days - just need to make them from scratch, since i have a new laptop


Good to see you're back up and running!
spotta
cleaninglady wrote:
I've finished the build but this does not fit into a Doepfer box.


I've just checked mine (I got worried!) and they go in fine on my Doepfer 9u low cost wood case.

Weird.
marvkaye
J3RK wrote:
You can get 910pF in styrene from anywhere that sells them. I have them. I can't remember for sure, but I think I got them at Mouser.


I've been looking (Mouser, DigiKey, etc, etc) and that's simply not a very popular value in the usual operating voltages we use (ie, less than 100V).. lots out there for 630V or 1KV (mica) but they're huge and expensive. There was a place mentioned here awhile back in another thread that seemed to have a great stock of all kinds of caps at reasonable prices, but I can't for the life of me remember exactly where I saw it. And "capacitor" surely isn't the most useful search term to try to narrow things down in the forums.......

Anyway, I'm gonna keep looking and if all else faiils I'll just fade back to that 1nF value, seems to be acceptable.

<Marv>
J3RK
Posted incorrect link. See below for the correct one.
J3RK
http://www.mouser.com/ProductDetail/Kemet/C315C911G1G5TA/?qs=sGAEpiMZZ MuAYrNc52CMZEKru23jgrIW5b1Gd6I59rw%3d

It looks like they don't have them in the styrene variety anymore.
marvkaye
J3RK wrote:
http://www.mouser.com/ProductDetail/Kemet/C315C911G1G5TA/?qs=sGAEpiMZZ MuAYrNc52CMZEKru23jgrIW5b1Gd6I59rw%3d

It looks like they don't have them in the styrene variety anymore.


Yes, that's a fact. Plus, $2.78 is kinda pricey, which is why I thought I'd make up my own using 0805 SMT ones. These guys are 1% and are only 32c apiece... I know adding leads is a PITA, but for $2,50/cap I would be willing to suffer through. Also, West Florida Components has 560pF and 350pF styrene for 25c apiece... those guys in parallel would work too.

<marv>
cleaninglady
spotta wrote:
cleaninglady wrote:
I've finished the build but this does not fit into a Doepfer box.


I've just checked mine (I got worried!) and they go in fine on my Doepfer 9u low cost wood case.

Weird.


Yeah , go figure... seriously, i just don't get it
ringstone
I had no luck finding 910pF styrenes, and the only 910pF caps I could find at Mouser were too expensive - given that 4 are required! 910pF aren't hard to find in Silver Mica though, I did buy some fairly cheaply but I think I will just subs ceramic NP0's, the Silver Mica are much larger and wider.

I'll probably save these for another Buchla clone project, as they seemed to be used in those designs - I'm pretty sure the 291 originally used a 910pF as well.

Cheers
Blair
cleaninglady
L-1 wrote:
I've connected V- thru pin on 1 board and V- via hole near bypass electrolyth on board 3.


Could you possibly post a picture of where to connect the wire on Board 3 ?

I just cant figure it out from the pictures so far.

Looking at the Schematic for Board 3 , it looks like there might be a hole i could solder a wire to further along the track that's connected to the Negative side of C5. Does that sound right ?
fluxmonkey
roman_f wrote:
hello guys
did anyone finish the 266 for Buchla or 5U?

i'm going to upload the build docs for Euro next days - just need to make them from scratch, since i have a new laptop


i am abt 85% done w/ my 5u build (for a friend)... anything potential issues i should be looking at?
Luka
ringstone wrote:
I had no luck finding 910pF styrenes, and the only 910pF caps I could find at Mouser were too expensive - given that 4 are required! 910pF aren't hard to find in Silver Mica though, I did buy some fairly cheaply but I think I will just subs ceramic NP0's, the Silver Mica are much larger and wider.

I'll probably save these for another Buchla clone project, as they seemed to be used in those designs - I'm pretty sure the 291 originally used a 910pF as well.

Cheers
Blair


i used mica in my one
i think NP0 will be fine
nickster
My boards are as tight as a mouses' ear! Got them stuck whilst trying to fit them. Eek more sand papering or I'll have to rebuild my case to make my rail spacing a tad wider. Oh well this is DIY at its best. hihi
J3RK
marvkaye wrote:
Yes, that's a fact. Plus, $2.78 is kinda pricey, which is why I thought I'd make up my own using 0805 SMT ones.
<marv>


Yeah, that is a bit expensive, and your SMT workaround makes sense to me. I just thought I had seen more of those when I ordered them a while back. (especially the styrene 910pF ones...) seriously, i just don't get it
jbaken
update- sample and hold works fine! had the CV input and output jacks backwards so when i plugged in to them i was canceling any signal that may have been there. Also, the sample and hold pulse input does NOT like LFOs (every other pulse input works fine with an LFO) ive been able to trigger it with a DUSG out, RCD out and various other 5-8v clock signals.
Everything on my board is up and running but I've noticed 2 possibly weird things-
FRV - the first output is bipolar. Not sure if this was intentional or if ive fucked something up somewhere..

QRV- I get really high frequency signals when the pot is fully counter clockwise regardless of the tuning position of my vco. for example- when the pot is set to 1 i can hear 3 different sounds from the N+1 output going to an audiorate vco- 2 low bass tones and one suuuuper high chirp. seems like there should only be 2 notes there? (n=1 +1 =2)..the chirp seems out of place since the notes get only higher as i move the knob clockwise. I usually just explore these QRVs with the knob around 12 o clock so theres less chance of getting these weird chirps.

having said that im having a ton of fun with this module. thanks for making these roman!!
camelneck
ringstone wrote:
I had no luck finding 910pF styrenes, and the only 910pF caps I could find at Mouser were too expensive - given that 4 are required! 910pF aren't hard to find in Silver Mica though, I did buy some fairly cheaply but I think I will just subs ceramic NP0's, the Silver Mica are much larger and wider.

I'll probably save these for another Buchla clone project, as they seemed to be used in those designs - I'm pretty sure the 291 originally used a 910pF as well.

Cheers
Blair


The 1000pF (or 1nF or .001uF) capacitors should be fine. In almost all DIY synth applications, you can use capacitors with a 10% (or greater) tolerance. Unlike resistors, which regulate current and voltage values, capacitors values rarely ever have to be that precise although there are some cases (such as the the pole capacitors in a VCF) where the capacitor values should be closely matched.

I haven't studied the schematics of the 266 in detail, but the 910pF capacitors that are used in the Buchla 281 and 291 are basically used for general applications (AC coupling, DC blocking, pulse shaping, BW limiting) and the capacitor value can vary by +/- 10% of the listed value. I suspect it is the same here since the 266 doesn't contain any audio filters.

One of the few exceptions is VCFs where you want the pole capacitors to have matching values. Thus, if the VCF's BOM was to call for four 47nF capacitors, I would much rather have four capacitors, each with a value of 50nF, rather than have 4 capacitors whose values are closer to 47nF (such as 46pF, 47pF, 48pF, & 49pF), yet do not match.

If you plan to do even a moderate amount of DIY synth work, you should buy a Volt/ohm meter that can also measure capacitors. Today, you can buy such meters for under $40. This way you can match your own capacitors instead of having to buy expensive 1% or 2% capacitors for filters.

Of course, you could pay $3.00 for a single 910pF with a 10% tolerance, but this means the capacitor can still vary between 819pF and 1001 pF. So why not buy 10 1000pF capacitors with a 10% tolerance for $3 instead. As long as one of them is 1000pF or less, you have a capacitor that is within specs and 9 spare for the same price.
marvkaye
camelneck wrote:

I haven't studied the schematics of the 266 in detail, but the 910pF capacitors that are used in the Buchla 281 and 291 are basically used for general applications (AC coupling, DC blocking, pulse shaping, BW limiting) and the capacitor value can vary by +/- 10% of the listed value. I suspect it is the same here since the 266 doesn't contain any audio filters.


I took a look at the schematics this afternoon, saw that the 910pF caps all had something to do with the Vactrols. If someone wants to take a look and suggest the actual function I, for one, would be happy to learn what the implication would be of replacing the specified part with a 1n.

camelneck wrote:

If you plan to do even a moderate amount of DIY synth work, you should buy a Volt/ohm meter that can also measure capacitors. Today, you can buy such meters for under $40. This way you can match your own capacitors instead of having to buy expensive 1% or 2% capacitors for filters.


I agree 100%. When I started getting seriously involved in SDIY I was surprised to discover than none of my DMMs had the ability to test capacitors... not even my 50,000 count bench meter. Went on the search for a tester that could do the job and landed upon the BK Precision Model 815 component tester. Nice tool, keep it at my side anytime I'm stuffing boards and use it routinely to verify capacitance on those teeny MLCC caps with markings that require a microscope to read. It also does diodes, transistors, SCRs, etc... very handy device.

On another note... way back on P1 of the thread, right at the top where the pics and build docs reside for the 5U version, there's a note that says to omit resistors R16 and R35 for 5V pulses for the S&H, however it doesn't state whether they're to be left off of PCB #1 or #2. I assume it's #1, as that appears to be the one with all the S&H circuitry, but I just want to make sure before I do something foolish. TIA for the help.

<marv>
cleaninglady
Still no love on the Neg Wire question...

Now i have another.

RE : Board #3 , there is something in the Docs that says :

To prevent shorting Ground Rail to the Output of FRV 2 , use a link for R6 and omit R7. Then put tape on the R7 pads on the solder side before soldering jacks.

I completely missed this , my jacks are soldered already.

Do i need to do this ? Dead Banana

Also , are those instructions in the beginning of the Board #1 Docs redundant or does some of that need to be done too ?
L-1
Quote:
Still no love on the Neg Wire question...


sorry, forget to answer. it's white wire soldered in via hole.

ringstone
camelneck wrote:
ringstone wrote:
I had no luck finding 910pF styrenes, and the only 910pF caps I could find at Mouser were too expensive - given that 4 are required! 910pF aren't hard to find in Silver Mica though, I did buy some fairly cheaply but I think I will just subs ceramic NP0's, the Silver Mica are much larger and wider.

I'll probably save these for another Buchla clone project, as they seemed to be used in those designs - I'm pretty sure the 291 originally used a 910pF as well.

Cheers
Blair


The 1000pF (or 1nF or .001uF) capacitors should be fine. In almost all DIY synth applications, you can use capacitors with a 10% (or greater) tolerance. Unlike resistors, which regulate current and voltage values, capacitors values rarely ever have to be that precise although there are some cases (such as the the pole capacitors in a VCF) where the capacitor values should be closely matched.

I haven't studied the schematics of the 266 in detail, but the 910pF capacitors that are used in the Buchla 281 and 291 are basically used for general applications (AC coupling, DC blocking, pulse shaping, BW limiting) and the capacitor value can vary by +/- 10% of the listed value. I suspect it is the same here since the 266 doesn't contain any audio filters.

One of the few exceptions is VCFs where you want the pole capacitors to have matching values. Thus, if the VCF's BOM was to call for four 47nF capacitors, I would much rather have four capacitors, each with a value of 50nF, rather than have 4 capacitors whose values are closer to 47nF (such as 46pF, 47pF, 48pF, & 49pF), yet do not match.

If you plan to do even a moderate amount of DIY synth work, you should buy a Volt/ohm meter that can also measure capacitors. Today, you can buy such meters for under $40. This way you can match your own capacitors instead of having to buy expensive 1% or 2% capacitors for filters.

Of course, you could pay $3.00 for a single 910pF with a 10% tolerance, but this means the capacitor can still vary between 819pF and 1001 pF. So why not buy 10 1000pF capacitors with a 10% tolerance for $3 instead. As long as one of them is 1000pF or less, you have a capacitor that is within specs and 9 spare for the same price.


Well, those silver micas were nowhere near $3 - I would have used them except their form factor was a little large for this project.

I agree with having a meter that will measure capacitance, however the cheaper meters aren't all that accurate in this regard (in my experience anyway). For smaller values you also must take into account the capacitance of the tester/leads as well - this could well be as much as the value of the cap! Take a reading under typical conditions (no capacitor under test), note the value, then you will need to subtract that from your readings.

Mind you, I believe that caps will also change in value under working conditions, so for really accurate readings, you probably need a proper LCR meter or something that can test them at different working frequencies hihi

Cheers
Blair
cleaninglady
Thanks L-1, after looking at the Schematic that's where i took it from.

The other end of the wire was in the outer hole of the THRU bus holes as in your earlier photo.

Unfortunately , after connecting it to power , i saw smoke coming out. After taking it out again the Capacitors C35 and C37 were very hot and C35 had swelled a bit at the top.

The crazy thing is...when i connect a DMM on Continuity test between that outer THRU hole and Neg on the Power Input , i get no beep to indicate Continuity.

Would you be able to post a picture of the bottom right corner of Board #1 so i can check my power section is OK ?

Also , i didn't do several thing in the Build instructions :

On Board #3 i didn't do this :

"To prevent shorting Ground Rail to the Output of FRV 2 , use a link for R6 and omit R7. Then put tape on the R7 pads on the solder side before soldering jacks."

I completely missed this , my jacks are soldered already.

On Board #1 i didn't do any of the 15V conversion stuff as i'm running on 12V ; so i have L2 , C37 , C38 installed.

Sorry for so many questions but i'm getting nothing from the module so far.
L-1
Will make pictures tomorrow at day light.
About R6 R7. I made these changes when jacks were soldered and panel installed too. But I used kobiconn jacks which don't have metal things at bottom. I just cut these resistors (only two) and made a link.
Check your V+ V- and ground for shorts at every board separately.
cleaninglady
Thanks very much !

I'll make those R6 , R7 changes ; might have to take some stuff apart maybe remove some jacks.

Hopefully , i haven't kiled any IC's with shorts.

You probably saved yourself a world of pain using those Kobiconns ! thumbs up
ringstone
cleaninglady wrote:
On Board #1 i didn't do any of the 15V conversion stuff as i'm running on 12V ; so i have L2 , C37 , C38 installed.


From what I can work out:

There were two lots of "voltage" mods for the Eurorack version.

The first was for running on native 15V.

The second was to make the 12V->15V conversion happen (required for 12V operation). The 15V was required to make a small part of the circuit behave as it did originally. Roman had to change this slightly to get it to operate correctly, hence the additional mods.

However, it was determined that the second mod was unnecessary. The conversion circuit could be done away with, and a few resistor substitutions adjusted the voltage levels.

However - the first mod now needs to be done on ALL boards, whether 12V or 15V. Since the 15V conversion circuit is now gone, you will be without power on some traces. Therefore you need to follow these instructions:

roman_f wrote:
for powering with 15Vs - solder С35, С36, С37, С38, L1, L2
do not solder C14, C40, C41, IC14, IC15, L3, L4, R44, D12, D13
install 2 shorting jumpers



check the voltages on THRU pads (+15/0/-15)
solder all the remaining parts on the PCB (excl. C14, C40, C41, IC14, IC15, L3, L4, R44, D12, D13)


Cheers
Blair

EDIT: Verified that this is in fact the case.
L-1
Quote:
Would you be able to post a picture of the bottom right corner of Board #1 so i can check my power section is OK ?


nickster
Thanks Blair for the clarification. I managed to get my boards to squeeze into my Eurorack so I can now continue with the building.
nickster
cleaninglady wrote:
Still no love on the Neg Wire question...

Now i have another.

RE : Board #3 , there is something in the Docs that says :

To prevent shorting Ground Rail to the Output of FRV 2 , use a link for R6 and omit R7. Then put tape on the R7 pads on the solder side before soldering jacks.

I completely missed this , my jacks are soldered already.

Do i need to do this ? Dead Banana

Also , are those instructions in the beginning of the Board #1 Docs redundant or does some of that need to be done too ?


In reply to your questions Janvanvolt states

janvanvolt wrote:
As i got asked, here are the summarized items i did to get the 266c (eurorack) running:

- omit D12, D13, IC15, IC14, L4, L3, R44, C14, C41, C40
- do NOT cut any traces
- for R46 use a 46.4k resistor on Board 2,
- for R59 use a 75K Resistor again on Board 2.
- do NOT follow instructions from page 1 on 266c-eurorack-1-schematics-v1.1
- check and apply the fix according to 266c-eurorack-3-schematics-v1.1


Hope this helps.
L-1
R16 and R35 on board 1 are unsoldered but device works. Should I leave as is or some resistors are needed here?
cleaninglady
L-1 wrote:
Quote:
Would you be able to post a picture of the bottom right corner of Board #1 so i can check my power section is OK ?




Thanks very much for the picture.Most helpful !!

My power section is identical but my Electro Caps at C35 and C37 keep blowing up. I have just looked at the Schematic and the power cable might be my problem.

I built my cable with the Negative at the bottom as usual with Keyed Headers i.e the little triangle points to the negative (pink) cable of the multicore. Power cables for this module need to be the opposite of this with the little triangle on the keyed header pointing to the Positive cable.

I need to make another cable basically.

I'll get back to you after that is done and i re-install all of the IC's i took out.
L-1
It's a reason to install reverse polarity protection diodes on every design.
cleaninglady
yup... hihi hopefully i didn't fry any IC's.
J3RK
This is slightly off topic, but when I think of silver-mica capacitors, I think of:



(Journey: Escape on the Atari 2600)

Carry on.
valis
J3RK wrote:
This is slightly off topic, but when I think of silver-mica capacitors, I think of:



(Journey: Escape on the Atari 2600)

Carry on.


Oh god thank you. I've been referencing this game for years and not one person has picked up on it. Don't stop believing!
J3RK
valis wrote:
J3RK wrote:
This is slightly off topic, but when I think of silver-mica capacitors, I think of:



(Journey: Escape on the Atari 2600)

Carry on.


Oh god thank you. I've been referencing this game for years and not one person has picked up on it. Don't stop believing!


I have a sad history with this game. I was probably around 4 or 5 or so I think when I had it, and I played it non-stop. Favorite 2600 game. One day, magic smoke poured out of the cartridge. (system was fine) My dad took it apart, to see if there was anything he could do, but alas! cry We couldn't find another copy of the game at the time either. I believe this was right about the time when everyone started liquidating 2600 games just before the big crash. It wasn't until emulation became popular that I got to see it again. w00t

I love the Silver-Mica-Groupies though! The Shifty-Eyed-Promoters might be ceramic discs. Mr. Green
valis
Haha. Great story. I must of gotten mine around the same time. My sister bought it for me while I had pneumonia and I played the hell out of it. I finally saw an emulator of it a few years back which was a relief because no one else had ever heard of the game. It was a totally hilarious game.

Okay, that will be my last post on the subject. Sorry all to hijack the thread hihi
nickster
Ok bringing things back on topic! I'm almost there well actually I discovered today that yet another part was missing from my BOM order! d'oh! So that will have to be ordered before I can get this baby working. Provided that I've not made any errors during my build.
So to cheer me up a bit I placed some of these knobs on to see what they are like. Trying to decide between these & the Davies clone ones. what does everyone think?
These are the same as Clarkes small knobs that can be bought from Jameco. If anyone wants the part number I can post this later.

J3RK
I think those look pretty nice! I'll likely use the smaller Alco knobs, but I think maybe L-1 mentioned that they're too big to go by the integrator jacks, so maybe one of these to go there would be nice. I need to start my build.
cleaninglady
I got it working , played with it for a few hours.

I can't understand the Integrator at all.
I'm finding it pretty hard to find Buchla "how the hell do it use this thing ?" docs around the net...

Any suggestions people ?

It seems that the FRV lower output isn't working , i'm seeing a dim light on the LED but nothing i can tell from the jack. (This might be because i haven't done the R6 / R7 and tape mod yet...)

Also , i'm not getting anything from the Sample and Hold section as far as i can tell.

Apart from all that ; this is a pretty intense module ! woah

Almost too much...just have to learn to finesse it.
jbaken
the integrator is a voltage controlled slew limiter. great for smoothing out the sample and hold or anything on the module really. send some random into the time cons jack and you'll get varried glide.

an alternative to using tape over the R7 through hole is cutting off some of the grounding metal surrounding the erthenvar jacks.. you may be able to get in there with some clippers and just snip off the little bit touching R7. desoldering these things is a huge pain- i put in a couple backwards and had to do this, avoid it if possible.

make sure to send a strong clock signal to the sample and hold (0-8v is good)
cleaninglady
jbaken wrote:
the integrator is a voltage controlled slew limiter. great for smoothing out the sample and hold or anything on the module really. send some random into the time cons jack and you'll get varried glide.

an alternative to using tape over the R7 through hole is cutting off some of the grounding metal surrounding the erthenvar jacks.. you may be able to get in there with some clippers and just snip off the little bit touching R7. desoldering these things is a huge pain- i put in a couple backwards and had to do this, avoid it if possible.

make sure to send a strong clock signal to the sample and hold (0-8v is good)


I ended up figuring the integrator was a Slew.

Still haven't had time to get back to the 266 , got called in for a hospital visit. Went under the knife on Friday , still in bed for a few days.

Sorry it took so long to say thanks.

I'll get onto the jacks and follow your advice. I lost the tip of a cheap minijack in the S+H so i'm going to have to desolder at least one. Luckily i have one spare !
frozenkore
Hey, for anyone building the Buchla panel, if you get the jacks from the BOM (Switchcraft 41), they will not fit in the holes of the RSFC panel. Kobiconn (sp?) jacks fit; however. It looks like the jacks in the BOM are 1/4" (~6.56mm) threaded and the Kobiconn jacks are 6mm. I don't have a caliper on hand to see exactly what the ID of the panel is, but just as a heads up, you might have to drill those out a bit more.

If anyone has had a different experience, let me know, thanks!

Cheers,
Brian
cleaninglady
One thing that might be worth noting is that if you build the Euro power cable in the usual way with Red cable to the arrow on the connector and also install the Keyed Power Header in the direction indicated on the overlay in the Docs , you will end up with Positive where Negative should be and vice versa.

I know because i did it myself and spent a day and a half trying to figure out why... Dead Banana

My advice would be to install the header with the Keyed slot facing inwards , not outwards as displayed in the docs. Or make cable upside down as i did.
Luka
you mean you think people follow standards in euro smile hihi
best to always test this stuff before building cables
nickster
Finished the EURO build today but as I expected, it no worky. very frustrating very frustrating very frustrating

No power is coming through to the LEDs & no noise from the noise unit either.

So I have some questions. Do the through power holes on boards 1 & 2 need to be connected with 3 wires (ie each wire runs to & from each hole)
Or does only one hole need to be connected to it's corresponding hole on the other board. I currently have all 3 pads connected with wires.

If I have managed to orientate the LEDS incorrectly will this affect the build as a whole?

Lastly should L2 (I'm guessing a ferrite bead) be included or left off board 1?
If I have no joy tomorrow I'll post some pictures and hopefully someone will spot where I've gone wrong. Bit bummed as I've been so careful on this one. Dead Banana
If anyone can help that would be really kind.
monokinetic
frozenkore wrote:
if you get the jacks from the BOM (Switchcraft 41), they will not fit in the holes of the RSFC panel.

Thanks a lot for the heads up on this, I was just in the middle of an order!

Quote:

Kobiconn (sp?) jacks fit; however.

I assume you mean the 16PJ138 ones?
frozenkore
monokinetic wrote:
frozenkore wrote:
if you get the jacks from the BOM (Switchcraft 41), they will not fit in the holes of the RSFC panel.

Thanks a lot for the heads up on this, I was just in the middle of an order!

Quote:

Kobiconn (sp?) jacks fit; however.

I assume you mean the 16PJ138 ones?


Yep, 16PJ138 is them. Now, you won't get the hex nut if buy those. Now, I don't currently have any, but the 3.5mm jacks from erthenvar should work (here). Those are also M6 like the 16J138. So, you could in theory just order the hex nuts and from erthenvar and use them on the 16J138. Just some thoughts.
ringstone
nickster wrote:

Lastly should L2 (I'm guessing a ferrite bead) be included or left off board 1?
If I have no joy tomorrow I'll post some pictures and hopefully someone will spot where I've gone wrong. Bit bummed as I've been so careful on this one. Dead Banana
If anyone can help that would be really kind.


L2 should be installed, it's L3 and L4 (as well as the rest of the 12V->15V conversion circuit) that should be left off. The -ve power rail runs straight through L2 just after it hits the PCB, and as those (L1, L2) are really just a wire link with a ferrite bead around it, without it, there will be no -ve power rail to the rest of the circuit.

From what I've read, people are having to connect a wire between boards as they are missing a -ve power connection, but not all 3 of the thru connections.

You've left out the conversion circuit/done the jumpers as per the 15V instructions too?

Cheers
Blair
cleaninglady
nickster wrote:
Finished the EURO build today but as I expected, it no worky. very frustrating very frustrating very frustrating

No power is coming through to the LEDs & no noise from the noise unit either.

So I have some questions. Do the through power holes on boards 1 & 2 need to be connected with 3 wires (ie each wire runs to & from each hole)
Or does only one hole need to be connected to it's corresponding hole on the other board. I currently have all 3 pads connected with wires.

If I have managed to orientate the LEDS incorrectly will this affect the build as a whole?

Lastly should L2 (I'm guessing a ferrite bead) be included or left off board 1?
If I have no joy tomorrow I'll post some pictures and hopefully someone will spot where I've gone wrong. Bit bummed as I've been so careful on this one. Dead Banana
If anyone can help that would be really kind.


(The following info is all for Euro builds , it may be relevant to 15V but honestly i don't know so proceed with caution).

You definately need to install L2 , there are a few things that need to be noted like the power cable POS and NEG orientation. I mentioned this in a post on page 16 of this thread.

I've got it working apart from 'probably rate of change' pot on the FRV doesn't seem to affect the output signal and the output LED is dim , not sure about that.

Also , my S&H doesn't seem to work. There was mention on Page 15 about the S&H from jbaken which i only just saw. So i'm going to check Jack orientation and try running it from some of my Best of CGS stuff for a hotter input voltage.

That R50 on board 2 you mentioned should be changed from 220R to 75K caused my QRV n+1 output to stop working so i changed that back. Where did that info come from BTW ?

I don't think the thru stuff needs connecting but a NEG wire does need to be run from the outermost hole (NEG) of the THRU to the negative rail on Board 3 , see Page 15 for details.

The bottom line for all of this is to read slowly and carefully through the entire Thread , (which i never do...) oops . I myself have a tendency to panic and ask questions , which is fine , but often the answers were right there in the Thread. Although i must admit that sometimes i've been working on the thing for so long , i'm exhausted and asking the wonderful people at Muffs is waaay easier. This is fun!

That's all i know right now , if i found i forgot anything ; i'll edit it. thumbs up
raisinbag
Has anyone put together a full build description of the euro build? I have been following and am so confused now by all the different posts of what to do and not do. I have been to scared to start until I see a consistent "yes mine works!" posts. I was hoping roman might post a fully up to date euro build document.
ringstone
cleaninglady wrote:
That R50 on board 2 you mentioned should be changed from 220R to 75K caused my QRV n+1 output to stop working so i changed that back. Where did that info come from BTW ?


I believe that should have been R59, not R50. It's one of the two resistors changed to adjust for the voltage being 12V instead of 15V. (It was changed on the BOM I sent you so yours would have been ok already).

Cheers
Blair
ringstone
raisinbag wrote:
Has anyone put together a full build description of the euro build? I have been following and am so confused now by all the different posts of what to do and not do. I have been to scared to start until I see a consistent "yes mine works!" posts. I was hoping roman might post a fully up to date euro build document.


The post I made a page or two back was intended to be a start along these lines (as well as a memory jog for me when I start my build!). I was hoping that someone who's got theirs working 100% might give some feedback/add anything else required, but I guess they're not really checking this thread any more... probably busy playing with their 266 hihi

Cheers
Blair
raisinbag
Haha. You are probably right. I do remember your post. I'll have a look again. I did want to make mine 15v but ihave a zuese coming and it will be able to run tons of units, so here I go into the 12v world!!! Weeeeeeeeeeeee!! w00t
ringstone
raisinbag wrote:
Haha. You are probably right. I do remember your post. I'll have a look again. I did want to make mine 15v but ihave a zuese coming and it will be able to run tons of units, so here I go into the 12v world!!! Weeeeeeeeeeeee!! w00t


Yep, so as far as I know, it's what I outlined in that post. Plus:
The changes to the resistors to enable correct voltages for +12V.
The wire to connect the -ve trace between the two boards.
The FRV output fix as outlined in the schematic pdf (I understand why the insulation for the output jack is put there but I'm a bit mystified by the other part of the fix).
As per what cleaninglady mentioned, take care and double check the polarity of the 10 pin power connector (it's reversed from what the usual Euro standard is). If you're using a keyed header, you may want to turn it around the other way (from what the silkscreen indicates).

Cheers
Blair
moogah
Where are people getting their euro panels for this?
synaptech
moogah wrote:
Where are people getting their euro panels for this?

bleeps did a run here:
https://www.muffwiggler.com/forum/viewtopic.php?t=58641&highlight=266

thumbs up
cleaninglady
raisinbag wrote:
Has anyone put together a full build description of the euro build? I have been following and am so confused now by all the different posts of what to do and not do. I have been to scared to start until I see a consistent "yes mine works!" posts. I was hoping roman might post a fully up to date euro build document.


I know how you feel...but on the other hand , i'm learning a lot through the amount of info i need to gather and the reassessing of certain parts of modules and individual parts of circuits.

In the end it's all good. Just scary and frustrating on the way.
Take your time , be gentle with the boards if you need to make changes and ask questions. There are some geniuses here and I feel privileged to have peeps like that around to help. we're not worthy
If a blockhead like me can do it , anyone can. zombie
raisinbag
Cool thanks for the cheer leading. I'm only tentative because there are multiple versions of what to do, and it is 3 boards AND even L1 had problems (speaking of Jedis). I'll get going on it soon and cross my fingers.

Hey I noticed some people are using different colour LEDs. Will the "current consumptions" (is that the right term) of different colour LEDs cause problems? Will I have to adjust the resistors associated with LEDs if I use different colours?
cleaninglady
The current consumption thing crossed my mind too. Don't really have an answer though.

I just went with Red all the way.
nickster
A very big thanks to everyone for their help. I'm going to install the L2 tonight and have a look into the wiring for the through pads. The wire to board 3 seems a bit confusing but I'll muddle through. Thanks very much once again. It's peanut butter jelly time!
jbaken
my module seems pretty much done and fully functional. (still not sure about one of my FRV's being bipolar.. and not exactly sure what a functioning QRV is supposed to sound like.. its not really the same as the doepfer video but really fun to use and somewhat makes sense nonetheless).
some notes-
-definitely solder L2
-I didn't connect a negative wire to board 3 - not really sure whats going on there for some people.. maybe its roman's connectors at fault?
-board 1 and 2 are connected via wires at the 3 thru connections.
-i oriented my power based on a continuity test w my meter. its also on the last page of the schematics of board 1.. - on top and + on bottom.

this was definitely not an easy build. up there with the west coast mini synth for me. roman's unfortunate situation certainly didn't help either. that being said its well worth the pain! its an unbelievable module.
cleaninglady
This is for 12v Euro build.

Thanks jbaken!

The S&H seems to be working when i send it signal from the BoCGS stuff. (Hotter Signal Voltage ?)

I sent DUSG Out to S&H Pulse In , CGS48 Osc to S&H CV In and S&H CV Out to 1V/Oct In of Plan B Model 15.

All seems good now on the 266 except the FRV 2nd (Lower) Output ; the 'probable rate of change' input and pot have no effect on the Output Signal.
There is definitely something coming out of the 2nd Output , just no variation. Also , the LED is a little dim.

Could this related to the R6 , R7 Earthing thing ? I did beep it out and it seemed fine but maybe i need to trim that jack casing a bit anyway ?

So close to getting this sorted but not quite.
jbaken
could definitely be the lack of R6 and R7 mods causing a problem. the R7 pad definitely touches the area where the FRV jacks are located (i think its the 2nd FRV output) im not exactly sure what the jumper on r6 does but i think its worth trying if you're experiencing problems with the FRV
the S&H definitely likes stronger trigger signals. bipolar or even slightly negative signals will not work. Ive got it to run off the DUSG trig out, RCD outs, and a clock module i just built specifically for this module (8v trig signal).
can anyone record a demo of their QRV sections? I'm planning on posting mine soon since it seems kinda funny sounding- not sure what to expect though.
nickster
Edit. This is for the 12v Eurorack build.

Never before in the history of synth DIY was a module more aptly named than this Source of Uncertainty.

It's been a monster. But now it's done and by Jove it works, success! Managed to get power to mine tonight and did a very quick check to see if it it all working. So far so good It's peanut butter jelly time! It's peanut butter jelly time!
Basically not installing L2 as suspected was creating the problem. I also managed to install my LEDs wrong way around which caused a nervous head scratching for a while. My ribbon cable housing broke when I tried to gently prise this away so I suspect that these houses that Roman was worried about are the cause of some ribbon trouble.
I will do a full road test tomorrow so until then I can't say 100% that all is working as it should, but so far things look positive.

Ok so for Eurorack follow the suggestions mentioned earlier in this thread. Also make sure the components on board 1 , L2, C38, C37, C35 are installed. Their values can be found on the 5U BOM. These are not listed on the Euro Build Docs which was why I missed installing them originally. Make sure wires run from all 3 through pads on board 1 to board 2. A wire running to board 3 does not appear to be needed at least on 12v builds. I am wondering if this was something specific to L1s 15v build but will try and confirm this tomorrow.

Lastly a lot of other very kind folks have offered their advice on this topic so a very huge thank you is in order to them. You all know who you are nanners
nanners

This has been an exceptional build which has driven me bonkers quite a few times. But so far so good. Im still hanging in there and my SOU is blinking away like a Norwegian Xmas tree on steroids.

A big thanks to Roman for making this happen in the first place. we're not worthy
fluxmonkey
humble request: as you post your issues/fixes/successes, could you specify which version you're referring to, in each post? help a brotha out...
nickster
fluxmonkey wrote:
humble request: as you post your issues/fixes/successes, could you specify which version you're referring to, in each post? help a brotha out...


Done! Once I've finished road testing tonight I may try and do a more comprehensive list of what I did. This obviously depends upon whether I am satisfied with the results.
raisinbag
Il be the first to read it!!!!!!! How yours works with "certainty!".
zeta
marvkaye wrote:

On another note... way back on P1 of the thread, right at the top where the pics and build docs reside for the 5U version, there's a note that says to omit resistors R16 and R35 for 5V pulses for the S&H, however it doesn't state whether they're to be left off of PCB #1 or #2. I assume it's #1, as that appears to be the one with all the S&H circuitry, but I just want to make sure before I do something foolish. TIA for the help.
<marv>


was that point anwered somewhere for 5U? getting a bit confused by euro and/or non euro answers.
roman_f wrote:
The only issue with 5U PCBs are swapped SRV1 and SRV2 outputs
you may cut 2 traces and wire in a proper order or leave it as it is

any more detailed info?
thanks in advance!
decaying.sine
raisinbag wrote:
Cool thanks for the cheer leading. I'm only tentative because there are multiple versions of what to do, and it is 3 boards AND even L1 had problems (speaking of Jedis). I'll get going on it soon and cross my fingers.

Hey I noticed some people are using different colour LEDs. Will the "current consumptions" (is that the right term) of different colour LEDs cause problems? Will I have to adjust the resistors associated with LEDs if I use different colours?


Most likely yes, you'll have to adjust some resistor values to get the brightness to your liking. You should be able to accurately estimate this off the board--using magic hihi
marvkaye
zeta wrote:
marvkaye wrote:

On another note... way back on P1 of the thread, right at the top where the pics and build docs reside for the 5U version, there's a note that says to omit resistors R16 and R35 for 5V pulses for the S&H, however it doesn't state whether they're to be left off of PCB #1 or #2. I assume it's #1, as that appears to be the one with all the S&H circuitry, but I just want to make sure before I do something foolish. TIA for the help.
<marv>


was that point answered somewhere for 5U? getting a bit confused by euro and/or non euro answers.


I've tried to review the entire thread looking for that answer but confess freely that I get sidetracked easily, especially with the abundance of information being presented, so I have yet to locate the single sentence that restates Roman's initial comment and expands upon it with the PCB number. (This minor confusion could have been avoided had there not been duplication of component numbers from PCB to PCB... ie, parts on PCB1 could have been numbered from 1-100, PCB2 from 200-300, etc). Anyway, I still haven't come up with the answer and don't know if this is a universal rule for ALL formats... Then, again, I don't know if the 5V pulse thing is as important to Euro or Buchla builders, the only reason it's important to me is because I'm trying to keep everything I build consistent with dotcom requirements (ie, 5v gates & triggers).

zeta wrote:
roman_f wrote:
The only issue with 5U PCBs are swapped SRV1 and SRV2 outputs
you may cut 2 traces and wire in a proper order or leave it as it is

any more detailed info?
thanks in advance!



Seems to me an easier solution is to simply swap the legends on the [5U] panel for SRV1 and SRV2... while it may introduce a bit of asymmetry or illogic with the locations of the outputs relative to their associated controls, it would eliminate the need for cutting traces and adding wires.

BTW, considering the complexity of this project and the fact that it's presented in mulitple formats, I personally think Roman has done an amazing job with this, given that there are really not that many issues with the various builds. Hats off and thanks again to him for making this possible.

<marv>
rico loverde
ive built a ton of stuff over the years but for some reason this one is really intimidating me. id love to see a clear and concise build guide for the euro one.
nickster
EURORACK BUILD

rico loverde wrote:
ive built a ton of stuff over the years but for some reason this one is really intimidating me. id love to see a clear and concise build guide for the euro one.


Firstly please don't be put off by the comments. Overall this build whilst large is fairly straight forward. In essence follow the Euro BOM but make sure the parts on Board 1 that I mentioned before are also included. On my BOM these were omitted by accident. But the parts were Not omitted from Romans Mouser file.
Follow Janvanvolts advice. I believe he was one of the early birds to get the Euro version working.

janvanvolt wrote:
As i got asked, here are the summarized items i did to get the 266c (eurorack) running:

- omit D12, D13, IC15, IC14, L4, L3, R44, C14, C41, C40
- do NOT cut any traces
- for R46 use a 46.4k resistor on Board 2,
- for R59 use a 75K Resistor again on Board 2.
- do NOT follow instructions from page 1 on 266c-eurorack-1-schematics-v1.1
- check and apply the fix according to 266c-eurorack-3-schematics-v1.1

Make sure jumpers are applied on Board 1 as shown by ringstone's post on page 15 of this thread. Also on page 15 you will see a photo of L1's board 1 PCB which has these jumpers installed in the bottom left hand corner. Also note the parts that are absent as per the above instructions.

Earlier in this thread Janvanvolt asks about some left over capacitors from the Mouser xls that have no housing. Roman states we don't need these so don't fret if you have extra caps in your hand.

C5 cap on board 2 has difficult to find markings as these are obscured by board holes. It is in fact just above IC 12.

Cleaninglady mentioned that you need to check that the 10 pin Euro power plug housing is inserted in such a way that you have the -12 pins connecting with the red cable on your Euro cable as usual. The -12 is at the top with +12 at the bottom. Check the PCB 1 diagram to confirm this. The PCB 1 is not marked with the polarity. The housing should have its notch on the inside of the board which is opposite from the way the board etching shows.

It is also worth noting Romans guide to attaching pots and jacks to board 3. See his post on the first page.
Apply the tape and jumper R6/R7 fix Before you soulder your jacks & pots in place.

Run 3 wires from PCB 1 through pads to PCB 2 through pads in a corresponding fashion. As Roman mentions this brings power to the 2nd board.
The extra wire running to board 3 mentioned by "L1" does not seem to be needed.

Lastly BEFORE you start make sure your PCBs fit into your Eurorack. Test assemble the boards and panel with screws and standoffs and if you have a tight fit sand down the outer edges of the PCBs. They won't need much taking off so don't be too vigorous when doing this.

I think I'm just about done with this now. I've road tested most of the module now except for the intergrator section which only got a brief look see. Generally I'm really happy with it. As an extra for me the noise section sounds really lush and compared to my a-149-1 it sounds far more musically useful.

Oh yes this module begs for some stackables so if you have them bring these to the party once your done. The Chewbacca Defense

Roman , thank you very much.
rico loverde
hey nickster thank you very much. that was perfect.
cleaninglady
Great Stuff nickster !

Again many thanks to yourself , L-1 , janvanvolt and ringstone for help on this. I spent quite a while on the phone nutting the power section out with Blair. It's amazing how easy this complex shit can be when you can talk it over and bounce ideas off others.

This is a challenging one but well worth it.

PS

I still haven't got my FRV 2nd Output sorted yet , but soon...
cleaninglady
Here's a vid i did the other day.

I had just finished the A-140 System 100 ADSR and wanted to show a bit of that and the SOU.

I don't do very good vids as i always have to do hand held. It puts me off.

If you follow wires as I move along them with the camera , it might help show whats going on.

frozenkore
Great video, thanks for sharing! nanners
frozenkore
Question on the Buchla build. On the panel there look to be two outs per one pad (+3db, -3db, and flat). Are these just mulited outs? I just want to verify before I go soldering up some wires between the board and the jacks.

Thanks!
cleaninglady
I wasn't that happy with the hand held video from yesterday so i'd found the mini tripod i'd been looking for and did another bit more bangin' vid.
Again showing off the recently finished SOU , A-140 ADSR with 291 Filter , MATHS and Plan B Model 15 Oscillator. This time with XoXBoX running the show...and the mighty TR-606. we're not worthy

Also , i never remember to describe the patch in my vids.
This time i attempted to do that quite extensively. Hope you enjoy it.

CV out from XoX into SRV - CV In of Source Of Uncertainty. Gate Out from XoX Into MATHS Channel 4 Trig In. Signal Out from Channel 4 of MATHS to Source Of Uncertainty SRV - Pulse In.
XoX Clocking TR-606 via DINSYNC. Upper Output of Source Of Uncertainty going to 1V/Oct Input of Model 15. Lower Output of Source Of Uncertainty going to A-140 Gate input. A-140 Inv Output going to Sync In of Model 15.
Sine Out of Model 15 going to MATHS Channel 3 Signal In. Model 15 Tri Out to 291 Filter Audio In. Model 15 Saw Out to Mixer. MATHS EOC Channel 4 Out to MA Mix Input 1. MA Mix Out to Model 15 FM Input. MATHS Sum Bus Out to 291 Filter FM CV Input. MATHS Channel 2 Signal Out to WIDTH CV Input of 291 Filter. MATH Channel 1 Out to 291 Centre Frequency CV Input. 291 Filter Low Pass Out to Mixer.

Sorry , the Channel 4 of the MATHS was obscured during the Videos as was the Output LED's of the Stored Random Voltages (SRV) Section of the Source Of Uncertainty (SOU).

frozenkore
frozenkore wrote:
Question on the Buchla build. On the panel there look to be two outs per one pad (+3db, -3db, and flat). Are these just mulited outs? I just want to verify before I go soldering up some wires between the board and the jacks.

Thanks!


NM, I see the traces on the 5U and Eurorack and that both jacks for each function (+3db, -3db, and flat) are connected to the same trace. So I'll just wire to one and jump to the other.

Thanks.
marvkaye
Here's are a few of the approaches I took with the 910pF caps on PCB2 (I've got 3 sets, so this is taking a long time... I only get an hour here and an hour there), thought I'd share a few of them.

First are the C0G/NP0 SMDs I installed on one of the boards. These are 0805 and mounted to the solder side of the board. Came out OK considering I didn't have proper pads to work with.



On the next board I paralleled 560pF and 350pF styrenes... unfortunately the 560's have radial leads and the 350 axials, but I couldn't find them in matching styles so used what I could get. Turned out ok, I'll secure them with a little hot glue to make sure they don't move around.



On the last board I just used 1nF styrenes instead as per the BOM. It'll be interesting to see if there's any difference in how they operate (assuming I get them done sometime this decade.)

<marv>
cleaninglady
Lookin' good.

I'd be very interested to find out about this if there are differences with the 910pF caps.

I used 1nF throughout.
zeta
anyone could please give me a hint finding 50nf's & 60k1.!?
preferably from europe.
those are the only ones missing to complete a 5u module.

thanks in advance
z
frozenkore
What is the NT pad for?

Edit: Is this just a test point?
magneticweb
been emailing roman for over a month with no response.
anybody been in contact?
logicgate
magneticweb wrote:
been emailing roman for over a month with no response.
anybody been in contact?



I believe he must be busy, he always replied to me with 1 day tops of waiting, but I';m waiting for a response too.
cleaninglady
frozenkore wrote:
What is the NT pad for?

Edit: Is this just a test point?


I'm highly curious about this myself. This pad is Noisy Triangle and i see it mentioned quite a few times in the Schematics but is it utilised ?
L-1
Quote:
anyone could please give me a hint finding 50nf's & 60k1.!?


47nF and 60K4
zeta
dankyou L-1!!! thumbs up
diophantine
I was looking at the schematic and wondering the same thing. 100R seems really low for any modern LED. Anyone play around with this? I will probably end up using a 1k resistor with the LEDs I'm using.

camelneck wrote:
I have a few questions about LEDs.

1) I still haven't made up my mind whether to use the red LEDs as the older 266 modules used or blue LEDs as the 266e modules use. The red LEDs look more authentic, but personally, I prefer the look of blue LEDs.

Does anybody have a Mouser part number for a 3mm blue LED that they would recommend?

2) All 6 of the 266's LED drivers consists of a 2N1711 transistor and a 100 ohm resistor. The 100 ohm resistor seems a bit low in value (which means the LED current is probably too high) for modern day LED's.

Has anybody experimented with different transistors and/or resistor values as far as the LED driver circuits are concerned?

3) I know this is off-topic, but does anybody know the LED colors for a Buchla 281 (not a 281e)? I'm sure the 4 output LEDs are red, but are the other 4 LEDs, which are lit when the FGs are in Quadrature mode, suppose to be red or orange in color?
nihilist
Anyone else have videos they can post of completions?
cleaninglady
EURO FORMAT - 266 S&H.

My 266 S&H section is finally fixed ; now working with other Euro modules' 5V signals.

Great Southern Genius Wiggler ringstone pointed me to this quote in the 5U build notes from roman_f on Page 1 of this thread :

Quote:
DO NOT install R16 & R35 - this will allow the S&H to work with 5V pulses, originally it's for 15Vs.


I had previously only been able to use the 266 S&H section with signals from my Best of CGS gear ; (because of the hotter signal...?).

So , i removed both the R16 and R35 resistors from Board 1 (the one with the power connector) and the S&H is working ; happily accepting signals from other Euro modules.

Thanks heaps for all your help ringstone !! SlayerBadger! we're not worthy
raisinbag
Cool. So when people are saying "don't instal Ra or Rb etc", does that mean leave those holes empty? Or use a jumper? I have been too chicken o build mine util all this stuff is worked out.
cleaninglady
In this case. Just put nothing in there. If they are in the board already , you could desolder or just snip them out with side cutters. (easier.)

I've been waiting for a couple of months to get this S&H section working.

It's great to have it 100%. It's motherfucking bacon yo
Pfurmel
cleaninglady wrote:
frozenkore wrote:
What is the NT pad for?

Edit: Is this just a test point?


I'm highly curious about this myself. This pad is Noisy Triangle and i see it mentioned quite a few times in the Schematics but is it utilised ?


If its the Noisy triangle, it is not used on the original Buchla. It is a random triangle, same as on a wogglebug, as far as I understand.
nickster
cleaninglady wrote:
EURO FORMAT - 266 S&H.

My 266 S&H section is finally fixed ; now working with other Euro modules' 5V signals.

Great Southern Genius Wiggler ringstone pointed me to this quote in the 5U build notes from roman_f on Page 1 of this thread :

Quote:
DO NOT install R16 & R35 - this will allow the S&H to work with 5V pulses, originally it's for 15Vs.


I had previously only been able to use the 266 S&H section with signals from my Best of CGS gear ; (because of the hotter signal...?).

So , i removed both the R16 and R35 resistors from Board 1 (the one with the
power connector) and the S&H is working ; happily accepting signals from other Euro modules.

Thanks heaps for all your help ringstone !! SlayerBadger! we're not worthy


I think I'll follow suit and remove these. I've been happy to use my Sergeish stuff for the S&H clock. But it would be good to be able to use the Doepfer LFO too. BTW my LEDs are pretty bright anyone got any ideas which resistors I should change and to what value to get this looking pretty? I've the Eurorack version in case people want to know.
marvkaye
cleaninglady wrote:

I had previously only been able to use the 266 S&H section with signals from my Best of CGS gear ; (because of the hotter signal...?).

So , i removed both the R16 and R35 resistors from Board 1 (the one with the power connector) and the S&H is working ; happily accepting signals from other Euro modules.


FInally!!! I've been waiting for someone to confirm from which board those resistors were to be removed, 1 or 2.... it's nice to get an answer at last. Forgive me if I missed it somewhere else in the thread, probably not the first time I've missed something and wont' be the last, I'm sure. Thanx for putting this out here.
nanners nanners

<marv>
cleaninglady
Yes , it's great to finally have the S&H working !! Easy fix too.

I'm just the bearer of good news ; ringstone is the one who found everything. He said those two Resistors (R16 and R35) weren't even on the S&H Schematic. I just checked and I couldn't find them.

Pfurmel , thanks for telling me what the Noisy Triangle actually does.

Almost a shame it isn't implemented on this module. Would be a fun addition.
raisinbag
Haha not sure what a noisy triangle is but it sounds cool. Can we just run a wire from that pad to a jack (tip) and make a little sister 4hp panel beside main panel?
zeta
cookie?!?, yesterday night i finally finshed soldering all 3, 5U pcb's.applause
happy like a king, i noticed that i still need the two LF398 and a NE556.d'oh!

anyway, instead of firing it up at midnight i just thought to disport myself by putting it into the case.
and there, kazumm, it doesen't fit. same problem cleaninglady described on page13 for euro, wasn't it.?.
well, it's a home-brewed case even so it might be of interest.
for now i've to hunt the missing chips & thinking about to solve the above.

terjewinther
Has anybody completed building the 5U version? And been able to test and check if everything is working properly?
thebot
terjewinther wrote:
Has anybody completed building the 5U version? And been able to test and check if everything is working properly?


Almost. I'm waiting on fedex bringing some 50uf caps and 22M resistors, then I'm done. Hopefully later this week.
zeta
i was lucky, bought the missing parts today. powered it up for the 1st time ca. 30min. ago. looksgood, soundsbetter. even though i got two non working leds.
sample&hold still to check..
but hey, i'm just a happywiggler who completed his 1st working module..or at least one wich seems to work It's peanut butter jelly time!
Luka
the SOU is your first working module

man you guys give in the deep end
mikecameron
no doubt. this build was a beast! Hallelujah for the panel PCB, I can't even imagine wiring this one up by hand.
diophantine
The panels were a beast even with the panel PCB! I can't imagine doing them with flying wires. Did a Buchla and 2 MU module panels in the past few days... building up the other PCBs should be the easy part, now. smile

What are people using for the thru power between the two boards? Or are you just hard-wiring them? I bought some pin rows & sockets from Newark, but they ended up being too short... (waste of $$!!).
ringstone
So, finished my Euro 266c over the weekend... actually went fairly smoothly, apart from a couple of issues - LEDs soldered in the wrong way around (blame 1:30 am soldering for that one) and I nicked and broke a track when filing down my boards to fit (actually a few, but I had caught and fixed the others). Anyway, a few things to note:

- Filing down the edges to fit may leave some copper exposed on those sides which could possibly short +/- 12V to your case, or could possibly break connections from some components to +12 or -12V power rails. I insulated the sides of the boards just in case.
- I made a header and socket to go between the Thru connectors on boards 1 & 2, so I could pull the boards apart for repair easily. I didn't need to run the wire to board 3 (jack board).
- IC9 and IC11 on PCB 2 are very close together! The original 2 chips I had didn't even fit... fortunately I had a different brand of 4030 that just made it with a bit of squeezing!
- I didn't do the FRV2 "output fix". I just cut away a portion of the metal on that socket so it wouldn't come into contact with the solder joints.
- I don't remember seeing any details on what the trimpot does. It adjusts the range of the Integrator (Slew Generator).
- I hooked up the noisy triangle test point to see what it sounded like, I don't think I'd bother breaking it out. It's a slight variation on the other noise outputs, but the cyclic nature is even more apparent to my ears.
- I love the Alt outputs on the Sample and Hold!

Anyway, thanks to the guys who did their builds first up, that sure made it a lot easier when it came to build mine!

And... here's the first thing I patched up, it's a little patch that plays an aleatoric composition, with the 266c running the show:

[s]http://soundcloud.com/mindlesseye/aac[/s]

Cheers
Blair
L-1
For those who can't imagine wiring. My old 266 build. 8_)

thebot
diophantine wrote:

What are people using for the thru power between the two boards? Or are you just hard-wiring them?


I used some MTA-100 connectors - male part on bottom of the board that sits on the top, wires hard wired into bottom board with connector attached to the other end. Thought better to do it like this in case I needed to separate the boards.
raisinbag
thebot wrote:
diophantine wrote:

What are people using for the thru power between the two boards? Or are you just hard-wiring them?


I used some MTA-100 connectors - male part on bottom of the board that sits on the top, wires hard wired into bottom board with connector attached to the other end. Thought better to do it like this in case I needed to separate the boards.


I'm so happy I procrastinated on building mine. So many good ideas.
fluxmonkey
for the Thru on my 5u build, i'm hardwiring from the bottom board, and using a .100 connector to plug into the header next to the main .156 in power on the top board. not quite enough space around the Thru pads on the top board to comfortably fit a connector...

b
mikecameron
I just used some resistor leads to wire the thru power. I figure if I need to get in there again, it's not that big of a deal to cut them, desolder and replace if needed.

I'm loving this module. so musical.

Impressive L-1. Did you lay out and etch those boards yourself as well? we're not worthy
L-1
Quote:
Impressive L-1. Did you lay out and etch those boards yourself as well?


Yes, in those days with Sprint Layout by hand.
cleaninglady
L-1 wrote:
Quote:
Impressive L-1. Did you lay out and etch those boards yourself as well?


Yes, in those days with Sprint Layout by hand.


Was it worth bringing out the Noisy Triangle to the Panel ?

I've heard it's a little bit like one of the Wogglebug Outputs.

I would sacrifice one of my Noise Source Jacks for it if that would work. hmmm.....
cleaninglady
Actually i just saw Blair's post. Answered my question. Nice track Blair. Good to have it done isn't it ?
w00t
L-1
I recorded noisy triangle out, I think you should decide yourself.

http://L-1.su/Noisytriangle.wav
ringstone
cleaninglady wrote:
Actually i just saw Blair's post. Answered my question. Nice track Blair. Good to have it done isn't it ?
w00t


Yep, sure is! Thanks for the hint on checking the overlay in the schematics BTW, it was really hard to tell what was what from the PCB...

I was going to record the noisy triangle so everyone could decide for themselves if it was worth it - but then I put everything back together before I remembered. Thanks L-1! I think it's similar to the "random triangle" on some Cwejman modules (such as RG-6) but it cycles repeatedly due to the nature of the noise source.

Cheers
Blair
cleaninglady
L-1 wrote:
I recorded noisy triangle out, I think you should decide yourself.

http://L-1.su/Noisytriangle.wav


Thanks ! w00t
fluxmonkey
just complete my 5u build; everything appears to be working 100%


terjewinther wrote:
Has anybody completed building the 5U version? And been able to test and check if everything is working properly?
mikecameron
anyone else having issues with the alt pulse outs being especially picky with their pulse input?

I know that they alternate with each pulse, some triggers I feed it cause it to not respond at all, although the S&H still works fine. Some triggers I have to buffer (from RCD/SCM) to get alt pulse outs working.

**edit

I should add that the alt cv outs work fine, and alternate as expected.
fluxmonkey
mikecameron wrote:
anyone else having issues with the alt pulse outs being especially picky with their pulse input?

I know that they alternate with each pulse, some triggers I feed it cause it to not respond at all, although the S&H still works fine. Some triggers I have to buffer (from RCD/SCM) to get alt pulse outs working.

**edit

I should add that the alt cv outs work fine, and alternate as expected.


yes, does seem particular abt the pulse. i was using a cgs LFO, when i used it's pulse out the SH did not trigger and i thot it wasnt working, tried again w/ the square out and it worked...
fluxmonkey




in johnee's hands now
emdot_ambient
Nice builds!

Where did you guys get your 5U panels? I've been hoping someone would do a run of them, or share an FPD. I'll be building mine in MOTM format but I'm worried i'll f-- up the spacing for the pots and jacks.
zeta
emdot_ambient wrote:
Nice builds!

Where did you guys get your 5U panels? I've been hoping someone would do a run of them, or share an FPD. I'll be building mine in MOTM format but I'm worried i'll f-- up the spacing for the pots and jacks.


got my panel from ben at resynthesis.

but i see fluxmonkey has a sputnik one ..nice.
b.t.w. how did you changed values for those chromatic leds and wich one to use.?
thebot
Got my 5U version up and working tonight after finally getting the ICs (thought I'd ordered them before, how annoyed was I this weekend!). For such a massive project it was a relatively easy build, really nice PCBs Roman, thanks a lot for such a great project. Overjoyed tonight at the randomness!
synaptech
Hmm I just finished assembling mine, it powers on but all the LEDs stay constantly lit and it doesn't appear to be fluctuating at all. No response to turning pots at all.

Could it be bad IDC cables? very frustrating
hellpony
Thanks to everyone who made this happen!
applause applause applause applause applause applause
They really play nicely together for some reason... hmmm.....
HueMonContact
hellpony nice build!

i just started on mine today... can't wait to get it finished!
rowman
hellpony that looks so good. Happy bleeps and bloops to you
jze
hi!

i was about to make some orders on mouser, and it seems that mouser is not selling any of more of the 4006 chips.

anyone know where i can find this chips?

also i've missed out on the group buys for the noise chip, MM5837, any chance is anyone going to make group buys for this?

best
fluxmonkey
4006 is listed as in stock at futurlec: http://www.futurlec.com/4000Series/CD4006pr.shtml

i think there were a couple places that supplied replacement parts for game (pinball machines etc) who had the MM5837, can't find it just now...
marvkaye
I need another couple MM5837's as well...
jooks
Finished the 266 after a long pause. Its great love
[img]http://www.flickr.com/photos/37701459@N04/8231979133/[/img]
Peake
4006 and MM5873 are at http://unicornelectronics.com/
themanthatwasused
jooks
Nice system you have there.
Will wait for the video when its all done.
harolddonnelly
Any one looking for a 266 euro style PCB set,

Trying to get rid of mine! $80!!!!

https://www.muffwiggler.com/forum/viewtopic.php?t=73170
logicgate
janvanvolt wrote:
As i got asked, here are the summarized items i did to get the 266c (eurorack) running:

- omit D12, D13, IC15, IC14, L4, L3, R44, C14, C41, C40
- do NOT cut any traces
- for R46 use a 46.4k resistor on Board 2,
- for R59 use a 75K Resistor again on Board 2.
- do NOT follow instructions from page 1 on 266c-eurorack-1-schematics-v1.1
- check and apply the fix according to 266c-eurorack-3-schematics-v1.1


Great!

Shouldn´t we also skip C37??
batchas
I ordered the 2nF caps at mouser a while ago ref. 80-R82EC1220DQ50J like said on the BOM for 2nd PCB.
Did anyone noticed that these are 2.2nF and not 2nF?

Guess it does not matter, like for the 1000pF caps which came instead of the 910pf caps, thanks to these +/- 10% tolerance mentionned here?
ringstone
batchas wrote:
I ordered the 2nF caps at mouser a while ago ref. 80-R82EC1220DQ50J like said on the BOM for 2nd PCB.
Did anyone noticed that these are 2.2nF and not 2nF?

Guess it does not matter, like for the 1000pF caps which came instead of the 910pf caps, thanks to these +/- 10% tolerance mentionned here?


Yes, 2n was specified but the link was actually for 2n2 caps (which are far easier to find and cheaper). Since quite a few of these are built now and working fine (including mine!) I don't think it's an issue. I just picked ones that were a bit on the low side of the rated value.

Cheers
Blair
batchas
ringstone wrote:
Yes, 2n was specified but the link was actually for 2n2 caps (which are far easier to find and cheaper). Since quite a few of these are built now and working fine (including mine!) I don't think it's an issue. I just picked ones that were a bit on the low side of the rated value.

Cheers
Blair

Cool! Thanx a lot for the confirmation.
batchas
I'd like to test my 266r (Buchla boards / 15v) but there's something I'd like to be sure about:
Do I need to wire 1a/2a - 1b/2b - 1c/2c together (see pix)?



Thanx!
thebot
@ Batchas - yes you do. If I'm remembering correctly they provide power through to the second board.
batchas
thebot wrote:
@ Batchas - yes you do. If I'm remembering correctly they provide power through to the second board.

Thanx! Was not sure as there's a lot of crossed infos in the thread (12V versus 15v).

First tested with Labor Supply... No LED lighten... Bad sign.. Thought I would test directly on Buchla as no smoke and not fire + always an issue when on labor stuff... Still did not make a video to show here what I might do wrong...

Anyway: connected to Buchla boat, switched on, all OK!
LEDs, Noise outs, random CVs, S&H, ins & outs... Cool.
I like this Noisy Triangle extra output!!!
batchas
Second 266r finished and tested: all OK. Nice!

So glad all went so well and so fast with both modules...
Thankful to Roman for his great boards!

Edit: Added front view.
I used RFSC panels and Roman v1.1 boards. Only the holes for tinyjax were too small, as they are for 3.5" audio plugs like mot wigglers asked for, but the rest went perfectly.
You might also have to know that the LED light is too shiny IMO. You might switch some resistors I guess. I did not modified as I did not know about this and I soldered all LEDs to put panel in place to test, but I'll leave all for now like it is, as I do not want to unsolder the all panel at the moment!
batchas
First tests with 266r (not calibrated) on Buchla.
Here checking mostly FRV… comparing quickly to 266e:

jze
hi I'm soldering up all the components now. I think i might have made a mistake somewhere, could someone tell me where R106 is. It's where the 22M resistors goes into.

Best
batchas
jze wrote:
hi I'm soldering up all the components now. I think i might have made a mistake somewhere, could someone tell me where R106 is. It's where the 22M resistors goes into.

Best

I populated and mounted mine, so I don't see the numbers either.
I'm not sure because of the img quality so please check on yours at it is not mounted already if I'm right.

It makes sense to take a picture from the pcb before starting to populate. I will with my next projects too!
jze
thanks man! yes next time will also scan before soldering!

best!
roman_f
jze wrote:
thanks man! yes next time will also scan before soldering!

best!


if you go to the last page of the schematics you'll see a pcb
batchas
I said it and I will say it again here: the 266r is awesome.
The build went very well because of Roman's boards quality and conception.

Here the last tests of the 266r, paired with a CVP, both now finished:
camelneck
I've finally started building my 266 module. I have all of the parts in stock except for the 2N1711 transistors. Since these transistors are used to control the LED's, I don't see why we can't use a substitute transistor with the same pin-out.

Has anybody done this yet?
If so what replacement transistors did you use?
Did you change any of the resistors in order to optimize LED performance?

Thanks.
raisinbag
If I recall I used bc5xx or 390x for those. I'll check later. Also didn't change LED resistors but used orange LeDs from tayda and they seem to be a decent brightness. Nothin overwhelming.
camelneck
I've finally started building my 266r module (Buchla format). (This is the original version with the RC4136 op amps.)

I do have a few questions regarding the QRV section of my 266r:

1) Is the CV outputs of the 266r's QRV section currently calibrated for 1V/Oct, 1.2V/Oct, or does the calibration depend upon the module's format (Buchla, European, or MOTM)?
(By that I mean 1V/Oct for MOTM/European format and 1.2V/oct for Buchla format so it will be compatible with existing Buchla modules.)

2) Assuming that the QRV's CV outputs are not 1V/Oct, is there an adjustment or a modification (such as adding a voltage divider) that can be made to the 266r that will allow one to calibrate it for 1V/Oct?

3) I currently have two dual 258J modules. Each of these 4 VCO's have a dedicated 1V/Oct input as well as 2 inputs with voltage processors.
Assuming that the QRV's CV outputs are not 1V/Oct, can you still get the QRV section to work satisfactorily with a 258J VCO by connecting it to one of the processor inputs and using one of the processor pots to tune the VCO?

POSSIBLE MOD??
FWIW: If the answer to Question 3 is yes, I guess one could use a couple of Fonik's attenuverter PCBs to make each of the QRV CV outputs 1V/Oct compatible. Even if you only needed a passive voltage divider (op amp not needed), this PCB would provide a place to mount your trim pots and the PCBs only cost $1 each.
camelneck
raisinbag wrote:
If I recall I used bc5xx or 390x for those. I'll check later. Also didn't change LED resistors but used orange LeDs from tayda and they seem to be a decent brightness. Nothin overwhelming.


Thanks! Please let me know which ones you used (such as BC550C).

BTW, I also got a bag of those 3mm orange LED's from TAYDA a few months ago and I like them, too. smile They are fairly bright and have a nice orange color (not that pinkish amber color).
raisinbag
Ya man, I just looked, I followed the euro bom and used 3904 and 3906 or everything except the j202. The gingy LEDs rock. I haven't looked but assume that the buchla bom would be similar with expeption to the areas that govern the Control voltage levels.
camelneck
raisinbag wrote:
Ya man, I just looked, I followed the euro bom and used 3904 and 3906 or everything except the j202. The gingy LEDs rock. I haven't looked but assume that the buchla bom would be similar with expeption to the areas that govern the Control voltage levels.


Thanks a lot!
djangosfire
I sent Roman a message before I built my Buchla version v1.1 pcbs - re: the super bright LEDS's.

His reply was:

"R100, R122 on 1st PCB
R34, R62, R110, R131 on the 2nd

use 680-820R instead of 100R"

So I used 680R and it turned out great - not too bright, much the same as original 266 IMO.

BTW - as mentioned earlier..... the build is incredible! Although there are a TON of parts, the BOM and the pcb layout are done so well - very clear. If you take your time to put it together, should work right off.

Thanks Roman for the project - awesome job here!!!
jooks
djangosfire wrote:

BTW - as mentioned earlier..... the build is incredible! Although there are a TON of parts, the BOM and the pcb layout are done so well - very clear. If you take your time to put it together, should work right off.

Thanks Roman for the project - awesome job here!!!

+1 we're not worthy
camelneck
djangosfire wrote:
I sent Roman a message before I built my Buchla version v1.1 pcbs - re: the super bright LEDS's.

His reply was:

"R100, R122 on 1st PCB
R34, R62, R110, R131 on the 2nd

use 680-820R instead of 100R"

So I used 680R and it turned out great - not too bright, much the same as original 266 IMO.


Thanks a lot Adam. I think I'll go with the 680 ohm resistors also.

I was going to try some larger resistor values because 100R seemed to be a bit small and in most all of the videos that I've seen the LEDs seemed a bit too bright although it is really hard to judge LED brightness in a video or photo.

Quote:
BTW - as mentioned earlier..... the build is incredible! Although there are a TON of parts, the BOM and the pcb layout are done so well - very clear. If you take your time to put it together, should work right off.

Thanks Roman for the project - awesome job here!!!


It is good to know that Roman did an excellent job of eliminating all of the bugs. I'm also impressed with the quality and quantity of the documentation that came with this project. The last 3 Buchla-related modules used PCBs that required 1 or more kludges and the documentation was a bit on the thin side.

Although I initially thought the 266r PCB set was a bit pricey (a bit more than I usually pay for PCBs), the design seems to be top notch. The fact that the LED's and pots mount directly on the PCB plus the use of ribbon cables to connect the 3 PCBs will "significantly" reduce the amount of wiring time as well as make the module a lot easier to troubleshoot and repair if it ever develops a problem.

Thanks Roman!
303monkey
Do you have to twist the ribbon cables for the early version of the 266?
Or have I positioned the connectors on PCB 3-b the wrong way around?
303monkey
Or can I just cut the key off of the plug?

Also, how did people mount their LED's?
pulse_divider
This thread seems to have gone dead but I'm hoping someone can answer this for me...
Is there a good explanation of how the 266 is supposed to function somewhere? Like a manual? I've found lots of info on the 266e but can't find any sort of technical description of how the 266 works. I've read this entire thread and still have a few questions.

I bought a 99% finished but untested Eurorack Sputnik WCRS and finished it up. Everything seems to work as I'd think it would except 1 thing, the Integrator section won't slew unless there is an external CV amount applied to the Time Constant input. When under external CV control it behaves as a normal CV-controlled slew. Is this normal? I'd think there would be a fixed voltage normalled to this that would be broken by an external source input.

I also noticed that the main CV Out of the Sample and Hold only passes positive voltage while the 2 Alt outputs will pass bipolar voltages. Is this intentional?

I can't find enough info on the original to see if they are supposed to be this way.
Thanks.
loss1234
Does anyone still have these pcbs for sale? Anyone
Want to sell a set?


Thanks
nickster
loss1234 wrote:
Does anyone still have these pcbs for sale? Anyone
Want to sell a set?


Thanks


I think roman was offering a new PCB recently so probably a good idea to mail him directly if you have not already.
nickster
djangosfire wrote:


"R100, R122 on 1st PCB
R34, R62, R110, R131 on the 2nd

use 680-820R instead of 100R"

So I used 680R and it turned out great - not too bright, much the same as original 266 IMO.
!


Thanks for sharing this info on the resistor swap values. Always thought my build lit up like Picadilly Circus so it will be nice to tame it down a tad.
jooks
pulse_divider wrote:


I bought a 99% finished but untested Eurorack Sputnik WCRS and finished it up. Everything seems to work as I'd think it would except 1 thing, the Integrator section won't slew unless there is an external CV amount applied to the Time Constant input. When under external CV control it behaves as a normal CV-controlled slew. Is this normal? I'd think there would be a fixed voltage normalled to this that would be broken by an external source input.

I also noticed that the main CV Out of the Sample and Hold only passes positive voltage while the 2 Alt outputs will pass bipolar voltages. Is this intentional?

I can't find enough info on the original to see if they are supposed to be this way.
Thanks.

The integrator is supposed to slew with only the pot so something probably wrong there. Probably soemthing simple since the function of it is ok.

Buchla only have positive cv so cant tell if thats expected behaviour for the S/h?
davebr
I'm building the 266 in a two board set. I don't want to dedicate that much front panel space in a MOTM panel using the third board. I'm modifying the various circuits as I go for MOTM levels. I've started a Buchla 266 Source Of Uncertainty page on my website but because there are so many individual functions in this module I have a separate page for each PCB.

So far I have brought up and verified the SRV function on PCB1. I have never seen a good explanation of SRV Out2 and in particular what the non-linear function of the bridge in the feedback loop is. I did an analysis and have lots of scope photos on my page. BTW it is a wavefolder. I also have my Mouser BOM listed although they are not really verified until I have both boards built and operational.

I'm thinking of packing this module into a 2U MOTM-style panel. This image shows my initial layout. I didn't include the LEDs on this panel but have a concept on my site. I'll continue to update the pages as I go through the remaining 5 functions and then assemble the module.

[EDIT - I finished building both PCBs and have lots of details on operation and output waveforms and levels on my web site. I also modified it for 5V inputs and outputs. I split each PCB as a separate page on the website since there is so much information.]

Dave

synthcube
wow! thats a great panel and a packed one!
terjewinther
Hi all,
After a very long delay I finished building this module, and all seems to work. Thanks a lot for this!
Thanks also to Dave for the mods - very good, will definitely do some of them.

I have one question though: the -3db and flat noise outputs have a very distinct low frequency "thud" every second or so in addition to the usual noise. Is this normal? The +3db noise output is nice and smooth.
Peake
Terje, if you're using the MM5837 noise generator, that is normal behavior. It's a very early digital device and it loops ever second or so, clearly audibly. There is a PIC which can be programmed for noise but it's not a direct swap for the MM.
terjewinther
OK, thanks a lot. That means everything on this module is working perfectly.
Great!


Peake wrote:
Terje, if you're using the MM5837 noise generator, that is normal behavior. It's a very early digital device and it loops ever second or so, clearly audibly. There is a PIC which can be programmed for noise but it's not a direct swap for the MM.
L-1
-delete
davebr
Whew! Done with my 266 module. The front panel was definitely not fun to hand wire. There are a lot of jacks on this and I didn't leave a lot of room for wiring. I had to wire up the panel from the inside out and in the order of the stacked boards. But, it came out nice and works great. More photos and details on my Buchla 266 Source Of Uncertainty module page.

Dave

davebr
davebr wrote:
Whew! Done with my 266 module. The front panel was definitely not fun to hand wire. There are a lot of jacks on this and I didn't leave a lot of room for wiring. I had to wire up the panel from the inside out and in the order of the stacked boards. But, it came out nice and works great. More photos and details on my Buchla 266 Source Of Uncertainty module page.

Dave

This 266 is kind of fun. I have a patch setup where I am clocking the QRV 2N output and running that through the integrator to the S&H. I am clocking the S&H at 8X so when the QRV outputs a CV value, the S&H will alternately clock rising or lowering CVs due to the integrator. I run the S&H outputs through a dual quantizer to my Living VCO with VCO1 and VCO2 going through separate spring reverbs and to left and right phasers. A bit of portamento and vibrato on the Living VCO and an LFO to modulate the QRV CV and I get some very nice random but rising and falling stereo sequences. Yes, I know I should record a sample - maybe later.

Dave
msprigings
A quantizer seems like a really useful companion.
themanthatwasused
Guys with spare euro pcb and chip set i am looking for one.
Hit me up with PM's.
Thanks in advance.
thumbs up
lvoemachine
hey, does anyone know which of the 2 FRVs is bipolar?
cleaninglady
I built this 266 and am happy with it apart from one thing.

Occasionally the QRV - 2 states output will stall and stop working.

When in this state , the only thing that fixes it is powering off the module and starting it up again. (Power cycling it, effectively...)

Anyone got an idea of what i could do to sort this out ?
rockwoofstone
I picked up a set of boards from RadioKoala, and just finished it. Very pleased with the result.

A quick patch using the finished module:
[s]http://soundcloud.com/rockwoofstone/eurorack-266-sou-test[/s]
emdot_ambient
applause Nice one. Sometimes it sounded like Morton Subotnick, then it would turn into Vangelis, ala Beaubourg. Good stuff.
rockwoofstone
Noticed something on my build, and in case it isn't an error I've introduced whilst building, thought I'd mention it here in case others have the same issue.

I noticed that the lower SRV output (the one with the variable distribution) wasn't behaving correctly. When I had the pot turned down, I got the mid-range distribution (give or take). When I turned it to around half way, I got the upper distribution; i.e. the range was offset by half a turn of the pot; I had no way of getting the low distribution using just the pot.

On examining the schematic, the SRV CV input is mapped from -5->+5 up to 0->10 at the input point (or thereabouts, dependent on the voltage ranges in your build). If nothing is plugged into that input, then the mid point is always being fed in on the CV circuit, being mixed with the output of the pot. In my case that meant that even with the pot turned down, the CV circuit is still feeding in ~5V, resulting in the mid range distribution, rather than the lower distribution.

Simple fix - I removed the R8 which corresponded to the SRV CV input, stopping the additional voltage being added to the CV input, and that stops the resulting 5V offset from remapping the CV range. Thus, the pot now behaves as expected, giving the full spread of distributions, and the CV input does the same, acting as a bi-polar addition to the pot setting. Alternative, you could just cleanly bypass this part of the circuit, but losing this resistor is a cinch if you've already got it all in place.

This may be an error I've made elsewhere, but I couldn't spot anything, and it now behaves exactly as I'd expect.

Be interesting to hear if anyone else has seen this...
mcbinc
The kit as shipped includes parts for the Dave Brown mods (resistor weight changes, integrator return-to-zero, Schottky protection, and shift register clock changes). The clock change requires lifting pin IC26:6 from ground and tying it high with a 10K resistor. With the Rev. 2 boards, it looks like this is done with a trace cut on the bottom. But there's also a ground plane flood on top that needs to be isolated from the pin. If you're going to build with the DB shift register clock change, you'll want to isolate the pin before you put a single part on the board.

(I'll post some bad photos if there's interest...)
bkbirge
Just getting to this (euro version) now in my backlog. Wow, what a long thread with tons of info. Kind of scary to tackle this.
bkbirge
For those of us without power grinders, how did you cut down the boards to fit? I'm thinking maybe it would be better to just take apart the 3U rack and rebuild it around the completed module than trying to hack off bits with a hand saw.
rockwoofstone
I just used emery paper. Laid it flat on a table, and rubbed the edge of the board on it until enough had been removed.
Jarno
A file works as well (you blunt it pretty quickly though, maybe use one with diamond particles).
Thalassa
Hello , I'm debugging for a friend a 266 Rev2 in MU format ( 2 PCBs ) . I have the schematics but it's a bit hard to follow the circuit on the PCB because I don't have a graphic / photo of PCB with the designators. Could anyone pass me a photo or graphic of the unpopulated PCB ? Thanks in advance.
Thalassa
Problem solved , there is an error on the PCB very frustrating very frustrating very frustrating very frustrating

The pin 3, the output of the noise chip is connected to ground , I had to cut the trace and connect a wire from the pin3 to the capacitor C22 , now it seems that everything is working.
Thalassa
Here it is a picture of the PCB
davebr
rockwoofstone wrote:
Noticed something on my build, and in case it isn't an error I've introduced whilst building, thought I'd mention it here in case others have the same issue.

I noticed that the lower SRV output (the one with the variable distribution) wasn't behaving correctly. When I had the pot turned down, I got the mid-range distribution (give or take). When I turned it to around half way, I got the upper distribution; i.e. the range was offset by half a turn of the pot; I had no way of getting the low distribution using just the pot.

On examining the schematic, the SRV CV input is mapped from -5->+5 up to 0->10 at the input point (or thereabouts, dependent on the voltage ranges in your build). If nothing is plugged into that input, then the mid point is always being fed in on the CV circuit, being mixed with the output of the pot. In my case that meant that even with the pot turned down, the CV circuit is still feeding in ~5V, resulting in the mid range distribution, rather than the lower distribution.

Simple fix - I removed the R8 which corresponded to the SRV CV input, stopping the additional voltage being added to the CV input, and that stops the resulting 5V offset from remapping the CV range. Thus, the pot now behaves as expected, giving the full spread of distributions, and the CV input does the same, acting as a bi-polar addition to the pot setting. Alternative, you could just cleanly bypass this part of the circuit, but losing this resistor is a cinch if you've already got it all in place.

This may be an error I've made elsewhere, but I couldn't spot anything, and it now behaves exactly as I'd expect.

Be interesting to hear if anyone else has seen this...

I never saw it because I didn't use PCB3 which has the level shifters on it. Since the original 266 input were unipolar, a CV of 0V would not add to the operation of the corresponding control. However, with the level shifter on PCB3 added, 0V now becomes -5V, so those jacks should all be normalled to -5V. It should operate exactly as you describe ** but ** this will impact any CV input that has the +/-5V > 0 10V level shifter. That would be (on V1.1 PCBs) SRV CV, QRV CV, FR1 CV, FR2 CV, and the Integrator. I assume you see a similar issue on those? It has been a while since I have been inside the 266 but I believe this is correct.

Dave
rockwoofstone
davebr wrote:
I assume you see a similar issue on those? It has been a while since I have been inside the 266 but I believe this is correct.


Interestingly enough, no, I don't see it on the others. At least, I don't on the Integrator & QRV. Tough to tell on the FRV, given the nature of the output, but subjectively, it looks OK.

Odd, because as you say, it should affect all 5. Bizarre! I'm not losing sleep about it though, as all is now working as it is, but interesting to observe, all the same...
rockwoofstone
davebr wrote:
That would be (on V1.1 PCBs) SRV CV, QRV CV, FR1 CV, FR2 CV, and the Integrator. I assume you see a similar issue on those?


I had the module out this evening to dig into this a bit more, and you're indeed absolutely right - it affected all of them! It had a less noticeable impact on the QRV, given the stepped nature of that input, so in general use, I hadn't spotted it, but once I got a few probes on the board, and took a more measured approach, the problem was indeed visible on every input! Easy to fix luckily.

Thanks Dave!
filmersam
I'm not getting any action from my QCV section and S&H. :(

Built the MU v2 version from synthcube.

It says to omit r160 and r170, should these be replaced with a jumper?

Also noticed IC18 should be upside down to the direction indicated on the PCB after testing the module. Is it possible I've killed IC18? I double checked my Schottky diodes on the rear of the PCB as per the now reversed IC18.

Should I do Thalassa's mod mentioned at the top of this page?

Thanks
Sam
elmegil
I've built a handful of the Synthcube kits, and I haven't noticed anything strange about IC18. Can you elaborate? Is pin 1 toward the edge of the board, or toward the center of the board, as you have it now?

Also, I just looked at the PCB for one of the synthcube kits I have waiting for me to do, and I don't see the problem noted above with the noise chip. You should be able to look between IC0A and IC0B and tell if your board has the same issue shown in the photo above or not.

Edit: regarding R160 & 170, if using the diodes leave them out and do not jumper them.
filmersam
Thanks Elmegil.
Talking to Dave Brown at the moment and he says R160 and R170 shouldn't be omitted.--?
IC18 has pin 1 to the center of the board.
There's a trace between Pin 3 of IC0B and IC0A- but IC0A is empty.
elmegil
filmersam wrote:
Thanks Elmegil.
Talking to Dave Brown at the moment and he says R160 and R170 shouldn't be omitted.--?


I haven't built with the schottky protection diodes, but this is based on Dave's documentation for the Sample & Hold (http://modularsynthesis.com/roman/buchla266/266sou_pcb1.htm). R160 & R170 on the Synthcube version correspond to R19 & R29 in his, see the attached diagram where he shows them being omitted. BTW if this is no longer current, there's no problem revising the build docs.

filmersam wrote:

IC18 has pin 1 to the center of the board.
There's a trace between Pin 3 of IC0B and IC0A- but IC0A is empty.


If IC18 has pin 1 to the center of the board, it should be fried, because you're powering it backwards. With it oriented that way, pin 7 would be 15V and pin 14 would be ground--you should check that.

What was the problem that you believed it needed to be turned around to solve?

IC0B and IC0A are never both populated. One is for the Electric Druid noise chip (which is a PIC) and the other is for a different noise chip. Pin 3 on each should be connected together, but the picture from Thalassa shows a version of the PCB where the ground plane overlaps that connection and therefore shorts the noise to ground (bad for either chip, and of course preventing any actual noise from making the rest of the circuit work).
davebr
filmersam wrote:
Thanks Elmegil.
Talking to Dave Brown at the moment and he says R160 and R170 shouldn't be omitted.--?
IC18 has pin 1 to the center of the board.
There's a trace between Pin 3 of IC0B and IC0A- but IC0A is empty.

I just got the build guide so ignore the R160/R170 comment. I was looking at the original schematics. Those resistors should be not installed if the diodes are installed. I assumed IC26 was IC18 but I just got the photo of the PCB so I now have the reference numbers. Pin 1 of IC18 should be facing the edge of the PCB as stated. It certainly helps to have all of the documentation.

Dave
elmegil
I figured it was something like that, Dave. I've said elsewhere, this particular project has so many different versions in the wild it can be a pain.....
L-1
I didn't read all pages of this thread. Maybe someone already noticed that, maybe no.

I've built this project (Eurorack) about year ago but didn't used the module.
But now I decided to sell this module therefore make everything as it must be. I applied all the mods from modularsynthesis.com (thank you Dave!)

Everything seems to wprking correct now but FRV OUT1 - no. It is -5V shifted. And schematic shows here 0+10V - -5+5V shifting instead of 1.2 - 1V/oct as at OUT2.
Now sorting out, how to correct this.

Yellow FRV OUT2, green FRV OUT1



L-1
Fixed thumbs up

L-1
How to fix this?

1. Remove this IC and R19 across it.
2. Replace R18 with 10K, R21 with 2K.
3. Connect inner pin (which is closer to IC) of R21 to outher pin of R19.
4. Connect inner pin of R18 to outher pin of R20.




bkbirge
L-1 wrote:
I applied all the mods from modularsynthesis.com


Do you have a direct link to the mods? I don't see it on his page, just an informational page on the 5U version. I've stuffed the diodes/zeners in my euro version but that's as far as I've gone because everybtime I think to work on it I get confused on all the mods that have to be done.
L-1
This is link. Yes they are for 5U but Euro has also 15V supply and identical schematic.
http://modularsynthesis.com/roman/buchla266/266sou.htm
L-1
I've built Euro version but used 15V supply. Now as I written above I decided to prepare the module for sale. So I decided to install the voltage converters.
The voltage converter for negative rail is made incorrect . And the modification where V- is inverted from the positive rail is working but is not good too.
So I've beadborded this negative converter to fix this.
The problem was in ON/OFF 5-th pin of the LM2576. Whed I turn the supply voltage on, the IC start switching, but the supply voltage raises not momentary and swith stops in OFF position. As result LM2576 is not working.
To fix this some startup delay for 5-th pin must be made.
I've installed simply RC-filter which provide a few ms startup delay.
Now it's working correct.

Power consumption:

165 mA for V-.

260 mA for V+.


How to fix.

Do not apply convertor mods described in schematic-1 V.1.1 or restore if already made.
Disconnect 5-pin of LM2576.
Connect resistor between 5-pin and voltage out.
Connect capacitor between 5-pin and ground.
Change the 470uH inductor at the positive voltage converter to 100uH.

Also I replaced L1 and L2 with links.

I started to make this RC filter from 0.1uF and 47K. It worked when I fed a cable from already powred case. But when I connected the module and turned on whole case, it not worked. I decided it's because big PSU capacitors charge and the voltage raises slower. I increased time constant by increasing values to 0.47uF and 750K. It started work with Doepfer case but not worked with Cwejman case. Further increasing values has no effect. The circuit started work with Cwejman case only when I changed inductor at the positive voltage converter to 100uH.




Tsese 4 additional resistors are because I used regulated versions LM2576T-ADJ and LM2577T-ADJ.


L-1
Also I normaled SRV and QRV clock ins one to another:

L-1
I thought that is all but no.

Since I made modularsynthesis.com modifications, those 1.2V/oct - 1v/oct dividers are not needed. It's understandable. I removed them for all outs.

One FRV out has -5V shifter, second - no. I made 0.. +5V modification for both outs and removed it. It's understandable too.

But these +5V shifters for other CV ins are for what?
They produce +5V offset even when nothing fed into CV ins. The module can't work correct with them.

I think they are not needed at all.

I described the integrator modification in previous post (and already deleted). But it's not needed if to remove this shifter and offset with them.

So I think all level shifters must be deleted, and modularsynthesis.com modifications for CV ins applied.

Will do it tomorrow. Please write if I don't right.
L-1
I corrected my post about voltage converter modification on previous page. The positive rail inductor must be changed too.

I removed my scope shots from previous page. They will be new.

I removed all voltage shifters from PCB 3. The device started to work correct. Power consumption reduced too because I remoced all chips from PCB 3.

Power consumption:

222 mA for V+

144 mA for V-


QRV now produces random gates when pot is on min. They are exactly 5V. And started to produce random melodies when to turn the pots.


QRV1, pot at min:


QRV2, pot at min:





FRV now produses very slow motion when pot is at min. One square is 10 s. Good to create howling winds.

FRV1, pot at min:


FRV2, pot at min:


When FRV pot at max. It creates fast motion. (One square = 0.4s)

FRV1, pot at max:


FRV2, pot at max:


To be continued.....


-
spotta
L-1 wrote:
To be continued...

This was my trickiest build to date due to the lack of info and I've always wondered if it was working correctly, nice to see someone who knows what they are doing tackling this thumbs up
L-1
spotta wrote:
L-1 wrote:
To be continued...

This was my trickiest build to date due to the lack of info and I've always wondered if it was working correctly, nice to see someone who knows what they are doing tackling this thumbs up



I even never seen in reality an original Buchla module. So I publish these shots to someone, who have and know, could check me.

But on the basis of the schematic, I think that my unit is working properly.
davebr
L-1 wrote:
I even never seen in reality an original Buchla module. So I publish these shots to someone, who have and know, could check me.

But on the basis of the schematic, I think that my unit is working properly.

Those six images look correct. I have a number of scope images on my 266 SOU Module page and a description of what most of the functions are. You can use that to compare yours to.

Dave
L-1
I wanted to make QRV to play pure notes. I've matched all resistors at QRV circuit to 0.1%. QRV2 (n+1) out now tracks perfect but QRV1 (2n) out tracks not so good, will try to make something with it.

I fed QRV2 out into L-1 Basic VCO prototype which tracks perfect (+- 1 cent) within 5 octaves. Triangle out recorded.

Watch and listen how QRV2 out plays pure notes:




QRV scope shots:

QRV1, pot at max:


QRV2, pot at max:



to be continued...
L-1
I've got good tracking at QRV1 out too!!! Now it plays pure notes.
It controls L-1 basic VCO prototype, square wave.
Watch and listen:




The schematic has an error or inaccuracy. QRV2 plays pure notes when range is 5 octaves. QRV1 needs 5 octaves + 3 semitones to play pure notes.

To fix this I added a bit of gain to IC4B. I changed R19 to 5.3K.

Now the module can be used for creating music, not only noises.

to be continued...
L-1
SRV1

SRV has 256 possible output states. So to have 1/4 semitone per state, we need 5.33V output range.

I removed this 12K marked red, which was installed because I made modularsynthesis.com modifications.
Also I made R84-R91 exact 25K, 50K, 100K, 200K, 400K, 800K, 1600K, 3200K.



I made simulation where added a resistor after D4. To have 5.33V range it must be 88K.



I installed this 88K and got good tracking. Not cent-by-cent but pretty acceptable.
1/4 semitone or 25 cents per state. Watch and listen SRV1 out controls L-1 Basic VCO:




Scope SRV1 out:

L-1
SRV2

SRV has 256 possible output states. So to have 1/4 semitone per state, we need 5.33V output range.

I replaced R113 with 17.6K to have 5.33V range.

I got acceptable tracking. It's possible to understood from the video - interval between states is about 1/4 semitone or 25 cents. Watch and listen SRV2 out controls L-1 Basic VCO:



Scope SRV2 out:

L-1
INTEGRATOR

I trimmed integrator to have a slope 10 s when pot is on max, and 10 ms when pot is on min.

Longest slope 10s:




Shortest slope 10 ms:

L-1
SAMPLE AND HOLD

Sample and hold has PULSE IN, and two pulse outs which are near IN sighned ALT wth arrows. They produce positive odd and even pulses from IN.

PULSE OUT1 yellow and PULSE OUT 2 blue:




PULSE OUT 2 blue with PULSE IN green:




I fed triangle wave into CV IN.
Also it has 1+2 CV OUT and CV1 OUT and CV2 OUT which are sighned ALT with arrows.
CV1 yellow and CV2 blue outs:




CV1+2 out produces only positive:



But look - how thick and terry is the wave. It's selfoscillation from an opamp. To remove this I installed 100p capacitor between 1 and 3 pins of IC4.
And look how nice it's now:

davebr
L-1 wrote:
SRV1SRV has 256 possible output states. So to have 1/4 semitone per state, we need 5.33V output range.

I removed this 12K marked red, which was installed because I made modularsynthesis.com modifications.
Also I made R84-R91 exact 25K, 50K, 100K, 200K, 400K, 800K, 1600K, 3200K.

I made simulation where added a resistor after D4. To have 5.33V range it must be 88K.

Of course you could drop the 2 LSBs for semitones outputs (5.33/64 =83 mV).

Dave
JJCarr
i've had one of these 266c modules for a while but i've never been able to get the s+h section to do anything?!
i'm guessing it got damaged in shipping somehow. any delicate parts or known issues i should be looking for?
cables and chips seem to be seated correctly.
JJCarr
OK, I'm back after 2 years with the same Euro build to troubleshoot. yaaaay!

what is the DEFINITIVE/FINAL mod for the power converter section on PCB 1?
i've read through the thread and applied what seems to be the latest omissions/jumps/etc. but am still having problems.

this is what's currently implemented:

-All traces that were cut in schematic now reconnected
-omitted d12, d13, L3, L4, IC15, IC14, C14, C41, C40
-C37 currently installed but conflicting info in thread on whether this is needed
-i have L3 jumped to C14 so that +12v actually exits the circuit like the schematic reads even though I don't see anything about this anywhere.
-when I take readings at the THRU outputs right now out1 reads +12v, out2 ground, out3 +10v (should be -12v, right?).

is this module supposed to run on 15v? what is this mod doing and why is the module (when functioning) seemingly just fine running 12v now?

I did not build this module and was having issues with the S+H and possibly the SRV. again, this is for a Eurorack format module.

Dead Banana PLEASE HELP Dead Banana
JJCarr
all issues with my module are solved.
for anybody else with this problem in the future, look for the photos of the power section of the euro pcb in the middle of the thread.
this thing has never worked so well, I'm so glad I finally figured out this issue. my S+H and SRV have never functioned properly since I purchased it and now it's BRILLIANT.
thanks to Janvolt for the info he provided in a pinch.
over and out (hopefully forever).
appliancide
Wow. It looks like there are a few additional modifications recommended since the last euro 266 I built.

None of the level shifters on PCB 3 are needed? So just jumper the input side of R11 to the output side of R13 on the IC1 shifters, and the input side of R19 to the output side of R21 on IC2?

I am curious to see which of the modularsynthesis and L-1 mods are useful on the 12v build. I'd much rather make adjustments to make it work on 12v, than to mess around with voltage boosters.

Madness!
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