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WIGGLING 'LITE' IN GUEST MODE

a legend is back...System-700 in eurorack
MUFF WIGGLER Forum Index -> Music Tech DIY  
Author a legend is back...System-700 in eurorack
Modulart_JP
Hi all !
Happy to introduce the new Pharmasonic SYS-700 series.
nanners
All modules are true clones of the Roland System-700.
10 modules are available already as DIY projects.
screaming goo yo
The fist batch of PCB's and front panels is available for pre-order now in my shop:
https://www.pharmasonic.jp/shop/index.php?id_category=43&controller=ca tegory

Pre-orders will be closed on June 30.
Don't miss this chance !

The BOM's as well as DXF files for the panels will be online very soon.
SlayerBadger!
tobb
Modulart_JP wrote:
Hi all !
Happy to introduce the new Pharmasonic SYS-700 series.
nanners
All modules are true clones of the Roland System-700.


Ah great,so with ua726 in the vco?
fitzgreyve
tobb wrote:

Ah great,so with ua726 in the vco?


A quick look at the PCB picture would indicate otherwise ?
Isaiah
Modulart_JP
These look great! Well done!
Are there any awkward components, or are they all fairly easy to acquire?
Could you post photos of each of the PCBs please?
Hoping that each PCB has mounting holes for the non-Eurorack folk...
Modulart_JP
1st off...
All BOM's and front panel DXF files are now available on the PCB's pages.

Instead of uA726, the VCO uses the "discrete" circuit that I used for my SYS-100 VCO clone and it works very well.
The only drawback being that the VCO needs a bit more time to be stable.

I will take pictures of each PCB next week.
I have plans to make Moog/DotCom versions of the modules.
The PCB's should be more non-euro friendly.
Some components are obsolete but still possible to source.
I have local suppliers that still carry them and I'll be able to offer some of them for sale in my shop.
For the very few components impossible to source, I designed the circuits using easy to source replacement.
LED-man
Are there sound demos available?
crustibooga
Looking good, if I can get the spare cash I'm well up for this build. Great job. applause
leeski
ACE applause
Modulart_JP
Added a link to a Mouser cart on each module's PCB page.
Keep in mind that the Mouser carts do not include all the parts and you should compare them against the BOM's to see what parts need to be sourced elsewhere.
Modulart_JP
SYS-700 710 Multiple Jack now available.
It combines both the System-700's 710A and 710B multiple modules into 1.
Virusinstaller
WoAh! That's really cool
Modulart_JP
Pics of the PCB's uploaded on my website.
Modulart_JP
Added the BOM and DXF for the Multiple 710.
Also, I added a few parts that can be hard to source to the shop.
Modulart_JP
Little reminder...
Pre-orders will be closed in 5 days.
sanders
Beautiful! Love that they don’t depart drastically from aesthetics of other Vintage Roland-inspired eurorack. I prefer putting interrelated systems of modular eurorack together, and it’s lovely when they share colors and visual cues.
ishi
Modulart_JP wrote:
Little reminder...
Pre-orders will be closed in 5 days.


done thumbs up
Modulart_JP
Thanks, guys !
thumbs up

Pre-orders will close in 24h.
screaming goo yo
Modulart_JP
Pre-orders for SYS-700 PCB's/panels/modules are now closed.
Thank you to all of you guys who placed an order.
Orders will start shipping next week in the order they were received.
I hope you'll enjoy the modules.
It's peanut butter jelly time!
wendallsan
I ordered a couple of the easier module PCB's and faceplates for the System 700 and am gathering parts for these projects while I wait for these parts to arrive. I hope to prove myself with these simple modules and then if successful purchase more modules to build a reasonable clone of the the venerable System 700 if PCB's are still available at that time.

Thanks very much for providing Mouser project links, that is very helpful in sourcing the parts to newcomers such as myself.

I am not sure what pots to order and am wondering how to best confirm whether a given pot will work with the PCB layout and circuit, and would like to know how to best get an answer without being annoying or redundant. I have built stomp boxes before, but have not mounted pots onto PCB's to date (the stomp boxs' knobs and switches were wired up rather than mounted on the board). I currently plan to build the 709 S&H and 716 Mixer modules.

I am considering these pots for the 9mm 100k linear pots used in the Mixer: https://www.mouser.com/ProductDetail/317-2090F-100K

I am considering this pot for the 16mm 1M reverse log pot used in the S&H: https://www.mouser.com/ProductDetail/BI-Technologies-TT-Electronics/P1 60KNP-0EC15C1MEG?qs=%2Fha2pyFadugBUJw%252BYyebjfggJPZslGu3%2Fs3FRGBEPe fG89ZdRvyWn3gasyk7zO83

Do these seem like reasonable pots for the job? Thank you for your time.
Modulart_JP
wendallsan wrote:
I am considering these pots for the 9mm 100k linear pots used in the Mixer: https://www.mouser.com/ProductDetail/317-2090F-100K

I am considering this pot for the 16mm 1M reverse log pot used in the S&H: https://www.mouser.com/ProductDetail/BI-Technologies-TT-Electronics/P1 60KNP-0EC15C1MEG?qs=%2Fha2pyFadugBUJw%252BYyebjfggJPZslGu3%2Fs3FRGBEPe fG89ZdRvyWn3gasyk7zO83

It looks like that 9mm pot doesn't have a bushing.
It would be better to use pots with one.
The 16mm one looks good.
However, you may want to use pots with all the same kind of shaft so you can use the same kind of knobs for all...

I am working on the build notes and the calibration procedures right now.
Dead Banana
Also, I am prototyping a new module: the 707 Amp./Env.Follow./Integrator
backfromearth
What would be great after the system 700, is all modules from the SH-05 !

I know the multi mode is already available : a good start !

I still regret having sold my SH-05 20 years ago....
ringroad1
backfromearth wrote:
What would be great after the system 700, is all modules from the SH-05 !


you really want the slow, low output AR envelope?

not much point, you could get a more flexible SH-5-style synth with the System 100 clone PCBs, the SH-5 VCF clone and the Ken Stone CGS30 bandpass.
Modulart_JP
ringroad1 wrote:
backfromearth wrote:
What would be great after the system 700, is all modules from the SH-05 !


you really want the slow, low output AR envelope?

not much point, you could get a more flexible SH-5-style synth with the System 100 clone PCBs, the SH-5 VCF clone and the Ken Stone CGS30 bandpass.


+1

At last the SYS-700 PCB's have arrived.
After being held by the Japanese Customs for almost a week...
Anyway, sorry for the delay, guys, but things will finally start to ship on Monday.
I am finishing the build notes and I will track down errors in the BOM's (if any) over the week end.
I'll let you know if there is any update.
wendallsan
Modulart_JP wrote:

I am working on the build notes and the calibration procedures right now.
Dead Banana
Also, I am prototyping a new module: the 707 Amp./Env.Follow./Integrator


Thanks very much for looking at the pots and for your thoughts on them. Also great to hear that more System 700 modules may still be forthcoming! If my builds of the 1st 2 modules go well, I will certainly be building more!

Will you be sharing your build notes somewhere soon, as it sounds like PCBs are shipping?
fomtoberheim
Modulart_JP wrote:
Pre-orders for SYS-700 PCB's/panels/modules are now closed.
Thank you to all of you guys who placed an order.
Orders will start shipping next week in the order they were received.
I hope you'll enjoy the modules.
It's peanut butter jelly time!


Just seeing this thread.

Will these modules be available again?
Modulart_JP
wendallsan wrote:
Will you be sharing your build notes somewhere soon, as it sounds like PCBs are shipping?

The documentation will be available for download on the PCB's pages in my shop.
I'm almost finished and everything should be online by the end of week.

Quote:
Just seeing this thread.

Will these modules be available again?

I have ordered a few extra PCB's and panels.
Therefore, if some of you missed the pre-order campaign, you have a second chance.
But your order will ship after I have shipped all pre-orders first.
wendallsan
Excellent and thanks!

I hope a second run of the PBC's and faceplates will be available at a later date. I've always wanted a system 700 (who of us here have not?) and hoped to pick up ~35 more modules to make that happen if my 1st couple came together well. I don't want to put in that order until I'm confident that this is something I can actually do 1st, which probably means it's a month or two off at least.
Modulart_JP
wendallsan wrote:
Excellent and thanks!

I hope a second run of the PBC's and faceplates will be available at a later date. I've always wanted a system 700 (who of us here have not?) and hoped to pick up ~35 more modules to make that happen if my 1st couple came together well. I don't want to put in that order until I'm confident that this is something I can actually do 1st, which probably means it's a month or two off at least.

Take your time, follow the build notes that I will upload soon and feel free to ask any question if in doubt, and everything should go well.
thumbs up

I found a few errors in the BOM's and I updated them.
They should be error free now.
SlayerBadger!
wendallsan
Modulart_JP wrote:

I found a few errors in the BOM's and I updated them.
They should be error free now.
SlayerBadger!


Checked the BOM for 716 and 709-- relieved to see the only difference is LESS parts for the 709, which is great as I had already ordered the electronics bits.

Looking forward to seeing those build notes! Keep up the excellent work!
Modulart_JP
Almost done with the build notes.
But you know how it is...It always takes longer than expected.

Don't expect too much of build notes for the 716 and 709 modules.
They both are very simple and straight forward with only a handful of parts and no calibration needed.
wendallsan
Modulart_JP wrote:
Don't expect too much of build notes for the 716 and 709 modules. They both are very simple and straight forward with only a handful of parts and no calibration needed.


This is actually great to hear, as these will be my 1st eurorack builds. Sure, a rack with an S&H and a mixer in it will not be terribly exciting, but I wanted to make sure I started easy and worked up from there. I figured the multi was TOO easy, though. sad banana

Keep up the excellent work! I look forward to a successful build and a larger order after my initial success.
Modulart_JP
Done...
The build notes are now available for download on the PCB pages.
There is none for the 710 and 716 modules.
SlayerBadger!
wendallsan
My boards have arrived! Time to build! It's peanut butter jelly time!
wendallsan
And BOOM. Done! The switch I got for the S&H doesn't fit the PCB, so I'll need to get a different sized one for the job, and the knob is obviously bigger than it ought to be. Otherwise I'm feeling accomplished, and realizing I probably should have ordered more than just these 2 modules ...

Modulart_JP
Wow ! That was quick !
applause

As for the parts footprint, I always recommend to wait for the PCB's before ordering the parts.
Or you can always ask me...

The knobs diameter should be 16mm at most for the small ones and 20mm for the big ones.

Important notice !!!
One batch of 705 Dual ADSR PCB's was mistakenly made with an older version of the PCB files that contain errors. very frustrating
I don't know how many of them were sent and I don't know who to...
we're not worthy
Just realized that today after building one for a customer.

If you have not built your module(s) yet, contact me and I'll let you know how to check if you have a bad board or not.
If you already have built your module(s) and the ADSR-2 does not work, contact me and I'll tell you how to fix it.
Luckily it's an easy fix.
wendallsan
Many things were learned during the build-- ordering parts after PCB arrives is on that list now. The knob and switch I got will eventually go into something, I'm sure!

Bolstered by this success, I just ordered 13 more modules in an attempt to build a copy of the System 700 "Block 1". Should be an exciting fall! I see that a couple of the more complex PCB's use a SMD part or two, that will be a first for me but doesn't seem too bad after watching some Youtube videos on the subject. Should I pull this off, there are of course 5 more "Blocks" after that if I'm not burned out by then!
Dead Banana
Modulart_JP
The 707 Amplifier/Envelope Follower/Integrator is now available.
PCB's, panels as well as assembled modules are in the shop already.
On the PCB page, the BOM, a DXF file if you want to make your own panel and the calibration procedure are available for download.

Also, it seems people have a hard time to source 2MA 16mm pots.
If so, check out my shop.
I am out of stock right now but I should have them back in stock by the end of the week.

702 and 703C build notes have been updated.
wendallsan
Modulart_JP wrote:
The 707 Amplifier/Envelope Follower/Integrator is now available.
PCB's, panels as well as assembled modules are in the shop already.


Wow that was fast! You seem to design these units as quickly as I'm building them. applause

Modulart_JP wrote:
Also, it seems people have a hard time to source 2MA 16mm pots.
If so, check out my shop.


And yes that 2MA 16mm pot has been tricky to find for me here in the US, along with the 50KA Dual 9mm pot used on the 703F and the 500ohm trimmer used on the 702. I am fairly sure I've managed to source everything else to put together the modules I've ordered so far. Perhaps if others are also having a hard time with these bits you could add them to your store as well. Let me know if you could possibly sell me those bits and I'll make payment accordingly-- I know I'll be ordering the 707 PCB+plate and the 2MA pot in the very least in the next week or so (I currently need 3 500 ohm trims and 1 50KA Dual 9mm pot).

And here I thought I wouldn't need to put in another order from you for a few months until I was ready to build more System 700 "Blocks" (the VCO bank aka "Block 4" was next on my todo list).

Mr. Green
wendallsan
PS-- I don't see a faceplate or full assembled modules for the 707 in your store at the moment, just in case you haven't turned those products "on" in your online store software or something.

Mr. Green
Modulart_JP
wendallsan wrote:
PS-- I don't see a faceplate or full assembled modules for the 707 in your store at the moment, just in case you haven't turned those products "on" in your online store software or something.


No, they are.
Just need to take a couple of pictures this week end.

You can find the 500 Ohm trimmers on Mouser.
This one will do:
https://www.mouser.jp/ProductDetail/Bourns/3362P-1-501LF?qs=sGAEpiMZZM vygUB3GLcD7iDNlz%2FNDKompMEyhqEJhVo%3D

The 2MA pots are back in stock.

As for the dual 50KA, I'm afraid your only option is Thonk.
wendallsan
I was able to find the 707 complete unit and faceplate products by paging through the products, but they were not showing via your search engine when searching for '707', which was why I had assumed they were not there.

Also great to hear that the 2MA pot is in stock, I'll be getting some of those. Finally, thanks for letting me know the dual pots could be obtained through Thonk and for the link to the trimpots on Mouser-- I don't know why I can never find things on my own when I try to look for them on that site, I guess it is just too big for me to fathom.
screaming goo yo

Looks like I can add your excellent 707 module to my project with just a couple more orders to various suppliers rather than 4+ due to having some extras on hand from building your other 700 modules, which is great! Glad I over-stocked a little bit.

Would this Mouser product be a reasonable part for the DPDT on-on-on switch used in the 707?

https://www.mouser.com/ProductDetail/CK/T211STKCQE?qs=%2Fha2pyFaduiFEp I%252BRR%252BMvzKCEmf8yZdVNise89%2FpMXFRPzeLiLesKRADhybY%252B0MMDXNe9C dQ3F4%3D

Thank you again for your sage advice and expertise.
Modulart_JP
wendallsan wrote:

Would this Mouser product be a reasonable part for the DPDT on-on-on switch used in the 707?

https://www.mouser.com/ProductDetail/CK/T211STKCQE?qs=%2Fha2pyFaduiFEp I%252BRR%252BMvzKCEmf8yZdVNise89%2FpMXFRPzeLiLesKRADhybY%252B0MMDXNe9C dQ3F4%3D



Looks like it would do.
The footprint seems to match.
But...
It is non-stocked.
You better stick to the reference I give in the BOM: Multicomp 2MD6T1B5M2RE
It is available in the USA at Newark:
https://www.newark.com/multicomp/2md6t1b5m2re/switch-toggle-dpdt-100ma -20v/dp/95M1947?ost=2MD6T1B5M2RE&ddkey=https%3Aen-US%2FElement14_US%2F search
Modulart_JP
I made a new revision of the 706 LFO.
The main difference being that it is possible to adjust the SQU wave now.
For those who have the 1st version, if you want to mod your module(s) to the 2nd revision, contact me and I'll let you know how.

713 Gate Delay module coming soon...
LektroiD
Hi, I have two modules not working as expected... Both appear to have locked frequency.

1st module (703C multimode filter):
* Green LED stays lit no matter which mode the filter is in.
* Audio is present, but sweeping the frequency does nothing, adjusting the trimmers does not shift the frequency and sending CV does nothing either.
* Mode switch sounds like it is going through low/band/hipass, as the sound becomes thinner as I switch through the modes.

Please note: Electrolytic caps are mounted on the reverse side of the PCB due to height restrictions, polarity has been checked





2nd module (711 Phaser):
* Audio is present but the frequency is locked.
* Tested the LFO circuit, and it is working ok.
* I used an old stock 2SC1000, not the 2SC1740 (awaiting arrival of 1740's).

Modulart_JP
Did you calibrate the modules ?
They won't work properly if not calibrated...

Quote:
* Green LED stays lit no matter which mode the filter is in.

Guess is you're using the wrong 4001 reference.
Please refer to the BOM.
For this particular component, the suffix is important.
LektroiD
Modulart_JP wrote:
Did you calibrate the modules ?
They won't work properly if not calibrated...
Quote:
* Green LED stays lit no matter which mode the filter is in.

Guess is you're using the wrong 4001 reference.
Please refer to the BOM.
For this particular component, the suffix is important.


Hi, and thanks for your reply. As I mentioned above, adjusting the trimmers does nothing, so it's impossible to calibrate until I get the fault sorted.

I used a CD4001UBE, as per BoM.

The fault appears to be the same on both modules.

I really appreciate you taking the time to me help out with this smile
ringroad1
Just in terms of narrowing down the problem or ruling things out, and presuming the numbering is the same as the original, then on the phaser it might be worth checking that you’ve got some audio input at R55/IC9C input. If there’s something there, but nothing at output of IC9B then there’s something wrong inbetween.

On the VCF it’s worth checking to see if the voltage varies at pin 6 of IC7, at base of Q1, and then it should probably vary a little bit on the collector of Q2 (the 733). Looks like you’re using Rochester 3080s, they should be ok.

On my versions of the 700 boards I had a load of strife with the LED level indicators. I’m sure this is just because I initially got that part of the circuit slightly wrong, but personally I’d whip the 4001s out until you’ve got the main part of the circuit working.

I'd get my versions out and give you some readings to check for but I'm not at home atm, hope you get it sorted.
LektroiD
ringroad1 wrote:
Just in terms of narrowing down the problem or ruling things out, and presuming the numbering is the same as the original, then on the phaser it might be worth checking that you’ve got some audio input at R55/IC9C input. If there’s something there, but nothing at output of IC9B then there’s something wrong inbetween.

On the VCF it’s worth checking to see if the voltage varies at pin 6 of IC7, at base of Q1, and then it should probably vary a little bit on the collector of Q2 (the 733). Looks like you’re using Rochester 3080s, they should be ok.

On my versions of the 700 boards I had a load of strife with the LED level indicators. I’m sure this is just because I initially got that part of the circuit slightly wrong, but personally I’d whip the 4001s out until you’ve got the main part of the circuit working.

I'd get my versions out and give you some readings to check for but I'm not at home atm, hope you get it sorted.


Hi, and thanks for your reply. I cannot see an IC9 on the PCB and the resistor locators are not on the silkscreen (also I can't see under the resistors to check I have the correct values). The only schematics I can find for a System 700 are barely legible, even then, I could not locate an IC9... Would it be possible to upload the schematics you are reading from, or give me the Pharmasonic part and pin numbers to check?

Many thanks

Also, I wonder if it would be possible to get a silkscreen overlay from Pharmasonic for each of the two boards, so I can double check the resistor values are correct?
filterstein
There are photo's of all the boards, just go to the corresponding pcb in the shop. For the filter:

https://www.pharmasonic.jp/shop/index.php?id_product=187&controller=pr oduct
LektroiD
filterstein wrote:
There are photo's of all the boards, just go to the corresponding pcb in the shop. For the filter:

https://www.pharmasonic.jp/shop/index.php?id_product=187&controller=pr oduct


Other than the visibility of the component values, I don't trust the photos of the boards too much, some of the ones I saw are older revisions which have different component values. That said, I've already compared the phaser board and it seems I have the resistors correct. The filter boards are too hard to make out. Something like this would be helpful...

http://www.yusynth.net/Modular/Commun/MOOGVCF/Moogfilter-silk2.gif
Modulart_JP
No, the numbering is not the same as the original schematics.

As mentioned before, the 1st thing you want to check on the filter is a CV variation at pin6 of IC7.
Set both trimmers half way, no audio signal nor CV in then check that you get a voltage variation when turning the freq pot.

Regarding the 711, where did you get the 324C chips from ?
Are you sure they are OK ?
They can be replaced with TL064 (or even TL074).
If you have a couple around, you may want to put them in place of the 324C to see if it makes a difference.
Again, calibrating is important because at some setting of the trimmer, you will not get any phasing.

I'll upload layouts on my website later today.
I'll let you know once done.

A couple of news...
713 Gate Delay will be available by the end of this week.
723 Analog Switch and 715 Multimode Filters modules coming soon...
nanners
LektroiD
Modulart_JP wrote:
No, the numbering is not the same as the original schematics.

As mentioned before, the 1st thing you want to check on the filter is a CV variation at pin6 of IC7.
Set both trimmers half way, no audio signal nor CV in then check that you get a voltage variation when turning the freq pot.


I'm getting a fixed 11.8V at pin6 of IC7 (741), turning the frequency pot makes no difference to the result. I also changed the 741 and the results are the same.

Quote:
Regarding the 711, where did you get the 324C chips from ?
Are you sure they are OK ?
They can be replaced with TL064 (or even TL074).
If you have a couple around, you may want to put them in place of the 324C to see if it makes a difference.
Again, calibrating is important because at some setting of the trimmer, you will not get any phasing.


The µPC324C chips were from Little Diode in the UK, I also had some NOS 324's. Both yielded the same results - ie. no phasing.

With TL064s, at a certain trim setting I'm hearing the LFO sweep a high frequency oscillation over a lot of distorted noise (not phasing, just a high pitched oscillation). The distortion can be tamed a little, but when I change the resonance, the distorted noise is back.

**UPDATE**
The 711 phaser is now working. I went through a few µPC324C's and it came alive. Seems these chips are hit and miss, shame these are not available from any of the major outlets.

Just a personal taste thing, but which timing cap regulates the speed of the LFO? I would like to slow it down a little.

Quote:
I'll upload layouts on my website later today.

Much appreciated smile
ringroad1
Yeah sorry, I should've realised the numbering would be different given that this version of the 711 doesn't include the spring reverb or the tuning oscillator.

LektroiD wrote:

I went through a few µPC324C's and it came alive. Seems these chips are hit and miss, shame these are not available from any of the major outlets.


FWIW I used an LM324 which I presumed to be the same - worked ok off the bat.

LektroiD wrote:

Just a personal taste thing, but which timing cap regulates the speed of the LFO? I would like to slow it down a little.


On the phaser, http://www.florian-anwander.de/roland_system700/711_a3.jpg is as clear as it gets from the original schematics, reckon it's the 0.22uF cap marked C33 in the schematic here.

Yves Usson posted his schematic for the 12db VCF here: http://yusynth.net/gear/ROLAND/R700-schematics/703B-C-VCF.pdf

+1 for schematics with DIY boards and part numbers on the board rather than values, we play these guessing games otherwise.
Modulart_JP
Uploaded the layouts for all SYS-700 PCB's.
They are available for download on the PCB pages in the shop.
LektroiD
Modulart_JP wrote:
Uploaded the layouts for all SYS-700 PCB's.
They are available for download on the PCB pages in the shop.


That's briliant! Thank you!

I have now repaired the fault. Thank you for taking the time to help out.
wendallsan
So far it sounds like I'm having more luck than others! My noise module is making noise as advertised!

Rockin' Banana!

Of course I'm starting with the simplest modules and working my way up. Will be building a couple of the VCA's next, and hoping to have full "block 1" worth of modules built by end of September.
Modulart_JP
thumbs up

If you take your time, you don't hurry, chances are the builds will go smoothly.
Good luck !
SlayerBadger!
wendallsan
Progress continues! I've gotten my 2 VCA's together and then the Amp/Env Follower/Integrator. Haven't plugged them in to do final testing/calibration yet so can't say that they actually work yet. Will be building the 703C filter next and then a couple of the LFO's.

I have one correction for your Mouser cart for the LFO-- the BOM has 2x 24k resistors, but the Mouser cart only includes one.

Other than that, it has been smooth sailing on this work here, fingers crossed that the momentum keeps up!

Pics!

The Faceplate spread


Multi



Bring the Noise!



The VCA Twins



The Amp/Envelope Follower/Integrator

wendallsan
I've got a question about the 703C filter.

In the BOM, there is a 1u electro cap and a 1u NON-POLARIZED (NP) electro cap (that I had no idea such a thing existed). There isn't anything on the board to identify which is which. I assumed that the NP cap is the one identified as C15 on the board, and that C10 is the regular 1u electro cap. Is this correct?

A follow-up question about NP electro caps-- can I assume that if an electro cap doesn't have a 'negative' stripe on it or some other obvious indicator, is it safe to assume it is NON-POLARIZED? I do have several of these that showed up from the Mouser cart orders, and was wondering about that, as I had never seen a 'non-striped' electro cap before.

Many thanks! I look forward to plugging this in and calibrating it once I know I've got my caps in the right place. Work on the LFO boards has begun.
Modulart_JP
Quote:
In the BOM, there is a 1u electro cap and a 1u NON-POLARIZED (NP) electro cap (that I had no idea such a thing existed). There isn't anything on the board to identify which is which. I assumed that the NP cap is the one identified as C15 on the board, and that C10 is the regular 1u electro cap. Is this correct?


The NP 1u cap is C10 and there is "NP" written on the board beside it.

NP caps have no negative stripe and usually there is BP written on them as well.
Non-Polarized electrolytic caps are also called Bi-Polarized.
BadPixel
These look delicious hyper As a total 700 newb, which modules would be the optimal to begin with?
wendallsan
BadPixel wrote:
These look delicious hyper As a total 700 newb, which modules would be the optimal to begin with?


I am a total noob to this as well, and started with the simplest ones I could find in the series (aka the patch bay and the mixer). I've then been working my way up the food chain of complexity and haven't had any major issues other than my own ignorance of electronics, which I'm slowly overcoming. It's taking me at a guess 3-4 hours to build the 'complex' ones like the VCO's and LFO's, but it speeds things up to do 3 VCO's at once, etc, for what that's worth.

I've always wanted a System 700 and this is the 1st feasible opportunity I've been given, so I'm jumpin' on it! I'll have some more pics of the the latest modules soon.
BadPixel
Ah, sorry. Building is not the issue. I was more thinking in the lines which modules to choose for a basic 700 setup. A couple of VCO’s, a VCF, ADSR and an envelope?
wendallsan
About half of my VCO's are populated. I have a question about the 1k and 100k resistors. There are two types: the 0.1% "matched" ones and the regular 1% ones. Which ones go where on the boards?

And thanks for letting me know about the "NP" indicator on the filter board. I had totally missed that and yes, I did get my caps in the wrong place, so some desoldering is called for, but not too much at least and I'm glad I asked before I turned it on and smelled smoke!
Dead Banana
wendallsan
BadPixel wrote:
Ah, sorry. Building is not the issue. I was more thinking in the lines which modules to choose for a basic 700 setup. A couple of VCO’s, a VCF, ADSR and an envelope?


3 VCOs, 2 LFOs, 2 VCAs and 1 of everything else will get you a close approximation of a "block 1"
hyper
BadPixel
Awesome thumbs up and yeah don’t let the magic smoke out wink
Modulart_JP
Quote:
About half of my VCO's are populated. I have a question about the 1k and 100k resistors. There are two types: the 0.1% "matched" ones and the regular 1% ones. Which ones go where on the boards?


The info is in the build notes PDF.

Quote:
Ah, sorry. Building is not the issue. I was more thinking in the lines which modules to choose for a basic 700 setup. A couple of VCO’s, a VCF, ADSR and an envelope?


A good start would be the Laboratory System config.

BadPixel
Modulart_JP wrote:
A good start would be the Laboratory System config.



Just what I was looking for, thank you thumbs up
wendallsan
Modulart_JP wrote:
Quote:
About half of my VCO's are populated. I have a question about the 1k and 100k resistors. There are two types: the 0.1% "matched" ones and the regular 1% ones. Which ones go where on the boards?


The info is in the build notes PDF.


D'oh! I didn't realize there was more than 1 page to that build notes PDF and hadn't noticed. Thanks for pointing that out.

I have a question about the rotary switch for the LFO now. I see in the Build doc how to wire it, but wanted to check if there is a 'right side' up to that switch or not. In other words, if you flipped it upside down from the photo in the build notes, would that matter at all? I don't see any indication on the switches as to what pin is "pin 1" and am concerned that I might wire it 'upside down' if such a thing exists.

EDIT: I see that there are 3 lugs on the inside ring of lugs on the switch and that those can be used to orient the switch to match what is shown in your illustration. Sorry for having missed that, no response is needed on this question.
d'oh!
wendallsan
I have finished building all the boards I've ordered to the best of my ability, and have arrived at the VCA's after finding several problems with my noise/ring mod module that I need to fix before testing further. I'm trying to calibrate it according to the build doc, but am confused by the instructions. It says:

Quote:

Linear adjustment:
The 1st step is the adjustment of the DC balance.
Set the switch to LIN, all pots to 0 and feed one of the modulation input with 10V.
Probe the VCA output with an oscilloscope (use high gain) and adjust the DC BAL trimmer so changing the CV amount produces minimum change


I have a David Jones O'Tool acting as voltage meter and a 2hp MIDI acting as CV source, which only seems to be able to output +5V. I have taken the following steps:

- set the switch to LIN
- set all the pots to '0'
- connected the 2hp module feeding a +5V source to the 1st modulation input
- turned up the 1st modulation input's pot to '10'/full

My expectation is that I can adjust the DC BAL trimmer so that it matches the voltage provided at the 1st modulation input (+5V). As I adjust the trimmer, the level comes to this value, but appears a little 'jittery' and seems like a very fine tune to arrive at it-- I'm not sure if this is typical or an indication of a problem. Once the output range is within view of the level meter (showing 0-6V DC), the slightest nudge on the trim pot seems to adjust it pretty widely, making it difficult to adjust in increments less than about 1-2 volts.

Once I have this set so that it is at the +5V level to match the provided modulation input, I figure a simple experiment would be to provide a changing voltage level to the modulation input to see if output is 'following' the input, which again is my best guess as to what should be happening. To my surprise, I see that the output slightly increasing as the input voltage drops. As the input voltage comes in at +5V, the output voltage is also at +5V, and then as the input voltage drops to 0 over the course of about 4 seconds, the output voltage raises to +6V. Likewise, adjusting the modulation input's pot down from full to 0 increases the output voltage from +5V to +6V.

Here's what I've done to troubleshoot so far:

- checked all solder joints
- checked resistance values and placement
- checked cap values, placement, and orientation
- checked diode placement and orientation
- checked transistor placement and orientation
- checked IC placement and orientation
- checked pot and trim values

All I can think to ask (and I shudder to do so, as I've done this on all the modules I've built) is that all my trims are on 'upside down' according to the silkscreen artwork, which allows them to match the positioning of the trim screw shown in the silkscreen art. All my trim pots have a screw at the left side of it, if I am looking at it from the 'front' (screw is facing me). In your artwork all the trims have their screw at the right side. My limited knowledge of electronics suggests the pot orientation doesn't much matter, as it's just adjusting between two points-- but you are welcome to tell me I'm wrong if this is possibly the issue.

Otherwise, I am open to suggestions on how I can begin testing this beyond the simple steps I've taken so far. The 'good' news is that I have built two VCA's, and they are both displaying this same issue, so if I can fix one, I should be able to fix the other with the same effort!
Modulart_JP
Your VCA is probably OK but your calibration is not.

The calibration procedure in the build notes is a copy of the one in the System-700 service manual and the 1st step is, in other words, the feed through adjustment.
In a perfect world, the CV's should not go through the VCA path.
In real life, it's different, there's a feed through and you get a very very small amount of the CV in the VCA path.
The goal is to minimize that.
With no signal in the inputs and a full CV (10V, not 5V) in 1 of the modulation inputs, you adjust the DC BAL trimmer so you get the smallest amount of CV at the VCA output.
Another way to do it is by ear.
With no signals in the VCA inputs, feed one CV input (amount fully CW) with an audio source (a VCO output, for example) and listen to the VCA output on your monitor system (headphone, speaker) with the volume very high so you can hear the very low level feed through signal.
Then adjust the trimmer so the level of that signal is at its minimum.
wendallsan
Modulart_JP wrote:
Your VCA is probably OK but your calibration is not.


I will take this as great news that my VCA's are PROBABLY working applause

I will take another pass at calibrating by ear, as my 2hp MIDI module appears to have no means to output more than +5V.

Thanks for the additional instruction on calibration, this is my 1st forray into eurorack and diy synths, so calibration is new to me.

NEXT QUESTION: would the C&K tactile switch available from Thonk work for the pushbutton on the ADSR? Alternately, would any parts from Mouser work for this? I realize I didn't wind up with a button and am putting together another order for parts, and would love to get all the remaining bits needed from Mouser if possible.
Modulart_JP
wendallsan wrote:
NEXT QUESTION: would the C&K tactile switch available from Thonk work for the pushbutton on the ADSR? Alternately, would any parts from Mouser work for this? I realize I didn't wind up with a button and am putting together another order for parts, and would love to get all the remaining bits needed from Mouser if possible.

The PCB is designed for that kind of switch.
Thonk carry them but you should be able to find them (or equivalent) locally.
wendallsan
As always, thanks for the answers. Soon I will run out of questions, because everything will be built and working!

Could I use the Amp portion of the Amp/Envelope Follower (EF)/Integrator to boost the +5V from my 2hp MIDI module up to +10V?

If so, I can focus on troubleshooting that module and then use it to test and calibrate the other modules properly. I've done some initial tests of this module and it appears that the amp portion is not working, although the integrator portion is working great. I have not tested the EF portion as the calibration instructions call for a 1khz sine wave at 10Vp-p, and that will take a little work for me to produce currently.

In my testing of the Amp portion of the module, feeding a CV or an audio signal into the Amp's input results in nothing being output from the amp out, regardless of position of the pot and switch involved in the amp. Additionally, the EF's green LED lights as soon as power is supplied to the module, probably also an indicator of something wrong.

I've taken the usual steps to troubleshoot this that I currently know to take, including checking solder joints, resistor values and placement, checked cap values, placement, and orientation, checked diode placement and orientation, checked transistor placement and orientation, checked IC placement and orientation, and checked pot and trim values. All components seemed to be properly placed and oriented.

Are you able to provide any suggestions on how to troubleshoot this, or alternately provide schematics for me to ATTEMPT to use to troubleshoot this on my own? Fortunately this is one of the more simple modules, so I'm hoping it'll be an easy fix.
Modulart_JP
You can contact me privately via my website.
I'm sure we'll figure out what's wrong.
wendallsan
Modulart_JP wrote:
You can contact me privately via my website.
I'm sure we'll figure out what's wrong.


Thanks! I have followed up on your site as requested.
Modulart_JP
2 new modules in the SYS-700 family:
713 Gate Delay and 723 Analog Switch

I think there is not much interest in making a clone of the module 712.
However the voltage processor may be useful and that's why I added it to the 713 module.

The 715 Multimode Filters is coming soon...
nanners
LektroiD
Hi, I'm building the oscillator which asks for a 453K resistor. Using standard values, I am able to make 454K by either 24K + 430K in series, or 470K + 13MΩ in parallel. Is 454K adequate for this, or should I try to source the exact resistor?

Also... Does anyone know a good source for the subminiature SPDT switches (as used on the VCO) at a reasonable price in the UK?
Modulart_JP
454K will do.

As for the SPDT switches, Farnell carry them:
https://export.farnell.com/multicomp/2ms1t1b5m2re/switch-spdt-0-1a-20v -on-on/dp/9473041?ost=2MS1T1&ddkey=https%3Aen-EX%2FElement14_Export%2F search
Don't know if it's what you consider a good price though.
LektroiD
Modulart_JP wrote:
454K will do.

As for the SPDT switches, Farnell carry them:
https://export.farnell.com/multicomp/2ms1t1b5m2re/switch-spdt-0-1a-20v -on-on/dp/9473041?ost=2MS1T1&ddkey=https%3Aen-EX%2FElement14_Export%2F search
Don't know if it's what you consider a good price though.


Thanks for this... I managed to find some from a company in Taiwan, just a case of waiting on shipping...

My next question is that 250pf capacitor... I have searched all over and cannot for the life of me find any, except those high voltage (>1KV) things used in power supplies, would these be ok, or should I use a 1000pf & 330pf in series to get 248.1pf? That's the closest I can get with standard values.
Modulart_JP
Please refer to the Mouser cart.
LektroiD
Modulart_JP wrote:
Please refer to the Mouser cart.


Thanks, I hadn't noticed the link initially.

The next problem is the LM301, Unfortunately I've now run out of my limited stock. I don't see them in the mouser cart (I have also tried Farnell, RS as well as smaller companies like Bitsbox). I can only seem to find them on ebay or aliexpress, so I'm doubtful of the authenticity. Have these been discontinued? Is anyone managing to get these in the UK?
wendallsan
LektroiD wrote:
The next problem is the LM301, Unfortunately I've now run out of my limited stock. I don't see them in the mouser cart (I have also tried Farnell, RS as well as smaller companies like Bitsbox). I can only seem to find them on ebay or aliexpress, so I'm doubtful of the authenticity. Have these been discontinued? Is anyone managing to get these in the UK?


I'm doing a build of several of these modules as well and have also had a bit of a challenge sourcing LM301's. I bought a bunch from China, and they all turned out bad, so apparently trying to score a deal on eBay is not the thing to do. I bought some OP07CPZ chips from Mouser in the US and these seem to have worked fine as drop-in replacements for LM301's in the modules I've tried them out in (including the mixer, the amp/E.F./integrator, S&H, and noise/ring mod modules). When my LM301's from China were causing problems, folks were telling me to replace them with 'pretty much any op amp' that had the same pinout, so it seems like the LM301 is not all the critical? If this is the case, I'd love to hear what acceptable subs could be used for folks having problems sourcing the LM301's. Also, the 3080's are a pain to find and are expensive to boot, which leaves me wondering if there are any acceptable replacements for those as well. I don't know enough electronics to know one opamp from another, other than looking at pinouts and curves in the graphs on the spec sheets for the IC's.

Here's a link to the OP07CPZ chips if anyone needs them:
https://www.mouser.com/ProductDetail/584-OP07CPZ
ringroad1
In a brief test I did a while back LM13700 worked fine in the 24db VCF, although I had to do some convoluted wiring up to check 'cos the pinout is very different.

Not a UK/EU supplier but Tayda say they have loads of LM301. I've bought some from them in the past, I don't remember having any trouble (not much of an endorsement, I agree)

The impression I get is that the LM301 is fairly rubbish so I don't think there's any need to buy anything fancy.
Modulart_JP
Quote:
The next problem is the LM301, Unfortunately I've now run out of my limited stock. I don't see them in the mouser cart (I have also tried Farnell, RS as well as smaller companies like Bitsbox). I can only seem to find them on ebay or aliexpress, so I'm doubtful of the authenticity. Have these been discontinued? Is anyone managing to get these in the UK?


You can buy them from me.
They are available for sale in my shop.
Jameco has them too at a slightly better price.
LektroiD
I was looking at the 708A ring modulator, it seems that there were variants (possibly factory modded), the user manual shows one type, yet I found an image of one with 6 extra switched inputs, which looks really interesting...
Modulart_JP
Does not look really genuine to me...
And I'm almost sure Roland would have done a far better job if it had been modded by them.
LektroiD
It was spotted in this sale: http://www.rlmusic.co.uk/rlm3/roland-system-700/

It seems the original 708A had the 4-way switches hardwired to the various oscillators in the synth. Looks like someone had the creative idea to add sockets in place of the hardwiring. It's an interesting configuration having the switchable inputs if you're playing a live sequence and you want to route another source into the RM without repatching. I guess that's another feature that made the System 700 so unique.

wendallsan
LektroiD wrote:
It's an interesting configuration having the switchable inputs if you're playing a live sequence and you want to route another source into the RM without repatching.


This looks like fun. I immediately find myself thinking about this plus CV controlled switches for those inputs. I guess we could throw that together with a 708 and a couple 723's?
LektroiD
wendallsan wrote:
LektroiD wrote:
It's an interesting configuration having the switchable inputs if you're playing a live sequence and you want to route another source into the RM without repatching.


This looks like fun. I immediately find myself thinking about this plus CV controlled switches for those inputs. I guess we could throw that together with a 708 and a couple 723's?


I was initially thinking of modding the 708, rather than filling the cabinet with switch modules. The only issue is the PCB covering the blank area of the panel, so no room for a switch. I'm now thinking of maybe a 2HP breakout panel and a couple of 4 way slide switches.
Modulart_JP
2x 4 position slide switches and 8 jacks won't fit into 2HP...
hihi
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