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WIGGLING 'LITE' IN GUEST MODE

[BUILD] MFOS Echo Rockit eurorack
MUFF WIGGLER Forum Index -> Music From Outer Space  
Author [BUILD] MFOS Echo Rockit eurorack
synthcube
edit 5-11/2017:
available here: http://synthcube.com/cart/mfos-echo-rockit-euro
____________________________________________________________

With gratitude to clarke68 for the panel design and barcode for the panel pcb layout, we're happy to announce the MFOS Echo Rockit for eurorack.

Shortly, we'll be offering panels, panel+pcb sets, full kits and assembled units for the PT2399-based echo.

Pots, jacks and switches mount to the panel PCB- no wiring! We'll post the BOM, schematics etc shortly. The original MFOS through-hole PCB layout is utilized in combination with the barcode panel pcb.








hmurdoch
definitely interested in this! would love cv control over delay time though. Should be a fairly simple mod?
stringsthings
Most excellent!
Devi
hmurdoch wrote:
definitely interested in this! would love cv control over delay time though. Should be a fairly simple mod?
thumbs up thumbs up thumbs up
DozenCrows
Something for the kludge space?
kingspill
Very much looking forward to this.
euromorcego
very interesting project! Just saw it now because it showed up in ModularGrid wink

But does it work with modular levels? The original runs on a single 9V battery, right?

And the MFOS page says

MFOS wrote:
Grounding issues will arise if the Echo Rockit is powered from one side of a dual supply system. The Echo Rockit's virtual ground will be at 1/2 of the positive supply which will make DC ground matching impossible. I think issues involving smoking ICs could arise if this advice is ignored. If you know of something I don't on this issue I'd be happy to hear it but I highly recommend the solution shown above in the "Powering an Echo Rockit from Your Dual Supply" illustration.

I see that the 78L05/79L05 has been included in the BOM. So I guess the suggested solution has been implemented (hard to see on the pcb). Does it work well in a modular context?

Any problem if the filter CV is like close to +12V or -12V?
synthcube
yes, it was designed to incorporate the MFOS circuitry for use on +/-12V euro systems... we're biased of course but love the couple of them we have set up here.
euromorcego
synthcube wrote:
yes, it was designed to incorporate the MFOS circuitry for use on +/-12V euro systems...

ok, great!

Do you happen to know if there is any problem when the input exceeds the 10V (as I understand, with the modification the Rockit essentially runs on +/-5V, so it should have a bit less headroom than the "usual" eurorack). I just want to make sure I can use it in a system without any thinking.
synthcube
we have not seen any issue, no... thanks
southphillysynths
Just started building my kit!

Another wonderful kit by synthcube thanks so much! Looking forward to more MFOS in my rig.

How are the PCBS connected? should the component pcb connect with the pins to the hardware pcb through the X pads?
synthcube
correct--- the single pin pads on the main PCB (that are used for flying wire connections for the original panel) connect via pin headers and female sockets to the panel PCB-- enjoy!
southphillysynths
synthcube wrote:
correct--- the single pin pads on the main PCB (that are used for flying wire connections for the original panel) connect via pin headers and female sockets to the panel PCB-- enjoy!


worried about the orientation of the square headers, should I use circular machine headers for a better fit?

Also missing the nuts to secure the back of the standoffs from the kit!
synthcube
we've had good reports from builders using the square ones, but no issue changing them-- and drop us an email we'll send the nuts!! Thanks!
euromorcego
now also started building (from pcb/panel).

One question: which jacks are needed? Is it the PJ301BM (e.g. from thonk) and what is the orientation? The seem to fit only one way ... but not in the way indicated on the silkscreen.

AND: the switches are all on-on, correct?

Some other comments: the single pins are a major pain. Not sure if the panel is really that much of an advantage versus wiring (or a panel plus panel pcb that is the connected via wires to the main pcb).

The holes for the switches are quite tight and won't work with the (more common) switches that have a solder lug.

Otherwise all seems fine for now ...
j450nn014n
I was just about to start building one today. I've been eyeing the box of parts for days longingly. :) As with the other 2 MFOS I've built, there was a lug on the pots that had to be cut off. Is that what you're referring to? If so, it's plier time.

euromorcego wrote:
now also started building (from pcb/panel).
The holes for the switches are quite tight and won't work with the (more common) switches that have a solder lug.
j450nn014n
I've worked through most of the confusions myself, with regards to the panel with the pots. I wish the resistors and caps were as clearly documented on this panel as they are on all other MFOS boards that I've put together. I can't actually see if the 78L05 voltage regulator slot is what it says. So blurry it could be 79L05, though i guessed.

My BIG QUESTION is about the instructions "mount all headers on this side" and Mount All headers first". What headers? Male or female. And what about the other pins. HOw is this supposed to go together? on other MFOS devices I just used hookup wire. Ok, should i put the female headers in x1-x28? And also ground and also BN & BP.

Instructions would really help, but I seem to have some of it figured out. Any thoughts? THanks in advance.
synthcube
the single pin headers can be installed either way-- female on one board, male on the other-- just make sure you use the same 'gender' on one pcb- no mixing and matching!
j450nn014n
synthcube wrote:
the single pin headers can be installed either way-- female on one board, male on the other-- just make sure you use the same 'gender' on one pcb- no mixing and matching!


Yes, I get that.I have designed my own boards. I was perhaps being a big oblique. I'll be less so.

How come there are no instructions with this board? The thing I liked about Ray's work was the amazing and often hilarious instructions. There were pretty good instructions with the pre-eurorack version, but nothing here.

I have no trouble just guessing and using common sense, but that does mitigate the joy of MFOS, don't you think?
synthcube
fair point and good feedback-- our goal is to create full documentation-- it is however a work in progress smile
j450nn014n
Let your fans do it... if you had a little wiki somewhere, people would just write all the bits they figured out and you could just package it up. I know I'd help just for fun.

I still don't understand why I'm soldering on pin headers though. Is there something I don't understand as to why I'd do this and not just solder it all together like on my noise toaster and WSG? Serious question. I'm not that experienced, and I'm worried that there's something I don't understand about why one way is better than another.
j450nn014n
The single pin headers directly join the two boards together. That's craziness. I doubt I'll ever get all the pins aligned, but that's another issue.

My big question is why are C6 & 2xPWR caps diagramed as polarized, yet they're non-polarized caps? This scares and confuses me. Am I doing something wrong?
synthcube
the euro version is set up so that the original pcb can be used, along with the new panel pcb for direct soldering of pots, jacks, switches etc. The single pin headers are a compromise to Ray's original PCB design and layout...

C6 is one of the non-polarized electrolytic caps. The 2XPWR caps are tantalum caps, which are polarized-- they have a small '+' sign to show polarity
j450nn014n
Right. Sorry. I was working from memory the 2xpwr were obvious. But why on the circuit board is C6 shown as polarized with a circle with a + next to it. Scares us noobs.

FINAL question: how can I orient the power and connect the ribbon and get around the pins x4, 5, 6, 20? See below. I'm so close to done, and not quite sure if I did it right. Thanks!





[/img]
synthcube
check the orientation of that power header- its supposed to be able to allow the cable to connect outside the boundary of the pcb sandwich
j450nn014n
Based on what you said, looking at the picture I sent, you're saying I have it backwards? I CAN see that the square hole on the mother board does correspond to the red stripe on the cable (though I've read elsewhere never to trust the rest stripe. But the image on the board itself suggests that the orientation is inwards.
synthcube wrote:
check the orientation of that power header- its supposed to be able to allow the cable to connect outside the boundary of the pcb sandwich


I will trust you and have faith. You designed it after all. Thanks for the fast response.
j450nn014n
Hi. I hope I can get some advice. I finished building my Echo Rockit. It starts up and makes sounds, but not the sounds I'd expect. I identified 2 problems so far. 1) the output volume doesn't work. If you turn the dial from 0-8 nothing happens, and then it jumps to 100%. Don't know what's wrong with that but solder is good. It is a 100k pot (tested with my multi-meter) and the values run correctly from 0-100 on the ohm meter setting. 2) the 79L05 voltage regulator is VERY HOT on the +12 side of things. I measured it at 140F. Is that ok? That's scary hot. I do know that the cap next to it is properly oriented.

None of the IC chips are hot at all, and they're all oriented properly. I'm no electronics guy, but I've successfully built a noise toaster and a WSG. Anyone willing to help trouble shoot this? or is there a better forum to ask these questions?

Thanks!
Bodo1967
j450nn014n wrote:
1) the output volume doesn't work. If you turn the dial from 0-8 nothing happens, and then it jumps to 100%. Don't know what's wrong with that but solder is good. It is a 100k pot


Sounds as if you used a logarithmic instead of a linear pot.

j450nn014n wrote:
the 79L05 voltage regulator is VERY HOT on the +12 side of things. I measured it at 140F. Is that ok?


No. They may get a little warm, but not that hot (140 °F is about 60 °C, which I am more familiar with). My guess is a wrong component since you wrote 79L05. It must be an 78L05 (on the main board, that is - or were you referring to the additional Eurorack board?

Speaking of which - where do these 79L05 (I see there are two of them in the Eurorack version BOM) go anyway?

I am currently building a 'conventional' Echo Rockit on a self-etched board, but there is only one of those voltage regulators (U2) on it, and that's an 78L05.
j450nn014n
Bodo1967 wrote:
j450nn014n wrote:
1) the output volume doesn't work. If you turn the dial from 0-8 nothing happens, and then it jumps to 100%. Don't know what's wrong with that but solder is good. It is a 100k pot


Sounds as if you used a logarithmic instead of a linear pot.

j450nn014n wrote:
the 79L05 voltage regulator is VERY HOT on the +12 side of things. I measured it at 140F. Is that ok?


No. They may get a little warm, but not that hot (140 °F is about 60 °C, which I am more familiar with). My guess is a wrong component since you wrote 79L05. It must be an 78L05 (on the main board, that is - or were you referring to the additional Eurorack board?

Speaking of which - where do these 79L05 (I see there are two of them in the Eurorack version BOM) go anyway?

I am currently building a 'conventional' Echo Rockit on a self-etched board, but there is only one of those voltage regulators (U2) on it, and that's an 78L05.


THANKS. I bought a kit from SynthCube, so perhaps they sent me the wrong pot? With your advice I can compare the pot I was given with some others I have lying around. The whole "logarithmic instead of a linear pot" is so obvious, but it never occurred to me.

I'm more familiar with 60C as well, but I posted F because I assumed more people would be used to that.

There are 2 x 79L05 on the eurorack version board to regulate the +12/-12 power coming in. And there's a 78L05 as well but it seems to be fine (cool and all that) up deep in the board. The problem is that all these parts are from the kit, so if they're wrong, I was sent the wrong parts or somethings. The 79L05 is pretty much the first component coming into the board, so I cannot imagine what else might be causing the problem.

Just for the record, I'm using a MakeNoise Skiff http://www.makenoisemusic.com/cases/skiff so it is not like I have some weird out of control power source (which is totally possible in my world).

Thanks for the confirmation... I hope someone's got some other thoughts.
Bodo1967
j450nn014n wrote:
perhaps they sent me the wrong pot?.


Are they marked with an A or B (as in, "B100K" or similar)? "A" is usually logarithmic (the original MFOS BOMs say "audio"); "B" is linear. There may be exceptions, but they are very rare, so in most cases you can go with this.

j450nn014n wrote:
There are 2 x 79L05 on the eurorack version board to regulate the +12/-12 power coming in.


Really? Not a 78(L)05 and a 79(L)05? I've built quite a few symmetric PSUs in my life, but never used two 79XX in them seriously, i just don't get it hmmm..... . Always a 78XX (+ voltage) and a 79XX (- voltage).

Perhaps double check on this? Do you have the proper voltages at the power in points on the main PCB?

Edit: Yes I see there are two 79L05 and one 78L05 in the Eururack version BOM. According to your information and what I wrote above I'd really have expected two 78L05 and only one 79L05 instead.
j450nn014n
Bodo1967 wrote:
j450nn014n wrote:
perhaps they sent me the wrong pot?.


Are they marked wioth an A or B (as in, "B100K" or similar)? A is usually logarithmic (the original MFOS BOMs say "audio"); B is linear.

j450nn014n wrote:
There are 2 x 79L05 on the eurorack version board to regulate the +12/-12 power coming in.


Really? Not a 78(L)05 and a 79(L)05? I've built quite a few symmetric PSUs in my life, but never used two 79XX in them :despair: :hmm: . Always a 78XX (+ voltage) and a 79XX (- voltage).

Perhaps double check on this?


ZMFG! You could be right! Damn. You see the silk screen on the board is so blurred that all you see is 7*xx. All I could do is assume that U2 was 78 and this one was 79. I could thus have them backwards. The kit came with 2 x 79 and 1 x 78.

I'm not that experienced, and I assumed that I was wrong. I was going to put the 78xx in the + voltage. As you can see from this picture... the silk screen is really blurred. (and yes, the power is backwards in this image. Don't be alarmed. I put it in the other way around.)



I'm going to go and swap it out for a 78XX and report back. THANKS@
Bodo1967
I think that probably should be an 78L05 at the bottom edge of the pic. The pin in question appears to be connected to the + side of the tantalum cap, which makes sense with a 78L05.

And yep, it is blurred, but I'd probably read a 78 there if I had to wink.

And the connector needs to be put in the other way round (cable facing away from the board), but I think that's been pointed out before wink.

78L05 on the main board is correct. I stick with what I wrote before concerning the need of two 78L05 and one 79L05 wink.
j450nn014n
Bodo1967 wrote:
I think that probably should be an 78L05 at the bottom edge of the pic. The pin in question appears to be connected to the + side of the tantalum cap, which makes sense with a 78L05.

And yep, it is blurred, but I'd probably read a 78 there if I had to ;).

And the connector needs to be put in the other way round (cable facing away from the board), but I think that's been pointed out before ;).

78L05 on the main board is correct. I stick with what I wrote before concerning the need of two 78L05 and one 79L05 ;).


1) swapped out the 79 for a 78 and that seems to be working fine.
2) I'll check what I got supplied with and I think I got 2 x 79; 1 x 78 by mistake.
3) connector issue was just that the silk screen layout 'suggested' that it go that way, but it was obviously wrong, as the voltages made it clear it should be the other (correct) way.

Going to deal with the pot issue and try it out again.

I'm making notes about this and other issues and will post them somewhere as a bit of a noob guide. I love Ray Wilson's instructions for the Noise Toaster. He really knew how to get into the mind of the learner and talk to him/her that way. It's not something other folks can easily do.

THANKS for your patient advice.
j450nn014n
Bodo1967 wrote:
I think that probably should be an 78L05 at the bottom edge of the pic. The pin in question appears to be connected to the + side of the tantalum cap, which makes sense with a 78L05.

And yep, it is blurred, but I'd probably read a 78 there if I had to ;).




So, I replaced it and it didn't work. I seem to have damaged the board removing the 79L05, because my soldering iron's acting stupid (seriously) but I was too stupid go get another soldering iron (the old uncool one), so it is my fault. I removed the IC, place it in an area called kluge space, ran some wires and hoped it worked. It did! I'm thrilled because I'm never able to troubleshoot or fix things. If it doesn't work, I'm screwed.

So thanks to you and synthcube for help.

I made a short video as evidence.
https://www.youtube.com/watch?v=yBktZP-Bmug
Brian2020
This delay looks interesting being that there is a tabletop version. My eurorack case is on the smaller side so this would be a great delay for my needs plus it will (hopefully) be easy to use with a Moog Mother32 and a Moog Minotaur. I can find a prebuilt model and the kit for almost the same price. The pre built is more but not by much. I enjoy putting pedals together so I was hoping for feedback about this build. First if it’s something I will likely screw up Id rather not go with the kit. Also curious if the build is enjoyable or satisfying to put together? Lastly have more comprehensive instructions come out yet? I’m spoiled from BYOC kits, they practically hold me hand through the process with incredible instructions and color photos to follow.

Thanks in advance for any feedback.

Brian
j450nn014n
Brian2020 wrote:
This delay looks interesting being that there is a tabletop version. My eurorack case is on the smaller side so this would be a great delay for my needs plus it will (hopefully) be easy to use with a Moog Mother32 and a Moog Minotaur. I can find a prebuilt model and the kit for almost the same price. The pre built is more but not by much. I enjoy putting pedals together so I was hoping for feedback about this build. First if it’s something I will likely screw up Id rather not go with the kit. Also curious if the build is enjoyable or satisfying to put together? Lastly have more comprehensive instructions come out yet? I’m spoiled from BYOC kits, they practically hold me hand through the process with incredible instructions and color photos to follow.

Thanks in advance for any feedback.

Brian


I put mine aside because I didn't build it well, but I blame myself more than the instructions. That was 7 months ago, and my soldering skills are much better, though I can still screw up anything. I would say it is an easy build, if you things right. What I need to do right now is go back and reflow everything. And use more flux. It is a crazy little thing, more a monster than an echo, though the echo's good.
LoopUdu
I‘m trying to find out which potentiometers fit on the panel-pcb. Anything I could find so far here in Kuala Lumpur doesn’t fit. Any friendly soul got a link, where I can buy them in Asia or Europe (US postal prices are ridiculously high)?
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