Go ahead!
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My implementation of the circuit should arrive in a couple days from JLC combined with the stomp adapter. also ordered what I think is the same pedal as you @analogoutput. Stoked to try it out. Also sounds like I’ll have to do @WesleyV / @antoine.pasde2’s mod! Good thinking
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Sounds handy! For anyone interested, this is the pedal I’m using:
https://www.sweetwater.com/store/detail/NX-P--nektar-nx-p-universal-expression-pedal
It’s nice that with a bit of fiddling you can get it to 0 resistance so 0 volts on the output when you roll back.
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Looks like a differently-branded version of my M-Audio EX-P.
Yeah none of it works 
some kind of power supply issue getting weird grounding behavior—but didn’t smoke, back to kicad haha
Also got me thinking a dual stomp box adapter should have dual 9v barrel jacks to power them
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Sorry to hear it didn’t work out, but keep us posted on your progress. As for the stomp box adaptor having a barrel jack for the pedals, that’s pretty smart. It might be easy to overtax the power supply but I suppose that’s up to the user to calculate.
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good afternoon, what I want is to add a toe switch to the m-audio EX-P expression pedal, so that it works just like a (mission engineering toe pedal).
and with this activate and deactivate the functions of the pedal, is it possible? as it should be done.
Hi ! Quick question, what’s the value of C1 ? Or is the value important ? I’m building my first modular synthesizer 
This schematic is really helpful ! Thanks
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Welcome in the forum @Alex1 , It’s 2 x 10uf polarized cap 
Thanks a lot ! How do you know it’s 10uf ? I’m trying to learn electricity. It’s hard haha
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I’m not an expert, just most of all modules power are like this.
@analogoutput said that in another thread about that
“The 10 µF capacitors … as a bypass, propping the voltage up when the circuit makes sudden demands.”
and i find this thread
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Thanks for the quick answer ! I will try to make sense of the thread you linked For me, you are an expert.
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No ! i 've learned a lot here and now i have some little notions, but there’s some real expert in theory in this forum 
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Hi Alex,
Those 10uf capacitors are pretty standard in most Eurorack circuits. They are sitting on the power rails to help even out any fluctuations in the power supply before they get to the rest of the circuit. The type of 10uf polar capacitor you are looking for will be shaped like a small cylinder, and should have “10uf” printed legibly on the side. It should also have a visible positive and/or negative symbol to indicate which leg is which.
When setting up your power filtering caps, there will be two caps. One from positive 12v to ground, and one from negative 12v to ground. You don’t want one going from positive 12v to negative 12v. Always make sure that that positive leg of the cap goes to the more positive voltage source - positive leg to +12v, negative leg to ground. With the negative voltage rail, ground is more positive than -12v, so put the positive capacitor leg goes to ground and the negative leg to -12v. Here is a link to some caps that will do the trick:
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Thanks for the tips ! Really appreciated This forum is a gold mine
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Was about to start a new thread - “could I make an expression pedal for CV voltage” - thought to search the board first, found this AMAZING thread already cracking the nut, with stripboard and even a video by king @analogoutput. I love this community! Definitely going to take a stab at this project.
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Seems I never updated the PDF schematic to reflect the final circuit, I just did that now. I think the stripboard layout was up to date.
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Hope you do indeed build this, and post your results. If you use my stripboard layout above, I have one suggestion - I originally changed up some resistors to narrow the output range, but in retrospect, I think you should probably stick with the 10k resistors recommended in analogoutput’s original schematic.
I thought maybe the narrower output range would make it safer for my other, non-kosmo gear, but it’s ended up being a non-issue and I’d rather just have the full 10 volt range. I’ll probably retrofit my module in the near future.
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This may be of interest as well:
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