Yash help - module works when touching finger to metal pot

Hey everybody, I recently built the “yash” from Rene, but from the Holmes Richards schematic, as it is so wonderfully easy to read. Anyway, everything works but only when my meaty finger is touching the bare metal potentiometer. I suppose this is a grounding issue, and will delete this topic if it happens to be a really stupid and quick fix.


whatever it is, don’t delete the topic. Come back with the answer and post it for anyone in the future to find.


Could you post some images of the module?

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Sounds like you need decoupling somewhere…or coupling…I think you need an electrolytic capacitor in you signal path somewhere…

No, a sample and hold should be able to take DC signals on both inputs.

Probably a grounding issue but not enough information given to know.

Maybe a junk potentiometer. I get cheap ones and they can be twitchy like that. As he describes it working when he touches it, I get something similar sometimes. Especially if it’s a signal attenuator. It seems to not work at all until “touching” (engaging in general) the pot makes it scream to life. Poorly manufactured pots with loose/faulty internals?.. Maybe replace the potentiometer…works for me often enough to try it.

It was a shitty potentiometer. Only worked when being touched or wiggling the wires going into it.
When I changed it and checked the whole thing again, all was perfectamento!

@analogoutput, I’m a regular on your github, thanks for making my modular journey much smoother!

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you were 100% on point. Check your pots before screaming “wolf” online, reader! :smiley:

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I have been happy to help! I don’t have much experience, but this forum has been a great resource to me. No doubt though, I get at least one crap pot every 2 modules I build… sometimes that’s one in every ten potentiometers but they are super affordable :100:

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I’m actually going to build the op-amp, nchannel jfet version when I get the jfet in the mail. I have not built a sample hold as of yet and if I hadn’t seen your post I’d not be doing it soon. I’ve built an LFO with triangle and square and also a white noise generator to go with it so I’ll be able to use it. I’ve already got a pretty long list of things I still want to build but I just moved the simple sample and hold to the top of the list. So thank you!