ppprograming

As some of you might remember I am working on debugging the Erica Synths S&H+Noise module. (thread here: https://www.reddit.com/r/synthdiy/comments/y6mskv/help_with_debugging_mkixerica_shnoise/ )

In order to investigate the basics / out of desperation I build the basic noise circuit on a breadboard using a 547C (I bought a whole bunch of 547 and 548 to help try things). I build the following diagram on a breadboard: (tried several transistor samples

https://imgur.com/1OKqwX1

However when I measure with the oscilloscope at the emitter I am not seeing any noise.

So I have constructed the module per instructions, everything worked on the breadboard.

It seems that the S&H part itself is working (when I connect another input I can sample that, slew is also working), but that the noise generating circuit is not generating any noise.

However, if I touch the transistor that is the noise source with my finger it suddenly does work (found out while trying to measure using oscilloscope). I've checked the joints and they are OK.

Does this mean the transistor is broken, or could it be something else?

So my kid managed to drop my synth destroying the lfo rate pot. I've replaced the pot which fixes some things (the lfo seems to run normally again).

However I'm left with something that doesn't make a clean sound anymore and also doesn't seem to track properly. Does anyone have a circuit diagram so I can check things to see if I can fix it before I scrap it for parts?

For my first real circuit I am working on a theremin. I wanted something that sounds good and uses easily available parts. Based on the Harrison simple Theremin.

So far I have only added a minijack connected to ground so that one is able to ground ones-self.

Planning on doing a second version with:

• More pots on the outside of the box (the trimpots inside are a bit annoying).
• A VCA controlled by a second antenna.

Does anyone have any tips for easy-to-tune frequency to voltage circuits?

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Regardless, some pictures of the result.

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[Power-supply board (+5V, +4.8-5V, ground)](https://preview.redd.it/eg9806jkoao91.jpg?width=4624&format=pjpg&auto=webp&a