Hoping DannDubbleEwe is still lurking... I just finished this yesterday, and -think- it's working. Just wanted to check something though. It's definitely a lot glitchier than I was anticipating. All the controls seem to do something, but I wanted to check something basic.
Do you get any sound from the Sub and Osc level controls when the Square control is at minimum? The Sub in particular. With the Square down, and the sub maxed, you just get some low volume glitchy noises that dont track with input, and I'm not sure if this is correct operation.
My assumption is that you need to have the Square level up a little to get the sub and osc sides to do anything meaningful, but want to check.
Also, and this may or may not be relevant, but I used 1uF 35V Tantalums as that's all I had in the parts box that would fit the spacing. They are polarised, where the circuit expects MLC NP, but I don't think that's an issue. Is it?
Also, I'll toss my vote in for a schematic. Even if it's only to ppl that purchased the PCB. I'm pretty sure I've built this error free, but would love to be able to confirm!!!