This was my first build and I was soo happy when I got it to work. It takes a 9-12V input through a barrel connector and has an on/off switch with LED indicator (which I had to rewire twice to get the right indication XD)

It is an Atari Punk Console a.k.a APC with a 555 LFO – worst design ever, don’t use in a modular or you’ll get serious bleedthrough issues, and two filters, one RC lowpass with a vactrol and a pot in parallel and one RC ladder to soften the squarewaves which works fine.

I still use it to test modules if I need a signal either audio or gate.