Version 0.2.3 from March 2021

VCO that I built for my modular synth drum machine project. It’s based on two LM358 and one TL072, deadly simple.


  • ✅ Square and triangle wave
  • ✅ Frequency range from 0 Hz to 3.5 kHz
  • ✅ FM input with variable attenuation
  • ✅ Current: +17mA (+12V), -7 mA (-12V)


This is the third PCB that I etched in lifetime. First one went into trash, second one works but soldering was a battlefield and this one is sufficiently fine 💡

Improvement Potential

See the comments on Instagram and Reddit.

Wait, there's more?

See all modules