I like the sound of this one. It sometimes remind me of the 303 acid sound. It isn’t quite the same but it can lean to that specific sound. It was a small disaster to build. Lot’s of parts and I just don’t like it when the resitors are standing up. But just because of the sound I might build a second one. This module is open source and on github.
https://youtu.be/gA3WmvU1QJ8 (not my video)
Difficulty to build: Hard