This was a quick weekend brush-up on my PCB manufacturing and soldering skills after 4 months of studying and finals-writing (no time for my favorite hobby!). It's a 556-based Mim's tone generator which I managed to stuff into a cassette I found lying around (even the 9V battery fit!). It is pretty fun to play with and can be listened to without amplification on the output and a pair of headphones. It is the successor to my previous Atari Punk Console.
A possible expansion is a R2R keyboard in place of the potentiometers, allowing for more musicality.
Attached is a sample of what the little synth sounds like, I would describe alot of it's music as "80's videogame car sound generator"