Here's a unique & awesome chiptunes lot on ebay.
I have various 80s sound chips + arduino + diy kits + extras.
Here's your chance to play with different sound chips and/or learn diy synth electronics.

I also have this cool lunetta synth pcb.
You can make cool sounds with this modular synth and use an arduino to drive it.

Also got a moog synth meant for experimenting and playing with an arduino

And a korg synth which is also meant to be hacked with an arduino