use of Melody On/Off button in Casio SA 76 77 78 || with demo - YouTube
Trying to do this pitch mod on a casio ka-20, similar to the sa-2, but to not avail. Does wire gauge matter when working with timing crystals? : r/CircuitBending
Vintage Casio Model SA-20 100 Sound Tone Bank Electronic Keyboard Piano 23.5" | eBay