Synth/FX DIY
The schematics here are released under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International license. See the Links page for further resources (other DIY pages etc.).
The circuits below use a star-rating system for level of complexity, with 1 star [*] being the simplest, and 5 stars [*****] being the most complex. Note that these ratings are somewhat subjective, and also relative– I’m not likely to post anything super-advanced, so even the most complex stuff here should be fairly accessible.
Guitar stuff (pedals/fx/etc.)
ReMock+ [**] – opamp distortion based on MockMan pedal
Noisemakers
NANDulator [*] – wonky CMOS noisemaker
Modutronic Messmaker [*] – lo-fi AM/FM noisebox
TrigPulser Mini [*] – CMOS NAND synth
Modular synth stuff
Sallen-Key LDR VCSVF [***] – simple +/-12V, 12dB/oct filter with voltage-controlled cutoff via homemade Vactrols
Lunetta Modules [varies, generally simple] – various CMOS logic-based synth modules
Misc.
Simple Signal Generator [*] – a very basic opamp-based tone generator
Circuit-bending projects
Kawasaki toy keyboard
Circuit-bent purple Kawasaki toy keyboard
A crappy video of my latest bending project: a purple Kawasaki toy keyboard.
Kawasaki toy drums
circuit bent Kawasaki Mega Deluxe toy drum pad
I added a pitch knob and 1/4