The synthcard is a business card shaped synthesizer component!
The synthcard project is a collaboration of some designers who thought it would be fun to introduce synth-diy through handout self-build cards.
This project could be built into a module for your synthesizer, or standalone. Any power input, from USB to 24V can drive the triangle core VCOs to buzz how you see fit. Fun for circuit-benders or experimentation!
Demo video over at my insta . also listen to this thing go
The Schematic might help you in analysis and development.
Open source at synthcard.com and github.com/SynthCard
The parts you’ll need to find to assemble this PCB are listed in the BOM/Guide