A Bit More

An open-source polysynth project takes the spirit of the Crumar Bit series in a new direction. It pairs an RP2040 controller with digitally controlled AS3340 VCOs and autotuning, aiming for a more stable and refined analog-style voice architecture.

This prototype is an 8-voice bi-timbral, polyphonic dual-VCO keyboard synth with portamento, octave switching, oscillator sync, dual LFOs, and a white/pink noise source. Its filter section is based on Matrix 12-style switching filters and offers 16 filter types, while MIDI in, out, and thru support make it practical as a modern hardware instrument.

The project is documented in a public repository, though the schematics are still incomplete and some code remains to be finished. It is a compelling look at a hybrid synth design that blends classic architecture with digital control and autotune.