Back in 2017, Paul designed a board for the Cirrus Logic CS42448 chip, which provides gobs of high-quality audio I/O, and shared it on OSH Park. PJRC forum member tubelab.com picked up a few of them, and created a 6-voice polyphonic hybrid digital/analog synth.

The eventual goal is to fit the project inside a guitar, but for now, it uses vacuum tubes for its Moog-style ladder filter, giving it that signature fat Moog sound.

The aim is to achieve six notes of polyphony with three oscillators per note, requiring 18 VCOs. Control is via standard 1V/oct or MIDI. Check out the video below for an overview, and stay abreast of updates via tubelab.com.