Analog Voice Card for a Polyphonic Synthesizer PCB

What is it?

PCB for a fully analog voice card with pole-mixing multimode filter. Multiple cards like this are typically used in a polyphonic synthesizer. It can also be used in a monophonic setup, there is only minimal additional circuitry like some pots, input jacks and voltage regulators required.

Specs

- Single oscillator with saw, triangle and pulse output

- Multiple VCAs to blend between different input signals, a main VCA for the envelope and a panning VCA for stereo output

- An additional external input that can be mixed in, eg. a noise signal

- One envelope generator for the VCA. It can modulate filter frequency and resonance, also with an inverted signal

- A pole-mixing multimode filter with 8 filter responses

- There are multiple options two switch and blend between different signals and filter responses

- PWM, FM and synchronization inputs

See https://github.com/polykit/polykit-x-voice-card for technical details