polyUanalog

When scientists decide to build a synthesizer, they think modularly. The polyUAnalog is an open-source hybrid analog-digital polyphonic synthesizer that lets you scale from a single voice to over 120 voices, with each voice built around the AS3397 synth chip featuring dual oscillators, a four-pole lowpass filter, and voltage-controlled amplifier. A Raspberry Pi handles the digital side of each voice, managing tuning, LFOs, and envelope generation to keep everything locked in and expressive.

Presented as a working prototype at SynthFest France 2024 by researchers from the University of Angers, the polyUAnalog uses a conductor board that orchestrates individual voice cards, making it genuinely scalable and hackable. The modular architecture means you can build exactly what you need—whether that's a lean mono synth or a sprawling 10-voice setup like the prototype, or push toward the theoretical maximum. MIDI input lets you control it from external gear.

Because it's fully open-source and available on GitHub, you can modify the design, build it yourself, and even develop it further. The developers ask only that you credit them if you take it commercial. This is synthesis for people who want to understand what's happening under the hood and have the freedom to shape it themselves.