Korg reissued the PS-3300 and I badly want one. It's a classic instrument, with three independent synth sections, an oscillator per key, and a low volume manufacturing run and premium price.
Fable and I built the PS-3100 instead. In software. Play it here.
The project is mostly an exercise in letting AI do the tedious parts of circuit archaeology. The first step was a harness that reads the service manual schematics board by board and emits SPICE netlists. After that, every stage of the pipeline exists to check the one before it.
ngspice simulates each netlist into reference frequency and transient responses.
SymPy derives the transfer functions and control voltage laws symbolically, so theory and simulation have to agree before anything moves on.
Faust implements the real-time DSP, fitted to the SPICE curves and continuously re-validated against them to keep the filters within ~±0.5 dB of band centers.
The last piece is a browser based playground. Every board resonators, signal generators, filters, envelope generators, chorus, mixers etc compiles to WebAssembly and gets its own page: sweep it, scope it, compare it against the SPICE reference. Then the boards compose into the full instrument.
None of the stages are novel on their own just tedious. Pretty amazing to see AI run the whole process of turning schematics into netlists, then generating the test rigs that keep the DSP mostly accurate against the physics. I had quite a bit of fun spending time listening to the output sounds instead of fighting SPICE/Faust config manually.