On: Yamaha DX7 chip reverse-engineering, part V: the output circuitry

[TonyTrapp]

Maybe the closest free plugin, but it's not on the level of accuracy as Plogue's Chipsynth OPS7, which is bit-accurate. The author has an interesting video here, with more to come hopefully: https://www.youtube.com/watch?v=XJ97iXQrqzw