Prophet-600

Six-voice analog polysynth

The Prophet-600 is a six-voice analog polyphonic synthesizer made by Sequential Circuits in 1982. Each voice has two digitally controlled oscillators, and the synth stores 100 programs in battery-backed memory. It was one of the first synthesizers to include a MIDI interface. A Z80 microprocessor runs the instrument.

Platform

Z80

Community

Front view of the Sequential Circuits Prophet-600 six-voice analog polysynth with wooden end cheeks — Photo: Sequential, manufacturer heritage image, via sequential.com

Notes

P600FW is a hardware-plus-firmware replacement: a slightly modified Teensy++ board plugs into the Z80 socket in place of the stock CPU, so this is not a software-only update.

Firmware 1

P600FW

Firmware remake for the Prophet-600 that runs on a Teensy++ board in the Z80 socket. Adds faster envelopes, unison with detune, a rebuilt voice assigner, MIDI out, SysEx patch dumps and arpeggiator clock sync.

by GliGli, Imogen

ActiveSource: openGPL-3.0-only

Distribution: Prebuilt image you flash yourself

synth-engine
polyphony
midi
lfo
performance
bugfixes

P600FW version history
Version	Date	Notes
main @ 20285dd (Teensy programmer HEX)	2026-04-13	Latest commit; alpha series, no tagged releases.
Stable 2.0	undated	Last stable release on the project page; marked outdated there in favour of the 2022+ series.