Sequential Circuits Prophet 600 with cat

The Sequential Circuits Prophet 600 is a 6-voice polyphonic analog synthesizer released in 1982.  It was the first commercially available synth to include MIDI functionality.  The 600's analog voice's are controlled by a Zilog Z80 CPU. Though state-of-the-art at the time of its release, the Z80's specs means the synth feels limited and slow to respond to changes compared to modern instruments.

Luckily, synthesizer enthusiast & engineer GliGli has written new firmware for the Prophet 600, designed to run on a Teensy++ development board.  Replacing the 600's Z80 with a Teensy++ running Gligli's firmware adds a long list of features to the classic synth, including:

  • Increased resolution for sound parameters
  • Faster, smoother amplifier and filter envelope generators
  • New LFO function generator with a wider range
  • Dedicated vibrato
  • Unison detune
  • Mix Overdrive
  • Full Midi In control of parameters
  • Improved tuning procedure

Swapping out the Z80 for the Teensy++ is a relatively simple process, and can easily be reversed if you decide you prefer the 600's original functionality.  Some basic modifications will need to be made to the Teensy++ board before usage. 

Warning: By performing this modification, you take the life of your Prophet 600 in your own hands. Take your time and be careful with your vintage synthesizer!

What you'll need

Once you have all tools & materials ready, we can move on to programming the Teensy++.

This guide was first published on Dec 26, 2017. It was last updated on Mar 08, 2024.

This page (Overview) was last updated on Mar 08, 2024.

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