Firmware Update Brings New Features To Classic Sequential Circuits Prophet-600 Synthesizer

This video, via Martin Ottesen, demos P600fw – a CPU/firmware upgrade for the Sequential Circuits Prophet 600 that gives it new capabilities. 

“With this update the synth is one incredible analog polysynth,” notes Ottesen. 

For more info, see the project site.

13 thoughts on “Firmware Update Brings New Features To Classic Sequential Circuits Prophet-600 Synthesizer

  1. Very nice features added including dedicated vibrato, unison and MIDI clock sync.

    Remember folks, people who improve synth firmware always go to heaven!

  2. I have this and it makes a huge difference!
    Hidden menus are a little less intuitive and it still has some glitches occasionally but all in all it makes the synth WAY more stable and usable.

  3. Wow. Sounds really interesting. I haven’t been able to find the finances required for this? Is it just a contribution? Excellent.

  4. Similar to these mods to the P600, I’ve been developing my own set of improvements for the Korg Polysix. I started by replacing its key assigner CPU with an Arduino and by replacing its stock keybed with a Fatar. Between these two changes, my Polysix has fun things like Aftertouch, Portamento, a sustain pedal, controllable detuning in unison/chord mode, and (the latest!) velocity sensitivity for the VCF. Pretty sweet.

    It’s so fun to hack these old analog synths using modern open-source technology.


    1. probably worth doing some other synth, the Polysix has been well sorted with the Kiwisix mod already. a complete firmware re-write.

      Maybe re-write the JD800 firmware? theres no Osc Sync, No Unison, and no CC midi out for any of the sliders! that would make a big diff! You would go to Heaven for sure!

      1. The mods that I did to the Polysix are not available on the Kiwisix. It doesn’t offer aftertouch, or portamento, or controlled detuning, or velocity sensitivity. My mods give me these features. And the hacking is fun!

        After finishing the velocity mod, I’ve also got a “Drive” mod underway and I’m looking at adding new LFO waveforms.

        Smell the solder!


  5. This is insanely cool and after seeing that he is currently working on adding MIDI Tuning Standard support to the Prophet-600, I think this guy should be first in line for a MacArthur Genius Grant to help further his humanitarian work.

  6. Would love to see this kind of CPU upgrade be developed for an Oberheim Xpander! I’m an owner and user and am surprised that no one has turned their attention to this, unless Gibson’s historical misuse and mismanagement of the brand makes the development of such a thing a real legal liability for the developer…good ol’ Henry J/Gibson isn’t known for his love and respect for all things Oberheim. If its weaknesses in terms of attack times and so forth lie in the aspects of the instrument that are CPU-dependent, then a developer who can address them with a modern upgrade would be making a major contribution to the art of synthesis here as well…more filter modes (or at least a greater ability to configure), LFOs that clock to MIDI, I can brainstorm quite a wish list. A CPU-upgraded Xpander would be unbeatable.

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