MATRIXSYNTH: An Oberheim Matrix-24 was Almost a Thing

Tuesday, March 12, 2019

An Oberheim Matrix-24 was Almost a Thing

Someone on the Analog Heaven email list noticed the Oberheim Matrix-12 and Xpander shared the same voice boards and that "the ribbon cable from the Processor Board to the Voice Board(s) has enough signals allocated and named to drive 4 Voice Boards. The two extra traces aren’t connected, and the firmware doesn’t support them, but it seems that somebody was thinking of a massive 24-voice Matrix.". The Xpander of course is essentially a six voice desktop version of the Matrix-12 with added CV. There was also a CV extension mod for the Matrix-12 that added the CV jacks on the left side panel. Someone else reached out to one of the developers of the Matrix-12, a gentleman named Marcus. The following is his reply:

"Yes, my original dream was to someday make a Matrix-24. When designing the Xpander we put a jumper on the voice board to allow up to four voice boards to be addressed independently, in anticipation of future models with more voices. In the Matrix-12 we used the first two addresses to create a 12 voice. The Matrix-12 main board was set up to address four voice boards, so that no hardware changes would have been required to make this work (other than the power supply would have needed to be beefed up). The intended UI was to have the voice select button (the one that has two LEDs labeled VOICE 1-6 and VOICE 7-12) toggle through four states to select between the four boards if we were going to make one without any changes to the front panel either (though other UI approaches would have been better).

Although the hardware was ready to go, a lot of work would have been needed on the main processor firmware, since that’s where all the editing, patch memory, and voice assignment work lives. Never did get started on any of that, and never had the chance to even make a prototype. I left Oberheim in April of 1985, and no one else pursued it as far as I know.



  1. Kind of makes you feel all moist and slippery, doesn't it?

  2. Thanks for copying the reply here - as I read it on AH I thought "this is a bit of synth history [and potential future development] that needs to be remembered!"

  3. Marcus Ryle, perhaps?



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