I upgraded the firmware on my beloved-but-long-unused 1986 Oberheim Matrix 6r! These synths are the royalty of analog fatness. I love their sound. This is the result I was looking for:
It’s remarkably clean inside for a machine made in 1986. I acquired it used in the early 90s.
Just look at the bank of six voices. The CEM3396 chips are the VCF/VCA chips that give this synth its distinctive lushness. And made each voice circuit like 5x smaller than possible just a few years earlier.
The firmware upgrade was just a simple EPROM swap. Out with the old, in with the new! I got the chip from a chap on Reverb who’s using new EPROM stock (not old ceramic parts) The firmware update itself allows the Matrix to be used with modern MIDI patch editors and is a testament of amazing microcontroller assembly language hacking. Check out the page by the author of the Matrix firmware update. Thank you so much!
And the result is the same as before the upgrade: it still sounds glorious.