Oberheim matrix 12

Synth Repair
1

Hi there!
Does anyone know where I can get screws for the wooden side panels for my Oberheim matrix 12? I also have an issue where some keys in the higher octave range don’t play, only when I press them really hard. I have changed the contact strips and cleaned the contact board. When the keybed is not in place it works fine, as soon as I mount it into the chassie some of them only work when I push really hard. Any ideas how to solve this?

Thank you and hope to get some answers soon

2

The screws are the same on many of the Oberheim keyboards of that era - they are a black flat-head machine screw, and the head rests in a nylon grommet with a steel cover (not sure what you call those technically). I don’t know the specs of the screws, but we have an OB-Xa in the shop right now, and I’ll try to get some more info on that and post again later.

I’m guessing there is some sort of flexing issue going on with the keybed, so maybe it is not resting straight when it is screwed in. You might be able to fix that by doing some shimming in certain places (using a flat washer as a shim on the mounting screws) - but you’d need to figure out where to put those shims to cure the problem. Another solution might be to shim the keys that are not playing - here’s a DIY guide for doing this, but with a different style of key:
https://syntaur.com/DIYdocs/DIY0017.html

Since your keys will be different from those shown, just focus on the fourth photo - I’m pretty sure that will solve your issue.

3

And if by chance you want to sell your Matrix, please let me know - I miss the one I had…

4

Thank you for the reply and grest tips!
I’ll try that with keybed, please let me know if you get any original screws, I can only find silver screws here in Norway…
I’m not selling the matrix, love it to bits and currently using it in my studio. Great piece of gear!
Out of curiosity, how much to the matrix retail for now?

5

I don’t blame you for keeping it! I believe they are selling for $5000 - $6000 these days.

6

I just saw one on Reverb for $10K or thereabouts.

8

The Oberheim screws --at least all those in my Matrix-12, OB-8, DMX, and DSX-- are all oval head, not flat head. I have a source for the screws and the metal washers, but not the nylon inserts (which is okay IMO since you don’t see the inserts at all and I haven’t found what purpose they may serve).

9

The nylon insert keeps the metal washer edge from digging into the wood. We carry a one-piece nylon washer that eliminates the need for the metal+nylon combination:
Washer, black, for end panel - Syntaur