Everything is finally falling into place

I am beaming like a proud father. For you see, my prodigal Matrix 12, beloved and yet wayward, has returned to me.

It’s difficult to express: I really am overjoyed that this is fully-working. I bought it this summer from a guy in Texas who claimed it was in perfect working condition. It was the culmination of years of looking for just the right synth, and it was the most money I’ve ever spent on a synth. I think it was about three times the amount I’ve paid for any other synth. I sold a TB-303 and a couple other things to scratch together the funds and then waited nervously for the day that an enormous box showed up on the porch.

The Matrix 12 is Oberheim’s last great synthesizer. The interesting thing about Oberheim is that they have a relatively small catalog of products, but almost every synth is well loved. ARP, Moog, Sequential Circuits…they all had some pretty embarrassing flops along with their successes. I feel like Oberheim didn’t really ever make a bad synth. Consider Tom Oberheim’s string of successes. He begins building the little SEM modules in the 70s. They are awesome. He packages them together into some of the first polyphonic synths: the 2-voice, 4-voice and 8-voice. These are utterly devastating synthesizers. He makes the various classic OB-X and OB-8 synthesizers, which is basically the sound of 80 arena-rock synths. Then Tom move on to the cult classic, the Xpander, which is the closest that the 80s were going to get to a modular synth in a box and predates stuff like the Nord Modular. And then finally, he goes out on a high note, releasing the Matrix 12, a strange and very beautiful analog synthesizer. Truly, the last scion of a great line. Understandably, I couldn’t contain my excitement as it traveled from the Lone Star State northward toward me.

It was, indeed, in nice shape. But I quickly found that I couldn’t get it to respond to any MIDI input. Everything else seemed to work. This is a complicated synth and I assumed that I was simply doing something wrong. I posted some pretty lame-sounding questions on the Oberheim Matrix 12/Xpander Yahoo group. No leads. I talked with the seller, who of course claimed that he never had any problems with the MIDI functionality.

As so all summer, it was a bittersweet purchase. I grew to really like the synthesizer itself – the sounds, the flexibility, the controls, the look. These are hard to find, and I felt like I got it for a reasonably decent price (despite it being the most expensive synth purchase ever). I bought mine in May. Another didn’t show up on eBay until a couple weeks ago. That’s a long time on eBay years.

But I’m so reliant on MIDI that I found myself shying away from using the Matrix 12 in songs. I recorded a few parts live, but I wanted to be able to sequence different parts and take advantage of its 12 multitimbral voices. That’s part of the Matrix 12’s draw: to be able to basically synthesize an entire song live on it.

I considered trying to repair it myself. First, it took ages to track down the schematics. This is truly one of the most different synths to find schematics for. There simply are no physical copies. I finally paid too much for some mediocre PDFs of the service manual and schematics. Hey, I was getting desperate. Once I had the schematics in hand, I gingerly opened it up and began trying to troubleshoot it. A couple hours later, frustrated and even more confused, I put it all back together and gave up. To add insult to injury, I discovered that my elite troubleshooting skills had somehow taken down the MIDI output functionality too. Great.

So I finally just called up an old coworker of mine who is a wizard with old 80s digital circuits and begged him for help. It took him all of one evening to hone in on the problem. Turns out the opto-isolator chip had gone bad. As luck would have it, I happened to have an extra sitting one from my recent MIDI to DIN-sync project (it’s the white chip in the pictures).

Of course, no repair story can be quite as simple as that. By the time I got to my friend’s house to pick up the synth, he had pushed a wrong button and accidentally corrupted the patch memory in it, or something. I don’t even know how that’s possible. So although the MIDI input certainly worked, the synth sounded like an awful atonal nightmare. I brought it home and reloaded all the factory patches on it. That helped somewhat, but there was still a mysterious and heavy vibrato on every note. I checked the routings and re-checked them, but couldn’t understand it. I reset the synth to its most basic patch, and it still had that monster vibrato on it.

Then I happened to bump the modulation lever, and the vibrato briefly cut out. I wiggled it around and found that the lever seemed to be the culprit. So I tore it apart again, sprayed the mod lever’s pot down with cleaner and wiggled it all around for a while. That did the trick.

Earlier this summer I began a mission to clear out all the non-working equipment and simplify things. I wanted to just have stuff that fully worked and that I really liked and used. I’m almost there now. I’ve got the Matrix 12 and the Minimoog at arm’s reach. I think they are a nice complementary pair, bunked one on top of the other. One is a monosynth, the other has twelve notes of polyphony. Both have great sounds, but in very different ways. Not that they don’t have some overlap, but the Mini is great for punchy, snappy parts, and I can easily adjust and evolve the sound as I play. The Matrix 12 excels at strings, pads, bizarre sound effects and slowly-morphing atmospheric patches. Truly the perfect pair!

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