Oberheim OBMx repair

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Dollboy
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Oberheim OBMx repair

Post by Dollboy » Tue Dec 10, 2019 1:59 pm

Hi. I have a (much maligned) Oberheim OBMx 4 voice which needs repair. I’ve had it for years, and before anyone weighs in with “ditch it” or similar advice, I have to say I love it. It doesn’t quite sound like anything else and that is a definite plus in my studio. The problem I have is with the second voice card, bought years after the synth when you could still pick them up for a couple of hundred quid. One voice is nearly always out of tune and sometimes makes no sound and one filter on one voice doesn’t sound (I forget which one).

I have had a few people look at it over the years but no one has ever even dented the problem. I’ve had it recalibrated and the firmware upgraded but it remains unfixed. No one has ever really been able to tell me what’s wrong with it. I can always use it as a monstrous monosynth and often as a two or three voice poly but can really only use all four voices for the SFX kind of sounds.

So my question is can anyone recommend a technician who might be in with a chance of diagnosing and fixing the thing?

nini54
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Re: Oberheim OBMx repair

Post by nini54 » Wed Jan 22, 2020 6:43 pm

Hi!
I have the same kind of issue on one of my voice card. I contacted Tom Virostek who has designed voice card from scratch for the OBMX : http://www.straylightengineering.com/pr ... 2%80%A2mx/ . Even if he doesn't sell voice cards at this moment, I thought he would be the best to solve the problem and had a great contact with him.

Right now I have an other issue on my OBMX (some notes are untuned on all cards ((4 voices)) and tuning table are not working) which makes me think I should first solve it before repairing my voice card. And as I live in France it's a bit complicated to send my obmx to him. I try to understand first the origin of my tuning problem (wrong os2 eprom? calibration to be done?) . But I believe he might be the right person for your problem.

Nicolas

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urgetoplay
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Re: Oberheim OBMx repair

Post by urgetoplay » Sat Feb 08, 2020 2:58 am

So, a few things worth mentioning. The voice cards have different revisions and you need to make sure they match up. Second, there was a lot of grabbing whatever was on the shelf when these machines were assembled. Pull your voice cards out and compare them component by component. Quality control suffered with these as well. Mine had one component in backwards ! Good luck !
Resonance in Humans is called Empathy.

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