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Vintage Synth Repair

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Isolation transformer / variac during restoration

2013-09-13 by Tom Butcher

Hi list,

I'm getting my feet wet with restoration and repair. I mistakenly bought a broken Oberheim DMX from Ebay and wound up accumulating some more parts that should give me enough to get it going.

I've read in various places that it's a good idea to use a variac or isolation transformer with voltage control to gradually bring up the device after cleaning and drying etc. Is this a good practice? I found an isolation transformer with voltage regular for about $200 I'm considering buying. From what I can tell, this would give me the ability to gradually increase the AC voltage to the power supply as well as circuit isolation from the AC mains.

So if I have that thing there's no need for the variac, right? Seems like the advantage to the variac is just more current capacity.

t

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