Sovtek Mig-50 project

[Jim Coash]

Years ago I acquired a Sovtek Mig-50 amp.  A friend who worked for ProCo in the rear of the old Gibson building on Parsons Street offered it to me as part of a deal.  It seemed to work OK and I thought it sounded pretty good.  A pair of 6L6s with a pair of robust transformers in a clean case.  My son had a bass player at the time who fell in love with it so I sold it to him.  Two years later he told me it was acting up so I offered to check it out.  He seemed willing to trade it for an Ampeg rack mount solid state amp I had at the time and I decided to go with that.  When I pulled it apart I found that two of the pots had been damaged beyond repair and instead of trying to find replacements I took the advice of another Sovtek owner and replaced all the pots (6) with new CTS units.  That required a little surgery.  I also found evidence of arcing around the two large filter cap cans next to the transformer.  One can was grounded to the chassis, the other held off by a fiber washer that had broken.  I ordered a  pair of JJ radial caps in a slightly larger value and fitted them to the chassis.  I used the schematic to re-wire them properly.  The amp has a rectifier block and the rest of the circuitry looks OK.  All of the tubes are relatively new, not original.  Now I am ready to plug it into the Variac and see what happens.  I wonder if any of you have advice on what else should be upgraded before I do.  Jim

[sluckey]

I would fix it as is, replacing only parts that must be replaced to return to normal operation. Once I had a working amp then I would start musing over upgrades.