Substitute transformer for Sovtek MIG 50?

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beasleybodyshop
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Substitute transformer for Sovtek MIG 50?

Post by beasleybodyshop »

So, I let a buddy borrow my MIG 50 for a couple of weeks while he was out on the road. Brings it back to me yesterday saying it kept blowing fuses.

He stuck a 10 amp fuse in where a 3 amp fuse was rated :evil: :evil: :evil: :evil: :evil: :evil: :evil: :evil:

Power transformer is toast. Aside from being madder than hell right now, I don't want to get a Mercury Magnetics transformer for it (they are the only ones I know of that sells a drop in replacement) as they are 265 dollars. And my.....friend....is broke.

Looks like the secondary is approx 300-0-300 with a 3.15v heater winding and a 60v bias tap. This thing runs a pair of 6L6s, so i would only need like 3/4 amps for the heater. Any reason i couldn't sub in a Fender bassman transformer?
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wyatt
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Re: Substitute transformer for Sovtek MIG 50?

Post by wyatt »

IIRC, the originals just used 5F6a Bassman transformer specs (uncompensated for modern wall voltage...which was by the B+ was always so high in them). So, you can certainly use a Tweed Bassman PT, if it fits the chassis, but if it's been compensated, you might find you B+ voltages lower.

You need 6.3V@3 amps for the heaters. Each 5881/6L6GC uses .9A of heater current. And each 12AX7 uses .3A...(.9+.9+.9= 2.7A)
beasleybodyshop
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Re: Substitute transformer for Sovtek MIG 50?

Post by beasleybodyshop »

Thanks, i meant 6.3vAC. MCI sells a tweed bassman trafo that im probably going to spring for.
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Stevem
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Re: Substitute transformer for Sovtek MIG 50?

Post by Stevem »

If the amp does not have such and to not have this failure again, install a inline fuse in the center tap feed to the OT and install a 1/2 amp fast blow type fuse in it.
And be dam sure to tell your buddy that fuses never blow for no reason!!
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