Sovtek JMP-50 Transformer?

[SwedishWings]

I was cleaning out some boxes and found this OPT.

3.2K primary impedance, probably 50W. I hooked it up in a 50W amp with 2xEL34 and it sounds ok, but i think it lacks a bit low-end compared to the original Marshall transformer.

What puzzle me is the marking "SOVTEK JMP50-2", that was written on the box and the transformer. Did such a thing ever exist?

 

[neikeel]

Size, shape and wire colours look like Drake 784-139 to me.
Maybe pop the end bells off and see what it says inside?

 

[Pete Farrington]

What do the inked stamps on the side of the lamination stack say?
If they’re not cyrillic characters, perhaps that indicates that it’s not of Russian origin.

 

[PelliX]

My guess would be that it was a replacement part for a JMP50 which also worked in some Sovtek model. It's very common to see stuff labeled like that in workshops. "This is a XXX which is for a YY123 and/or ZZ345". Plenty of that going on among my spares, at least... As @Pete Farrington pointed out, any stamped/original markings would be more decisive. The two markings on the top are just stamps to indicate it passed some QC tests.

 

[XTRXTR]

Size, shape and wire colours look like Drake 784-139 to me.
Maybe pop the end bells off and see what it says inside?

Agreed same color codes as all my Drake 784-139, They weren't exclusive to Marshall.

 

[Xenrelic]

That's a Marshall 50 watt replacement OT, it's basically a replica of the Drake 784-139, but built by Pacific Audio Transformers with a 3.2k - 3.6k Primary. They make the transformers that went into Ken Fisher's Trainwreck amps and Howard Dumble's Overdrive Special amps. Electro-Harmonix (formerly Sovtek/New Sensor) carries them in their catalog and I have a spare one direct from Pacific to confirm.

 

[william vogel]

Those QC ink stamps do look like Pacific for sure and the endbell covers are American manufacture. If I saw the way the core winding looked with the endbell covers removed I could say for sure. Each manufacturer has their own unique outer wrap insulation and I’m familiar with them. It looks pacific though.