Old Monkey Ward amp: way high plate supply

[Gtr_tech]

50s era Monkey Ward amp marked "Deluxe 2546" on the front panel. Mfgr'd by Clark Radio, very well built. Its a p-p cathode biased 6L6 arrangement with a 5U4 recto. Did a complete recap and replaced some open/drifted resistors. When I powered it up I got a plate supply of 565vdc at the first filter cap (cap input supply)

I would expect 400v *max* for K biased 6Ls. My first thought was that the CT for the plate winding was open, but that checks out. Grounding is solid.

Seems like a strange failure mode for a pwr xfmr.....

[Prairie Dawg]

Does it have a field coil speaker?

[Gtr_tech]

Nope....alnico. Anyway....I replaced the pwr xfmr and now get 450v unloaded, so that should get it back to where it needs to be.

Now you got me thinking. This *may* have had a FC spkr to begin with, and someone could've replaced it with a PM without subbing in the appropriate value resistor to drop the same voltage as the coil would have. Although it looks unmolested with the exception of a couple film caps that were replaced. Oh well....whatever the case, its back to normal now.