Amp tone help

[gordon]

Thanks for the advice. I'll check it out tomorrow morning. I briefly took a look inside today and didn't notice any obvious burn marks or anything. A transformer would be bad, unfortunately they do hum more than they should (my understanding is that they should make no or little noise...)

[gordon]

I believe the smell is coming from the board near where the tubes are connected. There is some black gunk around a solder that looks fairly new. Since this spot is near the tubes (not actually part of the solder on the tube connections) could it just be heating up and giving off a burning type smell?

[jmaf]

By black gunk I assume it's excess rosin from the solder? Or is it like some heat glue gun / sillicone? Unless the tube base is in direct contact with this, it would not generate enough heat to actually cause anything there to smoke o be noticeable from more than a foot away from the amp.

The trafos should not be humming noticeably loud, magnetostriction is barely noticeable at these levels of power. Unless the laminates are loose or they've gone conductive and you've got excessive eddy currents, then it may be the case you've got a bad tranny there. I would not want this to be the case, they're the most expensive parts in there.

[g1]

Could be some kind of arc-proofing (AKA "liquid tape" or "black goop") covering a part of the board that was burnt/arcing. Possibly it is still arcing under the goop.

[dumbassbob]

With the amp unpluged set a multi meter on the steel plates of Transformers If all is ok there will be no reading,if there is a bad trans,and the things overheated it will read Ohms.