B-15 makes noises after prolonged use. What's wrong?

[winegamd]

First step is to try swapping known good tubes. If that doesn't work, and you are not confident with a tone generator, oscilloscope, and multimeter, then take it to a tech.

 

[anotherhomeysan]

There has to be a goood amp tech floating around detroit.

Get that amp serviced. Could be the sign of a few things, but you want to make sure everything is in good shape so you dont fry a transformer. Your repair could easily be something under $100 with parts and labor by a reasonable tech. If the amp fails in certain spectacular ways, transformers can cost up to $260+ before getting installed.

Amp tech in Detroit:
Motor City Guitar about an hour north of Detroit is awesome. I'm from California but I know a tech (Scott Russell) who does tube amp repair for them. If you do find yourself looking.
Just don't head to the bass area... I spend hours there every time I am in the area, they have too many goodies.

 

[SirMjac28]

I don't have any technical knowledge but I would be willing to take a look at it if you pay shipping and it may take a year or two until the problem is corrected but I promise you I won't send it back to you until it's been thoroughly worked over.

 

[Edword]

Thanks for all the suggestions guys, I'm off to the local amp tech.

I'm sure he'll change the AC cord to a 3-prong plug in addition to fixing the noise. That 2-pronger makes me nervous!