Loud amp buzzing when turned on?

[Metalmann13]

When I turn on my Marshall AVT150H Valvestate amp I have noticed a loud buzzing noise. It happens once a day, but never more so maybe the issue is a component that has to warm up. I can stop the buzzing by turning it off and then turning it back on about 2 times. I've had this issue for a while now and I am the second owner. After I get the buzzing to stop the amp plays normal, but it is annoying every time I turn on my amp for the first time in a day. I just recently replaced the preamp tube and the amp stayed the same so the tube is not the issue.

-Thanks

 

[Salos]

Buzzing problems I've had were due to transformers, not tubes so it makes sense the tube rolling didn't fix it. I'm sure someone more knowledgeable can give you direction on how to address/test it.

 

[cardinal]

This amp has a solid state power section? So no output Transformer, I think. An amp like that may have a power transformer. Not sure if that could be the issue or if just some other components (filter caps?) have drifted out of spec or whatever.