BUZZ on Vox AC4

[izodiak]

So Ive got this vox ac4tv. Ive been playing it for a year now.When I bought it it had no noticeable buzz just when blasting the full '11' setting.
Now every time I go pass, lets say 4-5 (the 12o clock) it gets this crazy buzz coming out.

With EHX Nano chorus it becomes even more noticeable(it changes with pedals in the line,the buzz).. I was thinking of changing the tubes, but I met some guy('sound engineer') that said it might be a problem with the whole amps power brick inside it (dont know how its in english correctly).He said he could give it a check, but I dont want to give the whole amp to a guy who could just fuck it all up..

It was my main amp, even took it to few gigs(mic'd), and loved the sound..but the buzz now is getting on my band mates nerves..through out the rehearsal a crazy bzzzz..

So any suggestions, try to change the tubes,give it to the guy ?

[Peter Bond]

I too have started getting loads of buzzing from mine. I thought that it might have been the power supply but have thus far done nothing about it.