Marshall avt275 buzzing sound issue
Hi, I have avt275 about 12-15years old. Problem is when the is switched on there is an immediate buzzing sound, seems to be coming from the amp itself with all volume controls at '0', doesn't seem to be coming through the speakers and remains at a constant volume regardless of any adjustments with channels and volume controls.
The amp can be played through but the buzzing is loud enough to be a problem if mc'd up for stage use.
I've not yet stripped into it to investigate yet, but before I do was wondering if anyone might know what could be causing this and is it a common fault/easily fixable?