Ht Metal 1 Buzz

[MattBromage]

Just picked up a HT Metal 1 head, and when I switch the power on, there's a buzzing sound that I can only compare to a muffled tattoo gun. Anyone had this? Is it anything to worry about?

[hotrabbitsoup]

does it change if you put the amp in a different location, as in its picking up noise from something else. if so, then its ok.

if not then something is likley amiss. some noise is normal for a tube amp but the buzzing you describe is not. an easy check is to change the tubes. make sure you are very confident in knowing what you know about safety and electronics before opening it up.