Noise at start-up of one mono-block
I have a pair of Quick-Silver mid-mono monoblocks. Over the past couple of days, each time I switch the left one on and after the tubes heat up, (about 5 to 10 minutes) the amp makes a loud buzzing sound.
If I switch the amp off and on again then the buzz stops and does not come back until the amps has been shut-off over night.
Any ideas on what the problem could?
The amps are less than a year old.
The tubes are biased and the bias holds.
The noise occurs even if the pre-amp is off.
Is this the result of a faulty input or driver tube?