#1
i need to test my tubes, iv'e got buzz/hum, other web sites say pull them out one at a time untill you find the one that makes it stop. dumb question but how does that work... wouldn't the amp just stop working entirely with out a tube in it?
If its not fender than whatever]
#3
Tap the preamp tubes with a pencil with the amp on. If you can hear the taps through the amp, replace the tube.
Bad power tubes don't generally buzz (sounds more like a ground issue than a tube problem to me), but you can always replace them and see if that helps.
#4
they can still be producing hum and buzz with out being microphnic right?
If its not fender than whatever]
#5
Buzz? No.
Hum? Maybe. You could buy a couple preamp tubes and try swapping them for yours.