noisy amp

[dmcguitar]

How noisy should the mark v be? I have a few guitars and they all seem to have alot of noise in the higher gain areas... i would normally peg it as flourescent lighting or some other interference, but i don't play near them. Also when i play the same guitars through my 5150 II (a notoriously noisy high gain amp) i dont hear any of the static or noise.

(the 5150 has original preamp tubes, and i have replaced the power amp tubes a few times)

my mark V is brand new, and has stock preamp tubes, and 6l6s (i played it with mesa el 34s also, same result.)

do i attakc the preamp tubes, if so which one,
any other advice?

thanks
dave

 

[spawnofthesith]

I'd check your tubes, just get like a single new preamp tube, and start swapping it into each position to figure out the culprit.

I don't even use my ISP decimator with my Mark V anymore

 

[dmcguitar]

Should it be silent when in standby? Even with the fan off I hear a sound (from the amp head not through the speakers) that i would compare to the sound of shaking a lightbulb (when the filament is broken).

out of stdby, no guitar plugged in... If i tap the power tubes all i hear is the thud from the hit on the tubes (coming out of the speakers). I havent figured out how to access the preamp tubes... any words of advice?

I was trying to unscrew the front panel thinking that would give me easy access.. but it didnt seem to budge.

Again I am comparing this to my 7+ year old 5150 II, which gives me no odd noises... or hum when in high gain. (anyone know how to get a preamp tube outta the 5150 so i can try swapping that in the Mark V?

Thanks