Mark V 35 Combo noise

[PHYX]

On my channel 2 it’s very noisy and when I have the master like at .5 to maybe 1 at 10 watts it’s very noisy and the loudest sounds like it on max of the amp. Channel 1 seems to be ok. At 10 watt setting it have no problem adjusting my volume low. As for the channel 2 I can switch to 10, 25 or 35 watts and it supper noise and loud. Pull one power tube off one at a time but nothing. If I pull the two outside tubes out at once and leave two center ones in no noise. Ideas? PS_ I just remembered that when I switch channels on my foot switch it pops pretty loud. Again this is on my Mark V 35 combo

 

[user 21540]

Has the sound developed recently? There's a high chance it's related to a preamp tube. The best thing to do is sub a known good preamp tube in suspected trouble locations to see if tha eliminates the noise. V1 is always the likely suspect but on a complex channel switcher this may not be the case. Consult the manual to see the tube task layout. Not sure about the channel switch popping.