Pops and hums in 10W and 45W

[daverose]

Hi Mark V experts. Been having some intermittent trouble with my Mark V. Whenever I run in 10W or 45W I've been getting these very loud pops and a very loud humming that comes and goes. Sort of bangs in and bangs out. It happens on all 3 channels. If I switch whatever channel I am using up to 90W and then back down that usually fixes it but it usually does it again within a couple of minutes. I thought it might have been the Rectifier tube but I've changed that and it didn't help and it happens even when I have 45W mode set to Diodes. Anyone have any ides?

Dave

 

[jc986]

It is probably a tube-related issue. If you have spare 12ax7, I'd try it in the V1 spot since V1 affects all channels.

It could also be a sign your power tubes need replacing.

 

[fr0sty]

I would replace all the power tubes.

 

[daverose]

I had swapped V1 for another issue but that didn't solve it. My instinct says it's power related but it just seems odd that it works fine in 90W mode when all the tubes are on. I'll swap the power tubes and report back.

 

[Monstercastle]

I would think it's power tube related. If it were preamp I would think the pops would be heard on any setting.

 

[daverose]

Thanks all. Finally did the tube swap and it solved the problem. Even better than that I put in EL34's instead of the 6l6's and I'm loving them! They seems to have taken some of the harsh edge off the sound. They also seem a little more forgiving of my sloppy technique too! Thanks for the advice.

Dave