New-ish owner. Mark V 35 Tube explanation.

Fellas. First post. I've been lurking this forum for a few years, drooling over owning a Mark V someday. I got a new Mark V 35 combo about 8 months ago from the local music shop and could not have been happier. Gotta love 12 months, no interest financing. I love just looking at this thing, let alone hear it scream.

I have a bit of noise / hum in channel 2. Volume can be turned off on the guitar and amp, but I hear a hum / hiss noise. I want to troubleshoot the tubes. I've already had to replace a preamp tube. Need some help deciphering the tube diagram in the owner's manual.

I'm assuming V1-V10 means valve 1-10, but I don't know what the V1A or V1B mean and the manual doesn't explain.

Any help would be appreciated.

V1A and V1B are both inside the V1 tube. In other words, each pre-amp tube (AX7) has two different 'paths'. So, a single tube can be used for two different things. For example, the A side can be used for a gain stage and the B side used for reverb return (or whatever).

So, if your channel 2 is having issues, trouble shoot any pre-amp tube which has any mention of having a channel 2 gain stage (either A or B path of the tube).

Pull one preamp tube at a time and replace with a good one...till you find the problem.

That makes sense. That helps. Appreciate the advice. I'm gonna pick up a few tubes and see if I can get this fixed.

I have the same amp head, my set up is fairly noisy (saturation mod plus Tubescreamer in front) so I have the TC Electronics sentry in the chain. You can connect it so that the gate sits in front AND in the loop, and it does the trick very well.