Preamp tubes, or that and more?

My Mark V 90 watt is being noise on channel 2 and 3 in the 45 watt mode. My reverb is also starting to get a really loud hum the longer it is engaged. Do these all seem like preamp tube issues, or could it be other things as well?

Pre-amp tubes are the easiest place to start. look at your tube chart and start w/V1 - get a new one and swap it for whats there, if the issue is resolved then you are done, if not, go to the next one in line and repeat. If none of the pre-amp tubes seem to be the culprits, then try a new matched set of power tubes - the whole set. Make sure you note the tube type for the reverb driver, it may not be the same as the signal path preamp tubes. Process of elimination is a slow-but-steady way to see if the tubes are causing the noise.

I had a rectifier tube do weird **** to me on 45 and 10 watt mode not too long ago. I would check that as well.

I just had a recto tube crap out on me and the 45 watt setting on all 3 channels went completely dead.
I do have a new hum going on as well but I hadn't made the connection to the reverb circuit. Just hum.
So now I sit and wait for FedEx to bring me a new glass bottle of joy. (and a back up)

I will say this … when she went … she went big. The old recto tube tests completely dead on the tester.

All of the other tubes were still filled with joy.