So I started asking some questions in the ultimate tube guide sticky since I'm afraid something is wrong with my single recto, and I suspect it has to do with the output transformer, but I'm not an amp techie, so it is only based on things I've read. I'm looking for some more insight here, and as a last push, I'll probably end up calling Mesa to see if they can trouble shoot with me.

First of all, I did something bad the other day when I got my new cab and speakers. I inadvertently hooked up the leads to the input jack incorrectly. I turned the amp on, heard nothing, cranked it up a bit (1 o'clock master volume), hit a chord and heard nothing so I knew immediately something was wrong. I took the speakers out and lo and behold immediately saw my error. I was quite angry at myself already.

So I hooked up the speakers to the cab correctly, and turned the amp on again. However, I noticed that the amp had a huge drop in volume and even when cranking the amp, the loudest it got was equivalent to if I had the master volume on around 8 o'clock. I figured something might be wrong with the power tubes (was this a correct assumption?)

I swapped out the power tubes for an old, but not busted set I had and found that the amp's volume does increase with the master volume, but after a certain point (10 o'clock-ish) the volume jumps up and down randomly. I had suspected the problem was the output transformer, since sometimes when that goes, it takes out the power tubes as well, but this set of tubes seemed to be doing fine.

Does anyone know some major causes for the amp to jump in volume sporadically... or if anything else is suspect about what I described. Sorry for the long post, but I wanted to give as much information as possible. Thanks for reading this and any advice you have to give.
Epiphone Les Paul Standard (with EMG 81/85)
Mesa/Boogie Single Rectifier Solo Head Series 2
Marshall Valvestate 8100
Lopo Line 2x12 Slant w/ WGS v30 clones
Boss MT-2
Danelectro Fish and Chips
I would have guessed powertubes too. Did you replace the driver(PI) with a different tube to check that too? Also, you are using speaker cable, not regular instrument cable, and you definitely have the ohms matching correctly right? Nothing in the fx loop while you are testing. Might as well check your guitar to amp leads too.
"The fool doth think he is wise, but the wiseman knows himself to be a fool." - W.S.
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