Buzzing/Fizz on Sustained Notes?

Hey guys, new Mesa owner here.

I just picked up a used Dual Rec (2005 model), and I'm running it through a matching 4x12 cabinet. I love it, the pick attack sounds vicious as all hell, but when I let a note or chord ring out on channels 2 or 3, I get a pretty bad buzz/fuzz sound. I'm not sure if the sound is fault of the head or the cab, and I'm trying to find out what the culprit is here. Anyone have any ideas?

You might wish to turn down the presence, find the right treble control setting and slowly bring the presence back up. The amp produces a massive amount of harmonics, which sometimes translates as fizz/buzz.

You might also consider adjusting your pickups. I set both sides of the bridge pickup at 2mm from the bottom of the E strings when fretted at the last fret, and the neck pickup at 5mm. When too close, the sound is blatty and weird harmonics occur. Much too far, it sounds thin.

The thing is that I can bring the presence all the way down and it still buzzes. I hadn't adjusted the treble while doing that, but I'm starting to think that it might be an internal problem with either the amp or the cab. After Googling the problem a bit, I think the fact that I'm running the output control relatively low (9 o'clock or so, with the master volume around 12 o'clock on all three channels) may also have something to do with it.

Try setting the channel master of the loudest channel (usually the one on Modern mode) to somewhere around 9:00-10:00, then set your levels by adjusting the other two channels (and if you find your loudest channel too quiet, turn the other channels down instead of raising that channel up).

Thanks for the advice guys, but I think it's the cabinet that's at fault here. I tried both suggestions, and channel 3 still sounds like a goddamn bee hive. I noticed on channel 1 that if I hit the E string hard, I get that same buzz, and that it's probably a problem with the speaker.

I get a different buzz on Ch2 Vintage sometimes, yesterday being a time. I think my guitar was the culprit. The sensitivity of the amp input is extremely low and can easily pick up resonance which causes rattles and transfers into the pickups. My neck-through, humbuckered, LTD with walnut, mahogany, and maple ends up sounding like a manhandled, bolt-on Squire with a bad joint. Later it will change with the weather and be fine.

Shove some foam or a blanket under your cab or between it and anything it's close to to see if it is transferring vibrations. And I'm sure you considered it, but check the mounting screws on the speakers.

Okay, so it seems like this problem occurs when I turn the gain up past about 9 o'clock on channel 2 vintage. I'm guessing it's an issue with the tubes, since two of them don't glow at all when the amp is turned on. Anyone know what the specific problem could be?

I had my V3 go bad and i noticed that the tubes V3 and V4 weren't lighting up, changed V3 and all is good.

Power tubes can sometimes rattle. I had a pair that did the same and I replaced them. You can take a pencil and tap on the tubes and see which ones are causing it.