1994 Rev G....Keep or return? (possible PT issue)

I had been on the lookout for a early Dual Rec at the usual sites and noticed one with small logo and attached powercord at a Guitar Center in the used site. I called and talked to them about it. Decent condition (some tolex scrapes and dust, plus mismatched tubes) but otherwise worked and sounded great.
I placed the order and when it arrived it was as described, except the input jack is a little wonky and (the big issue) the PT hums and sends a vibration throughout the cabinet at all times. Now, it isn't like it is scary loud or anything....imagine the noise of turning on a fluorescent light and hearing that buzz. Like that. I'm assuming it is the Power transformer, since that seems to be the general area, but pressing it hard together didn't really do much to the sound. It has the power and seems to be working good, but the PT 561140 EIA606-410 doesn't seem to be cheap to replace.
This is my first DR in a long time and I don't remember this buzzing on my others. Is this and acceptable buzz, or is the PT on the way out? If so, have any of you ever had to replace the PT in a DR? Where did you find the parts?

Howdy.

Did you retube the amp already?

Eevil said:

Howdy.

Did you retube the amp already?

Click to expand...

Not yet. It has two different 6L6 duets (JJ and GT) and a random array of 12AX7’s but I was waiting to get an opinion on the hum before spending the $$ for all new tubes.

I bought some JJ power tubes to my Mark V and it’s humming pretty loud in normal voltage setting. With variac setting there’s a lot less hum... it’s all about poorly matched tubes and incorrect bias :shock:

Can you borrow a set of known good tubes or drop the amp to tech (with good reputation and not Mesa-itis)

I went ahead and bought a set of tubes so we will see what happens.

New set of Ruby 6L6’s didn’t fix it. I’m taking it to a tech to be looked at.

I finally got in touch with a tech (the local, recommended guy) but he is so busy he can't even look at it until 2 weeks from now. Called Mesa to make sure I get the right transformer part number and they said the amount of hum I'm hearing is normal. I guess I was just being overly cautious.
BTW, it turns out the transformer I have is the Mark series transformer instead of the correct one for a DR. Maybe it was already replaced?

Unfortunately this morning I noticed another issue. The Gain control on the orange channel seems to "switch" to the high gain when in clean at certain position in it's sweep. It actually sounds like something isn't grounded properly and it is switching from clean rhythm to gain. I can wiggle the knob and get it to go back to clean and "carefully" adjust the gain. Anybody ever seen THAT?