Single notes sound detuned on my Mark IVa combo

I have had a Mesa Mark IVa combo for a couple years now and its always functioned perfectly. I recently moved back home to my parents old house and suddenly the amp is acting strange. On the R2 and Lead channel single notes on the high e,b,g strings seem to have a detuned warble sound to them. The amp was carefully transported and the issue started as soon as I got here. I am wondering what the issue could be (Tube, Caps, Interference., Power..) it happens with all of my guitars and I know the problem is not with the cable. The house has a lot of ceiling fans switch my old house did not but they are all turned off. I first thought that was the issue. Any help would be appreciated. It's a great amp I want to be able to play it again.

A couple of thoughts:

(1) Are you sure you are getting full voltage from the outlet you are using?
(2) Have you tried it through other outlets in the house?
(3) if the voltage is not up to snuff, do you have a power conditioner?
(4) Do you get the same behavior in both tweed mode and full-power mode?

I had a kind-of, sort-of, similar issue when I tried running my Nomad on the same outlet as I was running a window A/C unit. (I know, not one of most intelligent decisions).

If it's not a power issue, I would wonder if something has happened to one of your preamp tubes (during the move). V1 is used across the board, so it should be okay. As far as I know, V2 is the only 12ax7 shared by channels 2 and 3. Perhaps something happened to it during your move.

PS: I am not a amp internals person. But, these are the things I would first check.

Hope this helps.