My Mark III's Sound Changed

[Kid Howren]

I had a really good sound going, then we hauled the amp across town for a gig, and when we got back, the sound had changed. The clean's not much different, but the distortion's really weird now. At some points it sounds like there's not enough distortion when I'm playing single notes or solos, but then when I'm playing parts that go between strings a lot, it's like there's too much drive and unnecessary noise coming out. My settings are like :

Volume : 8
Treble : 7
Bass : 2
Middle : 3
Lead Drive : 10 (I used to only need to put it on like 8, but if I do now, it sounds almost like Rhythm 2)
EQ in : The two outer switches are all the way up, the three in the middle are all the way down.

All in all, these are the only settings that are giving me any real distortion at all. I'm wondering if this is a problem with the tubes, as I bought it used a couple of months ago. I play stuff like Pantera and Metallica, so that should give you an idea of the sound I'm looking for. Any ideas what the problem might be? Thank you.

 

[DW]

Are you sure a tube just didn't get rattled loose or damaged during transporting the amp? Make sure they are all snugged up in their sockets. If that is fine and it still sounds wrong, perhaps try replacing just the EL34's (if you use them), then just the 6L6's, then the 12AX7's. (change those one at a time).

 

[Kid Howren]

Thanks man, I'll try that.

 

[Kid Howren]

Well, two of the tubes, an EL34 and a 6L6, are pretty loose. I pushed them up in their sockets, but they still wiggle a lot. The other EL34 and 6L6 in the front are kind of lose, but not nearly as much as these. I don't know of any way to tighten them. I'm pretty new to tubes. Thanks.