Mesa 2:90 Troubles

Hey everyone. Hoping you guys can help me out with some Mesa 2:90 issues I'm having.

I noticed recently that my TriAxis/2:90 rig started sounding a little "flubby", almost like engaging a wah pedal, just a lot of low-mid range in the sound. It wasn't just one setting on the TriAxis, it seemed to be across the board. Narrowing it down to my 2:90.

A quick word about my 2:90. The B-side has never worked on it. I got it used about 5 or so years ago, and it's just never worked. Recently, I've noticed that the presence knob on the B-side actually adds quite a bit of hum to my A-side when it's turned all the way up. Hard to avoid when Mesa instructs you to turn the volume down and the presence up on the B-side when not in use.

Anyway, I noticed one of the A-side tubes on the 2:90 was glowing blue rather than orange. Thought that was a little odd and could be the likely culprit.

So I wwapped out one from the B-side over to that one that was glowing blue on the A-side. Sure enough, my rig sounded awesome. Back to normal.

Jammed for 10 minutes when suddenly my output started to fizz out. Almost like my battery was dying on the EMGs or something. Then I smell hot air.

I look behind the rig and those two tubes I swapped were glowing fucking RED and they were HOT. So I turned the thing off quick.

Any recommendations on what is going on, and what I can do to resolve it?

Thanks everyone.

Time to go see a Mesa certified tech.

darkalone said:

Hey everyone. Hoping you guys can help me out with some Mesa 2:90 issues I'm having.

I noticed recently that my TriAxis/2:90 rig started sounding a little "flubby", almost like engaging a wah pedal, just a lot of low-mid range in the sound. It wasn't just one setting on the TriAxis, it seemed to be across the board. Narrowing it down to my 2:90.

A quick word about my 2:90. The B-side has never worked on it. I got it used about 5 or so years ago, and it's just never worked. Recently, I've noticed that the presence knob on the B-side actually adds quite a bit of hum to my A-side when it's turned all the way up. Hard to avoid when Mesa instructs you to turn the volume down and the presence up on the B-side when not in use.

Anyway, I noticed one of the A-side tubes on the 2:90 was glowing blue rather than orange. Thought that was a little odd and could be the likely culprit.

So I wwapped out one from the B-side over to that one that was glowing blue on the A-side. Sure enough, my rig sounded awesome. Back to normal.

Jammed for 10 minutes when suddenly my output started to fizz out. Almost like my battery was dying on the EMGs or something. Then I smell hot air.

I look behind the rig and those two tubes I swapped were glowing f%&# RED and they were HOT. So I turned the thing off quick.

Any recommendations on what is going on, and what I can do to resolve it?

Thanks everyone.

Click to expand...

My 2:90 did something similar, unfortunately you'll need to see a certified Mesa tech they should be able to fix everything and make it like new. They told me I was lucky, often when a tube blows they take out a couple of other components, looks like that's what happened in your case but don't worry too much it's probably just some small (relatively cheap) bits.

Good luck.

Tech Time!!!! No worries though, it'll be fresh when you get it home.