Is this an issue relating to the PreAmp Tubes dying in my amp?

[Sutton]

So I have a Mesa Boogie M Pulse 600 that I have been using with a Glockenklang 212 cabinet that I have been using for years now. I (perhaps foolishly) have never changed the preamp tubes in my head.

Anyway, one day I pretty much lost all the power in my amp, and pretty much the second I push the gain above 1, it sounds really bad, and like its being distorted and farting. And no matter how much I turn it up, it doesnt really get loud like it used to get.

Since there is sound coming out though, it cant be the crossover in the cabinet, right? Because I've replaced cables, and now I'm trying to figure out if its a head issue or cabinet issue.

So does anyone have an idea of whats going on? Do Preamp tubes die like this, and if so, does it seem to be doing what its doing?

[RickenBoogie]

Process of elimination. First, try another cab. Still have issues(?), it's the amp. If it's the amp, you can try changing the tubes, but they generally last for decades, so most likely a trip to an amp tech is in order.

[JimmyM]

i would definitely try changing the tube first. pre tubes do last a long time usually, but spotty quality control in the foreign made tubes we get now can have an effect on how long they last.

[Exploiter8]

Excuse my ignorance, but is this like the GenzBenz hybrid amps? Running a signal into the effects loop can bypass the preamp, thus possibly eliminating the preamp tube(s)? Just a (probably stupid) thought. Good luck with the amp.

X8

[jastacey]

If the tubes are the OEM Mesa tubes, they are re-branded Chinese tubes, I once had a M-2000, and when I swapped out the tubes it made a huge difference, but check the amp with another cabinet to rule out that issue