Subway Rocket eating V-1 tubes

[JW123]

Hey guys, I have a Mesa Subway Rocket. Ive been doing some smaller things and using it a lot lately. The last 3 times Ive taken it out it has eaten a V-1 tube. I didnt think much for a while cause I know how tubes are. But last night I did a 4 hr gig and replaced one, after having replaced one at a 4 hr gig this past sunday.

What would cause this to keep happening? I hate going to the local tech cause he keeps it forever, so I am here looking for ideas.

Thanks.

 

[nemesys]

It is possible that you just got a couple of bad tubes in a row. That said, it's also possible that one of the plate resistors or the cathode bias resistor for that tube have drifted over time, and the tube is being run too hot and burning out fast. Does the amp sound different?