Help me diagnos my problem . . . .

[Sleeping Martyr]

I have noticed that my amp loses tone (ie. burns through tubes, loses some volume, feeds back, gets fuzzy) faster than it should. It happens mostly on the lead channel and I've narrowed it down to the V2 tube which seems to go the fastest. Its a mesa .50 caliber+ thats not run excessivley hard nor played for excessive periods of time (maybe 3-4 hours per week). So what could be the problem that is wearing out my V2 tube faster than it should?? I'm using Tung-sol 12ax7s by the way so I don't think its a case of crappy tubes. Any suggestions??

 

[tone4days]

Re: Help me diagnos my problem . . . .

dunno

check here - http://www.grailtone.com/forum/index.php - for more specific help with a mesa?

 

[Imp]

Re: Help me diagnos my problem . . . .

biased way too hot?

 

[bungalowbill]

Re: Help me diagnos my problem . . . .

How do you know that the V2 tube is the culprit? Do you have a tube tester?

I would take it to a tech and have him give it a once over.

 

[Sleeping Martyr]

Re: Help me diagnos my problem . . . .

Just through trial and error of replacing tubes it seems to be that the V2 is the culprit because when I change it the problems subside. I don't think its the bias as Mesa's (at least this one) have a fixed bias do they not??

 

[Smilemon]

Re: Help me diagnos my problem . . . .

If the Bias is fixed maybe your power tubes are the wrong rating.

 

[muttonchopsrule]

Re: Help me diagnos my problem . . . .

wouldn't bias settings not be an issue since we're dealing with 12AX7's here?

 

[Sleeping Martyr]

Re: Help me diagnos my problem . . . .

I don't know about the power tubes, its done this with Mesa tubes AND JJs . . . mg:

 

[muttonchopsrule]

Re: Help me diagnos my problem . . . .

how savvy are you with electronics? if there are any resistors that are out of spec and allowing too much voltage to slam the problematic tubes, that could be something to look into. otherwise, have a tech look at it. if it keeps blowing tubes, that's probably an idication that something else in there needs to be attended to. if you do end up poking around in there, be sure to drain the filter caps and watch out for lethal voltages!