Amp overheating and losing power!

[larry_emder]

Hi, my amp is a mesa Studio .22+

i've had this overheating problem with it for ages - After about 15-20 mins of playing (at a bedroom volume) The sound all of a sudden gets a lot quieter, and distorts a little bit (on the clean channel). I realised that it was an overheating problem of some sort after i stuck a fan behind it and the problem went away.

So i'm not too keen to gig with it, as i dont want to risk a breakdown at a gig. Also, the fan mucks up the reverb tank (adds lots of that reverb noise that occurs when you bump the amp). And i like having reverb

Anyone have any ideas/suggestions on how this could be fixed? I'm thinking its got something to do with the tubes......should i replace em? cheers, Larry.

[HolyDirt]

Re: Amp overheating and losing power!

Sounds like faulty heaters in the tubes. I'd be surprised if swapping the tubes didn't fix it.

[larry_emder]

Re: Amp overheating and losing power!

Cheers for the quick response.....i *think* its a class a amp (is it?) - is this a common occurence in class a's?

[HolyDirt]

Re: Amp overheating and losing power!

Cheers for the quick response.....i *think* its a class a amp (is it?) - is this a common occurence in class a's?

Tube malfunction isn't uncommon in any class of tube amp. The fact is, tube's aren't super durable, and can be damaged by a number of things. Along these things is excess current... when you get the new tubes, have the amp rebaised by a guitar tech.

[larry_emder]

Re: Amp overheating and losing power!

Been reading a LOT of reviews about this amp that say that it runs really hot, many put a fan behind theirs. Maybe its just part of the design...

[HolyDirt]

Re: Amp overheating and losing power!

Been reading a LOT of reviews about this amp that say that it runs really hot, many put a fan behind theirs. Maybe its just part of the design...

Overheating isn't part of any amps design. My buddy has one of these as well and it doesn't do what you're describing. Either way, when biased correctly, the tubes of any power amp shouldn't cause the amp to operate like you say yours is.

[larry_emder]

Re: Amp overheating and losing power!

K, i'll get some new choobes - cheers

[Scott Miller]

Re: Amp overheating and losing power!

Always remember: 95% of all tube amp problems are the tubes.

[larry_emder]

Re: Amp overheating and losing power!

WELL

I bought new tubes the other day, the Mesa Boogie branded EL84 ones in the hope that this overheating problem would go away....

Its exactly the sam, lost volume after 20 mins of it being on - So i put the fan back on that is behind it, and the problem goes away again.

So i'm pretty sure the problem is NOT the tubes. Any suggestions?

[larry_emder]

Re: Amp overheating and losing power!

Also I noted that the old tubes i pulled out were SOVTEK'S....if that makes any difference

[HolyDirt]

Re: Amp overheating and losing power!

Also I noted that the old tubes i pulled out were SOVTEK'S....if that makes any difference

Alright. It could really be a huge number of things. A tech is probably the best idea at this point, unless you want to do hours upon hours of amp diagnostics...