Hot Tamale!

[ChrisinMO]

I posted this in the non Mesa amp forum (wrong forum) so thought I'd try here and maybe get some more responses.
Thanks for any feedback.


I just traded for a Nomad 45 and love it but it gets hotter than hell! After playing awhile the chassis and especially the PT gets so hot you can't touch it or you will get burned. Too hot to leave your hand on it. Is that normal??? I checked the temp and the PT was at 150 degrees; put a small fan in the back and it was running at about 100 degrees. What temp is everyone else's running at and what is too hot???

Thanks!
Chris

 

[bgh]

I've never measured the temperature on my 45, but it definitely gets very hot.

 

[ChrisinMO]

Mine was so hot you couldn't hold you hand on it or the chassis at the base of the tubes!

 

[elvis]

The power tubes dissipate more power as heat than they deliver to the speaker. They should be about as hot as a 60W incandescent light bulb.

 

[ChrisinMO]

Yeah, I'm more concerned about the PT being so hot. Does anyone know if they are designed that way???

 

[elvis]

Misinterpreted. Thought you meant Power Tubes (PT). I'm not positive, but in theory there should be very little power dissipation in the transformers. Could it be getting heated by the tubes and chassis? Or is it obviously a heat source?

If the windings are loose, they may be vibrating and causing friction heat. That would be bad. I think you'd probably hear a nice 60Hz hum coming out of the PT if that were the case. Alternatively it could be that it has gotten overly resistive in the windings.

I wouldn't expect more than a few Watts dissipated in the PT for a 50W amp. At the same time, I'm struggling to hypothesize where heat could be coming from.

 

[ChrisinMO]

Thanks for the reply. I know power tubes have to have something to do with the heat. (They're right on the PT). I think I'm going to build a head cab and use it as a head. Carrying that 2x12 weight around kills me. I'll just add a fan and leave it on. It runs at about 100 degrees with a fan. That should be fine.

Thanks.

Chris