To Hot to Handle?

I solved the problem by sticking with a SET 300B amplifier and using headphones when it is too hot to run the amp! That is only a couple of weeks per year in the SF Bay Area thank The Gods (for they are many).

What generates the heat in a tube amp? I know that the tube filiaments, turned on all the time even with no signal, generate a lot of heat. That is their purpose...to "boil off" electrons. The power transformer heat will vary somewhat with signal, as the current draw varies. There are probably a few resistors that dissipate power.

What else generates heat, and what are the relative amounts?

Actually, the filaments do not make most of the heat, which is a common misconception. The tube conducting makes most of the heat- by that I mean the tube conducting as a matter of its class of operation (class A or AB for example), and conducting due to the signal it is amplifying.

If you disconnect the B+ from the tube so that it is merely lit up but not conducting, you will find that most of the heat is gone.

One exception to this is the 6C33-BC power tube, which has a prodigious filament circuit (which overloads the socket that the tube uses and leads to the failure of the socket; the extreme heat that the socket otherwise sees in service contributes to a large degree to that too, so the smaller pins usually fail first).

So other then the 6C33, the filament is about 15-25% of the heat of the tube. The more class AB the circuit is, the larger the proportion of the heat is filament (since class AB circuits run cooler).

Just an update...

Rec'd my AES Six Pac's yeserday, have them set up and running.

Boy, break out the weenies, they a little bit warm to say the least. However it is workable, fan for the window, etc.

Thank you everyone for your opinion. Maybe I will invite you all to a BBQ over the amps....

Regards,

Good. Just when you are getting used to them you get to start tube rolling.