It is normal for an Amplifier tube to get verry hot.
RF Amp tubes also get very hot. I have a tube Pullers
from the 1960's just for removing hot tubes.
Stan

I'm working on a Hallicrafters SX-25 Super Defiant. It uses two 6F6
tubes in push pull in the audio
circuit. Boy do they get hot! Too hot to touch. If my finger lingers I'd
have an awful blister in less than a second. Is this normal? I've checked
the tube voltages and they seem to be where they should be...280 VDC on
plate, 6 volts on heater, 18 volts on cathode. Does anyone have any ideas
about how to help these things run cooler?

Steve