recommendations for amplifiers that don't emit tons of heat

for an example KT 88’s have a heater current of 1.6 amps each tube....where as the power dissipated is around 5mili amps

glennewdick---As you say, KT88 filament current is specified as 1.6 Amperes. The related filament voltage is 6.3 Volts. That's TEN WATTS of power dissipation that's consumed merely to "light up" the quiescent KT88 vacuum tube. In that state, the tube is merely at passive idle; it's not doing any functional amplification. It's serving only to emit heat + dim illumination. Additional power is then consumed when the tube is subsequently biased to pass current from cathode to plate. That's truly archaic efficiency.

Yes---and 1.6 A. x 6.3 V. = 10 WATTS.

And that power is consumed merely to "light up" one KT88 to a quiescent state, where it does nothing more than emit 10 watts of heat and light. Additional dissipation, over and above this wasteful filament dissipation, is required to perform active amplification.

the biggest power consumer in a tube amp is usually the heaters for the cathode

This statement is rarely true- I think the exception used in audio is the 6C33. For most power tubes - like a KT88- the heat made by the cathode is insignificant compared to the heat made by the tube as a result of plate current though it (its class of operation).

As a result, compared to a solid state amp of the amp power and **same class of operation** , tube amps will make marginally more heat.

If you put a tube amp in standby (no B+) even after sitting there all day the tubes won't burn you (the exception being the 6C33). But after being on only a couple of minutes the same tubes will be much hotter if B+ is also applied!

The problem is that if a solid state amp can't bring home the bacon, then it really doesn't matter how much heat it makes. In high end audio, the **sound** produced is the goal.