Can anyone explain what a power tube does inside an amplifier, eg kt88.

So does the plate collect the electrons until the charge is enough to push through the gate? And what prevents loss of  information? Once the tube gets warmed up, I guess it is just continous?

I have often wondered this.

The tube makes a larger copy of a signal, yes.

But how?

I imagine they are called valves because they act as gates, only opening to release the larger copy when it is large enough based on specs.

Again, how? How does it increase the size and  know when it has accomplished its goal? How does the gate open?

I can understand and explain how a gas engine does what it does, but not a tube.

Ive read some technical explanations but they always seem to avoid the actual answer to the actual question.

T