Power amp/Slave amp/Servo amp

[AG]

Just out of interest (I'm all sorted in terms of amp stuff) what is the difference between these three? I see them all on eBay when I look around...

[AG]

Bumpsizzle before I go to bed.

[neatobassman]

I know a power amp increase the watts, but I'm not sure what the others do.

[Aes820]

Poweramp adds the watts. It's just the power section.

A slave amp usually refers to one amp that is being ran off another amp.
It's less so a PA term and more so specfic with guitar or bass amps.
You can use your main guitar amp as it is to achieve your tone. And, if it has a slave output, run this into additional amps. Just for their loudness + speaker area.

I have heard of Servo controlled poweramps. Which have an idle function. This feature prevents current flow through the power section of the amp while there is no signal preset at the input of the amp.
I think, like an automatic 'mute' feature.

This may help prevent damage caused to speakers from audio signals with a DC offset bias.

Someone who knows more about Servo controlled poweramp may be able to help further.