Recievers or Amps and surround sound

Well, let me take a stab at this one but not sure it's 100% accurate. I've been studying my book for an answer on this. Best way I can describe it is that a power amplifier, whether it be 2 channel integrated or multi-channel surround sound amp or receiver, consists of 4 primary sections: power supply, input stage, driver stage, and output stage. The input and driver stages prepare the signal from the source component for the output stage which is where transistors or tubes drive electrical current to the loudspeakers. The transistors in the output stage are the workhorses of a power amplifier-the current that makes the loudspeaker cones move. The more transistors, the greater the amplifier's output current capability but then of course the larger the power supply required. In a higher end 5.1 channel surround sound receiver (i.e. Marantz, Rotel, NAD, etc), they'll be 5 discrete and seperate sets of of these transistors (amplifier stages)sending the various processed sounds (i.e. DTS Neo-6 Music, Dolby ProLogic II, Concert Hall, etc) to the 5 individual speakers. The right sound is sent to the individual speakers as predicated by that particular surround sound format via those sets of transistors.

That's a very general overview of how an amp works. Hope it helps.

(Ref: The Complete Guide to High End Audio by Robert Harley)

Thanks, that's what I was looking for. I am trying to understand why an amp rated for 225w on 1 channel is rated for 200w all channels(Anthem A2), 180w all channels(Anthem A5). I'm going to get Harley's book.

Arp:

Yes, definetely get yourself a copy of Robert Harley's book and leave it on your coffee table or out in the open in your listening room. That's what I do. It's jam packed with information. He did an outstanding job with it.

His other book is called "Home Theater for Everyone". Much of what is in his first book is reiterated in the 2nd one but it focuses specifically on surround sound systems and goes more in depth than the first book. Enjoy.