From dave@daveoakley.plus.com Sun Apr 15 08:21:48 2012
Subject:Re: Guitar amp watts vs PA watts? help me to understand

I'm not technically able to explain but in a nutshell, there are different classes of Amp types. Class A, B C, D, AB, H, G etc. Essentially they use different technology to amplify a signal. Using wattage as a measure of output between the different types is comparing apples and pears. Class A amps produce the most output per wattage but they are also inefficient in so much as they consume lots of power and produce lots of heat. Here's a technical explanation if you want one:
http://forum.qscaudio.com/forum/viewtopic.php?f=29&t=2752&sid=3c10afd780575cd8f5963985152b7980

UKDave