[font=trebuchet ms]Do some research, my son.

We had a fine ol' rant session, (several of them, actually), about the virtues of small amps. IIRC, a member named educatedfilm posted a link to a website that explained the psychoacoustic response that causes the harmonic content of tube distortion to seem louder.

I suspect it's not all that complicated, though. Transistor amps tend to be rated at a low level of distortion, such as "10 Watts @ 1 kHz @ 0.001% THD". As a transistor amp goes past this point, it rapidly reaches hard clipping, and becomes useless for any kind of musical sound. A guitar amp, especially a tube amp, will reach this miniscule level of distortion long before it runs out of power.

Most of us figure a guitar amp is just getting interesting when it starts to distort. And because of the way that tubes distort, they continue to produce pleasing sounds even though the output power far exceeds the level measured at the onset of distortion.

Anyway, use the search feature to dig through the old threads. If you find something that particularly tweaks your interest, post a reply to it, and we can all have a go at it.[/font]