Check out that thread. The peavy 5150 is compared to the duel rectifier and a lot of people prefer it. Sound clips can be found at harmony central http://acapella.harmony-central.com/forums/
If you look up "clips" on the gear section. You should find lots of clips there of it and lots of clips of other amps too. I know the engl powerball amp is supposed to be very good for gain aswell.
By virtue of their electrical properties, tubes generate a special waveform when they're saturated, which is why tube engineering has tremendous tonal advantages over solid state or DSP solutions, particularly for crunch and lead sounds. Tubes enter the saturation zone gradually or softly, which lends tube-driven tone its trademark yet totally unique character.
