Peavey Classic 50 212 Volume Test

At low volumes when the pre-amp is dominant, the sound is rich and saturated and naturally compressed. When you crank it, it sounds as if the clean channel was cranked up too and mixed in on top of the dirty channel, giving an ugly spikes of hard, unsaturated string sound.

Check out the wave forms (click to hear MP3 samples):

With power amp low:

With power amp cranked:

PRE is cranked in both of these samples; the only thing changed between takes is the master volume.

I tend to slap the strings pretty hard when I play. With the power amp relatively unengaged it doesn't matter -- the volume dynamics are pleasantly smooshed. With the power amp cranked, it does matter, you get these hard, unpleasant volume spikes (which don't come through well in the recording).

Audio samples recorded with cheap condenser mic (Audio-technica AT3031) placed about 10 inches in front of the amp pointing directly at the center of the amp's grill (in between the two speakers), through Hoontech Sta ADC&DAC2000, into Sonar, and compressed with Fraunhofer codec (for anyone that cares about these things).