ahiddentableau
Tele-Afflicted
I agree that that kind of approach seems to work especially well on something like a tweed champ. Whether it's the compression like you suggest or not I don't know. My guess is that a lot to do with it is the dirtier base tone. I think it's to do with something like the opposite of headroom. When your starting point is already more distorted the impact of the guitar volume is more noticeable, but also seems to allow the cleaner sound to work out better. I find it's the same thing when using a fuzz face. You turn it up full whack and then use the volume knob to get every shade from crystal clean to full on fuzz.