Does the UGB compress the signal? My thinking was no, the idea being that the UGB would bring the signal back to unity gain. However I've been listening to the steller DP's of Alpine '82. Garcia sounds fat, hairy, and wet, kinda like a strat into a dyna comp into a fender amp. Second thing is my 70's Vibrolux seems to achieve the same kind of thing. Very round sounding amp. Come to think of it lots of those pre coma shows have that kind of compressed sound, was Healy running the whole board through a rack compressor? If so I again marvel at that man's genus.