I just swapped a second PRRI for a Custom Vibrolux Reverb. It's the early version with the blue framed alnicos. I read some less than stellar reviews, but it's actually exactly what I was looking for (or a good stand in until I can get a Vibro King.) It breaks up right around the same volume as my PRRI (which has an Eminence Canis Major in it for more volume) but has a really big low end that balances out the cut of the highs/high-mids heavy Princeton Reverb. Also, it does hum with the reverb cranked, but it really hums no worse than any other amp I've played through. I just know they have somewhat of a bad rap, and am so impressed with mine that I thought I'd give em some good publicity. It isn't a blackface Fender, but wasn't intended to be. It's much meaner... and this thing is really what I've been looking for.