well, I don't have any yet, I've been setting back cash for a new gear overhaul..I'm set on an Engl 530 and Mesa Vtwin and probably a Mesa 20/20 power amp..
well...I have run 2 pre amps with one power amp in the past (I was using a Marshall JMP-1, and an ADA MP-1 with a Marshall 9200 power amp)...it was a killer set up...I got out of the rack thing quite some time ago, but it's strange a lot of people seem to be doing it again!