Bridge integrated amp and amp

Not sure what you mean, but I'll take a guess. A quick look at the NAD web site shows that the C272s are bridgable to mono. The C355 has a pre-out/main in facility as well as a second set of pre-outs. So you could use the 355 as a pre-amp to drive the C272s configured as monoblocks by taking pulling the jumpers between pre-out and main in and taking the pre-out signal from one channel to each one of the amps. You could also get 4 channels of amplification by driving the bridge C272s of the pre-2 outputs and leaving the jumpers in and driving 2 additional channels from the speaker outs of the C355. In either case, the 272s would make LOTS more power (about 2X) but it would affect other characteristics of the amp (slew rate and/or damping factor, I think). Only you can tell if its a good thing.

Here is what I have, maybe this will put things in a better light. I just recently purchased the power amps (great deal) but don't know if I would be better off to get a pre or use my integrated? Also I a have been looking at power conditioners.

psb G Design GT1 Towers
Axiom EP500 Subwoofer
NAD C542 HDCD Cd player
Blue Circle SBD D/A Converter
2x NAD C272 Power Amps
NAD C355Bee Integrated Amp

Personally I would get a pre and sell the integrated. With my Bryston B100 I used the pre out with a 3bsst amp. My integrated got hotter than normal. I figure with no biasing on the amp section of the B100 it was powered on at full out. On the other hand if you want to power more than 2 sets of speakers you may want to keep the integrated for that reason.