I am currently running M60's with a NAD c270 amp and a Rotel RC1070 pre-amp. I am considering getting some M80's for the new rec room in the basement. I am thinkng about duplicating the C270 and RC1070 for the M80's, but am also considering a Rotel RB1070 amp. Can someone please vefiy that these two amps are compatible with the M80 4 ohm resistance without any downsides?

Are there adjustments that need to be made to the amp when hooking up to a 4 ohm load, or does the amp adjust automatically?

The Rotel RB 1070 does a fine job with the M80s. I had it hooked to my M80s for a while as I was waiting for the RB 1080 to come into stock. Nad is pretty well know to handle 4 ohm loads as well. I wouldn't be concerned with either pushing the M80s.

Bob, just do the connections and ler 'er rip ... there is nothing different you'll need to do from that of your 60s.

The C270 will be just fine with the M80's. I had used a c370 with my M80's for a few years before I upgraded to monoblocks. The C370 has an identical amplifier section to the C270.