I have had a NAD 753 for a few years happily driving M60s. Amp supposedly has 70w per channel.

My neighbor is giving me an old nad 370 integrated amp with 120w per channel. I can use this as a power amp connecting pre-outs from 753 to pre-ins for 370.

3 questions
If you are listening to an amp rated at 70w for 5 channels, do you get more than that in two channels if you are listening in stereo? Which might mean this idea wouldn't give me too much benefit anyway

I am trying to set things up so I can compare the two set-ups as easily as possible. Is there anything bad about connecting the 753 Front outputs to one set of m60 posts and the 370 front outputs to the other. Only one amp will be driving at any given moment?

Don't think I can switch with a flick of a button - will have take pre-outs from the 753 and manually direct then back into itself or into 370 - can't think of better option.

Any opinions welcome - I mainly care about having the best possible set up for stereo music while still having 5 channels for music.

Thanks for reading.