Help with integrated amp choice

New to the site and admittedly proabably not at the level of sophistication of most on here but here goes.
Attempting replace my Denon 750 for around 2k driving a pair of Polk 10s 
Have had hooked up the NAD 368 and now the Nova 300.
First question with no input and the amp maxed out should there be any noise (hum/buzz)
Second it may be just my bad audio memory but the  Denon just seemed to be more accurate.
Now I know that may sound like heresy to some but is it my ears or my expectations?
Using California labs CD for the testing
I’m lost  just trying to listening to 60 - 70rock
Would appreciate any help and direction
Thanks 
Jim