Both AVR's will have input level adjustments for individual source inputs to allow you to normalise the volumes. As far as the volume difference between TV stations goes; some experimentation with the Denon's Audyssey
Reference Level Offset (10dB recommended for TV) and
Dynamic Volume settings should address this issue satisfactorily. I'm unaware if the Yamaha has any similar facility.
Personally, in a matchup I take Denon over Yamaha every time, mainly because I'm a devotee of Audyssey MultEQ and it's associated Dynamic EQ processing. If Yamaha ever partners up with Audyssey (highly unlikely), it would be a
very close call.
This side-by-side compo might help:
Crutchfield | Denon AVR-X3100W vs Yamaha RX-V777BT.
Good luck with your deliberations!
