When you switch to the "direct" or "straight" mode you are bypassing and turning off all the unneccesary circuitry, such as video switching, EQs, etc so you can expect a better quality sound. But it shouldn't be a huge, dramatic difference.

On the Yamaha's this may also turn off the parametric equalization if you performed one, which may make a considerable difference in your sound quality too. Although the Denon has this capability I have it disabled and never plan to use it.

Dave


M60s, VP150, QS8s(3), SVS PB12-isd, Denon 3805, Emotiva UPA-7