Concerning 720P vs 1080P:
Even if there are no HDMI connections, the HDMI circuitry is still active, so any changes concerning HDMI will still be audible on the other outputs.
My setup is TV, Oppo, DAC, integrated amp. All these have two wire power cords. HDMI 1 to TV. Coax to DAC. DAC to integrated, no other connections to any unit.
After seeing how setup menu items that seemed to not be in play or unrelated affected the sound of the Oppo (103), I started playing aorund with items in the TV setup menu. And some of the setup menu items in the TV have the same or greater effect as 720P does. Usually, the more I simplify or shut down, the better the sound.
Anyway, the TV has an option to turn off if receiving no signal for a period of time. This changed the sound quite a bit, but contrary to what I expected. It actually sounded better with the timer on and sounded better the longer the time. And it also has a timer for a screensaver for when running applications on the TV. The sound was better with this timer on and it sounded better the longer the time.
It has the option to use analog audio rather than the HDMI audio on one HDMI input, and it sounded better when set to accept analog, which I did expect. I think this one also improved the picture slightly. The TV has the option to dim the display when it gets darker. The normal backlight setting is in effect when bright, and then there is another setting for when it is dark. Anyway, it sounds better with the dimming option on with the backlight set to the same values. It did seem to sound better with the backlight at higher values, but I did not test much because the backlight setting is critical to the picture.
I was not using the TV to listen to anything and the HDMI audio on the Oppo is off. Some menu settings in the TV were affecting the sound from the coax out from the Oppo to my DAC with the only connection to the TV other than the power cord being the HDMI. I find this fascinating.
Last edited by kellybob; 07-18-2014 at 06:33 AM.