Quote:
Originally Posted by
Tornado Red 
Hi, I'm new, so please be gentle... I only have a rudimentary grasp of audio principles at this point, hope you folks may have some ideas to further this. Just upgraded speakers over the holidays to Polk monitor 75 mains, monitor 25c center. I have PSB side surrounds and rears with a Polk DSW550 sub. The 7.1 is going through a Yamaha RX V671 receiver. I'm happy with the speakers, but of course I'd like more power to the center and mains now, but have no pre outs on the Yamaha to run an amp, unfortunately. I'm getting my first Oppo (the 103) delivered, hopefully early next week. I've seen some discussion of it being used as a pre. Would I be able to run an amp from it to power my 3 up front speakers while letting the Yamaha do the surrounds? And if so, what happens to the 3 now amp powered speakers if I change sources from the Oppo to, say a cd player or tv in the system? Thanks, not really good at explaining things, hope it made sense...
There are several problems with this. First, as I think you've already considered, if you change your Yamaha to a different input device there will be no way for the audio to get to your front speakers since only the OPPO is wired to your proposed, new, separate amp for the fronts.
You'd have to run your other source devices through the OPPO using it's HDMI inputs. For the TV, if its HDMI supports Audio Return Channel (ARC) you can send audio from its own off-the-air tuner BACK to the OPPO on the cable that would normally feed video from the OPPO to the TV (assuming you wire HDMI direct to the TV).
Second, your Yamaha AVR may "helpfully" apply some delay in the audio going through it to better match up to the video going through it. The problem is that won't happen for your fronts because they are bypassing the Yamaha. To avoid this you will need to wire HDMI 1 from the OPPO direct to your TV and then find the setting in the Yamaha which disables video processing. E.g., video "pass through" or video output disabled. This should keep the Yamaha from adding audio delay on the channels still going through it.
Third, you will need to do Volume control using he OPPO's remote as of course the volume knob on the Yamaha won't affect what's going to your new amp for the fronts. And THAT means you can't use HDMI audio to the Yamaha because there's no Volume control on the HDMI audio output!
So now you've got HDMI 1 to the TV, HDMI 2 unused, 3 channels of multi-channel Analog audio from the OPPO to your new amp, the rest of the multi-channel Analog from the OPPO to the Yamaha, the Yamaha set to do no video processing, other source devices connected through the OPPO, and Volume control handled by the OPPO.
All in all, it might be simpler to upgrade your AVR.
--Bob
Edited by Bob Pariseau - 1/26/13 at 10:22pm