Best results will be running HDMI to TV like you said, and then running RCA for the audio from each source to the amp. Do this for the ones you want the best stereo sound from. (Although its hard to imagine anyone with multichannel caring all that much about sound. You would just ditch the HT and go stereo. Whatever.) Going RCA opens up a huge selection of high quality interconnects at killer used prices.
Audio output for a non-HDMI pre-amp
I have a McIntosh MX 135 A/V pre-amp which has balanced outputs for 7.1 and has component instead of HDMI inputs. Not wanting to upgrade to the latest McIntosh HDMI capable unit (very expensive), I was thinking of having the HDMI sources (blue ray player, cable TV, Apple TV) directly plug into the TV and using the optical audio out from the TV to supply the audio to the McIntosh which in turn would supply my 7.1 system.
Alternatively, I noticed that the blue ray player I am interested in, the Pioneer Elite UDP-LX500 has several audio output options including 1) analog audio out via traditional RCA jacks, 2) coaxial digital audio out and 3) toslink digital audio out. Would I get better sound, from the blue ray player, if I output the audio signal directly from the player to the McIntosh and if so, which audio out option would work best.
The McIntosh has these specs: DTS ES & Neo:6,
Dolby Digital EX, DTS-ES, Prologic II
Alternatively, I noticed that the blue ray player I am interested in, the Pioneer Elite UDP-LX500 has several audio output options including 1) analog audio out via traditional RCA jacks, 2) coaxial digital audio out and 3) toslink digital audio out. Would I get better sound, from the blue ray player, if I output the audio signal directly from the player to the McIntosh and if so, which audio out option would work best.
The McIntosh has these specs: DTS ES & Neo:6,
Dolby Digital EX, DTS-ES, Prologic II