Television digital output

Having recently moved away from a full surround sound set up I would like to now connect my 2-channel set up to the TV. Current system is HDX/n-DAC/555PS. I would like to connect up my Sky-HD box/PS3/Arcam DVD player to my n-DAC all of which are connected to my Sony TV via HDMI.

The n-DAC is about 6 feet from the TV and the Sky/PS3/Arcam are all just below it. I have a 3m Chord optichord. Is the best way to connect this all up via my TVs digital output or is the TV likely to down-mix, or otherwise play around with, the sound quality? Obviously I can connect each individual source to the n-DAC but this does treble the number of leads I have trailing across the room.

TV is an old Sony KD40D3000 which I'm likely to replace soon but I don't think I'll go back to surround sound.