You'd be able to play the NON hi-res versions from some SACD hybrid disks and DVD-A disks over coax/optical i/o. The only single cable connections I'm aware of are firewire (ala Pioneer Elite) and Denon link (propriatary) for DVD-A. Not much point on buying these disks for your application if you can't play them at their higher resolutions which would require the analog inputs.
Mort