Not dumb questions at all.
There is a version of the DSP which includes a built-in 4-channel amplifier and selectable inputs. The page does not mention a standalone DSP (for use with separate amplification) with those selectable inputs but it would be worth asking Axiom if such a thing was possible.
Then there are two version of and integrated DSP and amplifier. Both versions include our ADA1000-4 amplifier with the DSP built into it. The one version accepts either a pre-out or high level (speaker wire) out from your pre-amp or receiver. The other version will accept up to 3 independent sources (i-pod, CD player, etc) and has an input selector switch, a balance control, and a volume control on the front panel.
re: avoiding another A-D/D-A pass, even if you had digital inputs I imagine the DSP would have to re-sample from <input sample frequency> to <DSP sample frequency of 96 KHz> anyways. I guess it would be nice to avoid going through analog if your receiver / pre-pro could output 24-bit 96 KHz over HDMI... no idea if that is common though. I haven't heard any mention of digital inputs on the DSP though.
