Well, Wof, I appreciate buying 'used' stuff. It can be quite the value.
I'm a long-term equipment owner, myself, however, not doing too much swap. My last sytem was stable for 20+ years, more or less.
I am making an adjustment in what I own based on adding the computer and the incompatiblity of my current CA840c with the AirportExpress optical out.
The CA DM+ adds the BlueTooth link which should mate fine with my iMac. The double inputs AND the 'extra' async USB give me plenty of flexibility going forward.
My PS3 will go into one optical, an OPPO upsampler into the other. Music will be streamed from my Mac via BlueTooth. IF I do anything going forward, it'll be to get a cheap PC, strip it out and turn it into a music server. That'll go into the USB. I may not need the BlueTooth after that? Or maybe internet Radio?
I think I could knock together a regulated PS of the appropriate voltage without too much difficulty. This is 'cookbook' stuff without too much remaining in the 'experimental' area so all I need do is follow the directions and look at some 'sample circuits'.