I don't know if this is the right place to ask, but...
I've used a HTPC as a pre-amp for a 5.1 system for the past 15 years. The first 12 years I used internal sound cards (maudio Delta 410 and Asus hdav). A few years ago I wanted to switch to an external dac. There were not many choices. At the time my budget was around $400. I ended up getting a focusrite 18i20. This is a pro mixer with all sorts of inputs and outputs that I will never use, but it has dac that handles 8 channels. There was a significant improvement over the internal Asus card.
One of my biggest complaints about using a HTPC as a pre-amp and video/audio source has been the inability to play and rip SACDs. Now if I had an oppo 103 or 105, I could rip SACDs. I also know that the 105 can serve as an external dac. I may be confused, but is it also possible to have the 103 act like an external dac through the Ethernet connection?
Thank you for you time