Yoder, the DAC and HD are connected to the SOtM tX-USB which is installed in the single PCI slot. I moved the HD to one of the USB ports on the motherboard, this should isolate the two USB devices. The HD is USB only.
I am not familiar with Amarra or any other mac software. What is different from the mac software from my JRiver/JPlay combination. JRiver is just the visual front end for the music stored on the HD. JPlay is the "high-end digital transport".
I did not follow the advice of the article, I installed a DVD drive for downloading music instead of using a thumb drive, or by moving the HD to my main system and copying from there.
I have no idea on cost. There is one vendor that has been given permission to sell the CAP 2.0, I belive their cost was $1400, so I should have less than $1000.00 invested, and this could be reduced to around $750 with a different computer case, the one recommended was $320 plus freight, a big saving could be made here. Another $331 savings could be made by not using the rather expensive USB card and sub with the recommended $8.00 firewire card, but one would have to have a DAC that was FW capable. Also a smaller SSD could be used saving another $100 or so. With a different case and having a FW DAC one should be able to put one of these together for around $600-$700.
My HDTracks are of course Flac, normal CD's are burned in Wav, some say that is sounds better than Flac, who really knows, I am not worried about the larger file size.