The problem with the RayDAT card was either sloppy installation on my part or just a case of it not liking the first PCIe slot that I put it in. I note that the tolerance on the bracket is a little tight, because screwing the bracket down to the computer's frame made it want to pop out just a bit from the PCIe slot. When the card didn't show up in the device list, I made a guess that one of the "Unknown Device" entries was it.

Nope. Those were related to the motherboard's Bluetooth implementation. So that's installed now, the RayDAT is installed now, and all I have to do is wire it back up and install Cubase and everything will be back to normal down in the studio.

Phew.