I've learned that this interface (Sound Devices USBPre - the original) will work in Linux very easily but I first have to start it in Windows.
There is some OEM software initialization that happens when the USB port is plugged into a Windows machine. Once it's up and running, as long as it stays powered up, it will run in Linux just great.
So, I'd like to find out what the computer is telling it and try to duplicate this initialization in Linux. It's a very good sounding interface, has good live monitoring controls right on the front panel, it's built like a tank, and has a LOUD headphone out, all powered via the USB port.