A stock UA5 will only output via USB unless you have it connected to a computer and run software that allows real-time monitoring (signal path would be source>ua5>compuer>ua5>DAT).
A modified ("digimod", "w-mod", "p-mod", "t-mod") UA5 will output USB, spdif coax, and optical simultaneously - no need for a computer or software monitoring.
You cannot run UA5>DAT (no computer) with a stock UA5 - it must be modified. There are DIY instructions on this board somewhere.