Installing the Xonar U1 was a matter of plugging it into a spare USB port and waiting for Windows detect the Xonar.  Installing the drivers and utility from the included CD was as simple as following the onscreen instructions and restarting Windows when prompted by the setup.

 xonar audio center scrnsht  Asus Xonar U1 USB soundcard

The included utility is similar to that of the Asus Xonar D2 and offers the options of adjusting the levels and Equalizer amongst other things.  The analog output can be selected from speaker or headphones out and there is the choice of enabling the Dolby technologies as well the Virtual Speaker Shifter.  Alternatively, users can simply choose the DSP modes an let the software make the choice for them.  Kudos to Asus for making the software simple to use for end-users.