DacMagic 100
Using USB 2.0
Try this solution
Make sure you have the latest drivers installed
Your DacMagic 100 will arrive ready to plug-and-play in USB Audio Class 1.0 mode.
For use in USB Audio Class 2.0 mode with Windows PC's, the Cambridge Audio USB Audio 2.0 Driver will need to be installed.
Drivers can be found here.