If you are not getting audio from the PC-USB input on your Rotel system, here are a few things you can check.

• First, check the audio devices on your computer to make sure the Rotel device is set as the audio output device.

  Windows:

  Go to Control Panel -> Hardware and Sound -> Manage Audio Devices

  Mac:

  Go to System Preferences -> Sound

  Make sure 'Rotel PC-USB' is selected as the active sound device.

• If the Rotel device does not appear on the list of sound devices, make sure the USB cable is properly seated on both the computer and the PC-USB input.
• If you are connecting to a Windows computer and the Rotel device has been set to PC-USB Audio Class 2.0, you need to first install the driver or Windows will not recognize the device.
  

  Download PC-USB Audio Class 2.0 Windows Driver

• Also try restarting whatever program you are trying to play. For example if iTunes was open before you connected the Rotel device to the computer it must be restarted to recognize the change.