Samsung Galaxy S4 connectivity

Having some connectivity issues with my Samsung Galaxy S4.

When I connect to my Burson HA-160D and Macbook Pro through the USB I have no problems. However, when I try to connect to a Wyred4Sound MPre through the USB, it doesn't recognize the connection at all. Connecting the Macbook Pro to the MPre, with the same USB cable ( minus the Micro USB adapter ) works just fine.

Does anybody know what my problem is here?