Lampizator Amber II and MacBook Pro With JRiver

Lampizator owners I am need of some guidance.  I own the Lampizator Amber II DAC. I am using a MacBook Pro with JRiver loaded.  I connect an external hard drive with music files to the MacBook Pro.  I used this setup with a previous DAC with no problems.  

For some reason I cannot get sound through the speakers when using the USB.  There is a toggle switch that is used when switching between SPDIF or USB.  It plays through the computer instead.  No problem getting sound through the speakers with the SPDIF cable from Oppo 105D.

Any guidance would be greatly appreciated.  

Frustrating.

Thanks