USB->HDMI->SPDIF a waste of time?

Hey there,

Trying to go SPDIF out of a Nexus 7 tablet to DSP without doing an audio conversion using a DAC. Slimport MyDP (usb-hdmi) then an HDMI to SPDIF converter? Am I spinning wheels or will this work? Or is there a better way that is relatively inexpensive?

I am currently using the Behringer U-Control UCA202 and am not happy with it. The best way i can describe it is the stage is not as wide, the highs aren't as clear and output seems muted. I can switch Spotify between Iphone streaming bluetooth to Mosconii 6to8v8 DSP and Nexus 7 wifi thru UCA202/SPDIF rather quickly and the bluetooth sounds much better. Streaming Bluetooth through the Nexus 7 is even worse. My thought is that SPDIF should sound better than bluetooth. I have searched a little only to get thrown into the realm of dirty usb power, DAC debates, and a whole bunch of other stuff I dont fully understand.

Hoping to get a clearer thought on how much more money I want to throw at this Nexus 7 project. Is it possible to get a better signal out of the tablet than bluetooth over the Iphone.

Thanks for your time