USB vs SPDIF, which sounds better?


I am currently using an Audience AU24 SE USB cable between my Aurender N10 music server and the Lampizator Big 7 dac. Since both components have the SPDIF connection, I am wondering if the SPDIF would sound better than the USB. If so, what are some good digital RCA cables available today?  Thanks for your input.
respected_ent
respected_ent,
As a new N10 owner I'm still learning too.
As I understand it N10 USB out is not via the Aurender N10 clock but by your DAC clock. The Aurender clock is amazing and should be used.
DSD only feeds through USB so for best effect we would require USB & SPDIF cables attached at the same time, the N10 supports that. SPDIF for everything except DSD will use USB.
I've only used a modest Oyade USB cable so far but plan to get a SPDIF coaxial very soon. I was reading your topic hoped to find more information on a quality SPDIF cable.



The ground loop issues of a USB cable can be mitigated by using an unpowered version (data only) of the USB cable. Several high end companies offer this sort of cable (Sablon Audio, for example). 
@respected_ent  Mike Powell goes by the user name @mikepowellaudio here on Audiogon. 

@mid40sguy Yes, you are right about the clock and the DSD.  So, if both USB and SPDIF cables are connected from the N10 to the DAC, then how does the PCM signal know to go through the SPDIF connection and not through the USB connection?  Does N10 have an internal mechanism to detect that the SPDIF is connected, so it will use it as opposed to the USB? 

@celander Thanks for the info again.  I've tried the Sablon data only USB cable, and to me the Audience Au24 SE USB still sounds better in my system.