USB vs SPDIF, which sounds better?

Thanks @celander. You are exactly right. My N10 has the BNC output, but it’s my DAC that’s limited to the RCA connection. So, I may end up using one BNC/RCA adapter on the DAC end. In Mike’s video, I don’t see what USB and digital cables he used in the demo. I know different cables would make a difference, so if he wasn’t using the same level of cables in the demo, then it would sort of skew the result. Anyhow, I do believe everything being equal, the SPDIF should sound better than the USB. Now the question is what digital cable I should get. Any suggestions?

I used a number of SPDIF cables. One is a $500 BNC-terminated solid silver cable made by Mark Coles from Sablon Audio for Here’s his link:
http://sablonaudio.com/index.php/signal

Oyaide makes a decent, $150 BNC-terminated SPDIF cable composed of 5N’s silver braid (DB-510, 1.3m).Here’s an eBay link:
https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F283160127875

Mike Powell (OCD HiFi Guy) will respond to you quickly regarding what he used for SPDIF cabke(s) if you reply to his YouTube video clip or message him here.

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.