Does your DAC sound better through the S/PDIF or I2S inputs than through USB?

Yes my DAC sounds better from S/PDIF than USB. 

I have a crazy set-up because it sounds better to me. 

I stream from an Innuos Statement via Ethernet to  a Sonore  OpticalModule  that sends fiber to a Signature Rendu which sends USB  to an Antipodes S20 which sends S/PDIF to a Lampizator Golden Gate upgraded with the JL Audio USB.

While it makes no sense to me that a direct USB connection between the Statement and Golden Gate is inferior to the above, it does make me skeptical about using USB as both Innuos and Lampizator highly tout their USB. 

I2s is the best, followed by anything else, I used Ethernet before i2s, last is usb. My $1000 i2s cable is .75 meters long. A lot of the better dacs are not including usb, while some like Berkeley make a $2500 box to try to make usb sound better. https://www.berkeleyaudiodesign.com/alpha-usb2
 

Most people when asked this question state usb sounds better because they have never tried i2s. Why? because most dacs don’t include it, and most servers/streamers don’t provide it. The better products do provide i2s. Over a couple decades, when you saw the proprietary digital cable going from an sacd player into the preamp/integrated (like what Esorteric es-link provided as an example), was using i2s.

@rbstehno 

My server is an Aurender N100 and has only USB output. I’ve tried two different DDC’s in order to convert to I2S or SPDIF for my Gustard R26 DAC and the better one is the Gustard U18. (I haven't tried the Iris 12th or other DDCs so I'm not sure how the U18 compares.) I’ve tried the coaxial connection and the HDMI connection. Coaxial sounds best. The I2S through HDMI sounds a bit bright and more sterile.

My HDMI cable is a 0.75 M Audioquest Firebird, a $1600 new cable although it comes up frequently on US Audio Mart for much less than that. My coaxial cable is a custom silver, highly shielded cable made by Igor Kuznetsoff, which is likely better quality that my Firebird.

Most dacs these days are designed to be connected to a pc using the usb standard printer connection for it’s more robust and less likely to break. So if i2s and usb support the same format which usb use to be higher but on the smsl sux dac and the topping centerious they both sound good with usb or i2s, but I am using i2s and it sounds pretty decent, audio is best with xlr, usb, and i2s those should be the only connections available especially to bring prices down on overpriced audio equipment that doesn’t even measure well and ones that go beyond human hearing are nothing but a waste a few kilohertz higher sure but not double for there is no use for it 

my dac Ideon audio Ion sounds awsome   over USB.  They have killed usb hum , it is almost equal to I2S.