I2s versus AES/EBU to connect an streamer/server to a DAC?

I2S has no defined connectors in the standard so both end devices  have to match.  It was designed for point to point on circuit boards. USB is the highest speed most versatile standard interconnect at this time.

I experimented with connecting my Lumin U1 streamer to Denafrips T+ DAC via SPDIF, USB, and AES. I found AES sounded the most natural and full throughout the frequency spectrum, and was best across all types of music for my ears.

As with many things audio, it's a lot of trial and error. I do want to try I2s at some point.

I2s is the best way to go because it offers greater resolution and can handle DSD which SPDIF usually cannot.

I would only use I2s if it is a native output to input, otherwise USB or AES would probably be better.

IME RJ45 is preferred because of the larger conductor size but I found no benefit in going below 0.5m in length, whether HDMI or RJ45. PS Audio recommends 0.5m.

I had excellent results with WW Platinum, Furutech was good too but darker.

@soix +1 with the caveat that not all I2S is HDMI…some are rj45/ethernet type cables. Depends on the brand(s).

What @soix said. ✅️

Check with your DAC manufacturer as to which input is preferable.  It’s most likely i2S, and if that’s the case a DHLabs HDMI 2.1 is a solid recommendation, but use the shortest length possible as i2S wasn’t designed for distance.  Best of luck.