Is anyone using a HDMI cable for I2S connection between digital components?

You can get AudioQuest Cinnamon HDMI 4K cable for $29 on Amazon. Silver plated conductors. Good build quality. 

Best bang for the buck.

@soix 

OK -- thanks for confirming that. 

Any HDMI cable should work.  Its matching the I2S pin settings of the sending and receiving gear.  Denafrips has several videos that cover this.

https://www.google.com/search?q=denafrips+i2s+video&rlz=1C1RXMK_enUS988US988&oq=denafrips+i2s+video&aqs=chrome..69i57j33i160l3.19640j1j7&sourceid=chrome&ie=UTF-8#fpstate=ive&vld=cid:65f3af9f,vid:pXWvlC-5IPI,st:335

Unfortunately just like any other Audio Cable there is a difference and a high quality cable ($$$) is better.  My first HDMI was $ 100 and was better than the free one with the TV.  Then to a $350, then to $ 850.  Its like USB cables, quality (price) changes everything.

To all... thanks for the info. It's as clear as mud now. 😂 haha

@stuartk Most use an HDMI connection but can vary in their pin configuration that can lead to incompatibility issues.  Best to check with the manufacturer if a given DDC or streamer is compatible with their DAC.  

@soix 

I'm confused. I thought each manufacturer uses their own proprietary socket for I2S which makes it very difficult to find a cable that will connect between two components of different brands. Has this changed? What am not understanding? 

I've just used a good quality and short 8K HDMI cable and I thought it sounded fantastic. They're pretty cheap so you wouldn't be out much to try one.

I went from using an SPDIF cable to a cheap, short HDMI cable into my Musician Pegasus DAC and the performance upgrade was significant although this is specific to each DAC given the unique design of its inputs.  I’ve heard others say that upgrading to i2S is much more significant than the quality of the HDMI cable and that the HDMI cable should be as short as possible as it wasn’t designed to travel distance.  I chose the 6” version of this cheap Monoprice cable because it was the shortest I could find and experienced a huge upgrade over SPDIF, and although I’ll eventually upgrade to something like DH Labs I’m certainly in no rush given the sound quality I’ve got now for only $6.50.  Do your research on what input is best for your specific DAC, and if i2S is recommended start with this cable and see what you think as there’s very little risk. 
https://www.monoprice.com/product?p_id=13578

Hope this helps, and best of luck.