Note: I abandoned further work on this, because I no longer use an Amanero or XMOS module which require this sort of connector. Instead, now I use Belden CAT6 CatSnake between my Singxer SU-1 (clone) and my ES9038Pro DAC.
You can find the article on that, right here.
I am working on uploading a video for this common question I see in chat rooms on IRC and on forums in DIY. The big things to remember when making I2S cables is that these are data cables and because of that they are transmitting in a high frequency. This means the “skin” effect could play a role if you use a huge solid or stranded 14g wire to do this. I don’t think that would even fit anyway, but take a look at this chart.
So they recommend using even smaller gauge than I went with. I am simply recycling an I2S cable I got with one of the I2S capable modules. It was just about the right length, but I wanted to improve on the non-reliable connection you push on seen on the opposite end of the cable picture below. This is the cable I made using 20 AWG VM-1 cabling, so if you have wire as thin as the above gauges recommend, go with it! Although most people don’t own 48 AWG lol.
I will update this post with the video when I finish making it. Check back later for that.