The Snake River Boomslang is quite warm. Personally, I recommends something more neutral in this position, and if yer after a level of warmth, do it father down the chain. This is just a personal system building approach for me; might as well get all the info from source to the DAC, then think about ‘tuning’. 

Try a Black Cat Digit-110 aes/ebu cable. 

I have used Snake River, DH Labs, Cardas as well as Transparent. For my system the Transparent sounded best.

+1 Acoustic Zen. I don’t have their digital cable, but I have several of their interconnects and speaker cables and all are supremely musical yet still have excellent detail, imaging/soundstage, and tonality.  In short, they’re very natural sounding.  If this sounds like it’s what you’re after then AZ is well worth a look. 

I’ll second the Sake River Audio Boomslang AES/EBU. I replaced my DH labs silversonic, which is great for the price.  The Boomslang was a clear improvement in my system, albeit for a lot more money. 

Acoustic Zen.

Can't go wrong with a DH Labs SilverSonic.

Thank you.

Snake River Audio Boomslang AES/EBU

yes?

This is a pretty important connection. I am not sure what you would consider low end. Given the combined value of the two pieces is over $5K I would consider putting in at least a couple hundred and revisit once it is all broken in… or maybe just a cheap one until it is all broken in and you know what the units sound like together and then carefully choose one to complement them.