Hello Zephyr - my system for the most part is very close to the top end Purist Audio / mixed with top of the line Cardas. I listened to a few digital cables and - was surprised to hear that they did make a difference. This digital cable will be going between my Esoteric CD player and an Esoteric clock. I ended up going with a PAD Dominus Luminista ( BNC connection ) from an older although good, Purist digital cable that it actually did make a sonic difference in the system.
So even on a clock it was noticeable and that was question..... However that cable was $1,700 which is not cheap. I was now wondering as it is only about 4 weeks old - if there is an auditable break in period on that cable as it is feeding bits and not an audio signal ??....hmmmm don't know.