WIth some things the differences are clear.
ALthough I have heard what seem to be some digestible theoretical arguments about how or why different digital cables may sound better, I have not detected much if any noticeable differences to-date myself. I am of the mindset that the differences that may exist are relatively small and not as common on the grand scale of things in practice and that there are many other things one can focus on to improve sound that is more likely to produce dividends. Even power cords and analog ICs... I do hear significant differences with those almost every time.
Digital ICs is just one thing that has not mustered much concern on my part to-date. I'm sure others will disagree though. Especially those who design such things with very strict tolerances with such things in mind.
