Here is another option for a new cable: LINK
I just got this cable. So far it sounds pretty good. I got the shortest length (1.2m). Looks great and classy with my HD598.
I have listened to a few different songs and cannot notice a difference in sound quality (though maybe my ears are not that sensitive).
The only gripe I have, is that the headphone connector (the small jack) is a little stiff and hard to grab to pull out once put in, and can be a little stiff.