I have some prototypes.. I haven't worked on anything toooo solid yet since I built a prototype, really liked it.. and have been using it since. Its silver plated copper braided and in multifilament nylon sleeving, about 6 feet long. I got the ultrasone screw on jack from qables.com and fitted a make-do jacket that works for me. It sounds more detailed and less veiled than the stock cable and seems to have better resolution though maybe ever so slightly less bass, but thats the least noticeable difference and maybe the only con. since my friend has my USs for a while, I could let got of this for like 60$ or so.. Its got a neutrik mini jack which is ok but I have some switchcraft 1/4s if you'd prefer.. anyway, contact me if you like.. can chat on some messenger..
(My other cable is a shorter (2') mogami starquad cable with a more make-do kind of jacker but a nice switchcraft mini jack, sound is just as improved.. more detailed, higher resolution, less veiled, but no bass loss at all and less harsh highs.. I cant decide which I like better but they've completely retired my stock cable.. anyway, this cable isn't available right now..)... I could also build one :P but I've got less time for that lately ;/
-Russ