I'll tell this story somewhere it'll be appreciated; all of my friends think I'm crazy. In early February I got a nice used pair of Sennheiser HD600's off ebay with my tax refund. They were barely used with one soft dent in the mesh on the right cup. What the owner didn't tell me was that he had run over the cable with his chair (many times) and therefore the shield is visible in a couple spots where he cut the jacket. After a week of blissful listening I ordered some Canare L-4E6S, a set of Cardas headphone plugs, and a Neutrik right-angle 1/4" plug. People weren't kidding when they said those Cardas plugs are heat sensitive. Even putting the heatshrink on made their strain relief tail really soft. Anyway, I'm super happy with the final product of three hours of very, very careful soldering and a million continuity checks. I haven't A/B'd the stock cable yet, but I don't think it'll be a huge difference. The biggest plus for this thing is how robust it is and the pride in building it myself.
http://imgur.com/a/FFT06
http://imgur.com/a/FFT06