I did it too, I got a HD 650 cable as a replacement for the damaged cable of my former HD 535. The HD650 cable was cheaper (?!) (at Thomann cyberstore), of course I expected better sound quality, last but not least by avoiding the 6,3mm/3,5mm jack adapter.
In fact, it sounds better and the coating is thicker and softer resulting to less mechanical noise if you move the cable. The same cable connects now my HD565 Ovation.
But my HD650 cable connector seem to loose contact both in the HD535 and in the HD565 cans (mostly on the right side), which didn´t apear with the stock HD535 cable. I don´t know if the connector pins are bented or the plastic connector socket form doesn´t exactly match to the cans. The 650´s cable has a larger connector socket than the 565´s.
Anyway, contact cleaning spray doesn´t help really. I have to press the connector stronger into the can´s sockets, then I hear and "feel" a "click" and it sounds again loud and full. But after the next movement the loose contact is there again...