these look to have the same body as the ultrasone 580s and these beyers
are popular replacements for them. I believe some searching on headfi turned up some successful installs too. I used the pads off of my panasonic HTF600 with good results. They have the same shape as the beyers. TDS was going to go into BH or somewhere and see if there were any exact fit round velour options but I don't know if that has happened yet or not.
I had some akg 518djs for about a day. That wasnt enough to get a real good sound impression other than I liked them...the comfort wasn't acceptable to me at all. the cortex are much better. but as Marv said, they are a bit bulky.