It's look like some did: http://www.bursonaudio.com/asus-xonar-stx-sound-card-upgraded-with-burson-opamps/#comment-71 

i found the tf10 an excellent earphone for the price standpoint and don't have durability issue using it. I am using the vi version which comes with an even thinner cable. Weak part may come from the connection between the cable and the earphone. Many users also complain about the comfort of...

I won a voucher recently and I was thinking about the 8Go ipod touch... The thing is there is 2 refernces: MA623ZK/A and MA623ZK/B and they are also sold at different prices... but I can see/find any differences about them. Anyone knows?? cheers