Will the MD-Port mess with the sample rate or leaves it CD audio at 44.1kHz?

I'm looking for decent IEMs for a Cowon D2 which I'll buy later this week. I've read a lot about IEMs in my price range but it has not been very satisfying since usually there are some people who recommend these or those IEMs and some other people who advise not to buy those ones... Anyway...