No worries guys, found some good info from search archives posted by huggyg71.
But if anyone knows how to set up headphones so they work with 5500 I would be even happier!!
There seems to be know way of bypassing speakers. I do have a multi card reader with headphone socket which I have plugged into line out but I assume due to the digital connection this will not work. There is no headphone socket supplied with Dt5500 so if anyone knows of another option let us know.