Hello guys, since I got the pin assignment of the radio plugs this week I could solder a cable with DIN plug (both from CONRAD) together with which you can connect an MP3 player oä to the HU603 (or any other HUXXX). Now only one thing is missing: The radio does not recognize that one source is connected. What must be pretended to the radio think it is a changer connected?? If that is clear everyone can use less than 5 € and a soldering iron e inen MP3 player connect to his radio!! So WER has a WECHSELER and an OSZILLOSKOP that please contact us. Or if anyone else has any idea how to do that. Thank you. Greetings Andi