if u bought ur nw-a608 from japan , it is impossible to change the radio frequency that is bcoz sony made a certain range frequency for players in each country, eg. the range for japan nw-a608 is way smaller than the 1 in U.S. As far as i know it is impossible to change the frequency, which is very weird coz sony could hav made 1 player that hav a large radio frequency range. This information is according to my friend which also has a japan version nw-a608 !