convert a DS car charger to a USB charger

I am changing my old DS car charger to a USB charger for my MP3 player. The charger puts out 5.2 volts, is that safe to use with my 5 volt MP3 player our should I add a resistor to the circuit?

110100101108 years ago
usb specification is up to 5.25 V so theplayer should be able to stand that in fact there are players that dont like it. for example i know of a player that froze in some computers where the usb did supply a bit over 5.1 V if you charge the player when it is turned off there are less internal circuits that get the voltage