16-03-2015, 12:11 PM
Hi David, I agree with Sparky, keep it simple. Provided your not using a live chassis radio and your MP3 player is not earthed there is no need for isolation i,e. a transformer. The players output impedance is low, (50 ohms or so) so it will easily drive the gram input of the radio. Impedance matching is only important in that the load, about 500k ohms (the radio) does not unduly load the source (the player). Its unfortunate that these players rarely have line outs so your stuck with the phones out.
Peter
Peter
