My friend had an old cd changer to ipod/AUX adapter knocking about that I had, and this seems to work now; only trouble is that the sound quality isn't very good. This couldn't be down to the adapter could it? I've tried to play other stuff over the AUX and it sounds allright, but playing from the USB on the TPK the audio quality isn't very good at all, very crackly and just sounds like it has a really low bit rate

EDIT: Right, I tried playing from the AUX over the TPK, and that sounds fine, so it can't be the adapter or the audio processing on the TPK, but something in the way files are played from the USB that makes them sound bad....