As I mentioned over in the installations forum, I have an Empeg unit connected to the line in of a Philips Carin 440 head unit and it works fine.

Ideally, the existing head unit needs to have a line input that can handle the 4V output from the Empeg unit. If you have a line input that can only handle lower voltages then it should be possible to drop the Empeg's output signal voltage using a pair of resistors forming a voltage divider on each channel, which I tried then found wasn't needed. Taking this a step further it *might* be possible to feed an existing head unit via one of those "plug your personal CD player into your head unit's tape slot with a pretend tape with a wire hanging out" gadget, though I doubt if the quality you'd get using that route would do the Empeg unit justice.

Cheers,

Mark.