I found an adapter that plugs into the mach 460 head unit and outputs RCAs. The back has a 20 pin connector to add an external changer, even though it has a changer built in. Basically it just plugs in the back and you have to tap a 12v source and ground it. Then just plug your RCAs into it. The module also changes the CD button so it toggles between the CD changer and the DJ, which is your RCAs. Works nice and keeps your head unit fully functional. I don't have the link anymore because I bought it over a year ago. But if you search the net I'm sure you'll find it.