On the list for 2019 projects is upgrading the(std) factory stereo-original Alpine built radio/cassette/cd changer:It all still works good except the cassette,plan to keep the original head-fixing the cassette player-upgrading speakers if needed.adding amps and replacing the factory subwoofer setup with something more substantial-all with high grade "old skool"stuff.Mostly wondering if pre-amp outputs are avalible on the factory head unit or if I will have to dig into it to bring out some pre-amp outputs...