Headunit alternative?

[woofercooker]

I have a 2013 3 series with stock audio system i want to install some of my own SQ gear and bypass the oem system but i need a good source unit to then connect to my own amplifiers. Ive heard the headphone jack on an iphone isn't very good does anybody have any other idea's?

 

[Rilot]

Dock-port / lightning based aux output? It bypasses the internal amplifier that way.