Connecting to your docking port on your iPod/iPhone/iPad gives you access to an uncompressed music port that will connect to any auto head unit with a 3.5 mm (1/8") auxiliary input, dual left and right RCA's on your home stereo/receiver or professional XLR’r or ¼" audio connections on a soundboard or PA system.
You can also import music from your CD collection in a Lossless audio format for true CD quality sound. My Lossless imports on the iPod are limited to only Miles Davis - Kind of Blue and Herbie Hancock - River: The Joni Letters. Lossless uses a lot of memory and Apple's ACC(Advance Audio Coding) is better than the MP3 audio format and sounds pretty good for most music.
Let's get back to connecting your iPod/iPhone/iPad. The docking connector is a true line level connection, which means it is not controlled by your volume and is a steady-state signal. However, equalization settings on the player are still in effect and you can vary the treble and bass, depending on your preference. Of course mine is set for Jazz. At home I use a docking cable with the optional USB cable plugged into an AC outlet to USB 5V adapter for charging. In the car the 3.5 mm (1/8 inch) with optional USB allows charging from the cigarette lighter using USB 5V adapter.
