Hi. I was wondering about the iphone 5s and the lightning to usb cable. It says that the lightning cable can only output digital, so if i connect it to my cars cd player, and play music from it, wouldnt it bypass the internal dac in the iphone?
No, you need a very expensive external DAC that is licensed to bypass the internal DAC of iPhone. Something like Fostex HP-P1 which I think runs ~$600USD. All other times you are using iphone's internal DAC.