[shaocaholica]

Correct me if I'm wrong but I think a number of new(er) cars and 3rd party head units support digital audio over USB.  I know this works because I have an Alpine CDE-HD148BT which has a USB port on the back and I just plugged my iPhone5s into it last night and I was able to play music.  Not using a CCK or other fancy cables.  Just using the standard lighting to USB cable that comes with the phone.  Funny thing is, the track info (Artist, album, song, etc.) was also being passed over the same connection and the play/pause/fwd/back buttons on the head unit could also control the music app on the iphone.
 
What audio protocol is this?  Does USB audio support transport controls?  Or is this perhaps some Apple licensed protocol?
 
Without a CCK the iPhone isn't a USB host either and I'm not sure if that direction of audio data transfer is supported by USB audio spec.

 

[ProtegeManiac]

Some of them are iTunes/iPod/iDevice certified. Looks like that //////Alpine might be, considering they came out with the first "iPod transport" receiver that has no optical drive. The only thing I didn't like about it was they didn't make use of the space they saved to cram a Bass Engine Pro processor in there, when they have been cramming that next to an optical drive for years before it was phased out in favor of their external processors.
 
Most car systems/receivers were actually conceptualized with the iPod in mind - the first ones used a special cable to allow it to interface with the CD changer input, and allowed it to be fully controlled similarly through the headunit. Kenwood at some point was using an HDD-based replacement for the CD changer, but when storage got cheaper and people don't want that thing hanging in the trunk, we got USB ports for thumb drives. When Android got popular some of them added USB host compatibility, where the phone acts as the slave - essentially it's just a storage device when plugged in, without disabling the phone functions and also enabling calls to go through the audio system in the car.

 

[shaocaholica]

I was in a store the other day and realized that whatever my alpine was doing is exactly the same as a $50 radio alarm clock dock that's also lightning. So the days of digital audio over 30pin being special are over I guess since every dock stereo with lighting has to be digital wether it's $40 or $400.

 

[ProtegeManiac]

I was in a store the other day and realized that whatever my alpine was doing is exactly the same as a $50 radio alarm clock dock that's also lightning. So the days of digital audio over 30pin being special are over I guess since every dock stereo with lighting has to be digital wether it's $40 or $400.

 
Actually the lightning is better, there was just the transition period between having all the 30-pin accessories (if you have to plug in through cables, no problem; but some have a dock built into the DAC/transport, like the Pure i20) and the switch to Lightning, which on iOS7 also enables the iPhone5 to use the CCK for USB audio. I don't think receivers would have a problem since they just have a female USB-A port, ergo any sync cable and a properly updated FW on the devices on both ends should work.

 

[shaocaholica]

I guess I just missed the whole transition from 30p to lightning.  The Pure i20 isn't really anything special now that every dock -has- to go digital.