IPOD dock interface - digital or analog?

I want to use an iPod as a high-quality source unit for a car audio system, using Apple Lossless files. I will be using an Alpine CDA-9887 receiver. The iPod connects via an adapter cord that interfaces the iPod dock connector on one end to a DIN connector on the other that plugs into the back of the Alpine receiver.


Since Alpine is a "Made for iPod" program member, Alpine and Apple apparently consulted/collaborated/cooperated on the design because once the iPod is connected, the receiver controls are then used to control the iPod, and information normally displayed on the iPod screen now appears on the receiver's display. The Alpine literature refers to this interface as "FullSpeed" and says that the FullSpeed interface is digital.

My perception, right or wrong, from what I have been able to gather is that the iPod has internal D/A converters and amplifiers that output an analog signal to the headphone jack, whereas the proprietary iPod dock connection is a reconfigured USB interface which would pass a digital bit-stream. Unfortunately I have seen conflicting information on the car audio forums as to whether the dock connector is digital, analog, or both.

So I thought I would post here to get a definitive answer. Is the dock connection digital, analog, or both?

What I hope will happen is this: The iPod will connect to the Alpine receiver, control is turned over to the Alpine, a digital bit-stream is sent via the dock connection, which is then received by the Alpine, interpreted for codec used, and converted using the receiver's high-quality Burr-Brown D/A to analog for amplification.

I am told that the CDA-9887 supports Apple Lossless files, though the website literature on the unit doesn't specifically say so. However the information on the Alpine iDA-X001, a similar unit without a CD drive at all, which also uses the same FullSpeed interface, specifically states on the Alpine website "The Joy of Apple Lossless - The iDA-X001 supports Apple Lossless format giving you CD quality at half the storage space.". We'll see. I plan to take an iPod with music stored in Lossless to the dealer, plug it up and see if it works. :o I also plan to take files recorded in CD, Lossless, and AAC to see if any difference can be heard via this arrangement.

I have been hoping to be able to use an iPod as a high-resolution source for some time. Maybe this arrangement is it.

Thanks in advance for any input or insight you may have. Its a pretty significant investment.

Message was edited by: Synesis

G5 Powermac G4 Powerbook MacMini, Mac OS X (10.4.10)

Posted on Sep 1, 2007 8:36 AM

2 replies

Sep 1, 2007 7:32 PM in response to Community User

Wow.

I Googled "iPod dock interface" and found that the 30-pin interface provides leads for: analog audio out and in, S-Video, TxD and RxD, USB, and Firewire, as well as leads for charging, and accessory indicator leads.

So I guess the answer most any question about what it provides is "yes". No wonder there is so much confusion. But to Apple's credit, it is wonderfully universal.

So at least from the physical interface standpoint, it is possible that the equipment configuration I am looking at will do what I want to do.

This thread has been closed by the system or the community team. You may vote for any posts you find helpful, or search the Community for additional answers.

IPOD dock interface - digital or analog?

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.