Docking station for an iphone

Is there a docking station that can retrieve the digital audio signal from an iphone to be sent to a DAC? 

I’d like to know as well.

My understanding is you can use the Apple Camera adapter wire to go from Iphone Lightning port to USB and DAC. It cost about $35 as I recall. Its the only Iphone to usb wire option that works I read

Anyone using it that way? Sound quality?

The lightning to usb wire taht comes with Iphone to charge does not work for audio out. You'd think it would but you  have to buy the extra wire from Apple if you want to do that.   Clever Apple!  Should work to a tee I would expect if you have to pay extra for it.

There may be other kinds of devices that can do it. Have not done that research though.

As I side note, I have found quality of analog out audio from newer Iphone 6s and Ipad mini to be better than expected and might be good enough to fit the bill for many. But I would like to be able to use my external DAC as well with Iphone.

What is the source of what you are trying to play from the iphone? Are you looking for convenience or highest sound quality? What inputs types are on your dac? 
For convenience you can get a usb bluetooth receiver that will attach to the dac and grab any signal from the iphone or other bluetooth device. 

As with most things digital, a question usually leads to a few more before a good solution arises :-)  Cheers,
sbank what options do you know of?   I like sound quality and convenience.   Might sacrifice some latter for teh former if needed.
I'm pretty sure that Wadia made one.  I think it was the 171i that worked with the iphones.
Yes but there is an adapter for the lightning connection of the later versions of the iphone. I use this and it works fine. I have my I20 running out to a Bifrost Uber extrenal DAC. Sound fantastic!
I’m using a powered usb hub with the lightning adapter with an Ipad Air 2. I use a Halide dac as well as the built in dac in my integrated amp. Works very well streaming Deezer and is dead quiet. I am considering getting an ifi usb 2.0 hub to see if further improvements can be had.
What drove my interest in this was that I have a friend who streams Pandora via his iphone. As I am now helping him set up a macbook pro as a music server I will advise him to use that instead. I remain interested in the options for iphone use however. Thanks to all for this discussion.
The lightning connection coupled with a usb hub will work for an iphone as well.

One product that may be of interest is the "Shift" from Peachtree Audio. It is a portable battery powered usb dac that will also charge your phone. Apparently it was designed specifically for iphones.

So use lightning adapter with USB cable to powered USB hub with USB cable to DAC.  I have a Doukmall USB cable that separates USB power from audio signal which might also work in place of the hub.
I will likely be trying the apple camera adapter and powered sub hub sometime soon.   
As long as your device see's it as being self powered you should be fine. When I researched this about a year ago I found this blog which has some good info.

Mapman, I intend to try this also. Between a UDAC-2 and my phone I can have a portable headphone system.

Thanks chrdhanl37. Your posts and blog were the ticket.