ITunes from Iphone or Mac Air to Arcam Network Player

See link below on streaming from iPhone/ iPad / Mac Pro through an external USB input DAC etc.

Substitute your own DAC (with a USB input) for the AQ DRAGONFLY Red DAC in the link article

You will need some more link components first .

(1)buy the intermediary APPLE Lightning-to-USB Camera Adapter coming out from the MAC AIR 
(2) buy a quality - build suitable USB cable (don’t chintz it here ) to link the APPLE CAMERA adapter to the suitable  input into your external DAC 
(3) Buy a quality- build cable for DAC output (don’t chintz it here either ....) from your external DAC to the suitable input to your preamp .....

https://www.wifihifi.ca/LatestNewsHeadlines/Hands-OnReview:AudioQuestDragonFlyBlack1.5/Red.html

The ARCAM control app has been reviewed as “not the slickest either.....most find it a bit buggy. “

Back in 2015 Arcam says it’s “working on” the compatibility issues

I have similar failing grade control app issues with my ARCAM SOLO NEO unibox in my “B” system. To call it buggy is a gross understatement...frankly it sucks. To be blunt , my iPhone and iPad are useless with it.., full stop.

IMO you can forget about ARCAM ever fixing the app, and thus your options are either:

- just live with its significant control app warts along with its strengths; or
- sell it and move on to an APPLE friendly brand.