Valab Dac Moacbook and itunes

Ive just bought a Valab DAC which I am trying to use with a Macbook via a USB cable from the Mac into the USB input on the Valab. It works great with recordings Ive made in Garageband; the Valab is immediately recognised by the computer and works well, however I am trying now to play music from my itunes library on the computer but in this application the Valab isnt recognised and the music just comes from the tiny speakers in the Mac book.

Is there a way to get the Mac to recognise the Valab via the USB so I can play my itune library through the Valab?
Any advice greatly appreciated.
Open the 'System Preferences' application, which should be in the 'Applications' folder on your MacBook.

Click on the 'Sound' icon, which will be in the row of 'Hardware' items within the System Preferences window.

You should see two devices listed there, the internal speakers of the MacBook and the Valab USB device. Click on the Valab entry and the sound should be directed to it rather than the internal speakers.

Sometimes the MacBook will 'lose' the selection you've made previously and you'll have to go back into System Preferences and reset the Sound output to the USB device.
Open preferences and then audio and select it. Then open Utilities - Audio MIDI and select the correct sample-rate. Then try again.

BTW, iTunes playback on Mac is improved with Amarra or Pure Music.

Steve N.
Empirical Audio
Thanks Sfar and Audioengr
Really appreciate your advice, will let you know how it goes
All the best