The Galaxy Tab 4 is a dual-role Android device: it can work with a standard USB peripheral like the Mojo.
Android USB audio - A list of stock Android-powered devices reportedly interworking with compatible USB DAC
http://www.head-fi.org/t/595071/android-phones-and-usb-dacs
"To use Mojo with an Android device you will need an ‘on the go’ cable (OTG ). This is a special cable that tells the Android device to run in host mode and enable USB audio. Some devices with newer Android operating system ( 5 and above ) will then play all audio into Mojo.
If this does not work then you need to download either USB Audio Player Pro or Onkyo HF player to enable USB audio support. Both are available from the Google Play store."
http://www.chordelectronics.co.uk/mojo/manual/Mojo-User-Manual.pdf
Android USB audio - A list of USB Audio Player PRO resources (compatible USB DAC, compatible Android devices, ...)
"Important: connect your device BEFORE starting the app, otherwise it will not get detected!"
http://www.extreamsd.com/index.php/2015-07-22-12-01-14/usb-audio-driver
Android USB audio - FAQ
"Q: I have an Android device, a USB DAC and a USB OTG cable which are reportedly compatible, but I have not been able to make it work. Is there a trick to make it work?
R: …"
http://www.head-fi.org/t/595071/android-phones-and-usb-dacs