FWIW, when I had my Mac Mini wired directly via ethernet to the Devialet, I also had wireless on the Mac Mini enabled as my music is stored on a NAS.
However I do not use anything other than Roon so I cannot relate any experience using iTunes.
When you say the Devialet application, do you mean the one that you can use on your iPhone? For that to work, you would need to enable Wifi on the Mac Mini and possibly connection sharing as well. Apologies as I have since moved to both the Mac Mini and the Devialet being wired via ethernet to a $20 switch, so I cannot fully test this for you.
Try this:
Sharing Internet to a Wired Device
Launch System Preferences.
Select the Sharing pane.
Click Internet Sharing in the left pane.
Click the drop-down menu beside Share your Internet connection from and select Wi-Fi.
You may have to also select the port to enable ( which in this case would be ethernet )
However I do not use anything other than Roon so I cannot relate any experience using iTunes.
When you say the Devialet application, do you mean the one that you can use on your iPhone? For that to work, you would need to enable Wifi on the Mac Mini and possibly connection sharing as well. Apologies as I have since moved to both the Mac Mini and the Devialet being wired via ethernet to a $20 switch, so I cannot fully test this for you.
Try this:
Sharing Internet to a Wired Device
Launch System Preferences.
Select the Sharing pane.
Click Internet Sharing in the left pane.
Click the drop-down menu beside Share your Internet connection from and select Wi-Fi.
You may have to also select the port to enable ( which in this case would be ethernet )
Roon ROCK on Intel NUC6i5SYH/Ethernet | VPI Avenger | Devialet 440 Pro CI | Vivid Audio Giya G3 | Auralic Aires Mini | Synology 1812+ NAS
SXSW, US
