Go to naim.vtuner.com and create a login using an email address and the MAC address of your NDX2.
Find the URL of the channel you want to add. Hopefully the station will provide it on their website, or you can contact them and ask. Add this to vtuner, then it should appear in the Added Stations section of the iRadio input.
I have to be a member to add something. I send an e-mail to vTuner so I can add (i hope)
For threw this link: http://stream.syntheticfm.com:8040/stream I play it on my iMac. Then I can play extended and found my NDX-2. Only it is threw airplay. See pics.
Adding a station manually in this way is great if the station is not already listed in the Internet Radio input. In this case there are a couple of SyntheticFM stations already listed, so I don’t think you need to mess around finding URLs and adding them manually.
Just go to the app home page and type synthetic fm into the search, and you will find them. Then save them as favourites if you want.