My set-up:
NAS: QNAP TS219p (running Twonky Media Server Version 4.4.17)
Media player: Zyxel DMA-2500

I only used it so far with some shoutcast radio station, but what if you have a radio station that’s not listed on the shoutcast list?

Answer: CREATE A PLAYLIST!
Just create a playlist file in m3u format.

It should look something like this:

#EXTM3U
#EXTINF:-1,HARD.fm @192k mp3 – Your #1 Hardstyle Radio

http://192.mp3.streams.lsw.evo.hard.fm:8000/

Store your .m3u file in one of your Twonky media folders and re-scan your folders.

If I go to my media player i can connect to my Twonky server:

Then select Internetradio and there should your station be listed:

and PLAY!