Hello Jim, thanks for the link, I guess I've made some progress..
I could activate the DNLA system and I could see my soundbar and the television, but not the Apple TV neither the Bluesound node.
So I've been running my files with the soundbar as "zone" in the media center and I noticed the soundbar was connected using WIFI and not the ethernet cable.
May be that's why I wasn't able to read most of files: the media center was unresponsive with color wheel spinning most of the time or media center stopping reading, this mostly with big files like dsf or dff files.
So back to the usual player on the media center..
I noticed the Bluesound node is bluetooth ready, so I could connect the media player to the node in tools - options - audio using node bluetooth as "core audio" which is giving me 32 bits/48000 and keeping the media center pretty responsive.
I received a lot of music files in dsf, dff, DSD and others, I may say that it sounds completely different from the mp3 I'm used to play, the quality is at the rendez vous..
Next step will be to try to connect my soundbar directly to my computer and the media center so I can get rid of the Bluesound node which is a real piece of sh**, for mp3 and flag files this is ok, but it is not reading Hi Res files like dsf, dff, DSD64, 128, or 256.
So muchas gracias, I hope this will help others and I will upadte if it's ok for you.
Best wishes
Isa