I have the same NUC model next to me and sound via HDMI is working just fine with games, videos and music.
I recommend you trying the HDMI cable and use a direct connection (no video adapters). Besides this, I would recommend you updating the BIOS to latest version. Here you can get it:
I Tried updating the BIOS, no help, still the same problem
I then tried taking the HDMI out of my receiver, and move it to my TV, ( direct connection )
still the same problem
ps. when I use the minidisplaysport the sound is all degraded.
any other ideas
I now installed the driver from your link, the problem is still there!
I do not know if it has anything to say, but I installed the ram block in the lower slot !!
I have only one block installed, could it have something of say?
Can you please post your system information report here?
How to get it?
System Information: Click Start> Type System Information> Click File> Export> Save File> Attach using Advanced Editor Options.
I found the problem, It was not the NUC that had the problem, but my reciever.
I had an old PC for my Media center, and here there was no problem.
After updating my sound system, the problem has gone.
sorry for this