I've been having the same problem with my fresh build on a Gigabyte z170x-UD5 today, using onboard graphics and audio.
As of typing this, I'm doing a fresh install to try and re-apply drivers properly (since I spent so long trying to fix it that I may have muddled the whole thing more)
EDIT: Oop, I was trying to do HDMI audio, but if I could get audio jack audio stable instead that would be a good compromise for me