Hey,
Got the exact same issue here aswell since I updated to 1703 last night.
Running on GA Z68X-UD4-B3 with Realtek ALC889 codec on the latest available R2.70 drivers.
I've reinstalled it 3 times, tried it with the Microsoft drivers but neither did work.
I can select "Dolby digital live 5.1" in the settings, however when im trying to apply it it just end in a incompatability
error.
Please fix it its overall a pretty decent Update but the sound issues are killing it completly for me.
Thanks for your patience
crype07