I can't help, but I have a similar problem ..
When I'm trying to 'set up a microphone', the input levels automatically adjust themselves .. down to the point that the microphone is useless.
I've been looking for a solution, but when I saw your post I thought that perhaps if my board is generating a bunch of hiss, then the software may try to adjust it out and that would be that.
So perhaps we are both looking for a solution to the same problem. I've tried several different microphones and headsets on both the front and rear jacks with the same results.
Hope someone knows how to correct this!
Off Topic - when I search from the home page of 'Intel Support Community', I get results, plus there is a search bar on the results page.
Anything -- and I mean ANYTHING - I put into this new search bar will return 'no results found ..' .. kind of annoying.
Thank you for your time.
Audio drivers should be installed after the INF file to be sure everything works before proceeding with the installation. Newer systems seem to allow more leeway with regard to removing the driver at a later time and reinstalling. Since the levels may be adjusting to the speakers it may help to reinstall without microphone or speakers connected.