I found root of the problem.
It is Windows 10. This OS is so broken, that sound doesn't work properly. Neither does having 7gen. processor with Nvidia GPU (stuttering).
I tried Windows 8.1. I installed it with no problem, every driver made for Windows 10 works on Windows 8.1. Sound driver works without issues. No MaxxAudio, but it's nothing. Not to mention, I installed it entirely on a USB 3.0 flash disk - and it just works.
It is an absurd that Microsoft makes Windows 10 "The Only One Windows Compatible With New Hardware" and it has most bugs of all the systems. No updates for older systems when installed on "incompatible" 7 gen processors? That "update lock" depends only on checking processor name...