Demon's Souls 60 fps patch audio stuttering

The game works perfect with default 30 fps lock. 60 fps patch also works stable, but after about a minute of gameplay audio starts stuttering, can be fixed sometimes by going windowed mode and back to fullscreen. Tried everything i found on internet: different audio settings, SPU threads etc. Log file attached.

My specs:
Core i7-4770k Haswell
16 Gb DDR3 1600 Mhz
GTX 1050 Ti
Crucial M550 SSD Drive
Windows 10 x64