Thanks for the idea. The problem was the the device was connected to USB 3.0 port (for Dr.Dac2 it doesnt matter) but for X-Sabre made sense.
So now it works properly. No interruption, no clocking, and it is switching modes (44.1, 48, x2, x4.. etc) depends on quality of HD video and FLAC record automatically.
Put my Dr.Dac2 on the shelf and begun to choose headfone amp with XLК inputs. Believe that would be Quattro from Matrix.
wait, does this mean the x-sabre is not compatible with usb3 ports? i currently have only usb2 ports from my pc but new motherboards have only usb3 ports, and new macs only come with usb3. does the x-sabre not work with those?