This is the opposite of what the "theory" is. You should use the volume knob for your volume (analog) instead of digital volume (computer). You should set the DAC (D30) to max inside of windows at all times and in your applications, then you control the volume with the knob. You turn the "gain" up when the volume is at max and the volume is too low (which increases the amount of power by the multiplication of the gain). That's about what I use on my setup (D30/A30). I have also used the A30 now with some other DAC's (Schiit Fulla2 DAC-Out, SMSL M8, SMSL M8a, Schiit Modi Multibit). It sounds great with all of them and I continue to listen it basically all day every day!