I think RGD’s question is about using the digital volume control on the PC versus the analog volume control on the Adams.
In the audiophile world digital volume control is a no-go area as one loses resolution.
When using digital volume control to a large extend this is indeed true.
However do you need to worry?
A very simple experiment is to put the gain of the Adams to the max and to the min.
Try to macth the loudness in both cases and check if you hear any substantial difference when using massive digital volume control (max gain) or moderate (min gain).
My advice would be to adjust the gain on the Adams such that they play slightly to loud.
The use the digital volume control of JRiver.
This not only protect your speakers against any blast from the PC it also improves your confort.
If there is something as consensus in the audiophile world (there isn’t) it is that modes digital volume control (-10/15 db) doesn’t yield any audible degradation.
I did the experiment on a pair if K+H300.
Had a very hard time to hear any degradation at all even when using a higher reduction
http://thewelltemperedcomputer.com/Intro/SQ/VolumeControl.htm