Volume Setting on Audirvana

I’m using a Unison Research Amp/DAC and a Macbook air laptop in my system with
Audirvana. What is the optimum position of the volume setting on Audirvana for sound quality or does it make a difference?

On 100% or software volume control disabled. Audirvana claims that software volume control they implemented is in theory lossless, but as with every software volume control the output is now bit-perfect.

Alex- thanks
just to be sure i got it right, by software volume disabled you mean the slider is all the way to the right
i.e. 0 db; am i right?

Either that or just toggle the software volume control to off.