Best Volume Settings?

I have read various past threads concerning volume settings to achieve the best performance. In the latest issue of Stereophile, reviewer Jim Austin addresses this topic in the review of the Benchmark DAC3. He stated " most systems achieve their best noise performance in the top half of their volume range". Additionally he also stated " with the DAC3 set to its highest output level - the default setting - it was too hot in my system".

Interesting concept, so I decided to experiment with the volume controls with both my Hegel HD25 DAC and Primaluna Dialogue Premium Integrated Amp. As with the Benchmark, the default level setting for Hegel was its highest setting at 100. As a comparison, I reduced the Hegel's output level to 80 and using a db meter I then adjusted the PL to match the volumes as best as I could. As a baseline, I tried to achieve the average output volume of around 85dB which wasn't easy based on the dynamics of various recordings. With the Hegel set to 100, the PL volume control was approximately between 10 o'clock and 11 o'clock. With Hegel set to 80, the PL volume control was between 12 o'clock and 1 o'clock depending on the recording. All the recordings included voices which I always use as a guide to determine the best sound. The recordings included early rock music and female singers from various genre. In order to do a true comparison, I switched the order of the output levels with each recording since our minds can play tricks on which sounds better.

So here are my results. Overall the system sounded best with the Hegel set to 80. At the setting of 100, it sometimes sounded a bit smeared or glaring. With some recordings it wasn't so easy to distinguish any differences. So is it the Hegel set at the max level or the PL set at the top half of the volume range or both? Either way the Hegel will no longer be set to the max.

I appreciate if anyone has had similar results with both the input and output levels.