I believe this represents attenuation (negative numbers) or gain (positive numbers). Zero would be "unity gain" meaning that the signal is passing without attenuation or amplification. I have the same behavior on my Meridian gear and assume that NAD uses the same representation of signal cut or boost. Hope this helps.
NAD Negative powers on Volume Control?
Any idea on the philosophy behind this? I recently purchaased an NAD L72 Integrated home theater amp/tuner whose volume control starts at -61 and goes up. By 1 substantial volume has been reached-- why do this? I scaled down from McIntosh, their manuals are quite detailed but NAD offers few explanations for any of its features.