I can close my eyes and tell you what something sounds like. Try telling me what they look like on paper with your eyes closed.
I am not sure that is universal.
Both my old and new preamps have very similar harmonic structure, and they have a similar (lack of bad) sound… and the graphs on the reviews look exactly like what Ralph describes.
So just because you cannot hear it looking at the graph, doesn’t mean that Ralph and others can’t.
One negative thing about the ASR testing, is that they only focus on SINAD, and I find a hissing amp to be pretty distressing, and would take some harmonic distortion over hissing. And then there is no weighting, like a discount for 2nd and 3rd harmonic, compared to all/any spray to the right… but the Audio Precision test equipment just kicks out a signal number.
So I do not think that it is out of the question for Kurbio to ask for objective proof. Ralph has been talking about the distribution of the harmonics for a while, so to see it would be dandy way to objectively show some of what makes them sound good..