There are issues with blind A/B tests. I'm not an expert, but Robert Harley has written extensively on this over the years. In any case, without claiming that the AVA, Rotel and Odyssey amps I compared are anywhere near identical in specs, I know what I heard, in my room, with my gear, with my music. In the end, for each individual, that's what counts. To paraphrase Einstein: "Not everything that counts can be measured, and not everything that can be measured counts."