I, "chock up" the very noticeable improvement that I (and everyone to which I’ve demonstrated the effect, in the past 40 years) have heard, to a redirection of the magnetic flux that surrounds most power transformers. That’s called, "PHYSICS". In the case of my Cary’s: it may be attributed to the power and output transformers being within one inch of each other (not to mention the input wiring). Given the plethora of variables, that exist within this hobby; I’m not surprised there are experiential differences. Of course: opinions - experience = abject ignorance (however, "projected").