WC....I would have to disagree with you on the personality change, due to the equipment ( unless defective, or very poorly designed ). Our systems are susceptible to many things. Humidity, temperature, and some other incidentals, can effect the speaker drivers linearity in operation, and I have read articles on this ( they are on line ). Even though you might have a dedicated, isolated and very stupendous electrical system powering your gear, you are still dealing with drop outs, noise and other inconsistencies, from the grid, that can also effect the equipment, demonstrated by keoliphant and his Hegel. Computers in another room, power supplies for phones, florescent and led bulbs, RF contamination, microwaves, appliance motors, etc., can all effect the sq ( from a neighboring house, as well ). Tube gear ( all gear can, but especially tube gear, and tubes themselves ) can be effected by airborne microphonics ( I have experienced this many times ), as well as isolation, or lack of, of the gear. But once a product has truly broken in, I have found consistency in sq. Because I listen daily, I leave my gear on 24 / 7. We all know, some gear can be effected more than others; an example would be, more or less of a change, with one amplifier vs. another, when going through a conditioner ( the Hegel above ). Not to neglect our ears / brain mechanism’s, the pressurization that goes on, and, our moods, which can be triggered by a meal, fluids in our bodies, extreme thoughts, and of course, exhaustion, either mental, or physical. I hope this all makes some sense, as, I am tired...........later........
