nonoise
As for measuring, I had to turn down my volume by 2-3db because after changing directions, it was too loud.
auxinputThat being said, I also have experienced the 2-3db effect when changing fuses or power cords or op amps.
Really??? 2-3db difference in absolute volume because of changing the direction of the mains fuse? I’m stunned and speechless.
Cheers George