This is a really interesting article (to me anyway) about polarity. Back in the 70s we used to “opps” (reverse) only one channel of our phono signal polarity at the cartridge then reverse it back at the same channel at the speaker terminal. It therefore put once channel 180 degrees out of phase with the other through the entire, fully analog signal path until it got to the speakers. It was purported to speed up the amplification circuits. May have been smoke and mirrors or not, don’t remember, just remember doing it…
