and now for something completely different part 3

[JoaMat]

Perhaps you are right, but that’s nothing I can verify.

It’s correct that pos input is dancing. Now I think that the neg input is a perfect dancing partner which results in a working servo. With the servo the amplifier behaves similar to the ones without servo except that the bias doesn’t drift.

And cross talk? Not a problem - I’m married and used to cross talk.