Re: Can we finally settle this?
Lightness, chroma, and sync are encoded with different frequencies, response curves, and emphasis. There is noise and dropout masking because the tape signal is quite dirty. Later models encode a stereo signal into the drum head too. I'm not sure why, but there are always pots for tuning the horizontal and vertical alignment between even and odd frames.
I just took apart a Betamax to help digitize some tapes. It has one large control board, two large analog processing boards, an RF daughter card, some small servo boards, and a speaker driver board. Most of the boards have all wires exiting on the same side so that you can put the player on its side and fan out the boards like an open book. I honestly don't know why it drives speakers. That was a mystery even when it was "state of the art."