"Reckon it likely starts with "TDA..... "

Yeah, then you find it and find out you can't get quadrature, or itwon't ocne out of muting even with the switch. Or won't mute.

They weren't quite into change for the sake of a buck like today, but they did have the idea to be exclusive. that is why the "audiophools" for more for the 1970s stuff. Some of it did sound just as good or better, and there were practically no ICs. This **** can be fixed until the end of time.