LOL by what, other flawed equipment?

The subtraction of signals, for instance, takes the test equipment out of
the picture entirely.

Uh, no, that's just what you'd like my position to be so you can jump on the
bandwagon and toe the party line.

People who have built amplifiers and understand their architecture say one
thing. People who have not built amplifiers and don't understand their
architecture say another thing. I wonder why that is?