Gotta protect the integrity of that power

Most of it is gibberish, of course, but this statement

"Suddenly, the noise floor drops"

looks like it's saying something that could be tested (and surely isn't true).

Someone's slipped up.

Sylvia.

Too bad what happens at the powerpoint (and beyond that) as well.

If mains born noise really is a problem, the best solution is an isolation transformer, one with as much iron as possible.