The real question is what happens when you use a highout put MM with a phono stage set up for real low output MCs. I guess you sit there with a catchers mitt grabbing pieces of speaker cones and motors or leave the attenuator on max defeat, and listen for cross talk, selecting your tuner source even if you don't own a tuner.
What happens when?
What happens when you run a MC phono cartridge into a MM phono input on a pre?