Does ok on dynamic mics, not capacitor mics, tried swapping stuff round, wires mics, amps, but couldn't get 2 cap mics going together. dynamic mics are ok, no problems.
Mics lose a little brightness, but not too much to correct on the eq, lose a little volume too, but easily corrected on the amp gain knobs.
All told, it's certainly worth the few bucks of cost.
Works great for all line signals.