• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

McIntosh MC30 phase splitter

The Positive FB is only ~2db. I've both measured & calculated it. And it is not applied to the output stage but rather at a lower level stage where it is less of a distortion problem.
People talk &guess a lot but not many do the work to get the real answers.😀
 
stewart9, this ought to be obvious to you. If for no reason than this idea of yours that Frank and Gordon did things perfectly is utter bunk.

It is a commercial offering that made them $$. That in an of itself ought to be enough proof that the amp can be improved.
cheers,
Douglas