The reviews are true about the EAR Phono Classic

A couple months ago, I bought the EAR Phono Classic (Phono Box outside the U.S.), an upgrade from my long-standing phono pre-amp, the first iteration of the Acoustic Signature Tango. For my low-gain version of the Grado Sonata 2, I was told to set the Phono Classic for MC to get the necessary boost. I did so and started playing a lot of music.
I liked the amp and it sounded different than my Tango, but at times I felt not necessarily that much better. I found myself spending a lot of time trying to pinpoint what, exactly, was missing.
Herb Reichert reviewed the piece in Stereophile and said he much preferred the MM setting, except when used with a SUT.
Last night, for the first time, I depressed the switch in the back to MM and turned the front knob on the EAR to maximum volume and then played a record.
OH MY GOD! I was up all night. Using the MM button completely transformed my system. I couldn't believe the realism, depth, image - all that stuff - pouring out of my speakers unlike ever before. Hearing Zoot Sims on the unjustly forgotten classic "A Gasser" by Annie Ross practically had me in tears.
In short, Herb was right: The MM setting - for whatever reason - is radically better than MC on this amp. It turned the EAR into a world class piece, probably the finest piece of equipment I've ever owned next to my Pulsars.
I have no idea why the settings on the same amp would produce such startlingly different reproduction, but there you have it.