i just got one of these PEM's. i use it in the loop of my mark IVa combo. as we all know, these small box, 1x12 combos have some "un-dial-out-ables", that gives them major limitations. I normally use a boss ge-7 to scoop some 400hz and a touch of 800, to make the combo more ear pleasting. I replaced the GE-7 with the PEM in my chain, and dialed it to what sounded good to me. I'm not really aiming to copy any particular era of metallicas tone, but they were my favorite band growing up and learning to play, so i naturally gravitate towards their sound. I go for a mix between the punch and sizzle of garage days re-revisited ep, and the balls and thickness of garage inc. the cover albums have my favorite tone. The puppets tone is great, but its got a nasal quality to the mids that i can never really dial in exactly, even with this PEM (although i could have put in more effort to try) The justice tone is too scooped, Ride the lightning's tone is too muddy, The kill em all tone is passable for being amateur hour, the bob rock era metallica tone is god like, but it is a lot of bob rock magic and amp blending.
The settings that i used to sculpt the lead tone to my liking, actually made all the other channels sound a lot better too, which is nice. I kinda like how there are no frequencies printed on the pedal knobs, and you're kinda just turning the knobs until they sound good. I'm not sure i quite understand the concept of high shelf filters, but i seem to like the frequency set almost all the way up and the shelf knob almost all the way down. is that close to being set flat?