ruh roh.
On a lighter note.. I vaguely recall from my dat-head days that someone was modding the mv100 unit to prevent preamp overload. I'd like to see the guts of this unit. I'm sure there's room for improvement and switching out a few caps and resistors might go a long ways to improve a modest unit.
I modded the gain on my mv100 when I had it (about 10 years ago I think?). IIRC, I re-did the gain so it was something like 12-18-28 rather than 20-40-60. The mv100 can take a pretty hot mic signal, but it has a relatively low max output voltage. So it can easily overload on the outputs when you're recording a PA-driven concert (ie, a loud source).
I found that set at 20db gain (it's lowest setting), it would often distort due to overloading the outputs when I was running neumann km184's -- which are pretty typical output for condensors, something like 15mv/Pa.
Unless you mod the gain structure, if you're using an mv100 for concert recording, I'd recommend using the -10db attenuators on your mics (which km184's don't have), or using attenuator cables.