I bought one of these as my own B-day present. It was used, cheap (the price of a MB), and it came whit his original box.
I play whit it whit my amp, and made this video:
First the mic straight into the amp, then whit the Mic100 preamp. Those 2 segment where at the same volume (tested whit decibel-o-meter app), and the last segment is louder.
First test whit the Mic100 is whit gain at 0 and the output at 1/4, then the gain almost all the way up, and the output almost down.
Harp: Honer Marine Band in A Mic: DIY $2 dynamic element from a vocal mic. Amp: Laney Cub 10 (Eminence 1028k speaker) Tone:5 Volumen:10 Gain:3.
The Mic100 add some nice grit to the sound, and there is no change in sound (I like that).
Last friday I use it on a gig, first straight into the PA, then whit my Harpbreak. Straight into the PA is a nice pedal (works as a DI Box) you need to eq your chanel, and the Mic100 give you the dirt. Whit the Harpbreak works as a Di Box, and can add some diferent dirt than the HB, so you can have a more complex sound.
The Mic100 is a copy of the Art Tube Mp, so I guess I am going to buy that pedal and put a nice tube in it.
Overall, the Behringer is works great to play straight into the PA. ---------- Sorry for any misspell, english is not my first language.