This is the same circuit as the Hog's soccer bass boost.
It's a pedal that boosts the bass and treble cut.
Warning this is not a booster for bass (the instrument).
It is a circuit to a transistor super simple. I took an hour to make mine identical to the original schema.
A switch ON / OFF and a knob volume.
I made this thinking to use it with a bass or keyboard.
On a guitar or bass: it cuts too much treble to my liking, there remains only a very dull no shine or attack.
On a keyboard: it is the worst. It was just the impression of having his head between two pillows.
Short, I have not found the value of this pedal.
It may be appropriate to another.
FYI, the circuits of linear power boost, bass boost and mole screaming bird are almost identical, only a few condos are changing, so it is very easy change to switch from one to another.