Zvex Mastotron can get close to the sound of the legendary Woolly Mammoth. Our feeling is that Woolly Mammoth's sound is a bit more aggressive/hairy. Mastotron is very versatile and can also be used with active pickups. You can also use it with line-level signal thanks to the source impedance control (Relax/Push). Turning the Relax/Push also changes the nature of this pedal from subtle and quite natural to full-bore fuzz mayhem!
The Mastotron is a new, heavy silicon fuzz design that includes a couple of unusual features... source impedance control, subs control, and pulse width coltrol. It works equally well with bass and guitar, and can easily be interfaced with digital devices like recorders as well as keyboards.