In the words of Benson Amps:

We call this our Preamp because it is! The circuit is based on the our Chimera 30 watt guitar amplifier, but substitutes FET transistors for the vacuum tubes. The result is an extremely amp-like and versatile clean boost/overdrive/fuzz pedal that imparts rich harmonics and a very musical EQ to your signal chaintruly a Chimera in a box!