In the words of Benson Amps:

This pedal is based on our now famous amp-in-a-box Preamp pedal with one important tweak: the replacement of the first FET transistor with a germanium gain stage – stolen from our servo-biased Germanium Boost pedal which is ideal as a versatile gain stage since it reliably imparts a germanium tonality, mostly doesnt care about temperature, and doesnt affect frequency response. The result is an alternate universe take on our flagship pedal that marries the incomparable feel of the germanium with the careful equalization and tone controls of the preamp pedal.