The GM II is an unbridled four EL84 amp with a distinct British voice featuring a switchable HI/LO INPUT GAIN and a MASTER volume control.

The low end of the pre amp is regulated by the SHAPE control giving three choices: 1-Bright, 2-Regular, and 3-Meaty. The CUT attenuates the high end and is bypassed when turned fully counter-clockwise. The BASS controls the overall low end, while the TREBLE knob acts on the overall high end. The VOLUME manages the loudness of the pre-amp and there is zero negative feedback making the GREASE MONKEY II incredibly harmonically complex.