It has that rich vintage sound, T-Rex is known for. Besides the warm crunchy sound, this pedal gives a lot of steady bottom.You can flip back and forth between the two gain settings A and B - by clicking switch A or B. The lid (A or B) is indicating the active gain. The pedal is turned off, by clicking the switch (A or B) that is lid.
Dr. Swamp page at TRex 's website...