EarthQuaker Devices Crimson Drive Overdrive Guitar Effects Pedal Cutting and dynamic overdrive designed around a single germanium transistor and vintage germanium diodes. Creates a very open tone with excellent harmonics and a pleasing raw grit that cant be duplicated with more common FET or opamp based overdrives. With a simple twist of the gain control, the Crimson Drive can go from a gritty Rangemaster style treble boost to a rattling overdriven sound that is reminiscent a vintage plexi style amp at full bore. Works great with single coils as well as humbuckers. Excellent clean up with your guitars volume control.