The Dirt Transmitter produces dual transistor crumbling fuzz tone. It has Bias, Fuzz, Level and Tone controls. The bias control affects the voltage to the transistors which can create gated velcro fuzz when turned counter clockwise or bring it back to life by turning it clockwise. Moving the bias is key to getting a wide range of sounds. The fuzz control can produce tones from overdrive like break up to thick ripping fuzz.