The Duo Drive Blender is a pedal that combines two unique distortion circuits - a crunch circuit and a heavy circuit. It has volume controls for both circuits so that they may be combined in any combination you desire.
This pedal has 4 simple controls - the level control is essentially the overall volume of the pedal. The tone level controls the overall EQ of the tone - much in the same way the tone control works on your guitar. The two miniature knobs in the middle are the volumes of the two respective circuits. You can adjust these knobs to blend in as much of each circuit into the final tone as you desire.
It has two 1/4 inch jacks on the side - one for the input, one for the output. It runs off 9v DC regulated supply and can also take an internal 9v battery. When the pedal is not in operation, it is true bypass.