The PZ-DI has a variable load selector switch that allows you to set the input impedance of the direct box, so you can optimize the performance with your instrument's pickups. The 1 meg ohm position delivers the classic impedance found on most active DI boxes, while the 220k ohm setting warms up the tone of magnetic pickups to provide the feel and tone as if your instrument were connected directly to an amplifier. The third setting is an ultra-high 10 meg ohm impedance that is specifically designed for piezo transducers, helping compensate for the harsh or squawky tone that can occur when a piezo is connected to a lower impedance input.