High-quality active DI Box. Can be operated with 9 V batteries or 48 V phantom power. The input signal has three levels of attenuation. High-impedance input; higher output level than with a passive DI box. An active DI box for all professional audio quality applications. The ultra low noise discrete op amp design incorporating FETs handles even the most critical input sources such as piezo pickups. An integrated DC/DC converter isolates the mixer ground when phantom powered.