The ADB-1 is an active, phantom powered direct box. Unlike passive DI where the frequency response of the signal can be altered depending on the connected impedance, an active DI buffers the input signal with an amplifier. This assures that the sound source will reach the mixer balanced and noise-free. The input-buffering amplifier also ensures clean, pure and powerful sound when using extremely long cables. The DI can be powered either from the phantom power of mixer or by using 9V battery.