Powered by an internal 9-volt battery or via phantom power at the XLR output, the X-Direct features a switchable low-pass filter that cuts out all very high-frequency interference. This Bessel filter on the output is placed out of the audio range and is primarily intended to reduce radio frequency interference before it gets into the main system. The filter also reduces computer noise artifacts when used as an interface between a computer-based audio workstation and monitors. Phase inversion switch reverses signal polarity at the source. Stylish, compact, and durable chassis; input attenuator switches for a wide range of signal levels; and an input through jack for tapping off the signal chain. A ground lift switch lets you totally separate the input and output signal grounds, reducing hum and ground-loop noise.