Active DI BoxUsed for - This active DI box is used for connecting high impedance line level unbalanced outputs such as from a guitar or keyboard to a low-impedance, microphone level balanced input usually found on mixing consoles. To create the balanced output, the DI box performs level matching, balancing and impedance matching to reduce noise, distortion and ground loops. Connections6.35mm Input - Unbalanced high impedance line level 6.35mm Input (e.g. from a guitar)6.35mm pass through parallel output - Unbalanced high impedance line level 6.35mm output (for monitoring purposes. e.g. plugging into a guitar amp)XLR Output - XLR male balanced low impedance microphone level output (for connection to a mixing console's microphone input) Technical Info;Power supply not included (can also be purchased from us)Can be powered by a 9V PP3 battery, 12Vdc or +48V phantom power.Switchable attenuation - 0dB, -20dB, -40dBGround lift function - more information belowLow battery LEDInput Impedance - 1 M Ohms Output Impedance - 600 Ohms, balanced Dimensions - 100 x 45 x 100mmWhy use a DI box? - Once the unbalanced signal is converted to a balanced XLR output, the signal can be sent over long distances with less signal loss. There is an additional line level 6.35mm output that is a pass through socket, it is paralleled to the input connector and delivers the input signal unchanged, it is normally used for monitoring purposes. i.e. attaching a speaker local to you. Ground Lift Switch - Ground lift is a technique which is used to reduce or eliminate noise when connecting two or more pieces of audio equipment. It is difficult to ensure that all equipment that is connected together share the same common ground which can sometimes lead to unwanted hum and noise. The ground lift disconnects pin 1 on the XLR connector and then acts as the new ground point for the circuit. Peace of mind - RoHS Compliant.