DI-1 & DI-2P

  Passive Direct Injection Boxes - User Guide

MTR's Direct Injection Boxes take a signal from an instrument (guitar, bass, keyboard etc.) and, by presenting a very high impedance to the instrument and balancing the output, prepares it for direct connection to a mixing console in the studio or live on stage. The DI-2P is a two channel version for stereo keyboards, or for two different mono signals.

Connections: Connect the instrument to the jack socket marked Input. If needed, a second jack to jack lead can be connected from the Link socket to the input of a combo, so that the musician can monitor himself on stage or in the studio.

The balanced XLR Output socket (pin 2 hot) should be connected via a balanced 2 core screened lead to the stage box, or input socket of the mixer. Note that this unit also can be used in reverse, i.e. a balanced signal can be fed into the XLR socket, and an un-balanced signal will appear at the jack sockets. Use when a phantom-powered mic is to be connected to a mono input, such as on a video recorder or unbalanced mixer-amplifier.

Ground: The Ground switch push-button is used to eliminate hum loops. Start with the button pushed in, in the 'GND' position, and if hum occurs due to an earth loop with the combo or mixer, release to 'LIFT'.

Attenuator: The 3 way attenuator allows accurate input level matching: start at 0dB and decrease to -20 or -40 if distortion occurs. Use the -40dB setting for very high volume speaker outputs.  If you are using this DI box with a valve amplifier, the speaker(s) must remain connected to provide the necessary load for the amp's own output transformer.

Specification:

Frequency response:  20Hz-25KHz ± 2dB
Attenuation switch:   -40dB, -20dB, 0dB
Input impedance:      47K ohms, mono jack + jack link
Ground Switch:         Connected/Lifted
Output Impedance:    600 ohms, bal XLR, pin 2 hot

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MTR Ltd, Ford House, 58 Cross Rd, Bushey, Herts, WD19 4DQ   UK
Tel: +44-(0)1923-234050   Fax: -255746    e-mail: mtrltd@aol.com    www.mtraudio.com