Proel DIRECT100A - Manual (Page 2)

INTRODUCTION
The name DI box comes from direct injection box, that means exactly: To inject a signal directly or take an
audio signal from the source and send it directly to a mixer console or recorder. Direct boxes perform several
important functions: they are designed as impedance matching and signal balancing devices. This means that
they take the high impedance of a guitar or keyboard and ‘transform’ it to the low impedance used in balanced
sound systems. Balanced signals inherently cancel noise and, due to their lower impedance, are capable of very
long cable runs. Balanced signals are the norm in professional recording, broadcast and live sound. By properly
matching the impedance you will enjoy better sound, less noise and an extended frequency response.
DIRECT100A is an active direct box with an isolation transformer. This means that it includes a powered circuit
to convert the impedance and balance the signal and, with the isolation transformer, a full isolation from
grounds avoiding hum and buzz problems. It derives its power from the mixing console phantom power or
from a battery.
CONTROLS AND AUDIO CONNECTION
1. PAD - switch
The pad switch reduces the input signal to the circuit to ensure a clean and distortion-free signal.
Two steps are possible: 0 dB and -20 dB. Always use as little as attenuation as possible to get the best possible
signal with reference to the noise floor.
2. INPUT - unbalanced JACK or female XLR
Connect the source instrument to this 1/4” jack to receive the signal. The input impedance depends on PAD
setting: > 250 Kohm with no pad, 47 Kohm with pad insertion.
3. LINK - unbalanced JACK
Connect this 1/4” jack to the input of the backline instrument or monitor amplifier. It is directly connected at
the input.
4. ON - blue LED
The ON LED shows when the DIRECT100A is powered. If the led doesn’t light, be sure that the phantom power
of the channel where the DIRECT100A is connected is activated.
5. PWR - switch
The power switch is used for both battery and phantom power. NOTE: To prevent damaging of your speaker
and avoid switching noise, first connect the DI box and then hook up the respective channel or mute the mix
channel before activating or connecting the DIRECT100A.
6. GND LIFT - switch
Use the GND LIFT switch to either connect the ground pin of input and output or keep them completely
separated. Depending on the grounding of the connected devices linking or disconnecting will reduce hum
and buzz noises and prevent ground loops.
7. BAL OUTPUT - male XLR
This male XLR output connector is the balanced microphone level output of the DI and it is wired with pin-1
ground, pin-2 hot and pin-3 cold. To power the DI box it must be connected to the phantom powered MIC input
of the mixing console. Connecting the DI box to a mixer LINE input the DI box must be powered with battery.
8. 9V BATTERY HOLDER
For best reliability and long life, we recommend you use only high quality 9V PP3 type alkaline battery.
ENGLISH