LD Systems IMA 120 Bedienungsanleitung Seite 11

FUSE
2
Fuse holder for 250 V fuses (5 x 20 mm). IMPORTANT NOTE: Replace the fuse only with a fuse of the same
type (see printed instructions on the housing). Should the fuse blow repeatedly, please contact an
authorised service centre.
ON/OFF
3
Rocker switch for switching the device on and off.
EMERGENCY
4
The 5-pole terminal block connection is used to install an acoustic emergency call system. The poles
+, - and G correspond to a balanced line input. The poles C and + are used to connect a separate mute
switch (terminal block included). The Emergency contact closure (pins C and +) allows muting of all
other input channels, independently from the VOX settings.
CLIP: The red CLIP LED indicates when the input is operated at the distortion limit. Reduce the signal
level using the GAIN control or on the playback device so that the CLIP LED is no longer lit.
VOX: The VOX (Voice Operated Exchange) control offers the possibility to set a threshold for the
emergency audio signal, thus activating an automatic mute circuit. When the level at the EMERGENCY
input reaches the set threshold, all other microphone and line channels are muted. This ensures that
the emergency signal can be heard clearly. In addition, the EMERG indicator at the front of the amplifier
lights up in this case. As soon as the level of the emergency signal falls below the set threshold, the
muting of the other channels is cancelled again and the EMERG display goes out. With the appropriate
setting, the EMERGENCY channel always has the highest priority. The emergency signal is transferred
internally directly to the LINE OUT audio output. If the VOX control is set to minimum (turned all the way
to the left), the automatic muting via VOX circuitry is deactivated and the EMERGENCY channel can be
used as an additional line channel.
GAIN: Control for adjusting the pre-amplification of the incoming audio signal. Adjust the gain control
so that the channel's clip LED only lights up briefly during signal level peaks. Avoid permanent glow
of the clip LED by reducing the pre-amplification. It may also be necessary to reduce the signal level
on the source device. The level of the emergency signal is not influenced by the current setting of the
main volume control (Master Volume), but is adjusted via the GAIN control.
MIC/LINE 1
5
Microphone/line channel with switchable gong function (signal tone). The connection can be made via
the XLR/jack combo socket as well as via terminal block. In this case, the poles +, - and G on the terminal
block connection are intended for the balanced input signal.
The poles C and + are used to connect a separate mute switch (terminal block included).
The contact closure offers the possibility to mute the MUSIC channel via an external switch/button.
In addition, the internal gong/signal tone function can be controlled in this way if the circuit is
activated (see point 6 MIC/LINE 2, CHIME).
MIC/LINE: If a line signal is present at the XLR/jack combo socket or at the terminal block switch MIC/
LINE channel 1 to LINE mode via the associated MIC/LINE switch (switch pressed). If a microphone is
connected, activate MIC mode via the MIC/LINE switch (switch not pressed).
PHANTOM ON/OFF: When using a condenser microphone, it is necessary to activate the 24 V phantom
power supply (PHANTOM ON/OFF switch pressed: ON). Always make sure that the microphone is
connected and the channel volume is set to minimum before switching on the phantom power.
Before disconnecting the microphone from the unit again, deactivate the phantom power and
turn the channel volume to minimum.
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