4
In order to protect it from potential overloads, the MZ54 is equipped with a 0.5A mains fuse (27). If the fuse blows
up, you must replace it with an identical one. NEVER REPLACE THE FUSE WITH ANOTHER ONE WITH A
HIGHER VALUE.
CAUTION:
Fuse substitutions have to be performed by a qualified technician.
4. INPUTS
The MZ54 accepts two types of balanced audio inputs: microphone (MIC) and stereo line (LINE).
4.1. Inputs 1 to 4, program
Input Channels 1 and 2 accept microphone or line signals. Channels 3 and 4 accept line signals only. Finally,
Channel 5 is dedicated to priority signals and accepts microphone or line signals.
All input terminals are Euroblock connectors, except the XLR type for MIC/LINE L Input 1.
Euroblock connectors wiring diagram is the following:
Hot or direct signal
>
Pin +
Cold or inverted signal >
Pin -
Ground
>
Pin
⊥
4.2. Input 5, priority
The signal received at the input #5 is processed as a high-priority signal, having two kinds of operation:
Priority mode or
Talkover
:
Attenuates the current program signal in any zone output selected with the ZONE micro-switches on the front panel
and overlays the Input #5 signal.
Priority mode can be activated by automatic detection of a signal at the 5th input, or by closure contact (dry
contact) on the back panel.
Internal
jumpers
are used to select activation mode (signal detection (default) or contact closure), attenuation (- 20, -
30 (default) or - 80 dB) and recovery time (1, 2 (default) or 3 seconds).
Emergency/Evacuation mode:
Mutes the current program signal in
All
zone outputs and replaces it with Input #5 signal.
Additionally, zone outputs volume closure controls (front panel knobs and remote panels) are ignored, as the signal
diffusion has a preset volume adjusted with VOL control on the back panel.
This mode is only activated by closing the contact on the back panel.
And for XLR connector:
Hot or direct signal
>
Pin 2
Cold or inverted signal > Pin 3
Ground
>
Pin 1
Microphones should have a low impedance (200 to 600
Ω
) and be monophonic. For UNBALANCED connections,
you must short pin 3 (negative) to ground.
For inputs with a MIC/LINE selection, suitable operating position should be set with the dedicated back panel
switch: Engaged: line signal
Released: microphone signal
NOTE:
In microphone mode the MIC LEVEL knob located next to the previous switch is enabled.
The gain for each input source (1 to 5) is set with the GAIN rotary knob on the front panel. Please refer to section
6.
CONSIDERATIONS
for more information.
