7
English
100 V/4 Ω FAILED INPUT
G
CH 1
10
11
9
230 V~/50 Hz
100 V/4 Ω FAILED INPUT
G
CH 4
100 V/4 Ω FAILED INPUT
G
CH 3
STANDBY
MUTE
100 V/4 Ω FAILED INPUT
G
CH 2
100 V/4 Ω FAILED INPUT
G
CH 1
100 V
4 Ω
7
8
5
6
➍
Rear panel
4.2 Adjusting and connecting
the amplifier
Always switch off the amplifier before making
any connections!
The amplifier is equipped with screw terminals;
to facilitate handling, it is possible to remove
the screw terminals from their plug-in con-
nections on the amplifier and to reinsert them
after connection .
4.2.1 Setting the operating mode and
connecting the speakers
Either
100 V speakers
or
low-impedance
speakers can be connected . Never connect a
combination of these speaker types!
The position of the sliding switch (5) de-
termines the operating mode of all channels .
Set the switch according to the speaker type
and then connect the speakers to the terminals
“100V/ 4 Ω” (9) for each channel .
A 100 V speakers:
Set the switch to the position “100 V” .
The total load of the speakers must not
exceed the rated load of the amplifier, i . e .
the maximum total load for each channel is
120 W . However, a total load of 10 – 20 %
beneath this maximum value is recom-
mended to make sure that the amplifier
is not constantly operated under full load .
Fig . 1 on page 2 shows the connection of
100 V speakers .
B Low-impedance speakers:
Set the switch to the position “4 Ω” . The
minimum total impedance of the speakers
is 4 Ω for each channel . Fig . 2 on page 2
shows various options of how to keep the
minimum impedance of 4 Ω . However, there
are more possibilities .
Attention:
Make sure that the position of the switch
is never changed by accident . A wrong setting may
damage the speakers and the amplifier .
4.2.2 Connecting signal sources
Via the terminals INPUT (11), a mono signal
source with line level (e . g . preamplifier) can
be connected to each channel . Balanced signal
transmission will improve interference suppres-
sion; therefore, the signal sources connected
should be balanced . If the output of a source
is unbalanced (e . g . for an RCA jack), connect
the terminals “−“ and “G” of the correspond-
ing input with each other . Connect the signal
conductor to the terminal “+” of the input and
the ground conductor to the terminal “G” .
4.2.3 Fault indication output
For remote monitoring, each channel pro-
vides a fault indication output via the termi-
nals FAILED (10) . When the protective circuit
responds for a channel, a DC voltage of 4 .6 V
will be available at the corresponding output
FAILED . The maximum load of the output is
50 mA . A unit for optical or acoustic fault re-
porting can be connected to the output .
4.2.4 Connecting external switches
To mute the amplifier, a switch (NO switch)
can be connected to the terminals MUTE (8) .
The terminals STANDBY (7) can be used
to connect a switch that allows you to switch
the amplifier on (switch closed) or to go to the
standby mode (switch open) .
Note:
If
no
switch is connected to the ter-
minals STANDBY, make sure that the ter-
minals are bridged via a jumper (
☞
fig . 5) .
Otherwise, it will not be possible to switch
on the amplifier by means of the POWER
switch (2) .
➎
4.2.5 Power supply
Connect the plug of the mains cable (6) to a
mains socket (230 V/ 50 Hz) .
5 Operation
To avoid switching noise, first switch on the sig-
nal sources before switching on the amplifier .
After operation, switch off the amplifier first .
1) Before switching on the amplifier for the
first time, set the level controls (3) of all four
channels to zero to make sure that the initial
volume will not be too high .
2) Use the POWER switch (2) to switch on the
amplifier . The LED indicator (1) above the
switch will light up; in the LED indicator
strip (4) of each channel, the LED indica-
tor “100 V” or “4 Ω” will indicate the
operating mode . After switch-on, the LED
indicator PROT for each channel will light
up briefly and the amplifier will be muted
(switch-on delay) .
Standby:
The amplifier is in the standby mode,
if only the LED indicator above the POWER
switch lights up after the switch has been
pressed .
−
If a switch has been connected to the termi-
nals STANDBY (7), the switch can be used to
switch on the amplifier .
−
If
no
switch is connected to the terminals
STANDBY, make sure that the terminals are
bridged (
☞
note in chapter 4 .2 .4); other-
wise, it will not be possible to switch on the
amplifier .
3) At each channel, feed the signal of the
source connected to the input and then use
the level control to adjust the volume for the
corresponding speaker zone . In the LED in-
dicator strip, the LED indicator SIG will light
up when a specific signal level has been
reached (the higher the level, the brighter
the LED indicator) . The LED indicator PEAK
will light up when the level is limited by the
integrated limiter because the maximum
value admissible has been reached . The LED
indicator PEAK should only light up briefly
for signal peaks . If the LED indicator lights
up for a longer time, turn back the level
control accordingly .
If a channel is not used, turn the corre-
sponding control to zero .
4) If a switch is connected to the terminals
MUTE (8), it can be used to mute and
unmute the sound for all channels .
5) If a switch is connected to the terminals
STANDBY, it can be used to switch the
amplifier to the standby mode . To switch off
the amplifier, use the POWER switch; the
LED indicator above the switch will go out .
After the amplifier has been switched
off (or switched to the standby mode via a
switch connected), the LED indicator PROT
lights up briefly at each channel .
5.1 Protective-circuit response
Each amplifier channel is equipped with a pro-
tective circuit against overheating, overload
and short circuit at the speaker output . When
the protective circuit responds for a channel,
the upper LED indicator PROT in the LED indica-
tor strip (4) for the corresponding channel will
light up . In addition, the fault is reported via
a unit connected to the corresponding output
FAILED (10) (
☞
chapter 4 .2 .3) .
1 . In case of overheating, do not switch off the
amplifier, but set the corresponding level
control (3) to zero . This will reduce the load
on the power amplifier and the correspond-
ing fan will still cool it . If cooling at the place
of operation is insufficient, improve the air
circulation . If the protective circuit responds
again after the amplifier has cooled down
and is operated normally again, the amplifier
may be overloaded (see item 2) .
2 . In case of overload in the operating mode
“100 V”, reduce the number of speakers
connected or, if possible, reduce the power
consumption by the speakers .
3 . In case of a short circuit, locate and eliminate
the short circuit .
Always switch off the amplifier before making
any changes to the connections! If it is not pos-
sible to eliminate the fault, take the amplifier
to skilled personnel .
Specifications
page 3
Subject to technical modification .
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®
INTERNATIONAL
GmbH & Co. KG. No part of this instruction manual
may be reproduced in any form or by any means for
any commercial use.