3 Applications
This amplifier with an RMS output power of
120 W is specially designed for PA systems .
Either 100 V or 70 V speakers or low-impedance
speakers (minimum impedance 4 Ω) can be used .
Features:
4 × input channel, switchable line level or mi-
crophone level, with XLR / 6 .3 mm jacks and
screw terminals
1 × input channel, switchable between two line
stereo signal sources, with screw terminals
and RCA jacks
1 × screw terminals for the telephone signal
1 × input and output with RCA jacks to insert an
audio unit for signal processing (automatic
volume control, equalizer etc .)
1 × CD / MP3 player
1 × AM / FM radio
1 × alarm siren, to be switched on via internal
and external switch
1 × signal chime, to be activated via momentary
pushbutton
1 × priority circuit for INPUT 1
4 Setting Up the Amplifier
The amplifier is designed for insertion into a rack
for units with a width of 482 mm (19"), but it
can also be used as a table top unit . To ensure
sufficient cooling of the amplifier, air must always
be able to flow freely through all air vents .
4.1 Installation into a rack
For installation into a rack, the amplifier requires
a space of 2 RS (2 rack spaces = 89 mm) . To pre-
vent the rack from becoming top-heavy, insert
the amplifier into the lower section of the rack .
The front plate alone is not sufficient for fixing
it safely; additionally use lateral rails or a bottom
plate to secure the unit .
5 Connections
Prior to making or changing any connections,
switch off the PA-8120RCD and the units to be
connected .
Many of the connections are underneath the
two protective covers (41), e . g . the connections of
the speakers . For connecting, remove the covers .
WARNING Never operate the amplifier with-
out the covers (41) . If you touch
the terminals, you will risk an elec-
tric shock .
5.1 Speakers
Either connect 100 V or 70 V speakers to the
terminals (40) [figs . 4a and 4b] – the maximum
load of the amplifier by the speakers is 120 W;
otherwise, the amplifier may be damaged
or connect a speaker or a speaker group with a
total impedance of 4 Ω, 8 Ω or 16 Ω to the ter-
minals (39) . The figures 4c to 4n show different
ways to obtain the correct impedance, however,
there still are further possibilities .
When connecting the speakers, always observe
the correct polarity as shown in the figures .
8
5.2 Microphones
Four microphones with an XLR plug or 6 .3 mm
plug may be connected to the combined XLR /
6 .3 mm jacks (35) of the inputs 1 – 4 . For micro-
phones with free connection cables, use the screw
terminals (36) as an alternative . When connecting,
these terminals can be removed from their plug-in
connection for better handling .
The microphone at the input 1 may take
priority over all other inputs when a switch con-
nected to the terminals PRIORITY (26) is closed .
1) When connecting a microphone, set the
switch No . 1 of the corresponding DIP switch
block (47) to the lower position (ON) .
2) If a phantom-powered microphone is used,
set the switch No . 4 of the corresponding DIP
switch block to the lower position (ON) . The
phantom power supply is only available at the
XLR contacts and the screw terminals . Micro-
phones connected via 6 .3 mm plugs are not
supplied with phantom power .
CAUTION!
1 . Only use the switch when the unit has been
switched off (switching noise) .
2 . Do not connect any unbalanced micro-
phone when the phantom power has been
switched on (48 V); the microphone may
be damaged .
3) To switch on the high-pass filter, e . g . to im-
prove the speech intelligibility or to suppress
subsonic sound, set the switch No . 3 of the
corresponding DIP switch block to the lower
position (ON) .
4) If there is a different phase between two
microphones (poor bass reproduction of a
sound source), the sound may possibly be
improved by switching over the switch No . 2
at one of the corresponding DIP switch blocks .
5.3 Audio units with line output
6 units with line output (mixer, MP3 player, etc .)
may be connected:
1) Connect units with a mono output to the
combined jacks (35) or to the terminals (36)
of the inputs 1 to 4 . For basic setting, set the
corresponding DIP switches Nos . 1 to 4 (47)
to the upper position .
2) Connect units with a stereo output either to
the RCA jacks (34) or to the terminals (45)
of channel 5 . Use the switch No . 1 of the
corresponding DIP switch block (46) to select
between the input jacks AUX 1 (upper switch
position) and AUX 2 (lower switch position
ON) . If required, use the switches No . 2 and
No . 4 to match the level . The volume of the
unit connected will be increased in the lower
position (ON) .
When connecting a stereo unit to one of
the inputs 1 to 4, use a stereo-to-mono adapter
(e . g . SMC-1 from MONACOR) and an adapter
cable (e . g . MCA-154 from MONACOR);
otherwise, signal parts may be missing .
3) For switching on the high-pass filter, e . g .
to improve the speech intelligibility, set the
corresponding DIP switch No . 3 to the lower
position (ON) .
5.4 Audio units for signal processing
An audio unit (e . g . an equalizer or an automatic
volume control) for signal processing can be in-
serted via the RCA jacks AMP IN and PRE OUT
(33) . To do this, remove the jumper (31), connect
the input of the audio unit to the jack PRE OUT
and the output to the jack AMP IN .
Note: A signal interruption occurs in the amplifier if
only one of the two jacks (33) is connected or the unit
inserted is not switched on, if it is defective or not cor-
rectly connected . In this case, the speakers remain mute .
5.5 Recorder or additional amplifier
A recorder and / or another amplifier (e . g . if more
speakers are required than allowed) can be con-
nected to the RCA jacks TAPE OUT (32) .
The same mono signal is present at both
jacks . Neither the control MASTER (3) nor the
tone controls BASS and TREBLE (2) will affect this
signal . Therefore, the output signals of these jacks
can be sent to two different units .
5.6 Telephone system
The telephone system allows to reproduce an-
nouncements via the PA system .
1) Feed the signal from the telephone system
(line level) to the terminals TEL PAGING (43) .
2) During an announcement, adjust the volume
with the control GAIN (44) .
As soon as a signal is available at the input TEL
PAGING, all other input signals, except for the
siren signal, will be muted automatically .
5.7 Priority control, talkover
A switch connected to the terminals PRIORITY
(26) allows to mute all input signals, except for
the input signal of the channel INPUT 1 and the
siren signal . Thus, for a good intelligibility, it is
possible that only the announcement via chan-
nel 1 can be heard .
If the connections PRIORITY INPUT 1 (30) are
connected by means of a jumper or a switch,
INPUT 2 to INPUT 4 and AUX 1/ 2 are automat-
ically muted as long as a signal is available at
INPUT 1 (talkover) .
5.8 Separate switch for the alarm siren
To remotely activate the alarm siren, connect a
switch to the terminals SIREN (28) .
5.9 Antenna connection and
mains connection
1) Connect an FM antenna to the jack FM (27)
and an AM antenna to the terminals AM (29) .
In areas with good reception, the antennas
provided can be used .
2) Finally connect the supplied mains cable to
the mains jack (37) first and then connect the
mains plug to a socket (230 V/ 50 Hz) .