All operating elements and connections de -
GB
scribed can be found on the fold-out page 3.
1 Safety Notes
This unit corresponds to all relevant directives of
the EU and is therefore marked with
WARNING The unit uses dangerous mains
voltage. Leave servicing to skilled
personnel only and do not insert
anything into the air vents! Inex-
pert handling of the unit may
result in electric shock.
During operation, there is a hazard of contact
with a dangerous voltage up to 100 V at the
speaker terminals (10). Always fold down the
protective cover when operating the amplifier.
Always switch off the amplifier before making
any connection.
Please observe the following items in any case:
G
The unit is suitable for indoor use only. Protect
it against dripping water and splash water,
high air humidity and heat (admissible ambi-
ent temperature range: 0 – 40 °C).
G
Do not place any vessel filled with liquid on the
unit, e. g. a drinking glass.
G
Do not operate the unit and immediately dis-
connect the mains plug from the socket
1. if the unit or the mains cable is visibly dam-
aged,
2. if a defect might have occurred after the unit
was dropped or suffered a similar accident,
3. if malfunctions occur.
In any case the unit must be repaired by
skilled personnel.
G
Never pull the mains cable to disconnect the
mains plug from the socket, always seize the
plug.
G
For cleaning only use a dry, soft cloth; never
use water or chemicals.
G
No guarantee claims for the unit and no liabil-
ity for any resulting personal damage or mate-
rial damage will be accepted if the unit is used
for other purposes than originally intended, if it
is not correctly connected or operated, or if it
is not repaired in an expert way.
If the unit is to be put out of operation
definitively, take it to a local recycling
plant for a disposal which will not be
harmful to the environment.
6
2 Applications
This amplifier with a RMS output power of 120 W
(PA-312) or 240 W (PA-324) is specially de-
signed for PA systems. Either use 100 V or 70 V
speakers or low resistance speakers (minimum
impedance 4 Ω).
.
The amplifier is equipped with 6 inputs:
1 × line level input TEL INPUT for important an -
nouncements (e. g. from a telephone sys-
tem) taking priority over all other inputs, i. e.
with a signal present at the input, the signals
of the other inputs will be faded out
1 × microphone input MIC 1 for important an -
nouncements taking priority over the inputs
MIC 2, MIC 3, INPUT 4 and INPUT 5,
i. e. with a signal present at the input MIC 1,
the volume of the signals at the inputs of
lower priority will be attenuated
2 × microphone inputs MIC 2 and MIC 3
2 × line level inputs INPUT 4 and INPUT 5, e. g.
for background music from an MP3 / CD
player, radio or tape deck
3 Setting Up the Amplifier
The amplifier is designed for installation into a
rack for units of a width of 482 mm (19"); how-
ever, it is also suitable as a tabletop unit. In order
to ensure a sufficient cooling of the amplifier, air
must always be able to flow freely through all air
vents.
3.1 Rack installation
For rack installation, fasten the two mounting
brackets (1) with screws to the sides of the
amplifier. In the 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 mounting brackets alone are not sufficient
for fixing it safely; additionally use lateral rails or
a bottom plate to secure the unit.
The hot air given off by the amplifier must be
dissipated from the rack, otherwise heat will
accumulate in the rack which may not only dam-
age the amplifier but also other units in the rack.
In case of insufficient heat dissipation, install a
ventilation unit into the rack.
4 Operating Elements
and Connections
4.1 Front panel
1 Mounting bracket (2 ×) to install the amplifier
into a rack for units of a width of 482 mm (19")
2 Input MIC 1 (6.3 mm jack, unbal.) to connect
a microphone
The jack is connected in parallel with the jack
MIC 1 (12) on the rear panel; however, it is
not able to supply phantom power.
The input MIC 1 has a priority circuit: When
an announcement is made via this input, the
volume of the inputs MIC 2, MIC 3 (14),
INPUT 4 and INPUT 5 (16) will be automati-
cally attenuated so that it is easier to under-
stand the announcement. To adjust the level
of volume attenuation, use the control MUTE
LEVEL (11).
3 Input level control to mix or fade in / fade out
the input signals
4 Tone controls BASS and TREBLE
5 Control MASTER for the volume of the mixed
signal at the line outputs and speaker outputs
(17, 10)
6 Output level indication
LED TEMP to indicate overheating
LED PROT to indicate short circuit or over-
load of the speaker outputs (10)
If the overload LED CLIP lights up more than
briefly, turn back the control MASTER (5) or
the corresponding input control (3).
If the LED TEMP lights up, improve the venti-
lation of the amplifier. As soon as the ampli-
fier has cooled down, the LED TEMP is extin-
guished.
If the LED PROT lights up, switch off the
amplifier and eliminate the overload or the
short circuit at the speaker outputs. Then the
LED PROT is extinguished. If you are not
able to identify the fault, consult skilled per-
sonnel.
7 POWER switch with power LED ON directly
above