Setting Up The Amplifier - IMG STAGE LINE STA-1500A Bedienungsanleitung

•
Immediately disconnect the mains plug
from the socket
1 . if the unit or the mains cable is visibly
damaged,
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 .
•
Never pull the mains cable to disconnect
the mains plug from the socket, always
seize the plug .
•
For cleaning only use a dry, soft cloth; never
use water or chemicals .
•
No guarantee claims for the unit and no
liability for any resulting personal damage
or material damage will be accepted if the
unit is used for other purposes than orig-
inally intended, if it is not correctly con-
nected or operated, or if it is not repaired
in an expert way .
If the unit is to be put out of oper-
ation definitively, take it to a local
recycling plant for a disposal which
is not harmful to the environment .
3 Applications
This stereo PA amplifier is specially designed
for sound applications, e . g . in function rooms
or clubs . It is able to operate in stereo mode,
mono parallel mode or mono bridge mode .
Each of the two amplifier channels is equipped
with a filter to be used as a high-pass filter or
low-pass filter for a crossover network . With
an additional STA-900A or STA-1500A, it is
quite easy to set up a PA system with satellite
speakers and a subwoofer .
Extensive protective circuits are provided
to protect the amplifier and the speakers con-
nected . Two temperature-controlled fans will
ensure sufficient cooling of the amplifier .

4 Setting Up the Amplifier

The amplifier is designed for installation into a
rack (482 mm / 19"), but it can also be placed
on a table . 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 rack installation, 2 RS (rack spaces =
89 mm) are required . Leave a clearance of one
rack space for ventilation above the amplifier .
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
damage the amplifier but also other units in
the rack . In case of insufficient heat dissipa-
tion, install a ventilation unit into the rack .
To prevent the rack from becoming top-
heavy, insert the amplifier into the lower
section of the rack . The front panel alone is
not sufficient for fixing it safely; additionally
fasten the rear of the unit or use lateral rails
or a bottom plate to secure the unit .
5 Connections
Prior to making or changing any connections,
switch off the amplifier and all units to be
connected .
5.1 Signal input and
feed-through output
1) Connect the output of the signal source
(e . g . preamplifier, mixer) to the XLR jacks
L-CH IN and R-CH IN (4) .
– The jacks are designed for balanced
signals . When connecting sources with
unbalanced signals, use suitable adapter
cables (XLR to RCA or XLR to 3 .5 mm or
6 .3 mm connector) .
– The input signal should have line level .
For maximum undistorted level control
of the amplifier, an input signal of 1 V
is required .
– For the parallel mode and the bridge
mode, only connect the input of the left
channel L-CH .
2) If the input signal is required, for exam-
ple, for an additional amplifier, the signal
can be routed from the XLR outputs LINK
OUT (5) .
5.2 Speakers
In the stereo mode and parallel mode, the
highest output power is obtained when
4 Ω speakers (minimum admissible load
impedance) are used . It is also possible to
connect 8 Ω speakers, but the output power
will be slightly reduced . In the bridge mode,
the highest output power is obtained with
an 8 Ω speaker (minimum admissible load
impedance in bridge mode) . The required
power rating (P ) of the speakers can be
min
found in the table below .
Connection options
Operating mode
for each output
Stereo mode or parallel mode: Connect
the speakers to the speaker jacks L-CH OUT
and R-CH OUT (12) . The following figure
shows the pin configuration for a speaker
plug:
L /R –
2+
2-
1-
1+
– After inserting the speaker plug into the
jack, turn the plug clockwise until it en-
gages . To remove the plug, pull back the
latch on the plug and turn the plug coun-
ter-clockwise .
– When connecting the speakers, make sure
that all speakers have the same polarity .
Bridge mode: Connect the speaker to the
jack BRIDGE (11) . The following figure shows
the pin configuration for a speaker plug:
Bridge –
2+
2-
1-
1+
The table below also shows connection op-
tions for multiple speakers at one output .
The minimum power rating (P
speaker at the corresponding impedance (Z)
is also shown . When interconnecting multiple
speakers, always observe the correct connec-
tion of positive and negative terminals .
Important: The total impedance at each
speaker output must not fall below 4 Ω in
the stereo mode and parallel mode or 8 Ω in
the bridge mode!
Z for each speaker
4 Ω
STEREO
PARALLEL
8 Ω
BRIDGE 8 Ω
8 Ω
STEREO
PARALLEL
16 Ω
BRIDGE 16 Ω
2 Ω
STEREO
PARALLEL
4 Ω
BRIDGE 4 Ω
4 Ω
STEREO
PARALLEL
8 Ω
BRIDGE 8 Ω
Speaker connection
L /R +
Speaker connection
Bridge +
) of each
min
P for each speaker
min
STA-900A STA-1500A
450 W 700 W
330 W 550 W
900 W 1500 W
225 W 350 W
165 W 275 W
450 W 750 W
225 W 350 W
165 W 275 W
450 W 750 W
113 W 175 W
83 W 138 W
225 W 375 W
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