IMG STAGE LINE STA-1500A Instruction Manual Download Page 9

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English

•

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

min

) of the speakers can be

found in the table below .

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 –

L /R +

Speaker connection

– 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 –

Speaker connection

The table below also shows connection op-
tions for multiple speakers at one output .
The minimum power rating (P

min

) of each

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!

Connection options

for each output

Operating mode

Z for each speaker

min

for each speaker

STA-900A

STA-1500A

STEREO