output R-CH so that it is also possible to connect
both speakers via a 4-pole cable to this jack .
For bridge mode connect the positive con-
tact of the speaker to the positive terminal (13)
of the left output L-CH and the negative contact
of the speaker to the positive terminal of the
right output R-CH [see fig . 2] . (By the signal
inversion in bridge mode, the positive termi-
nal of the right output becomes the negative
connection for the speaker .) The speaker can
alternatively also be connected to the Speakon
jack L-CH (11) . According to fig . 2, connect the
positive terminal of the speaker to contact 1+
and the negative terminal to contact 2+ of the
plug .
Table fig . 3 also shows possibilities of con-
nection for several speakers to one output . In
each case it is stated which power rating (P
each speaker must have as a minimum with the
corresponding impedance (Z) . When intercon-
necting several speakers, special attention has to
be paid to the correct connection of the positive
and negative terminals .
Important: The total impedance at each out-
put must not fall below 4 Ω in stereo mode and
parallel mode and must not fall below 8 Ω in
bridge mode!
5.3 Power supply
First connect the mains cable to the mains jack
(16) and then the mains plug of the cable to a
socket (230 V/ 50 Hz) .
6
Operation
6.1 Selecting the operating mode
Select the desired operating mode with the DIP
switches MODE Nos . 1 to 6 (9):
Stereo mode – display:
MODE STEREO
In stereo mode, both channels are operated in-
dependently of each other .
switch configuration
STEREO
Parallel mode – display:
MODE PARALLEL
Parallel mode is recommended to provide PA
applications e . g . for two rooms with the same
mono signal and to be capable of adjusting the
volume individually .
The input signal is internally switched from
the left channel additionally to the right channel .
A signal at the right input is ignored . The volume
is separately adjusted for both outputs .
switch configuration
PARALLEL
Bridge mode – display:
MODE BRIDGE
The bridge mode (BRIDGE) is used to obtain a
higher power at one speaker .
For this purpose, both amplifier channels
are combined to one mono amplifier: The input
signal of the left channel is additionally switched
to the right channel in an inverted way . Thus, the
voltage at the output is doubled if the speaker
is connected for bridge mode, as described in
chapter 5 . A signal at the right input is ignored .
The volume is adjusted with the left control (1)
together for both outputs .
switch configuration
BRIDGE
6.2 Filter
The integrated filter can be used as a cross-
over network for 2-way speaker systems (sub-
woofer / satellite) . Select the function corre-
sponding to the connected speaker with the
switch FILTER (10) .
Position
Filter
Low pass filter with −6 dB at 120 Hz for
SUBWOOFER
bass speakers
High pass filter with −6 dB at 120 Hz for
SATELLITE
mid-high range speakers
FULLRANGE
No filter for full range speakers
6.3 Switching on / off
To prevent loud switching noise, always switch
on the power amplifier in an amplifier system
)
min
after all other units have been switched on and
switch it off first after operation . Prior to first
switching-on, set the controls (1 and 5) to the
left stop to "−80 dB" .
Switch on the amplifier with the POWER
switch (6) . The ACTIVE LEDs (2, 4) serve as a
power indication and the display (3) shows the
selected operating mode . After switching-on,
the red LEDs PROTECT (2, 4) light up for a short
time . During this time, the switch-on delay is
activated to protect the speakers .
6.4 Level adjustment
Adjust the output of the mixer or preamplifier to
its rated level (0 dB) or the maximum undistorted
output signal . Turn up the controls (1 and 5) until
the maximum desired volume is reached . The
LEDs "−25 dB", "−20 dB", and "−15 dB" (2, 4)
show the adjusted input level . If the red LEDs
LIMITER light up, the limiter circuit is active and
prevents overload of the amplifier . In this case
slightly turn back the controls .
CAUTION Never adjust the amplifier to a
very high volume . Permanent
high volumes may damage your
hearing! The human ear will get
accustomed to high volumes which do not
seem to be that high after some time . There-
fore, do not further increase a high volume
after getting used to it .
6.5 Groundlift switch
If an interfering hum noise can be heard without
a music signal, a ground loop may be the reason
for this . Ground loops may occur when two units
have contact both via the signal ground and via
the earthed conductor of the power supply or
a conductive connection of the housings in the
rack . To separate the ground loop thus occur-
ring, set the DIP switches No . 7 and No . 8 (9)
from the upper position to the lower position .
switch configuration
Groundlift
7
Protective Circuits
The protective circuits are provided to prevent
damage to the speakers and to the amplifier . The
integrated level limiter reduces the input signal
when the limit level at the output is reached .
Thus, in case of overload of the amplifier, distor-
tions can be prevented which might damage the
speakers . If the limiter is active, the LED LIMITER
(2, 4) of the corresponding channel lights up .
An additional protective circuit separates
the speakers from the output of the channel
concerned . If it is active, the corresponding red
LED PROTECT (2, 4) lights up:
1 . for a short time after switching-on (switch-on
delay)
2 . in case of overload/overheating (e . g . also by
short circuit at the output)
3 . if a DC voltage occurs at the output
During normal operation, the temperature at
the power transistors is shown on the display (3)
separately for both channels . With higher tem-
peratures, the fan control ensures that the fan of
the channel concerned runs at a higher speed .
In case of a defect, e . g . a short circuit at an
output, the display changes to
PROT, OVERLOAD&FAULT
LED PROTECT of the channel concerned lights
up) . – In this case, or if the LED PROTECT is
not extinguished after switching-on, or if the
protective switch (15) has been released (only
for model STA-1400), the amplifier must be
switched off and the cause for the defect must
be eliminated . If required, reset the protective
switch by pressing it down .
8
Specifications
Model
STA-600
STA-1000 STA-1400
RMS output power
(1 kHz, 0.1 % THD + N)
Stereo, parallel at 4 Ω
2 × 300 W
2 × 500 W
Stereo, parallel at 8 Ω
2 × 200 W
2 × 350 W
Bridge mode at 8 Ω
550 W
1000 W
Input sensitivity for rated
power at 8 Ω
Input impedance
20 kΩ (bal.) / 10 kΩ (unbal.)
Frequency range
20 Hz – 20 kHz (±0.3 dB)
with 1 W at 8 Ω
High pass filter /
120 Hz (−6 dB), 24 dB / octave
low pass filter
Attenuation factor at 8 Ω
THD
Channel separation
S / N ratio with
rated power at 8 Ω
*20 Hz – 20 kHz with rated power at 8 Ω
Output circuit
Ambient temperature
Power supply
230 V/ 50 Hz
Max. power consumption
1000 VA
Dimensions (W × H × D)
482 × 88 × 418 mm, 2 RS
Weight
12.5 kg
Subject to technical modification .
All rights reserved by MONACOR
GmbH & Co. KG. No part of this instruction manual
may be reproduced in any form or by any means for
any commercial use.
SHORT CIR.
(in addition, the
2 × 700 W
2 × 450 W
1400 W
1 V
> 300
< 0.1 %*
> 60 dB*
> 95 dB
class AB
0 – 40 °C
1600 VA
2300 VA
15 kg
16.7 kg
®
INTERNATIONAL
7