Operating Elements And Connections; Safety Notes - IMG STAGE LINE STA-250 Instruction Manual

All operating elements and connections de -
scribed can be found on the fold-out page 3.
1 Operating Elements and
Connections
1.1 Front panel
1 Volume control
each for the channels L-CH and R-CH
Note: In parallel operation and bridge opera-
tion the control of the channel R-CH has no
function.
2 Status LEDs
each for the channels L-CH and R-CH
PROTECT
lights up when the protective circuit discon-
nects the speaker from the amplifier: for a
short time after switching-on and in case of
overload/overheating of the amplifier
LIMITER
lights up when the limiter circuit is active and
reduces the signal to prevent overload
SIGNAL/ -20 dB/ -10 dB
show the level of the output signal
3 LC display to show the operating parameters
and status ( chapter 1.3)
4 Button LOAD 4/ 8 OHM to select the speaker
load for the correct calculation of the power
indication on the display (3) [if required, press
several times]
5 Mains switch POWER
1.2 Rear panel
6 Selector switch for the adjusting range of the
filter frequency of the corresponding control
CROSSOVER FREQ. (7), each for the chan-
nels L-CH and R-CH:
"×1" (switch disengaged):
45 – 960 Hz
"×10" (switch pressed down):
450 – 9600 Hz
7 Control CROSSOVER FREQ. for the filter
frequency, each for the channels L-CH and
R-CH
Note: In parallel operation and bridge opera-
tion the control of the channel R-CH has no
function.
8 Input as a 6.3 mm jack, balanced, for con-
nection of a signal source with line level, each
for the channels L-CH and R-CH
Note: In parallel operation and bridge opera-
tion the input of the channel R-CH has no
function.
9 Selector switch for the use of the filter, each
for the channels L-CH and R-CH
HIGH high pass filter
BYPASS no filter
LOW low pass filter
10 Input as an XLR jack, alternatively to the
6.3 mm jack (8), each for the channels L-CH
and R-CH
Note: In parallel operation and bridge opera-
tion the input of the channel R-CH has no
function.
11 ON / OFF switch LIMITER for the automatic
level limitation
12 Selector switch for the operating mode
STEREO/ PARALLEL/ BRIDGE
( chapter 6.1)
13 Switch GROUNDLIFT to separate the signal
ground from the housing ground:
GND
signal ground and housing ground are con-
nected
LIFT
signal ground and housing ground are sepa-
rated (groundlift)
14 Circuit breaker to protect the unit; to reset the
released switch, press down the button with
the unit switched off
15 Mains cable for connection to a socket
(230 V~/50 Hz)
16 Speaker jack R-CH
17 Speaker output R-CH as screw terminals, as
an alternative to the speaker jack (16)
18 Speaker output L-CH as screw terminals, as
an alternative to the speaker jack (19)
19 Speaker jack L-CH
20 Speaker jack BRIDGE for the bridge opera-
tion
1.3 Display
Standard indication during operation (fig. 4)
a output power of both outputs, calculated
according to the output voltage measured
and the load impedance selected [button
LOAD 4/ 8 OHM (4)]
Note: The calculation is not effective in
bridge operation.
CLIP ON/ OFF
b for both outputs; if
shown, the amplifier input is overloaded. In
this case reduce the input level with the cor-
responding control (1).
PROT ON/ OFF
c (= PROTECTION,
1.1, item 2, status LED PROTECT)
d temperature at the power transistors of both
channels
e vertical bargraph indication for the output sig-
nals of both channels
Indication for a few seconds after actuating a vol-
ume control (1), the switch LIMITER (11) or the
switch for the operating mode (12) [fig. 5]
STEREO/ PARALL/ BRIDGE
f
operating mode
g check for the switch LIMITER (11)
LIMT ON
= limiter switched on
LIMT OFF
= limiter switched off
ATTEN
h (attenuation) for attenuation of the
input signals shows the position of the vol-
ume controls (1) numerically (i) and as a ver-
tical bar (j)
Indication for a few seconds after actuating the
button LOAD 4/ 8 OHM (4) [fig. 6]
k selected load impedance for the calculation
of the output power shown (a)

2 Safety Notes

The unit corresponds to all relevant directives of
the EU and is therefore marked with
WARNING The unit is supplied with haz-
It is essential to observe the following items:
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 vessels filled with liquid, e. g.
drinking glasses, on the unit.
G
The heat being generated in the unit must be
carried off by air circulation. Therefore, the air
vents at the housing must not be covered.
G
Do not set the unit into operation, and imme-
diately disconnect the mains plug from the
mains socket if
1. there is visible damage to the unit or to the
mains cable,
2. a defect might have occurred after a drop or
similar accident,
3. malfunctions occur.
The unit must in any case be repaired by
skilled personnel.
G
A damaged mains cable must only be re -
placed by skilled personnel.
G
Never pull the mains cable to disconnect the
mains plug from the mains socket, always
seize the plug.
G
For cleaning only use a dry, soft cloth, never
use chemicals or water.
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
CLIP ON
is
is not correctly connected or operated, or not
repaired in an expert way.
G
Important for U. K. Customers!
The wires in this mains lead are coloured in
chapter
accordance with the following code:
green/yellow = earth
blue = neutral
brown = live
As the colours of the wires in the mains lead of
this appliance may not correspond with the
coloured markings identifying the terminals in
your plug, proceed as follows:
1. The wire which is coloured green and yel-
low must be connected to the terminal in the
plug which is marked with the letter E or by
the earth symbol
of the selected
green and yellow.
2. The wire which is coloured blue must be
connected to the terminal which is marked
with the letter N or coloured black.
3. The wire which is coloured brown must be
connected to the terminal which is marked
with the letter L or coloured red.
Warning – This appliance must be earthed.
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.
.
ardous mains voltage. Leave serv-
icing to skilled personnel only and
do not insert anything through the
air vents! This may cause an elec-
tric shock hazard.
, or coloured green or
GB
7