PA Digital Power Amplifier
These instructions are intended for install-
ers with knowledge in 100 V technology for
PA applications . Please read the instructions
carefully prior to installation and keep them
for later reference .
All operating elements and connections
described can be found on the fold-out
page 3 .
1 Overview
1.1 Front panel
1 Display
2 Button MENU
To activate one of the setting menus,
keep the button pressed for two seconds
until
EDITING MODE
the display . Then either press the knob
PUSH / LEVEL (8) to activate menu 1 (fig . 3)
or press the button MENU again to acti-
vate menu 2 (fig . 4) .
The first line of the menu is selected . To
go to the next menu line, briefly press the
button MENU .
3 Button SELECT to change the setting in
the menu line selected
4 Button ENTER / INFO
When the setting menu is activated
to save the menu settings and exit the
menu
When no menu is activated
to activate info menu 2 (fig . 6)
5 Button ESC / BUZZER
– To exit the menus
– If there is an acoustic warning signal
in case of a fault, press the button to
deactivate the warning signal .
6 Button MASTER RST to reset the master
microprocessor
7 LEDs
CLIP lights up when the amplifier is over-
loaded . Reduce the volume accord-
ingly .
SIG lights up when a specific signal vol-
ume has been reached .
ON lights up when the amplifier is
switched on .
8 Knob PUSH / LEVEL
To adjust the volume, first press the
knob for two seconds until
ap pears on the display .
SETTING
Then turn the knob to adjust the vol-
ume . Finally briefly press the knob to
save and lock the volume adjusted .
To show the amplifier settings, briefly
press the knob . The information is in-
serted on the display (fig . 5) . Press the
button MENU (2) to go to the next line .
To exit the information menu, press the
button ESC (5) .
9 Button CPU RST to reset the second mi-
croprocessor
8
10 Button OCP RST to reset the protective
circuit when
on the display (
11 Button POWER to switch between oper-
ation mode (press button briefly) and
standby mode (keep button pressed until
the display is extinguished)
12 LED STAND-BY: lights up when the am-
plifier is in standby mode
1.2 Rear panel
To make handling easier, all green screw ter-
minals (15, 17, 18, 19) can be disconnected
from their plug-in connections .
13 Mains jack for connection to a socket
(230 V/ 50 Hz) via the mains cable provided
14 RS-485 interface for remote control of the
amplifier, e . g . via a PC
starts flashing on
15 Screw terminal AC PWR REMOTE for a
switch to change between operation
mode and standby mode via remote
control
16 Support for the mains fuse
Always replace a blown fuse by one of
the same type .
17 Screw terminal SPEAKER OUTPUT to con-
nect the PA speakers
18 Screw terminal PGM IN for the input
signal
19 Screw terminal PRIORITY IN for an input
signal taking priority over the signal at
the input PGM IN (e . g . for emergency
announcements): As soon as a signal is
available at the terminal PRIORITY IN,
the signal at the terminal PGM IN will be
muted .
20 Screw terminal 24 V⎓ for an emergency
power supply unit .
2 Safety Notes
This unit corresponds to all relevant directives
of the EU and is therefore marked with
WARNING The unit uses dangerous mains
During operation, there is a hazard of con-
tact with a dangerous voltage up to 100 V
VOLUME
at the speaker terminals (17) . Always switch
off the amplifier before making or changing
any connection .
•
The unit is suitable for indoor use only . Pro-
tect it against dripping water and splash
water, high air humidity and heat (admissi-
ble ambient temperature range: 0 – 40 °C) .
•
Do not place any vessel filled with liquid on
the unit, e . g . a drinking glass .
•
The heat generated inside the unit must be
dissipated by air circulation; never cover the
air vents of the housing .
appears
OVER CURRENT
chapter 6 .2 .3)
☞
voltage . Leave servicing to
skilled personnel only and do
not insert anything into the
air vents! Inexpert handling of
the unit may result in electric
shock .
•
Do not operate the unit and 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
The amplifier PA-1250D with a 250 W RMS
output power is specially designed for PA
systems . It is equipped with a switch mode
power supply unit and a class D power am-
plifier and provides an efficiency of more
than 90 % . An LC display shows the most
important operating parameters and allows
to make settings via a menu .
4 Setting up the Amplifier
The amplifier is designed for installation into a
rack for units of a width of 482 mm (19") but
can also be used as a tabletop unit . In order
.
to ensure sufficient cooling of the amplifier,
air must always be able to flow freely through
all air vents .
4.1 Rack installation
For rack installation, the amplifier requires
a space of 2 RS (2 rack spaces = 89 mm) . To
prevent the rack from becoming top-heavy,
insert the amplifier into the lower section of
the rack . The mounting brackets are not suffi-
cient 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 damage the amplifier but also other
units in the rack . In case of insufficient heat
dissipation, install a ventilation unit into the
rack (e . g . DPVEN-03) .