All operating elements and connections can
be found on the fold-out page 3.
1 Operating Elements
and Connections
1
Button MUTE to mute the corresponding
channel
2
Indication CLIP for each channel
lights up when the channel is overloaded
3
Volume control LEVEL for each channel
4
On / off switch POWER
5
Balanced inputs as XLR jacks for each chan-
nel; in case of bridge operation, only connect
the odd-numbered input in each case
6
Unbalanced inputs as phono jacks for each
channel; in case of bridge operation, only con-
nect the odd-numbered input in each case
7
Switch for the operating mode, each for one
channel pair
NORMAL = each channel operates separately
BRIDGE = bridge operation
8
Speaker terminals
9
Support for the mains fuse
Only replace a blown fuse by one of the same
type!
10
Mains jack for connection to a socket (230 V~ /
50 Hz) via the supplied mains cable
2 Safety Notes
The unit corresponds to all required directives of
the EU and is therefore marked with
.
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
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
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
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 , or coloured green or
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.
3 Applications
This digital amplifier is suited in an optimum way
for simultaneous PA application in several
rooms. For this purpose model STA-450D is
equipped with four channels, model STA-850D
with eight channels. Each channel is able to
deliver an rms power of 50 W. For a higher out-
put power two channels each can be bridged.
Due to the bridge circuit an rms power of 100 W
can be delivered per channel pair.
4 Setting-Up
The amplifier is provided for installation into a
rack (482 mm / 19″), but it may also be used as a
tabletop unit. In each case, air must be allowed
to flow freely through all ventilation slots so that
a sufficient cooling is ensured.
4.1 Rack installation
For rack mounting, 2 rs (rs = rack space =
44.45 mm) are required. To prevent top-heavi-
ness of the rack, the amplifier must be inserted
in the lower part of the rack. To ensure a safe fix-
ing, the front panel alone is not sufficient. In addi-
tion, the unit must be supported by means of lat-
eral rails or a bottom plate.
The heated air blown out by the amplifier
must be able to dissipate from the rack, other-
wise a heat accumulation will occur in the rack
which may not only damage the amplifier but
also other units in the rack. In case the heat is
not dissipated sufficiently, a fan unit has to be
inserted into the rack.
5 Connecting the Amplifier
All connections must only be made or changed
with the unit switched off!
1) Connect the
signal sources
(e. g. CD player,
preamplifier, mixer) to the jacks INPUT (5, 6).
The XLR jacks (5) are designed for bal-
anced signals and require for rated power an
input signal of 550 mV as a minimum.
Connect signal sources with unbalanced
signals to the phono jacks (6). For rated power
a signal of 1 V as a minimum is required.
For channel pairs intended for bridge oper-
ation (
chapter 6.1), only connect the odd-
numbered input in each case.
2) Connect the
speakers
to the terminals OUT-
PUT (8). The table on page 3 shows the
required power rating (P
MIN
) of the speakers.
For channels operating in
normal opera-
tion
[switch (7) in position NORMAL], con-
nect in each case the marked core of the
speaker cable to the red terminal and the
other core to the black terminal. For normal
operation the highest output power will be
reached with 4 Ω speakers. Speakers with
lower impedance (Z) must not be connected,
otherwise the amplifier may be damaged. 8 Ω
speakers may be connected, however, in this
case the output power will slightly decrease.
For channel pairs operating in
bridge
operation
[switch (7) in position BRIDGE],
connect in each case the marked core of the
speaker cable to the left, red terminal of the
channel pair and the other core to the right,
red terminal (see imprint BRIDGE at the ter-
minals). In bridge operation the maximum
output power will be reached with an 8 Ω
speaker. Speakers with lower impedance (Z)
must not be connected, otherwise the ampli-
fier may be damaged. Speakers with higher
impedance may be connected, however, in
this case the output power will slightly
decrease.
3) First connect the
mains cable
to the mains
jack (10) and then the mains plug of the cable
to a socket (230 V~ / 50 Hz).
If the unit is to be put out of operation
definitively, take it to a local recycling
plant for a disposal which is not harmful
to the environment.
WARNING
The unit is supplied with haz-
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.
6
GB