Behringer A500 - Manual (Page 6)

6
REFERENCE AMPLIFIER A500
2. CONTROL ELEMENTS
CHANNEL INPUT 1 (MONO). Connect the signal source
whose output needs to be amplified.
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Please use only one of the three input connectors
per channel at any one time!
Here you will connect an output of your mixing console,
your HiFi preamp or another signal source.
Our rack mixing console EURORACK PRO RX1602, with its
eight mono-usable balanced stereo channels, is an ideal
choice for signal processing and source selection.
The connections for both channels are laid out as RCA,
XLR and 1/4" TRS stereo connectors. The cinch inputs are
intended for use with outputs laid out as unbalanced signals
with a -10 dBV line signal level. Because these inputs are
more sensitive than others, you can directly connect a CD
player or a DAT recorder. Of course this input can also be
used for connecting mixing consoles and similar equipment.
The XLR and 1/4" TRS stereo connectors are laid out
balanced, but they too can of course be used to connect
unbalanced signals. Their sensitivity is +4 dBu (also see
ch. 4).
Generally speaking, you should choose balanced over
unbalanced signals in order to guarantee the highest noise
protection.
Due to safety considerations, the inputs can not be used
in parallel. However, if you are using cinch and XLR or
1/4" TRS connectors simultaneously, the cinch input is
given preference, and the other signal is muted.
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If you wish to use the A500 in mono-bridged mode,
please only use one of the channel 1 inputs!
CHANNEL INPUT 2. These are the inputs for channel 2.
The STEREO/BRIDGED MONO switch is used to toggle
between the two operating modes of your A500.
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Please power the A500 down using the POWER
switch each time you change the operating mode.
Similarly, only connect/disconnect speaker
connectors if the A500 has first been powered off!
OUTPUT 1, OUTPUT 2 and BRIDGED MONO: These are
the speaker connectors of your A500 laid out as
1/4" TS mono connectors. When in mono-bridged mode,
only use the BRIDGED MONO output.
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Keep in mind the minimum power impedance of 4
Ohms per channel in stereo mode. When in mono-
bridged mode, a loudspeaker whose impedance is
at least 8 Ohms must be used.
In addition to XLR or 1/4" TRS connectors, you can also
use binding posts for connecting speaker cables. When in
mono-bridged mode, make sure to connect your cables to
both middle connectors–as shown on the unit itself.
FUSE SWITCH/VOLTAGE SELECTION. Before connecting
the unit to the mains, please check if the voltage selector
corresponds to your local voltage. When replacing fuses,
you should only use fuses of the same type and rating. With
some units, the fuse switch can be put into two different
positions in order to select between 230 V and 120 V
operation. Please bear in mind: If you wish to use your
equipment outside of Europe running on 120 V, you will
have to use a fuse with a higher Ampere value.
The mains connection is made via a standard IEC
RECEPTACLE. A matching cable is enclosed.
SERIAL NUMBER.
2.2 The back
9
8 13
10 11 12 6 7
Fig. 2.2: Control elements and connections in the back
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Your power amp should always be the last device
you power up, since some equipment in the signal
path creates strong impulses which are then
amplified in the amp and are passed onto the
loudspeakers, possibly damaging them.
Consequently, always let your power amp be the
first device you power down.
Each channel features a volume control. Use it to adjust
gain on your A500. Both volume controls should be turned
all the way to the left whenever you power the unit up or
down. If an active signal is present on the input, turning the
volume down will protect your speakers and your ears
from unwanted “pops” or transients.
The PROT LED lights up whenever the protective circuitry
mutes the speaker output. Please turn your A500 off
immediately whenever this LED is lit.
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The protective circuitry is activated if the amp gets
too hot. Let your A500 cool down a little before you
turn it on again. Besides, check if the heat sink has
enough space around it to perform its job.
The high-precision power indicator gives out current signal
strength.
The CLIP LED lights up when the signal is distorted. Should
distortion occur, reduce the input level, so that the CLIP
LED no longer lights up.
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If the CLIP LED remains being lit, check the cable
connection to the speakers because there might
be a short on the speaker output.