AUSTRALIAN MONITOR CM500 User manual

DCM500
500w Power Amplifier
Operating Manual
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HI MAINS
DCM 500

ProductDescription
TheDCM500 isa 500watt poweramplifier designedfor commercialinstallations. Itcan beused foreither lowimpedance
(4 ohm) or 70v/100v line speaker systems. The amplifier can be mounted in a standard 19” equipment rack or it can be
used on a shelf or table. The DCM500 features a line level input (with parallel output) and is normally used with mixers,
mixer amplifiers or other power amplifiers. The DCM500 will operate from 230/240 VAC @ 50 Hz (115 VAC @ 60
Hz with factory modification) or 24 VDC and will meet its full performance specification on either voltage supply.
The DCM500 also features a DC battery trickle charge facility, auto-sensing fan cooling, plus overload, short circuit
and over temperature protection.
DCM500, 500 Watt Power Amplifier
Front Panel Features
Power Switch
The rocker switch located in the front centre of the panel turns AC power on to the DCM500. Rocking the power switch
to the right to turns the AC power ‘on’. When the AC power is ‘on’, a blue LED will glow. Please note that this switch
does not switch DC voltage. If a DC voltage supply is connected to the DCM500, the amplifier will operate as soon
as the connection is made, regardless of the position of the AC power switch. If both an AC and DC voltage supply are
connected and you rock the AC power switch to the ‘off’ position, the DCM500 will automatically continue to
operate normally from the DC supply (and the ‘mains failure’ LED in the amplifier status display window will also
glow under these conditions).
Level Control
The output level control is located in the centre of the front panel, just to the left of the mains rocker switch (re-
cessed screwdriver adjustable pot). Turning the control clockwise will increase the output of the DCM500 towards
it’s maximum output level while turning the control counter-clockwise will decrease the output level. Adjust this
control for the desired output level depending on the level of the input signal (from a mixer or other signal source).
The factory default setting for this control is such that a 1 volt input will give a 100 volt output.
AmplifierStatusDisplay
The amplifier status display highlights the operating condition of the DCM500. The status display indicates:
High Temperature: This red LED glows if one of the fans has failed and the amplifier has been shut down by its
temperature control circuitry. If this LED is glowing and the fans have not failed, it means that the amplifier is operating
in an ambient environment that is too hot for fan cooling to make any difference to the temperature of the amplifier.
Power: This LED glows blue if AC power is switched on to the DCM500. Note that this LED does not indicate the
presence of a DC supply voltage.
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HI MAINS
DCM 500

Rear Panel Features
AC Power Inlet
The 3 pin IEC power inlet is located on the bottom left of the rear panel and accepts a standard mains power lead fitted
with an IEC connector. Before plugging in a power lead, please check the rear panel of the amplifier to ensure that the
voltage label shows the correct AC operating voltage for your part of the world.
The inlet is equipped with an in-built AC fuse holder fitted with a 10 Amp slow blow fuse plus a spare fuse. Please
ensurethatthemainspowercordis disconnectedbeforeattemptingtocheck orreplacethisfuse.Powerconsumption
is800VA(max).
Speaker Output Terminal Strip
Located on the top left of the rear panel is the speaker output terminal strip. Reading from left to right, the connections
are: COM Common or “-” for low impedance speaker loads (4 ohms).
4The “+” for 4 ohm speaker loads (use with common)
COM Commonor “-” for70v or100v speakerloads (maximum loadof 20ohms at100v)
70 The “+” for 70v line speaker loads (use with common)
100 The “+” for 100v line speaker loads (use with common)
Please ensure that the correct “Common” is used. Low impedance and 70/100v loads can be used simultaneously but
please pay careful attention to the overall speaker load. When used individually, the low impedance load should be 4
ohms or higher while the 100v line load should not fall below 20 ohms. When both outputs are used simultanously,
ensure that neither output is loaded to maximum.
24 Volt Power
Located on the rear panel are the red and black connection posts for 24v power. This feature can be used as either a back-
up facility (if mains power fails) or for applications where AC power is not available. The left side red post is the +
(positive) terminal while theright side black post isthe -(negative)terminal. The DCcurrent drainis 30 Ampsmaximum
at full power. This socket also provides trickle charge to a DC battery supply (if connected) when the DCM500 is
operatedfrom AC mainspower.The levelof trickle charge is300 mA,maximum.
MainsFailure: The LED glows red if there is a failure in the AC mains power supply. However, this LED will only glow
if there is a DC supply voltage present. If no DC supply voltage is present then this LED will not glow.
OutputLevelVU Meter:A 10 segment LED VU meter is provided to give an indication of the output signal level of the
amplifier from -25 to +3 dB. During normal operation, the LED’s will oscillate with changes in the program signal. Care
should be taken to avoid more than occasional illumination of the red LED’s. If the LED’s in the red zone are lit
continually, then the output level control (or the level of the input signal to the DCM500) should be adjusted to reduce
the output level. Too much output level can cause distortion, activate the internal limiter or possibly damage the
connected speaker system.
230 V 240 V
AC FUSE 10A S/B
ENGINEERED BY AUDIO TELEX COMMUNICATIONS PTY LTD SYDNEY AUSTRALIA
24 VDC
INPUT
DC FUSE
2 X 35A
C1004 OHM VOLT 70

Twin DC Fuse Receptacles
Located on the rear panel are two DC fuse receptacles. Access each DC fuse by turning the cap counter-clockwise
with a screwdriver. The value of the fuse is 35 Amps. Please ensure that the AC power switch is in the ‘off’
positionand thatthemainspowercordisdisconnected beforeattemptingtocheckorreplacethis fuse
Cooling Fan (Air Intake)
The cooling fans are temperature sensitive and will only switch on when the temperature of the DCM500 had reached a
pre-determined range. The fan will stay on and only switch off again once the temperature of the DCM500 has fallen
below a pre-determined level. If the DCM500 is operating continually at conservative levels and proper load conditions,
it is possible that the cooling fan will not switch on at any time during normal operation. When operating, the fan works
with air flow from the front to the rear of the DCM500.
Fuse Sizes
Mains,240 VAC:10 AmperesSlow Blow.
XLR Audio Input and Parallel Output
The input to the DCM500 is transformer balanced @ 10K ohms. When signal is connected to one XLR, the other
XLR becomes a line level output allowing the input signal to be distributed (split) to other amplifiers. In some
projects, the same input may be looped through to multiple amplifiers using this method. Up to 6 amplifiers can be
looped together without any noticeable loss in level. A distribution amplifier should be used when more than 6
amplifiers need to be looped.
The XLR’s are wired as follows: Pin 1: Shield. Pin 2: Hot, +, Positive. Pin 3: Cold, -, Negative

1.Savethecartonandpackingmaterialeveniftheequip-
ment has arrived in good condition. Should you ever
need to ship the unit, use only the original factory pack-
ing.
2.Readalldocumentationbeforeoperatingyourequip-
ment.Retain all documentation for future reference.
3. Follow all instructions printed on unit chassis for
proper operation.
4.Donotspillwaterorotherliquidsinto orontheunit,
or operate the unit while standing in liquid.
5. Makesurepower outlets conformto the powerre-
quirements listed on the back of the unit.
6. Do not use the unit if the electrical power cord is
frayed or broken. The power supply cords should be
routed so that they are not likely to be walked on or
pinched by items placed upon or against them, paying
particular attention to cords and plugs, convenience re-
ceptacles, and the point where they exit from the
appliance.
7. Always operate the unit with the AC ground wire
connected to the electrical system ground. Precautions
should be taken so that the means of grounding of a
piece of equipment is not defeated.
8. Mainsvoltage mustbecorrectandthe sameas that
printed on the rear of the unit. Damage caused by
connection to improper AC voltage is not covered by
any warranty.
9.Havegaincontrolsonamplifiersturneddownduring
power-up to prevent speaker damage if there are high
signal levels at the inputs.
10.Powerdown&disconnectunitsfrommainsvoltage
beforemaking connections.
11.Neverholdapowerswitch inthe“ON”positionifit
won’tstay thereitself!
12. Donotuse theunitnear stoves,heatregisters, ra-
diators,orotherheatproducingdevices.
13.Do notblockfan intakeor exhaustports.Do not
operate equipment on a surface or in an environment
which may impede the normal flow of air around the
unit, such as a bed, rug, weathersheet, carpet, or com-
pletelyenclosed rack.If theunitis usedin anextremely
dusty or smoky environment, the unit should be peri-
odically “blown free” of foreign matter.
14.Do notremovethe cover.Removingthecover will
expose you to potentially dangerous voltages. There
are no user serviceable parts inside.
15.Donot drivetheinputs withasignal levelgreater
thanthatrequiredtodriveequipmenttofulloutput.
16.Do notconnect theinputs /outputs ofamplifiers
or consoles to any other voltage source, such as a
battery, mains source, or power supply, regardless of
whether the amplifier or console is turned on or off.
17. Donotrun the output ofanyamplifierchannel
backintoanotherchannel’sinput.Donotparallel-or
series-connect an amplifier output with any other
amplifieroutput.
Audio Telex Communications Pty Ltd is not respon-
sible for damage to loudspeakers for any reason.
18. Donotground any red(“hot”)terminal. Never
connecta“hot”(red)outputtogroundortoanother
“hot”(red)output!
19. Non-use periods. The power cord of equipment
should be unplugged from the outlet when left un-
used for a long period of time.
20.ServiceInformationEquipmentshouldbeserviced
by qualified service personnel when:
A. The power supply cord or the plug has been
damaged.
B. Objects have fallen, or liquid has been spilled into
the equipment
C. The equipment has been exposed to rain
D.The equipmentdoes notappear tooperate normally,
or exhibits a marked change in performance
E. The equipment has been dropped, or the enclosure
damaged.
Important Safety Information

Engineered by Audio Telex Communications Pty Ltd, Sydney, Australia
A.B.N. 78 001 345 482 Inc in NSW
Sydney (NSW & ACT Sales)
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ExportSales &Corporate HeadOffice
Private Bag 149, Silverwater NSW 1811
149 Beaconsfield Street, Silverwater NSW 2128
Australia
Ph: 61-2- 9647 1411
Fax: [phone]
E-mail: [email protected]
www.audiotelex.com.au