AUSTRALIAN MONITOR AM1600 User manual

Operation Manual
AM1600

!WARNING!
DO NOT EXPOSE TO EITHER
RAIN OR MOISTURE
!CAUTION!
RISKOFELECTRICALSHOCK
DO NOT OPEN
IMPORTANT!
Please read carefully.
Thisoperationmanualcontainsimportantinformationregarding
safetyprecautions,installation,performance,operationand
maintenance of your AM1600 power amplifier. You should
familiarize yourself with the contents of this
Safety Precautions
and Labelling
manual before operating your amplifier.
Therearpaneloftheunithasanumberofmarkingsand
internationally recognized symbols related to the
hazards and precautions that should be taken when
operatingMAINSconnectedequipment.
ThepresenceofaLIGHTNINGFLASHwithanarrowhead
containedwithintheboundariesofanequilateraltriangle
isintendedtoalerttheuserthatdangerousuninsulated
voltagesmayexistwithintheunit'senclosure.These
voltages may be of a sufficient magnitude as to
constitute the risk of an electrical shock.
This symbol is reinforced with the text:
ThepresenceofanEXCLAMATIONMARKcontained
within the boundaries of an equilateral triangle is
intended to alert the user that there is important
operatingandmaintenanceliteraturethataccompanies
the unit.
Theunitshouldnotbeoperatedinasituationwhereit
mayencountertheentryofwater,rain,oranyfluids.To
exposetheunittotheaboveconditionsmaymakethe
operationoftheunit hazardous and increasetherisk
of electrical shock.
The user should not attempt to service the unit. Only
qualified and knowledgeable personnel familiar with
the internal workings of the unit should attempt any
repair, servicing or authorized modification to the
unit. The unit does not contain any parts which the
usercanserviceorre-useinthisoranyotherproduct.
If you are in need of special assistance and the
information you require is outside the scope of this
manual,pleasecontactyournearestserviceagentor
Australian Monitor direct:
THE TECHNICAL OFFICER
AUSTRALIANMONITOR
C/-AUDIOTELEXCOMMUNICATIONSPTYLTD
PRIVATEBAG149,
SILVERWATER. N.S.W. 1811
AUSTRALIA.
Phone Fax
Local [phone] (02) 9748-2537
International 61-2-9647-1411 61-2-9748-2537
Email [email protected]
Internet www.australianmonitor.com.au
REFERSERVICINGTO
QUALIFIED PERSONNEL.
NO USER SERVICEABLE
PARTS INSIDE.

Features:
- Custom designed, 3RU heavy duty alloy chassis.
-Modularconstruction.
- Symmetrical layout - even weight distribution.
-Linear,well-regulating,highcurrentpowersupply.
-Highefficiencytoroidalmainstransformer.
-Continuoushighpowercapability.
- Lateral Mosfet Class AB output stage.
- Binding post and Neutrik "Speakon" output
connection.
-Inputsignalstrapping(loopthrough)connectors.
Protection Features
-Suppressionof inrush current atmainsturn-on.
- Side chain mains switching control.
-Inputmutingat turn-on.
-Inputovervoltageprotection.
-Radio-frequencyinterferencesuppression.
-Short-circuitprotectionand indication.
-Activebalancedinputs.
-21 Position detentedattenuators.
-Massiveheat-sink/heat-exchangers.
- Efficient front to back cooling.
- Quad, twin speed axial fans.
-Multi-rolelevel / fault indication.
-Frontandrear carry handles.
-Frontandrearmounting points.
-High-quality,close-tolerancecomponentsused
throughout.
-Thermaloverloadprotectionandindication.
- Mains Circuit Breaker.
-Individualhighcurrentrailfuses.
-Layout,grounding,decouplingandcomponentry
have been optimized to provide the user with
stability, reliability and longevity.

Contents Page
1. Introduction 5
2. Controls,ConnectorsandIndicators 6
2.1FrontPanel 7
2.2RearPanel 9
3. Installation 11
4. Operation 13
5. Bridge Mode 15
6. TwoOhmorNotTwoOhm 16
7. Maintenance 17
8. Warranty 18
9. Specification 19
List of Illustrations Page
Figure 1. Block Diagram 5
Figure2.FrontPanelLayout 6
Figure3.RearPanelLayout 8
Figure 4. Case Dimensions 10
Figure 5. "Speakon" Connector Wiring 12
Figure 6. Bridge Mode Speaker Wiring 15

1. Introduction
Congratulations on choosing Australian Monitor for
yourprofessionalamplificationrequirements.
The design of your AM1600 Audio Power Amplifier
embracesalltheaspectsofawelldesignedunit.The
visual design, mechanical, electrical and sonic
parameters,alongwithourdedicatedmanufacturing
process, have all been optimized to provide a
professional tool that exhibits quality, reliability and
longevity.
TheAM1600amplifiersare3unit(5.25")tall,19"wide
rack mountable units.
Each channel of the amplifier comprises a balanced
active input with an attenuator driving a differential
classA drivestage which in turn drives a fan-cooled,
class AB MOSFET output stage configured as a
sourcefollower.Theunitoperatesfromahighcurrent
capablelinearpowersupply.
Theseunitshavebeenspecificallydesignedtodeliver
their high power output with minimal distortion, and
providethecriticaldegreeofcontrolrequiredbyyour
speakers, at high duty cycles for extended periods.
Figure 1 Amplifier Block Diagram
Introduction 5

6 Controls & Connectors
Figure 2 Front Panel Layout
2. Controls,
Connectors
& Indicators
Insert - 1 VU Meter / Satus Indicator

Front Panel
Figure 1 shows the panel layout of the AM1600. The
functionsofthecontrolsandindicatorsareasfollows:
1.Attenuator
Levelcontrol foryouramplifierisprovidedbya21
positiondetentedpotentiometerandindicatesgain
reduction in decibels from the 0 dB position
(maximumgain,noattenuation).
2. VU Meter - Status Indicator
LevelIndication(seeinsert-1)
Eachchannelfeaturesavariable10segmentdisplay
showing the actual power/volume level available
beforeclipping(takingmainssupplyandloadduty
intoaccount).
Thedisplayiscolourcoded,andcalibratedin3dB
increments.
The10LEDs are:
Green = -27dBto-21dB
Yellow = -18dBto-6dB
Red = -3dBandthetwoLEDsindicating
the clipping point.
PowerOnIndication
Two Green LEDs either side of the mains switch
(above the "ON" legend) are used to indicate that
theunitison.Thefirst GreenLEDindicatesthe15
Volt preamp supply is present (the left hand side
displayshows-15V,andtherighthandsideshows
the+15V).
The next LED outwards is also a supply indicator
and shows that the Positive High Current Output
Railisavailabletothecorrespondingchannel.
NOTE:Theamplifierisnotdamagedbyrunninginto
clipping,butspeakersmaybe.Tomaximisethelife
of your speakers, try to keep clipping infrequent.
3. Power Switch
PresstheswitchDOWN forpowerON andUP for
power OFF. At start-up (turn-on) the input to the
amplifier is muted by 30dB for approximately two
seconds.
4. Thermal Indicator
Whenswitching the amplifieron, this redLED will
flash momentarily, indicating correct operation of
the Mains In-Rush Current Suppression circuit.
AfterestablishmentofInrushCurrentSuppression
circuit the LED will extinguish. This LED will not
illuminateduringnormaluseoftheamplifier.
In the advent of a thermal overload this LED will
illuminateredindicatingthattheinternaloperating
temperatureofoneorbothamplifierchannelshas
exceededasafelevelofoperationandthe amplifier
willbeshutdown.Thefanswillcontinuetorunand
oncetheamplifierhascooleddownsufficiently,the
amplifierwillstartupautomaticallyprovidingInrush
CurrentSuppressionandinputsignalmutinguntil
establishment of the amplifier after which it will
returntonormaloperatingmode.
NOTE:Youshouldalwaysensurethatthefangrille
iskeptcleanandfreefromthebuildupofdustand
lint.Thiswillensurelongeroperationofyouramplifier
and reduce the possibility of it prematurely going
intothermalshutdownmode.
5. Fault Indicator
ThisamberLEDwillilluminatewhenafaultcondition
exists.
The fault detection circuit monitors the difference
betweendriveandoutputinyouramplifier.
Ifyouhaveashortonthespeakeroutput(orablown
negativerailfuse)theLEDwillflashbrightlyinsync
with the programme. This LED will also flash with
programmepeaksforgrossoverloadsoriftheload
is 2 ohms or less.
The circuit has two stages of operation:
1.Itwillprovideindication(e.g.grossoverload)but
does not affect the input signal (a faint flash).
2. It will indicate and mute the input signal (e.g.
shorted output) (brightly flashing or permanently
on).
Intheadventofafailurethedisplaypanelrevertsto
a fault display to assist in diagnosis of the fault.
- The VU meter will light up fully and the Positive
Output Rail LED will extinguish if the positive
supplyrailisnotavailable(checkrear+verailfuse).
- The fault Led will glow brightly if the Negative
OutputRailisnotavailable(checkrear-verailfuse).
- Failure of the pre-amp supply will cause the
amplifier to be muted and indicator LEDs to be
extinguished.
Controls & Connectors 7

8 Controls & Connectors
Figure 3 Rear Panel Layout

Rear Panel
6. Balanced Input
A female 3-pin XL type connector is provided on
eachinput:
Pin 1 = Signal Ground;
Pin2=Hot(non-inverting or in phase);
Pin3=Cold(invertingorreversephase).
6a.SignalStrapping
A male 3-pin XL type connector is provided and
wired in parallel with the female input XLR for
strapping/loopingsignalbetweenamplifiers.
7. SPEAKON Output Connector
TheNEUTRIK(NL4MP)4waySPEAKONconnector
isprovidedasthemainspeakeroutputtermination.
Thisemergingstandardofloudspeakertoamplifier
connection allows access to both channels of the
amplifier via the one connector for bi-amp
applications.Channel-Aisconsideredthedominant
channelandhasbothchannelswiredtotheSpeakon
connector. See the installation section of this
manualfordetailedinformationonSpeakonwiring.
7a.Binding Post Outputs
Binding posts (banana jacks) are provided for
speaker output termination with banana plugs or
barewire.Theredpostisusedaspositiveandthe
black post is used as negative.
8. Mains Lead
Youramplifierissuppliedwithaheavydutymains
lead(powercord)appropriatelyratedforthemains
supply voltage marked on the rear panel of your
amplifier.
The wires in the mains lead are coloured in
accordancewiththefollowingcode:
BROWN = ACTIVE;
BLUE = NEUTRAL;
GREENANDYELLOW = EARTH.
Controls & Connectors 9
! CAUTION !
Your amplifier must always be earthed!
9.Mains CircuitBreaker
A “push to reset” thermal acting circuit breaker is
suppliedonyouramplifierprovidingoverallprotection
of your amplifier’s power supply and the
interconnectingmains.Thebreakerwillisolatethe
"active" mains conductor in the event of a high
current internal fault or in continued overload
conditions.
Thebreakerwillnotbeabletoberesetimmediately
after tripping. A cool down period of around 30
seconds is required before the breaker will reset
backintocircuit.Ifthebreaker"trips"immediately
afterareset,thenafaultmayhavedevelopedwithin
theamplifier.
10. D.C. Rail Fuses
YourAM1600 amplifierisfitted with10Ampfuses
perrail-perchannel,asoverloadprotectionforthe
outputstageof youramplifier.
These fuses are in series with the high current
supply railstotheamplifier'soutputstageandwill
blowwhen:
1) An internal fault exists;
2)Thereisasustainedoverload;
3) There is a sustained short circuit;
4)Sustainedloadfault.
Front Panel Indication will result if one of the
corresponding Rail Fuses is to "blow".
- The VU meter will light up fully and the positive
Output Rail LED will extinguish if the positive
supply Rail Fuse "blows".
-TheFaultIndicatorwilllightupandpulseinsync.
withtheprogramsourceifthenegative supplyRail
Fuse "blows".
Replace only with 10 Amp, 3AG fast acting type
fuses.

Figure 4 Dimensions
10 Installation