Australian Monitor IS600 User Manual

600W/1200W/1600W STEREO PRO AUDIO AMPLIFIERS

INSTALLATION AND OPERATION MANUAL

IS SERIES

1. Save the carton and packing material even if the equipment has
arrived in good condition. Should you ever need to ship the unit,
use only the original factory packing.

2. Read all documentation before operating your equipment.
Retain all documentation for future reference.

3. Follow all instructions printed on unit chassis for proper operation.

4. Do not spill water or other liquids into or on the unit, or operate the
unit while standing in liquid.

5. Make sure power outlets conform to the power requirements 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
receptacles, 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. Mains voltage must be correct and the same as that printed on the
rear of the unit. Damage caused by connection to improper AC

voltage is not covered by any warranty.

9. Have gain controls on amplifiers turned down during power-up to
prevent speaker damage if there are high signal levels at the
inputs.

10. Power down & disconnect units from mains voltage before making
connections.

11. Never hold a power switch in the “ON” position if it won’t stay
there itself!

12. Do not use the unit near stoves, heat registers, radiators, or other
heat producing devices

13. Do not block fan intake or exhaust ports. 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 completely enclosed rack. If the unit
is used in an extremely dusty or smoky environment, the unit
should be periodically “blown free” of foreign matter.

14. Do not remove the cover. Removing the cover will expose you to
potentially dangerous voltages. There are no user serviceable
parts inside.

15. Do not drive the inputs with a signal level greater than that
required to drive equipment to full output.

16. Do not connect the inputs / outputs of amplifiers 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. Do not run the output of any amplifier channel back into another
channel’s input. Do not parallel- or series-connect an amplifier
output with any other amplifier output.

Australian Monitor Inc is not responsible for damage to
loudspeakers for any reason.

18. Do not ground any red (“hot”) terminal. Never connect a “hot”
(red) output to ground or to another “hot” (red) output!

19. Non-use periods. The power cord of equipment should be unplugged
from the outlet when left unused for a long period of time.

20. Service Information Equipment should be serviced 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 equipment does not appear to operate normally,

or exhibits a marked change in performance
E. The equipment has been dropped, or the enclosure damaged.

IMPORTANT SAFETY INFORMATION

THIS SAFETY INFORMATION IS OF A GENERAL NATURE AND MAY BE SUPERSEDED BY INSTRUCTIONS CONTAINED WITHIN THIS MANUAL

INTRODUCTION AND CONTENTS

The Australian Monitor Installation Series IS600, IS1200 and IS1600
are 2 RU stereo power amplifiers. The IS600 delivers 300 watts per
channel @ 4 ohms & the IS1200 delivers 600 watts per channel @
4 ohms and the IS1600 delivers 800 watts per channel @ 4 ohms.

Designed for permanent installations where high quality
audioreproduction is required on a small budget, the IS series
deliver the sound quality & features contractors require.

The IS series continues the Australian Monitor tradition of
delivering an amplifier packed with clever features at a
contractor friendly price.

INTRODUCTION 3

FRONT PANEL 4

REAR PANEL 5

INSTALLATION 6

OPERATION 8

MAINTENANCE 10

SPECIFICATIONS 11

IS SERIES INSTALLATION & OPERATION MANUAL

Caution:

AUS, EUR, USA

Copyright 20th Feb 2005

Rev B: 15th Nov 2005

This symbol is intended to alert the user to the presence

of uninsulated “dangerous voltage” within the product’s

enclosure that may be of sufficient magnitude to

constitute a risk of electric shock to persons.

This symbol is intended to alert the user to the presence

of important operation and maintenance (servicing)

instructions in the literature accompanying the appliance.

To prevent electric shock do not use this (polarised) plug

with an extension cord, receptacle or other outlet unless

the blades can be fully inserted to prevent blade exposure.

To prevent electric shock, match wide blade of plug to

wide slot, fully insert.

PAGE 3

ATTENUATOR

There are 2 level controls on all IS models.
Each control is labelled for the channel
which it controls. 0dB indicates minimum
attenuation.

CLIP INDICATOR

This LED displays the status of the output
stage and displays two levels of operation.
These levels are:

Below clip level (unlit)
Clipping & above (red)

The LED will change to red once the
output exceeds the clipping point of the
amplifier’s output stage. The threshold is
referred to the amplifier supply rails and
alters with changes in the mains supply,
changes in the load and duty cycle
fluctuations.
The attack and decay time (ballistics) of
the status circuit are those of a Peak
Programme Meter (P.P.M.)

NOTE: The amplifier is not
damaged by running into
clipping, but speakers may be.
To maximise the life of
your speakers, try to keep
clipping infrequent.

POWER SWITCH

This switches AC power to the amplifier.
Press the switch to up for power on and
down for power off. At start-up (turn-on),
the input to the amplifier is muted for
approximately two seconds.

PROTECT INDICATOR

This red LED will illuminate when thermal
shutdown occurs.

ACTIVE INDICATOR

This LED will illuminate blue and indicates
that the amplifier is ON and receiving AC
mains power.

SIGNAL INDICATOR.

This LED displays the status of the output
stage and varies in intensity in proportion
to the output signal level.

PAGE 4

FRONT PANEL

53

4

1 2 35 4 6

1

2

6

IS SERIES INSTALLATION & OPERATION MANUAL

PAGE 5

REAR PANEL

BALANCED XLR INPUT

7

A female 3-pin XLR type connector is
provided for each input:
Pin 1 = Signal Ground;
Pin 2 = Hot (non-inverting or in phase);
Pin 3 = Cold (inverting or reverse phase).

8

BALANCED 6.35MM TRS INPUT

A female 6.35mm TRS connector is
provided for each input.
Tip = Hot (non-inverting or in phase);
Ring = Cold (inverting or reverse phase);
Sleeve = Signal Ground.

9

INPUT SENSITIVITY SWITCH

This switch allows the amplifiers input
sensitivity to be correctly matched to
the equipment providing the amplifiers
input signal. See the Operation section
(page 8) for more details.

10

PARALLEL/STEREO SWITCH

This switch determines whether channels
A & B are receiving separate signals
(i.e. Operating in stereo mode) or whether
the input signal from channel A is being
fed through to channel B.

NOTE: This is not Bridge mode.

14 98 10 117

11

12

5131 12

GROUND LIFT SWITCH

When this switch is engaged, it
disconnects signal ground from the input
connectors on both channels. It is
intended to be used when "hum" is caused
by earth loops (due to different ground
potentials between source equipment and
the amplifier) or stray magnetic field pick
up on the input ground/shield wiring.

The amplifier should be turned off
before engaging this switch!

SPEAKER OUTPUT CONNECTOR

A 4 pole speaker connector is provided
as an additional speaker output.
This standard of loudspeaker-to-amplifier
connection allows access to both
channels of the amplifier via the one
connector for bi-amp applications.
Channel-A is considered the dominant
channel and has both channels wired
to the speaker connector. See the
installation section of this manual
for detailed information on speaker
connector wiring.

13

MAINS FUSE

The IS600 is fitted with an 8 amp slow blow
fuse & the IS1200 is fitted with a 15 amp
slow blow fuse. The IS1600 is fitted with
a 15 amp slow blow fuse.

14

MAINS CONNECTION

Your amplifier is fitted with an
internationally recognised IEC mains inlet
connector. Please ensure that the
connecting mains lead for use with the
IEC connector is of an approved type and
is of sufficient current carrying capacity.

NOTE: Your unit must always
be earthed!

15

BINDING POST OUTPUTS

Touch-proof binding posts (banana jacks)
are provided for speaker output
termination with banana plugs or bare
wire. The red post is used as positive and
the black post is used as negative.

IS SERIES INSTALLATION & OPERATION MANUALIS SERIES INSTALLATION & OPERATION MANUAL

PAGE 6

INSTALLATION

POWER REQUIREMENTS

Ensure that your mains voltage is the same as the rear panel mains
voltage marker (+/- 10%).

MOUNTING

Your amplifier is designed for standard 19" rack mounting and occupies 2
EIA rack units.

COOLING

Each channel of your IS Series amplifier is cooled by an axial fan which
draws cool air from the front of the amplifier and expels heated air out
the rear of the amplifier. These amplifiers include two-speed fans which
normally run at half speed, switching to full speed when the internal
heatsink temperature exceeds 500C. An unrestricted airflow into and
out of the amplifier must be provided. Any restriction of the air flow
will cause heat to build up within the amplifier and possibly force the
amplifier into its thermal shutdown mode. If the amplifiers are to be
operated in an environment where the airflow is restricted, such as
sealed racks, cooling should be supplemented by extra cooling fans to
evacuate the heated air and aid the flow of cool air through the amplifier.

INPUT WIRING

IMPORTANT

Do not directly connect pin 1 on the amplifier’s input XLR or TRS jack, to
the amplifier’s chassis, speaker ground or power ground!

NOTE: Input signal ground is not to be used as a safety
ground (earth).

The input to your amplifier is a balanced 3-pin configuration and requires
all three pins to be connected. Only high quality twin-core shielded cable
should be used. When wiring for a balanced source, the connector going
to the input of your amplifier should be wired as follows:
Pin 1 = GROUND / SHIELD.
Pin 2 = HOT (In Phase - non inverting).
Pin 3 = COLD (Reverse Phase - inverting).

When wiring for an unbalanced source you must ensure that pin 3 is
connected to pin 1 (input ground), either by linking the pins in the input
connector or by the source equipment’s output wiring.

When wiring for an unbalanced source:
Pin 1 = GROUND/SHIELD
Pin 2 = HOT (in phase with the amplifier’s output),
Pin 3 = GROUND/SHIELD (joins to pin 1).

NOTE: In-line XLR connectors often have a termination
lug that connects directly to the chassis of the
connector. Do not link this lug to pin 1 at the amplifier s
input as it will defeat the amplifier s input grounding
scheme. This lug is often referred to as a "drain" and
is used to provide a termination to the chassis for
shielding purposes when a floating signal ground
is required between the source and destination, or
when disconnecting the signal ground is required to
reduce earth loop noise, or noise induced into signal
grounds from stray magnetic fields.

OUTPUT WIRING

When wiring to your speakers, always use the largest gauge wire
your connector will accept. The longer the speaker lead, the greater
the losses will be, resulting in reduced power and less damping at the
load. We recommend using a heavy-duty, two core flex (four core flex
if bi-amping) 10 to 12 gauge (2mm2 to 2.5mm2 or 50/0.25 or equivalent)
as a minimum.

IS SERIES INSTALLATION & OPERATION MANUALIS SERIES INSTALLATION & OPERATION MANUAL

PAGE 7

BINDING POST OUTPUTS

When terminating to the 4 mm binding post (banana jack) output
connectors, banana plugs or bare wires can be used. The red terminal
is positive and the black terminal is negative (ground).

SPEAKER OUTPUTS

When using the 4 pole speaker connector for speaker output, use only
the mating 4 pole in-line connector. This connector is designed so that
both speakers can be fed from a single connector. Two speaker
connectors are provided on the amplifier. The "Channel A" speaker
connector actually carries both channel A & Channel B outputs (see:
Speaker Connector Wiring Diagrams). The "Channel B" speaker
connector carries the Channel B output only. This arrangement allows
you the option of connecting to the outputs separately or together.
Connecting through a single connector has the advantage of
minimising connections, preserving phasing and simplifying channel
allocation, which is particularly important when bi-amping.

IMPORTANT

Do not overload your amplifier by connecting the channel B
output twice!
Channel A is used as the "dominant" channel and when sourcing
a dual output from Channel A, the following standard should be used:
Channel A = Left or Low Frequencies.
Channel B = Right or High Frequencies.

INSTALLATION

IS SERIES INSTALLATION & OPERATION MANUAL

PAGE 8

OPERATION

IMPORTANT

All signal source equipment should be adequately earthed.
This not only ensures your safety, but everybody else’s as well.
Faults can and do occur in mains connected equipment where
the chassis can become "live" if it is not properly earthed. In
these instances, the fault in a "floating" (ungrounded) piece of
equipment will look for the shortest path to ground, which
could possibly be your amplifier’s input. If the fault current is
large enough, it will destroy the input to your amplifier and look
for the next available path, which may be you!

Before making any connections to your IS Series amplifier, observe the
following:

Ensure the mains voltage supply matches the label on the rear
panel of your amplifier (+/- 10%).

Ensure that the power switch is OFF.

Ensure that all system grounds (earth) are connected from a
common point. Avoid powering equipment within a system from
multiple power sources that may be separated by large distances.

Check the continuity of all interconnecting leads to your amplifier;
ensure that there are no open or short circuited conductors.

Ensure that the power handling of your load (speakers) can
adequately cope with the power output of the amplifier.

Before operating your IS Series amplifier, ensure that:

The attenuators are at the "OFF" position (fully anticlockwise).

The GROUND LIFT Switch is not engaged (should be in the
"Ground" position).

POWERING UP

REMEMBER
The amplifier should be the last piece of equipment that you turn on
and the first piece of equipment that you turn off.
We recommend turning the attenuators on your amplifier down when
turning the unit on. When you power up your IS Series, your amplifier
goes through an initialising period before it will accept signal. The
Inrush Current Suppression (ICS) circuit is in operation for the first 0.5
seconds. This limits the mains current, to prevent "nuisance-tripping" of
circuit breakers. During this period you will hear a couple of relays
"click", indicating mains is now directly applied to the amplifier and the
signal path is connected. While the ICS circuit operates there is also a
30dB mute on the signal input. After two seconds this mute will
release, allowing any applied signal to pass un-attenuated. When
switching the amplifier off, wait a couple of seconds before switching
the amplifier on again. This allows the ICS circuit to reset.

LEVEL MATCHING

The normal operating position for the attenuator is the maximum
position (fully clockwise, no attenuation). In this position the amplifier
operates at full gain. Turning the attenuator down (anticlockwise)
reduces the input sensitivity.

NOTE: If full power output is required, you should
operate your amplifier with the front panel attenuator
above the half way (12o clock) position, otherwise
clipping of the input circuitry (and its resultant
distortion) will occur before full output power is
achieved.

SENSITIVITY

Your amplifier is a linear device operating with a fixed input to output
voltage gain (less attenuation). The maximum output voltage swing is
determined by the applied mains voltage, load, load type and the duty
cycle of the applied signal. The input sensitivity for your IS Series
amplifier when the attenuator is at maximum position (fully clockwise)
is determined by the Input Sensitivity switch.

There are 3 settings for rated power into a 4 ohm load.

0.775V in for rated power out

1.0V in for rated power out

1.44 V in for rated power out.

Each channel of your IS Series amplifier has a nominal balanced input
impedance of 20kOhms (@1kHz) and should not present a difficult load
for any signal source. (i.e. the equipment feeding signal).

IS SERIES INSTALLATION & OPERATION MANUAL

PAGE 9

OPERATION

HUM PROBLEMS

Most equipment is designed for minimum hum when used under ideal
conditions. When connected to other equipment and to a safety earth
in an electrically noisy environment, problems may occur. The three
"E"s of hum and hum related noise which can plague your audio
system are:
a) Electrostatic radiation,
b) Electromagnetic radiation, and
c) Earth loops

Electrostatic radiation capacitively couples to system elements,
causing an interference voltage that mainly affects higher impedance
paths, such as amplifier inputs. The source is generally a nearby high
voltage, such as a mains lead or a speaker lead. The problem can
usually be reduced by moving the offending lead away, or by providing
additional electrostatic shielding (i.e. an earthed conductor which
forms a barrier to the field).

Electromagnetic radiation induces interference currents into system
elements that mainly effect lower impedance paths. Radio transmitters
or stray magnetic fields from mains transformers are often the cause of
this problem. It is generally more difficult to eliminate this kind of
interference, but again, moving the source away or providing a
magnetic shield (i.e. a steel shield) should help.

Earth loops can arise from the connection of the various pieces of
equipment and their connections to various safety earths. This is by far
the most common cause of hum and it occurs when source equipment
and the amplifier are plugged into different points along the safety
earth where the safety earth wiring has a current flowing through it.
The current flowing through the wire produces a voltage drop due to
the wire’s resistance. This voltage difference between the amp earth
and source equipment earth appears to the amplifier’s input as a signal
and is amplified as hum.

There are three things you can do to avoid earth loop problems:

1. Ensure the mains power for the audio system is "quiet" i.e.
without equipment on it such as air-conditioning, refrigeration
or lighting which may generate noise in the earth circuit.

2. Ensure all equipment within the system shares a common
ground/ safety earth point. This will reduce the possibility of
circulating earth currents, as the equipment will be referenced
to the same ground potential.

3. Ensure that balanced signal leads connecting to the amplifier
are connected to earth at one end only.

SIGNAL GROUND-LIFT SWITCH

When proper system hook-up has been made, you may still have some
hum or hum related noise. This may be due to any of the previously
mentioned gremlins. Your IS Series amplifier has a "Signal Ground Lift"
switch which disconnects the input ground wiring from the amplifier. A
substantial drop in hum and/or hum related noise can result from the
judicious use of this switch.

NOTE: If the input ground lift switch is used, you must
ensure adequate shielding of the input wiring. If the
signal source equipment does not provide adequate
shielding (i.e. a definitive connection to ground), you
must disconnect the shield from the input connector s
ground pin (Pin-1) and re-connect it to the "drain"
contact on the input connector. This will ensure the
shield on your input wiring actually goes to the
amplifier chassis and subsequently to earth.

DO NOT CONNECT PIN-1 DIRECTLY TO THE DRAIN
CONNECTION.

You will defeat the amplifiers internal grounding scheme and possibly
cause instability in the amplifier. Always ensure that your amplifier is
off and the attenuators are down when you engage this switch. This
switch should only be used when the amplifier is operated from a
balanced signal source.

NOTE: Be wary of quasi-balanced outputs, these are
often no more than floating unbalanced outputs.

IS SERIES INSTALLATION & OPERATION MANUAL

PAGE 10

MAINTENANCE

Only competent qualified persons should attempt any
service or maintenance of your amplifier. Your IS
Series amplifier will need minimal maintenance.
No internal adjustments need to be made to the unit
to maintain optimum performance. To provide years
of unhindered operation we suggest a maintenance
inspection be carried out on a regular basis, say
every 12 months or so.

NOTE: The following instructions are intended for
action by qualified personnel only.

FAN S

Due to the openness of the air path through your IS Series amplifier,
very little dust should settle within the amplifier. The unit has been
designed so that any dust and/or foreign particles that do settle within
the amplifier will not unduly hinder the cooling of the amplifier. The
grille in front of the fans will act to limit the amount of dust and lint
entering the amplifier. You will find that in time there will be a build up
of dust and lint on the grille which may hinder the airflow through the
amplifier. You should periodically remove the dust and keep the grille
clean. Removal of dust from the rear grille will also aid cooling. Over
time, dust may build up on the leading edge of the fan blades and
reduce their cooling efficiency. The time taken for this to happen will
depend on the environment and the amount of use. The fan blades are
accessible once the lids are removed and can be easily cleaned.
You need only hold the fan rotor still and wipe the dust off the blades.
Many users stall the fan and use compressed air to blow the dust off
the fan blades. It is important to note that the fan blades must be held
still whilst blowing air over the blades otherwise you may burn out
the bearings in the fan.

FUSES

Along with a rear panel mains fuse, there are four (4) internal rail fuses
in the unit. These rail fuses are in series with the positive and negative
output supply to each amplifier channel and provide overall protection
for the output stage. If the amplifier is subjected to heavy use such as
short circuits, these fuses will eventually fatigue and may require
replacing to ensure they do not fail at an inconvenient time.

NOTE: Make sure the unit is off and is unplugged
from the mains. Give the main filter capacitors
time to discharge before removing lids and inspecting
the fuses.

You should replace the fuse if the element is sagging or discoloured.
Only ever replace with the same type fuse and current rating.

When checking for a failed fuse, do not rely on visual inspection alone.
You should use an ohm meter to check continuity.

IS SERIES INSTALLATION & OPERATION MANUAL

SPECIFICATIONS

IS600 IS1200 IS1600

OUTPUT @ 8 OHMS 2 x 200 watts 2 x 400 watts 2 x 500 watts

OUTPUT @ 4 OHMS 2 x 300 watts 2 x 600 watts 2 x 800 watts

FREQUENCY RESPONSE (-3dB) <10Hz - >50kHz <10Hz - >50kHz 10Hz - >50kHz

THD <0.03% @1 kHz <0.03% @1 kHz <0.03% @1 kHz

CROSSTALK 60dB 60dB 60dB

DAMPING FACTOR (into 4 ohms) >200 >200 >200

DAMPING FACTOR (into 8 ohms) >100 >100 >100

INPUT IMPEDANCE 20Kohm 20Kohm 20Kohm

SIGNAL/NOISE RATIO (20-20kHz) >90dB >90dB >90dB

WEIGHT 16.5kg 20.5kg 22.0kg

DIMENSIONS (WXDXH) 483x452x89mm 483x452x89mm 483x452x89mm

IS SERIES INSTALLATION & OPERATION MANUAL

PAGE 11

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AUSTRALIA AND NEW ZEALAND

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