Australian Monitor AV2.4P User Manual

AUDIO AMPL

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SS

ON

UDIO

AMPL

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AV2.2P AV2.4P

PROFESSIONAL AUDIO AMPLIFIER

OPERATION MANUAL

AV2.2P AV2.4P

R

FE

I

IMPORTANT SAFETY INFORMATION

This operation manual contains important information regarding safety precautions, installation, performance, operation and
maintenance of your AMAV power amplifi er. You should familiarize yourself with the contents of this manual before
operating your amplifi er.

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 amplifi ers 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!

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 fl ow

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 amplifi ers or consoles to any

other voltage source, such as a battery, mains source, or power supply,

regardless of whether the amplifi er or console is turned on or off.

17. Do not run the output of any amplifi er channel back into another

channel’s input. Do not parallel- or series-connect an amplifi er output

with any other amplifi er 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 qualifi ed 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

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

producing devices.

THIS SAFETY INFORMATION IS OF A GENERAL NATURE AND MAY BE SUPERSEDED BY INSTRUCTIONS CONTAINED WITHIN THIS MANUAL

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.

INTRODUCTION AND CONTENTS

Congratulations on choosing Australian Monitor for you professional
amplifi cation requirements.

The AMAV stereo power amplifi ers are designed for the demanding
commercial audio-visual Market. Two amplifi er models are available within
the AMAV range. The AV2.2P delivers 100 watts per channel at 4 ohms
from an elegant, 1RU slim line package. The AV2.4P delivers 200 watts per
channel at 4 ohms from an elegant, 2RU package. Both amplifi ers feature
front panel dual colour status LEDs, on board limiter, ground lift switch and
the option of bridged operation.

Add to this the AV2.2P and AV2.4P’s whisper quiet operation, achieved via
its convection cooled design and you have an elegant, high quality audio
amplifi er.

The AV2.2P and AV2.4P offers the power and the features demanded by any
quality AV application.

INTRODUCTION 3

FEATURES 4

CONTROLS, CONNECTORS AND INDICATORS

FRONT PANEL 5

REAR PANEL 6

INSTALLATION 7

OPERATION 9

MAINTENANCE 10

BLOCK DIAGRAM 10

SPECIFICATIONS 11

CAUTION

RISK OF ELECTRIC SHOCK

DO NOT OPEN

CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK,

DO NOT REMOVE COVER (OR BACK),

NO USER SERVICEABLE PARTS INSIDE,

REFER SERVICING TO QUALIFIED SERVICE PERSONAL.

WARNING!

TO REDUCE THE RISK OF FIRE OR ELECTRIC HOCK

DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE.

AV2.2P / AV2.4P – OPERATION MANUAL

Caution:

AUS, EUR, USA

Rev A: Mar 2007

This symbol is intended to alert the user to the presence
of uninsulated “dangerous voltage” within the products
enclosure that may be of suffi cient magnitude to constitute
a risk of electric shock to persons.

This symbol is intended to alert the user to the presence
of important operational 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

FEATURES

> Custom designed, heavy duty steel chassis.

> Rear rack mount ears.

> Symmetrical layout - even weight distribution.

> High current power supply.

> High effi ciency toroidal mains transformer.

> Silent convection cooling.

> Balanced inputs and buffered attenuators.

> Input signal strapping (loop through) connectors

PROTECTION FEATURES

> Suppression of inrush current at mains turn-on.

> Signal ground lift switch.

> Stereo or bridged operation

> Binding post speaker output connection

> 1 Watt output indication (2.828 volts).

> Output clip indication.

> High-quality, close-tolerance components throughout.

> Internal, independent DC supply rail fuses.

> Input muting at turn-on.

> Input overvoltage protection.

> Radio-frequency interference suppression.

> Short-circuit protection.

> High overload mains fuse.

> Layout, grounding, decoupling and componentry have been
optimized to provide the user with stability, reliability
and longevity.

PAGE 4

AV2.2P / AV2.4P – OPERATION MANUAL

CONTROLS, CONNECTORS & INDICATORS

1 2 1

3 4 3 5

Front Panel

1

Status Indicators for Channels A and B

These are dual colour LEDs which indicate the status of the output stage.
They indicate three levels of operation:
Below 1 watt( unlit )
1 watt and above( green )
Clipping( red )

2

Power ON indicator

This LED will illuminate Blue to indicate that the amplifi er is ON and is receiv­ing the mains power.

Attenuators for Channels A and B

3

Level control for the amplifi er is provided by potentiometers on the front panel.
There are two such controls, one for each channel.

The AMAV AV2.2P/AV2.4P amplifi ers differ only slightly in their size and share the same features on their front panels. Figure 1 shows
the panel layout of an AV2.2P. It is similar to the AV2.4P. The functions of the controls and indicators are as follows:

4

Power ON Switch

Press the switch upwards for power On and downwards for power Off.

5

Rack Ears

The amplifi er is supplied with a pair of Rack Ears for mounting the amplifi er in
a 19” Rack.

PAGE 5AV2.2P / AV2.4P – OPERATION MANUAL

CONTROLS, CONNECTORS & INDICATORS

5 2 3

6 4

Rear Panel

Balanced Input (Channel-A)

1

There is a pair of XLR connector provided for balanced signal input.
A female XLR is wired in parallel with the male XLR for strapping/looping
signal between amplifi ers.

2

Balanced Input (Channel-B)

Same as Channel - A but for Channel-B input signal

3

Signal GND Lift switch

Pushing this switch IN 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 ampli­fi er) or stray magnetic fi eld pick up on the input ground/shield wiring. (It does
not interrupt signal ground continuity on the strapping connector).
The amplifi er should be turned off before engaging this switch!

5

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. For bridge connection, use only the red
posts.

AC Power Inlet

6

The amplifi er is fi tted with an IEC mains inlet connector. Please ensure that
the mains lead is of an approved type and is of suffi cient current carrying
capacity.

4

Bridge Switch

Pushing this switch IN engages the BRIDGE/MONO mode of operation. In this
mode the amplifi er will only accept signal applied to channel A’s input XLR’s
and the level of both channels will be controlled by channel A’s attenuator. The
output from channel B will automatically be of the opposite polarity (reversed
phase) and speaker termination should be sourced from the red binding-post
outputs.

1

PAGE 6 AV2.2P / AV2.4P – OPERATION MANUAL

INSTALLATION

Power Requirements

Power consumption for your model AV2.2P / AV2.4P amplifi er is indicated on
the rear panel for maximum output.

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

Mounting

The amplifi er is designed as a table top model as well as for standard 19” rack
mounting.
The AV2.2P occupies 1 EIA rack unit (1.75”/44.45mm).
The AV2.4P occupies 2 EIA rack units (3.5”/88.9mm).
The rack mounting ears are packed separately with the amplifi er.
The mounting centres for the AV2.2P rack ears are:
Vertical: 1.26” (32mm)
Horizontal: 18.4” (467.36mm)
The mounting centres for the AV2.4P rack ears are:
Vertical: 3” (76.2mm)
Horizontal: 18.4” (467.36mm)
The slots in the mounting fl ange will accept bolt diameters up to 1/4” (6.35mm).

We recommend that you provide additional support for the amplifi er,
This support can be provided by secure shelving, support rails or a rear rack
mounting strip to match up with the rear rack mount ears provided on your
AV2.2P/AV2.4P amplifi er.

Cooling

Both the AV2.2P and AV2.4P uses a convection cooling system. The cabinet is
designed to it allow the heat sink surface to cool effi ciently. One rack space
should be provided above and below the amplifi er for maximum cooling.

When wiring for a balanced source, the connector going to the input of the
amplifi er should be wired as follows:
Pin 1 =GROUND/ SHIELD.
Pin 2 =HOT(In Phase - non inverting).
Pin 3 =COLD(Reverse Phase - inverting).
When wiring from an unbalanced source you 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 amplifi er’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.

IMPORTANT: Do not link this lug to pin 1 at the amplifi er’s input as it
will defeat the amplifi er’s input grounding scheme.

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 fl ex (four core fl ex if bi-amping) 10 to 12 gauge (2mm to

2.5mm or 50/0.25 or equivalent) as a minimum.

When terminating to the 4mm 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).

An unrestricted airfl ow to the unit must be provided. Any restriction of the air
fl ow will cause heat to build up within the amplifi er.

If the amplifi er is to be operated in an environment where the airfl ow is
restricted (such as in sealed racks) cooling should be supplemented by cooling
fans to evacuate the heated air and boost the fl ow of cool air.

Input Wiring

IMPORTANT: Do not directly connect pin 1 on the amplifi er’s input
or strapping XLR to the amplifi er’s chassis, speaker ground or power
ground!

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

The input to the amplifi er is a balanced 3-pin confi guration and requires all
three pins to be connected. Only high quality twin-core shielded cable should
be used.

AV2.2P / AV2.4P – OPERATION MANUAL

If running in BRIDGE mode, only the red binding posts are used.

PAGE 7

INSTALLATION

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
amplifi er 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 fi eld).

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

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 AMAV amplifi er has a “Signal Ground Lift” switch which disconnects the
input ground wiring from the amplifi er. 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 defi nitive 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 amplifi er chassis and subsequently to earth.

IMPORTANT: Do not connect pin-1 directly to the drain connection.
You will defeat the amplifi ers internal grounding scheme and possibly
cause instability to the amplifi er.

Always ensure that your amplifi er is off and the attenuators are down when
you engage this switch. This switch should only be used when the amplifi er is
operated from a balanced signal source.

Earth loops can arise from the interfacing 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 amplifi er are plugged into different points along the safety
earth where the safety earth wiring has a current fl owing through it. The cur­rent fl owing 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 amplifi er’s input as a signal and is amplifi ed as hum.

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

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.

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.

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

NOTE: Be wary of quasi-balanced outputs, these are often no more

than fl oating unbalanced outputs.

PAGE 8

AV2.2P / AV2.4P – OPERATION MANUAL

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 “fl oating” (ungrounded) piece of equipment
will look for the shortest path to ground, which could possibly be your
amplifi er’s input. If the fault current is large enough, it will destroy the
input to your amplifi er and look for the next available path, which may
be you!

Before making any connections to your AMAV amplifi er, observe the following:

Ensure the mains voltage supply matches the label on the rear panel of your
amplifi er (+/- 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 amplifi er; 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 amplifi er.

Level Matching

The normal operating position for the attenuator is the max position (fully
clockwise, no attenuation). In this position the amplifi er operates at full gain.
Turning the attenuator back (anticlockwise) reduces the input sensitivity.

NOTE: If full power output is required, you should operate your
amplifi er 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 amplifi er is a linear device operating with a fi xed 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 AMAV Series amplifi er when the attenuator is at
maximum position (fully clockwise) is nominally:

+4.0dBu (1.23 volts in) for rated power into a 8 ohm load
+2.2dBu (1.0 volts in) for rated power into a 4 ohm load.

Each channel of your AMAV amplifi er has a nominal balanced input
impedance of 20kOhms (@1kHz) and should not present a diffi cult load for
any signal source.

Before operating your AMAV amplifi er, ensure that:

- The attenuators are at the “OFF” position (fully anticlockwise).

- The GROUND LIFT Switch is not engaged (should be in the
“out” position).

- The BRIDGE Switch is not engaged if you are not running the
amp in bridged mode.

Powering Up

REMEMBER: The amplifi er should be the last piece of equipment that
you turn on and the fi rst piece of equipment that you turn off.

We recommend turning the attenuators on your amplifi er down when turning
the unit on.

Your signal source (i.e. the equipment feeding signal to the amplifi er) should
have an output impedance of 600 Ohms or lower to avoid unwanted high
frequency loss in the cabling.

Input overload occurs at +19.1dBu (7.0 volts)

PAGE 9AV2.2P / AV2.4P – OPERATION MANUAL

MAINTENANCE

Only competent or qualifi ed persons should attempt any service or maintenance of your amplifi er.

Your AMAV amplifi er 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.

Fuses

Along with rear panel mains fuse, there are four (4) rail fuses provided
internally in the unit. These rail fuses are in series with the positive and
negative output supply to each amplifi er channel and provide overall
protection for the output stage. If the amplifi er 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.

WARNING: Make sure the unit is off and is unplugged from the mains.
Give the main fi lter 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.

PAGE 10 AV2.2P / AV2.4P – OPERATION MANUAL

SPECIFICATIONS

Parameter AV2.2P AV2.4P

Output Power*

Both Channels driven : 8ohm : 75W 150W

Single Channel driven : 4ohm : 120W 240W

Both Channels driven : 4ohm : 100W 200W

Bridge mode : 8 ohm : 200W 400W

Voltage Gain 20.0 V/V 28.3 V/V

Output Impedance (1kHz) 0.04 ohm 0.04 ohm

Damping Factor > 200:1 > 200:1

Slew rate > 30V/µs > 30V/µs

Frequency Response 20Hz ~ 60KHz 20Hz ~ 60KHz

THD (@ 1 KHz) < 0.02% < 0.02%

IMD SMPTE (60Hz : 7 KHz 4 : 1 < 0.03% < 0.03%

Input Impedance 20kohm 20kohm

Input Sensitivity 1 Vrms 1 Vrms

Input CMRR > 80dB > 80dB

S/N Ration : Linear > 97 dB > 97 dB

A - Weighted > 100dB > 100dB

Crosstalk > 65 dB > 65 dB

Dimension (H x W x D) mm 44mm x 482mm x 299.5mm 88mm x 482mm x 299.5mm

Shipping Weight 10 kg 15 kg

* 2ohm loads per channel not recommended
4ohm bridged loads not recommended

PAGE 11AV2.2P / AV2.4P – OPERATION MANUAL

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