Australian Monitor ACM120XL User Manual

ACM120XL

120w Mixer Amplifier

Operating Manual

ACM120XL, 120 Watt Mixer Amplifier

Product Description

The ACM120XL is a 120 watt mixer amplifier designed for commercial installations. It features 8 microphone/line input
channels and can be used for either low impedance (4 or 8 ohm) or 70v/100v line speaker systems. A host of unique
features including multiple levels of muting, a VOX relay output and VCA master level control make the ACM120XL a
very flexible amplifier. The unit can be mounted in a standard 19” equipment rack (rack ears supplied) or it can be used
on a shelf or table.

Front Panel Features

Microphone/Line Level Controls

The level controls for the 8 inputs are labeled Ch 1-Ch 8. These level controls are used to set up a suitable “mix” of all
the various input sources connected to the ACM120XL. For example, microphones, CD players, cassette decks etc.
Once a suitable mix of all inputs has been set up, the overall level can then be adjusted by the “Master” level control on
the far right of the ACM120XL front panel.

Bass Control

The Bass control is part of a 3-band equalization system within the ACM120XL. The Bass control allows the user to
increase or decrease the amount of bass in the system. The control allows for 12dB of cut or boost at 100Hz. If no bass

cut or boost is required, the control should be left in the center (0) position.

Middle Control

The Mid control is part of a 3 band equalization system within the ACM120XL. The Mid control allows the user to
increase or decrease the amount of mids in the system. The control allows for 10dB of cut or boost at 600Hz. Depending
on the speakers and application, a small cut (decrease) in the mids normally makes the system sound ‘warmer’. If no mid
cut or boost is required, the control should be left in the center (0) position.

Treble Control

The Treble control is part of a 3 band equalization system within the ACM120XL. The Treble control allows the user to
increase or decrease the amount of treble in the system. The control allows for 10dB of cut or boost at 10kHz. Generally,
a small increase of the treble control makes a system sound ‘brighter’. If no treble cut or boost is required, the control
should be left in the center (0) position.

Master Control

The master control sets the overall output level of the ACM120XL. It is used in conjunction with the input level controls.
When setting up levels, please ensure that proper gain structure practices are followed. In other words, it is not
advisable to run the input channels at 10 and the output level at 1. Instead, aim to keep all of the input controls and the
master control at around the same level.

Power Switch and “On” LED

The black rocker switch on the right hand side of the front panel is used to switch the amplifier on and off. The ‘up’
position is on. When the amplifier is connected to an appropriate AC power source and is switched on, the blue LED will
illuminate.

Signal LED

The green “Signal” LED located next to the On LED indicates that the ACM120XL is passing audio. The signal LED is
a simple method to trouble-shoot installations especially in multi-amplifier projects.

Rack Mounting

The ACM120XL is supplied with rack ears attached to allow mounting within a standard 19” equipment rack. As is the
case with almost all audio products, adequate ventilation and air flow is required. When installing multiple ACM
amplifiers within the one rack, it is recommended that at least 1 rack unit of ventilation space is left between every two
amplifiers.

For table or shelf mounting, the rack ears can be removed using a screwdriver. Once the rack ears are removed, please
reinstall the screws.

Rear Panel Features

230V/240V Slide Switch

The operating voltage of the amplifier is user selectable between 230V and 240V via a slide switch located on the top left
side of the rear panel. This switch should be set to match the AC voltage of your country.

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 4 Amp slow blow fuse plus a spare fuse. Power consumption is 250 watts (max).

---Please ensure that the mains power cord is disconnected before attempting to check or replace this fuse.---

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 or 8 ohms).
4 Positive “+” for 4 ohm speaker loads (use with common)
8 Positive “+” for 8 ohm speaker loads (use with common)

COM Common or “-” for 70v or 100v speaker loads (maximum load of 80 ohms at 100v)
70 Positive “+” for 70v line speaker loads (use with common)
100 Positive “+” 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 80 ohms. When both outputs are used simultaneously,
ensure that neither output is loaded to maximum.