AUSTRALIAN MONITOR MX81 User manual

8 CHANNEL MIC/LINE MIXER
INSTALLATION AND OPERATION MANUAL
MX81

HEADING
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
MX81 INSTALLATION & OPERATION MANUAL PAGE 3
The MX81 is an 8 channel audio mixer that operates from 110/230-240
VAC @ 50/60 Hz or 24 VDC via an external 24VDC supply.
The MX81 offers high quality audio performance & a wide array of
features in a standard 1 RU size. For table mounting, rubber feet are
supplied but these can be removed if rack mounting is intended.
There are eight dual purpose inputs consisting of balanced XLR inputs
switchable between mic & line level and dual RCA aux/line level
inputs. Each input has front panel trim control, status LED and bass
& treble controls.
Priority muting is available as an optional addition as is remote
VCA master control and tone generation.
The MX81 also features 4 segment LED output metering & the ability
to internally switch input 1 to be either pre or post master.
With both Headphone out & Record out also available the MX81
is extremely versatile & represents excellent value for money.
Thankyou for purchasing the Australian Monitor Installation
Series MX81.
INTRODUCTION 3
FRONT PANEL 4
REAR PANEL 5
INTERNAL ADJUSTMENTS 6
INSTALLATION & TROUBLESHOOTING 7
BASIC SETUP & OPERATION 8
DIMENSIONS 9
BLOCK DIAGRAM 10
SPECIFICATIONS 11
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.
Caution:
AUS, EUR, USA
Copyright 24th Jan 2006
Rev A 24/01/06

PAGE 4 MX81 INSTALLATION & OPERATION MANUAL
FRONT PANEL
GAIN TRIM
This control is used to adjust the input
gain and affects both the XLR and the
RCA inputs. The input gain can be
adjusted by +/- 15dB. This allows a wide
rage of program sources to be set up with
optimum gain structure. With the gain trim
in the centre position, the boost/cut is set
to 0dB. See the block diagram on page 10
for details of the gain structure.
LEVEL
Controls the level of the input signal.
INPUT STATUS LEDS
Each input has an LED status indicator.
The LED is green when there is signal
present and red if the signal is
approaching clip. If the LED begins to light
red this would indicate the internal signal
level is 6dB before clip. Note that the front
panel level control is post status LED and
as such, the status LED is NOT affected
by the level control. If an input channel is
clipping use the gain control to adjust
the correct amount of input level.
CHANNEL TONE CONTROLS
Each input has a 2 band EQ.
Bass – +/-12dB 100Hz shelving
Treble – +/-12dB 10kHz shelving
MIC / LINE
Each input has a switch which controls
the sensitivity of the XLR input. In the
off/out or "MIC" position the XLR input is
suitable for use with microphones; in the
on/in or "LINE" position the XLR input is
suitable for use with a balanced line level
signal. Note: The Mic/Line switches only
affect the XLR input.
MASTER
This pot controls the overall mixed output.
HEADPHONE
This 1⁄4” jack socket allows headphones
to be used for monitoring. It can be set
as pre or post master volume control.
See “Internal Adjustments” on page 6.
Default factory setting is pre master
volume control.
MASTER VU DISPLAY
This VU display indicates output level.
POWER SWITCH
This switch switches power from the
mains. The up position is on.
NOTE: When using the 24VDC
socket the unit is on regardless
of switch position.
POWER ON LED
This indicates there is power to the unit.
NOTE: When using the 24VDC
socket the power LED will
always be on.
1
2
3
5
6
7
8
9
10
4
1
45 8
2 610 7 93
☛
☛

MX81 INSTALLATION & OPERATION MANUAL PAGE 5
REAR PANEL
CHANNEL INPUTS
Channels 1 to 6 have two inputs, channels
7-8 only have an XLR input:
XLR input - This is a balanced input.
It accepts mic or line level signals
depending on the front panel gain
switch position. The XLR will also
have +15V phantom power if
selected on the switch.
RCA input - This is an unbalanced line
level input. The two RCA sockets are
summed to mono internally.
REC OUT
The REC OUT output is on unbalanced
RCA connectors. The output is dual mono
and is not affected by the MASTER volume
control or the EQ tone controls.
OUTPUT
The OUTPUT XLR provides balanced line
level signal.
NOTE: When wiring the LINE
output as unbalanced, Pin2
should be wired as hot and
Pin1 should be wired as
ground/shield. Do not wire Pin3.
24VDC SOCKET
This 2.1mm x 5.5mm barrel socket is
provided for 24V emergency systems and
is not switched by the front panel power
switch. Note:The 24VDC socket does not
provide trickle charge facility. Tip of the
connector is positive.
IEC MAINS INPUT SOCKET
This is a standard IEC 3 pin socket. It
accepts a standard IEC mains cable,
provided. The fuse draw contains the
mains fuse and a spare. The mains fuse is
a time lag (slow blow) HRC 20mm x 5mm
ceramic type fuse.
The ratings are:
230V/240V model 63mA
115V model 120mA
Always replace the fuse with
one of the same value and type.
NOTE: Always disconnect
power to the amplifier before
replacing fuses.
OPTIONAL MODULE INPUTS
This socket is used with a tone module
and/or VCA module.
1
2
3
5
6
4
5
4
6 3 2
☛
1

PAGE 6 MX81 INSTALLATION & OPERATION MANUAL
INTERNAL ADJUSTMENTS
P/P – PHANTOM POWER
This switch is accessible through the lid of
the MX81. 15V phantom power is available
for condenser or electret microphones on
the XLR input when this switch is in the
’ON’ position.
CHANNEL 1 ROUTING
If channel 1 is being used as a priority
input it can be routed so that the master
volume does not affect channel 1.
The default factory setting is pre master
fader meaning the master volume affects
channel 1 in the mix. The jumper header
is located mid way above channel 1 pot.
Move the jumper to link the two pins
nearer the channel 1 pot to set channel 1
to post master fader.
HEADPHONE ROUTING
The headphone level can be routed so
that it is affected by the master volume.
The default factory setting is pre master
fader meaning the master volume does
not affect the headphone volume.
The jumper header is located just behind
the front panel above the master pot.
Move the jumper to link the two pins
nearer the inputs to set the headphone
to post master fader.
OPTIONAL MODULES
The MX81 can have installed:
- a VCA module
- a Tone Generator module
- a Priority Muting module
See your local Australian Monitor dealer
for more information.
2
13
4
1 2 344 4

MX81 INSTALLATION & OPERATION MANUAL PAGE 7
INPUT CONNECTIONS
For wiring balanced in, pin 2 is hot. Unbalanced wiring on the
microphone inputs is not recommended. Balanced input wiring
(shielded pair cable) is recommended.
Unbalanced RCA wiring should be keep as short as possible.
Typically less than 3m.
LINE OUTPUT
The LINE output XLR can be used to connect up to 6 booster amplifiers.
Balanced wiring (shielded pair cable) is recommended.
NOTE: When wiring the LINE output as unbalanced,
Pin2 should be wired as hot and Pin1 should be wired
as ground/shield. Do not wire Pin3.
RECORD OUTPUT.
The Record output wiring should be kept as short as possible.
Typically less than 3m.
INSTALLATION & TROUBLESHOOTING
TROUBLE LIKELY CAUSE REMEDY
Power LED not on Power not reaching unit Check mains connection
Check mains fuse
Check power switch is on
Poor S/N ration Incorrect gain structure See setup guide
Distorted sound Input is overloaded Reduce input gain
Reduce input level at source
Output is being over driven Reduce output volume
No sound but unit is on Volume turned down Check volume controls
Tones and/or VCA control does not work Module not installed Purchase optional modules
Condenser microphone does not work Phantom power not switched on Switch on phantom power
☛

PAGE 8 MX81 INSTALLATION & OPERATION MANUAL
The inputs of the MX81 can accommodate a wide range of sources
including dynamic microphones, DVD and CD players. The output
may be used to drive power (booster) amplifiers, other mixers or
mixer amplifiers.
Each installation will require setting the appropriate relative mix of
levels between microphones and program. Because of the variation
in levels between the possible sources, the MX61 offers a number of
gain stage adjustments so you can set the correct levels for your
application. Also consider what the output is driving . . .
Setting up correct gain structure through the whole system is
important to achieve optimal results. The following step by step
procedure has been devised to assist during the setup process.
When the MX61 was shipped to you from the factory, it was set up
in a particular way. In the following procedure it is essential that
you are starting from these initial settings.
• Program Input Gain Controls – half (12 o’clock)
• XLR Mic/Line switch – MIC
• XLR Phantom power - on
• Input Level Controls – off
• Output Level Control – off
STEP BY STEP SETUP
CONNECT THE SOURCES
First connect all the required sources to the appropriate input
connectors. If the source is a microphone, set the MIC/LINE
switches to the "MIC" position. If the source is an electret or
condenser microphone, set the phantom switch to the "P/P on"
position.
CONNECT THE OUTPUTS
Turn the amplifiers off. Connect the MX81 output to the amplifiers'
line level input. Check that the MX81 is on, and then turn on the
amplifiers. If the amplifiers have a level control, set them it to a
sensitivity of 0dBu. If in doubt, set it to maximum.
TEST THE INPUT LEVELS
For each source, try to achieve the highest signal level possible.
i.e. for a CD player, cassette deck or other music source, put on
the loudest anticipated program music or for a paging mic make a
‘loud’ page. During this signal condition, the input status LED should
light green and may occasionally turn red for a short period.
If the status LED stays red (more than 10% of the time), you should
reduce the input gain trim. If the status LED never turns red at all,
you may wish to increase the input gain trim if required.
SET THE LEVELS
Turn the input levels up to 5. Turn up the output level until it is
at an appropriate level for the listening environment. You will
now have to adjust the relative levels of the inputs to achieve a
good balance. The aim of these adjustments is to have all level
controls at between 3 and 7. This may not be possible however.
A good rule of thumb is that input level controls should be higher
than the output level controls.
BASIC SETUP & OPERATION
1
2
3
4

MX81 INSTALLATION & OPERATION MANUAL PAGE 9
DIMENSIONS

PAGE 10 MX81 INSTALLATION & OPERATION MANUAL
BLOCK DIAGRAM

SPECIFICATIONS
FREQUENCY RESPONSE 20Hz - 20kHz (+0,-3dB)
TOTAL HARMONIC DISTORTION < 0.1% @ 1kHz
SIGNAL TO NOISE RATIO > 90dB (all pots at centre position)
CROSSTALK >70dB
TONE CONTROLS
BASS @ 100HZ +/- 12dB
TREBLE @ 10KHZ +/- 12dB
SENSITIVITY Mic Sens 4.36mV, -45dBu Imp 1k3ohm
(Trim in centre 0dB) Line Sens 0.775V, 0dBu Imp >100k
RCA 200mV, -12dBu Imp 30kohm
MAX LEVEL IN XLR mic -15dBu line +30dBu
RCA >30dBu
MAX LEVEL OUT +21dBu
PHANTOM POWER 15V DC
OUTPUTS
MASTER OUT Nominal Level 0dBu into 1kohm
Imp 100ohm
MONO HEADPHONE OUT Nom -6dB into 200ohm
Imp 10ohm
MONO REC OUT Nom -12dB into 10kohm
Imp 10kohm
POWER INPUT AC: 230V/50Hz or 115V/60Hz,
3 pin IEC320-C14 connector;
DC: 24 Volts via 2.1mmx5.5mm DC socket
POWER CONSUMPTION (MAX) 7 VA
FUSES
MAINS (115V) 120mA
MAINS (230V) 63mA
DIMENSIONS h x w x d 44mm x 482mm x 182mm
(1.75“x19”x7.2”)
SHIPPING DIMENSIONS h x w x d 90mm x 505mm x 270mm
(3.5“x19.9”x10.6”)
WEIGHT
NET 2.75kg (6.1lb)
SHIPPING 3.75kg (8.3lb)
MX81 INSTALLATION & OPERATION MANUAL PAGE 11

SYDNEY
(NSW & ACT SALES)
149 Beaconsfield
Street Silverwater
NSW 2128
Private Bag 149
Silverwater NSW 1811
Phone: [phone]
Fax: [phone]
Email:
n[email protected]
MELBOURNE
(VIC & TAS SALES)
22/277
Middleborough Road
Box Hill VIC 3128
PO Box 151 Blackburn
South VIC 3130
Phone: [phone]
Fax: [phone]
Email:
[email protected]
BRISBANE
(QLD SALES)
42 Commercial Road
Fortitude Valley
QLD 4006
PO Box 871 Fortitude
Valley QLD 4006
Phone: [phone]
Fax: [phone]
Email:
[e-mail]
ADELAIDE
(SA & NT SALES)
31 Walsh Street
Thebarton
SA 5031
PO Box 157
Hindmarsh SA 5007
Phone: [phone]
Fax: [phone]
Email:
[email protected]
PERTH
(WA SALES)
299 Fitzgerald Street
West Perth WA 6005
PO Box 404
North Perth
WA 6906
Phone: [phone]
Fax: [phone]
Email:
[email protected]
AUCKLAND
(NZ SALES)
Unit B, 11 Piermark
Drive Albany 1331
New Zealand
PO Box 512
Albany 1331
Phone: [phone]
Fax: [phone]
Email:
[email protected]
AUSTRALIA AND NEW ZEALAND
www.australianmonitor.com.au
INTERNATIONAL SALES
149 Beaconsfield Street Silverwater NSW 2128 Australia
Private Bag 149 Silverwater NSW 1811
Phone: [phone]
Fax: [phone]
Email: [e-mail]
SENNHEISER ELECTRONIC CORPORATION
1 Enterprise Drive
Old Lyme CT 06371 USA
Phone: [phone]
Fax: [phone]
Email: [email protected]
EUROPE/ASIA/MIDDLE EAST
www.australianmonitor.com.au
USA/SOUTH AMERICA
www.australianmonitor.com