Inter-m MX-1243 User manual

MX-1243 Audio Mixer
AUDIO MIXER

Contents
Contents
1. Unpacking and Installation.....................................................................................................1
2. Features ................................................................................................................................2
3. Front Panel Controls...............................................................................................................3
4. Rear Panel Controls ...............................................................................................................6
. Applications ..........................................................................................................................7
6. Block Diagram.......................................................................................................................8
7. Specifications.........................................................................................................................9

Unpacking and Installation
Unpacking and Installation
Although it is neither complicated to install nor difficult to operate your Audio Mixer, a few minutes of your
time is required to read this manual for a properly wired installation and becoming familiar with its many
features and how to use them. Please take a great care in unpacking your set and do not discard the carton
and other packing materials. They may be needed when moving your set and are required if it ever
becomes necessary to return your set for service.
Never place the unit near radiators, in front of heating vents, in excessively humid or dusty location to avoid
early damage and for your years of quality use. Connect your complementary components as illustrated in
the following page.
MX-1243 1
PROFESSIONAL AUDIO MIXER
RISK OF ELEC RIC SHOCK
DO NO OPEN
CAUTION
CAU ION: O REDUCE HE RISK OF ELEC RIC SHOCK.
DO NO REMOVE COVER (OR BACK).
NO USER-SERVICEABLE PAR S INSIDE.
REFER SERVICING O QUALIFIED SERVICE PERSONNEL.
WARNING
o prevent fire or shock hazard, do not
expose the unit to rain or moisture.
his symbol is intended to alert the user to the
presence of uninsulated “dangerous voltage”
within the product’s enclosure that may be of suf-
ficient magnitude to constitute a risk of electric
shock to persons.
his symbol is intended to alert the user to the
presence of important operation and mainte-
nance (servicing) instructions in the literature
accompanying the appliance.
Caution: o prevent electric shock do not use this (polarized) plug
with an extension cord, receptacle or other outlet unless
the blades can be fully inserted to prevent blade expo-
sure.
Attentions: Pour prévenir les chocs électriques ne pas utiliser cette
fiche polarisée avec un prolongateur, une prise de
courant on une autre sortie de courant, sauf si les
lames peuvent étre insérées à fond sans en laisser
aucune partie à découvert.

Features
Features
- 12CH INPUT AND 4 OUTPUT
Any sound source of microphones, cassette decks, electric guitars, organs can be applied to the 12 channel
input, and 4 AUX SEND, MONO OUT and MAIN L, R OUT are provided for convenient use.
- 3 BAND TONE CONTROLS
3 band tone controls are provided to adjust the acoustic characteristics according to microphones, speakers
and room structured.
- AUX SEND AND AUX RETURN
For the convenient use of effect equipment, reverb, delay or phasor AUX SEND and AUX RETURN function
are provided.
- OUTPUT MONITORING
You can monitor by LED meter and headphone.
- PFL/AFL FUNCTION
The PFL/AFL function allows you to monitor through headphone any input channel before the channel fader
and AUX output channel after the AUX SEND volume.
- PHANTOM POWER
Phantom power is provided for easy connection of condenser microphones requiring an external power
supply.
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PROFESSIONAL AUDIO MIXER

Front Panel Controls
Front Panel Controls
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PROFESSIONAL AUDIO MIXER
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1. OUTPUT LEVEL METER
These meters show the level of output signal appearing at the STEREO OUT L, R and MONO OUT.
2. POWER SWITCH AND INDICATOR
The POWER switch is used to turn on and off the AC main power, and the LED is illuminated when the
AC main power is ON.
3. PHANTOM POWER SWITCH
This switch turns on and off the phantom power supply. The phantom power supply provides power for
condenser type microphone through the microphone cable.
When switches on, it produces 48volts DC (with 6.8kohms source impedance) at pins 2 and 3 on all of
the microphone input connectors. Pin 1 (the shield conductor) provides the ground return path.
This will power standard condenser microphones and will not affect most dynamic microphones. When
switches on or off, the voltage will ramp slowly up or down; it takes a few seconds to reach full level.
This prevents unwanted transients from reaching the microphone inputs.
4. PFL/AFL INDICATOR
This indicator will light when a PFL or AFL switch is turned on.
. AUX RETURN CONTROLS
These controls adjust the level of the L and R signals that are received at the rear panel AUX RETURN 1,
2. You can use the AUX RETURN as auxiliary inputs, as well as affects returns.
6. AUX SEND CONTROL (OUTPUT CHANNEL)
This control adjusts the level of the signal output from the AUX SEND OUT.
7. AFL SWITCHES
Press this switch to monitor the AUX SEND signal through the HEADPHONE.
8. BALANCE CONTROL
This knob assigns the signal of AUX RETURN, determining the stereo of the sound.
9. HEADPHONE LEVEL CONTROL
This control is used for adjusting the level of headphone monitoring.
10. HEADPHONE JACK
Connect the headphones here. You can monitor the following signals.
1) Pre-fader signal When the corresponding PFL switch is ON.
2) AUX SEND signal When the corresponding AFL switch is ON.
3) Normally when PFL and AFL switch is OFF, the headphone will monitor the same signal as the
STEREO L/R jacks.
11. MAIN OUTPUT FADERS
The stereo and mono master faders independently adjust level of the L/R and MONO channel main buss
signals appearing at the STEREO L/R and MONO OUT connectors.
12. TRIM CONTROLS
This control adjusts the input sensitivity of each channel from –16dB to –60dB for microphone source
through the XLR input, and from +24dB to –20dB for line source through the phone jack input.
For the best performance, adjust this TRIM control so that PEAK indicator LED lights occasionally.

MX-1243
PROFESSIONAL AUDIO MIXER
13. MIC/LINE SELECTOR SWITCHES
These switch are used for selecting input level MIC and LINE. When a microphone is connected to the
MIC IN jack, set this switch to MIC. When a line source is connected to the LINE IN jack, set this switch
to LINE.
14. EQ CONTROLS
Each input channel equalizer is divided into three band. This level is adjustable over a wide range of
boost and cut.
HIGH ±12dB at 12kHz
MID ±12dB at 2.5kHz
LOW ±12dB at 80Hz
1 . AUX SEND 1, 2 CONTROL (INPUT CHANNEL)
You can adjust the level which is assigned to AUX 1, 2 output from each input channel.
Since AUX signal is placed before the channel fader, it will be unaffected by the position of channel
fader.
16. AUX SEND 3, 4 CONTROL (INPUT CHANNEL)
You can adjust the level which is assigned to AUX 3, 4 output from each input channel.
Since AUX signal is placed after the channel fader, it will be affected by the channel fader level.
17. PAN CONTROLS
This control assigns the signal of each channel to the STEREO L and R busses, determinating the stereo of
sound.
18. PEAK INDICATORS
This warning light indicates an overload situation. This indicator light in red when the pre EQ, post EQ,
or post fader signal of the corresponding channel’s input reaches a level 3dB below the clipping level.
19. PFL SWITCHES
Press this switch to monitor the pre-fader input channel signal through the HEADPHONE. This is useful
when you wish to monitor only the signal from a particular channel, or take a counter measure for a
problem.
20. CHANNEL FADERS
This is the main level control for each input channel. It determines level of the signal sent from the corre-
sponding input channel to the master stereo buss. Faders of channels not in use should be pulled down.

Rear Panel Controls
Rear Panel Controls
1. AUX RETURN JACKS
These are stereo type phone jacks. Usually the output from effects units such as delay and reverb are
returned to the main stereo mix via these jacks. However, you can use these as auxiliary inputs.
2. AUX SEND JACKS
These are final output of AUX and connected unbalanced phone jacks.
3. MIC IN
These XLR type connectors be connected with microphone. (Pin assignment 1 GND, 2 HOT, 3 COLD)
Impedance range is 50Ω to 600Ω.
These the phantom power switch ON to apply +48V DC to pin 2 and 3 of these connectors.
4. AC POWER ENTRY MODULE
An inlet socket to connect the power cable and fuse holder. A correct capacity of fuse should be applied.
Please make sure the value of fuse before replacing.
. MONO OUTPUT
This is XLR type connector used to connect a power amplifier. (Pin assignment– 1 GND, 2 HOT, 3
COLD)
6. STEREO L/R OUTPUT
These are XLR type connectors used to connect a stereo power amplifier.
(Pin assignment– 1 GND, 2 HOT, 3 COLD)
7. LINE IN
These are balanced input connector which can be connected line level equipment.
Impedance is 10kΩ.
6MX-1243
PROFESSIONAL AUDIO MIXER

AC INPUT
220V 60Hz, 25W

FUSE
0.4A / 250V
LR
L/MONO 1
RL/MONO 2R
4321
AUX SEND
AUX RETURN
MAIN OUTMONO OUT
MIC IN
121110 9 8 7 6 5 4 3 2 1
12 11 10 9 8 7 6 5 4 3 2 1
LINE IN
123
4567

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PROFESSIONAL AUDIO MIXER
Applications
Applications
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

AC INPUT
220V 60Hz, 25W

FUSE
0.4A / 250V
LR
L/MONO 1
R
L/MONO 2R
4321
AUX SEND
AUX RETURN
MAIN OUTMONO OUT
MIC IN
12 11 10 9 8 7 6 5 4 3 2 1
121110 9 8 7 6 5 4 3 2 1
LINE IN

8MX-1243
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Block Diagram
Block Diagram

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MX-1243
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Specifications
Specifications........................................................................
- ELECTRICAL 0dB=0.775Vrms
Maximum Output Level
Input Sensitivity & Impedance
T.H.D
Frequency Response
Input Channel Equalization
Hum & Noise
(Average, Rs=150Ω)
(Measured with DIN AUDIO)
Crosstalk
Maximum Voltage Gain
Gain Control
LED Meters
Channel Peak Indicators
Phantom Power
+24dB @ 600Ω, 0.5% THD at 1kHz (BALANCED) MAIN OUT L/R
+24dB @ 600Ω, 0.5% THD at 1kHz (BALANCED) MONO OUT
+20dB @ 600Ω, 0.5% THD at 1kHz (UNBALANCED) AUX SEND 1–4
100mW @ 40Ω, 0.5% THD at 1kHz HEADPHONE
-60dB @ 600Ω, BALANCED MIC (CH1–CH12)
-20dB @ 10kΩ, BALANCED LINE (CH1–CH12)
+4dB @ 10kΩ, UNBALANCED AUX RETURN
0.1% @ +14dB, 20-20kHz
MAIN OUT L/R @ 600Ω, MONO OUT @ 600Ω, AUX SEND @ 600Ω
+1dB/-2dB, 20-20kHz @ +4dB
(MAIN OUT L/R @ 600Ω, MONO OUT @ 600Ω, AUX SEND @ 600Ω)
±12dB 12kHz Shelving (Max ±15dB) HIGH
±12dB 2.5kHz Peaking MID
±12dB 80Hz Shelving (Max ±15dB) LOW
-127dB Equivalent Input Noise
-95dB Residual Noise
(MAIN OUT L/R @ 600Ω, MONO OUT @ 600Ω, AUX SEND@600Ω)
-76dB MAIN OUT L/R, MONO OUT
(INPUT VR & FADER MIN/OUTPUT FADER MAX)
-68dB AUX SEND 1-4
(INPUT VR & FADER MIN/OUTPUT VR & FADER MAX)
-70dB Adjacent Input Channels
-70dB Input to Output
84dB MIC to MAIN OUT L/R, MONO OUT
76dB MIC to AUX SEND
44dB LINE to MAIN OUT L/R, MONO OUT
36dB LINE to AUX SEND
20dB AUX RETURN to MAIN OUT L/R, MONO OUT
44dB MIC IN/LINE IN
“0” +4dB OUTPUT LEVEL
Red LED on each channel lights when pre-EQ or post-fader signal
reaches 3dB below clip level.
+48Vdc
- GENERAL
* Specifications and design subject to change without notice for improvements.
Power Source
Power Consumption
Weight
Dimensions
AC 110V - 240V, 50/60Hz
25W
7.5kg
482(W) x 104(H) x 310(D) mm

PROFESSIONAL AUDIO MIXER
Specifications
Specifications
- ELECTRICAL
OUTPUTS
STEREO L/R Output....................................................................................+4dBm/600Ω, BALANCED
MONO Output...........................................................................................+4dBm/600Ω, BALANCED
AUX SEND 1~4 Output.....................................................................................+4dBm/600Ω, UNBAL
Headphone Output ........................................................................................................100mW/40Ω
INPUTS
MIC (CH1~CH12).................................................................................... –60dBm/600Ω, BALANCED
LINE (CH1~CH12).....................................................................................–20dBm/10kΩ, BALANCED
AUX RETURN....................................................................................................+4dBm/10kΩ, UNBAL
T.H.D (20Hz~20kHz)......................................................................................................................0.1%
Frequency Response.......................................................................................20Hz~20kHz (+1dB, –2dB)
EQ Response
High.......................................................................................................±12dB Shelving (Max ±15dB)
Mid .............................................................................................................................±12dB Peaking
Low........................................................................................................±12dB Shelving (Max ±15dB)
E. I. N .......................................................................................................................................–127dB
Residual Noise.............................................................................................................................–95dB
Crosstalk .....................................................................................................................................–70dB
Maximum Voltage Gain
MIC to L/R, MONO Out..............................................................................................................84dB
MIC to AUX SEND ......................................................................................................................76dB
LINE to L/R, MONO Out.............................................................................................................44dB
LINE to AUX SEND......................................................................................................................36dB
AUX RETURN to L/R, MONO Out................................................................................................20dB
Phantom Power........................................................................................................................+48V DC
- GENERAL
Power Source ................................................................................................AC 110V–240V, 50/60Hz
Power Consumption .......................................................................................................................25W
Weight.........................................................................................................................................7.5kg
Dimensions...............................................................................................482(W)?104(H)?310(D)mm
* Specifications and design subject to change without notice for improvements.

MADE IN KOREA
December 2005 9007908910 A
Inter-M, Ltd. (Korea) began operations in 1983.
Since then, Inter-M has grown to become one of the largest manufacturers
of professional audio and commercial sound electronics equipment in the world.
Inter-M has gained worldwide recognition for its own branded products,
as well as private label manufacturing of electronics sold under other names (OEM).
The company is no longer just a Korean company, but rather a global company
that is truly international in scope, with factories and offices in Korea and China,
and sales and marketing operations located in Japan, Europe, and the U.S.A.
With more than 850 employees around the globe,
Inter-M is well-poised for further growth and expansion.
INTER-M AMERICAS, INC.
1 EAST BEACON LIGHT LANE CHESTER, PA USA 19013-4409
TEL [phone], FAX [phone]
Home Page http //www.inter-m.net, E-mail [email protected]
INTER-M Corporation
SEOUL OFFICE 653-5 BANGHAK-DONG, DOBONG-KU, SEOUL, KOREA
TEL [phone]~8, FAX [phone]
Home Page http //www.inter-m.com, E-mail [email protected]