Crest Audio CENTURY LM User manual

CENTURY SERIES
OWNER'SMANUAL
LM

Congratulations on your purchase of a Century Series console. All of us at Crest Audio in Paramus, New
Jersey, USA, support your decision, knowing your console contains the finest combination of design and
manufacture in the industry.
While your new Century Series console is one of the most feature-packed available, great effort has been
put into making it simple to operate.
This manual explains the functions of your new console, how they operate and how they relate to each
other. If properly cared for, your new console will provide you with trouble-free, sonically accurate mixing
clear into the next Century and beyond.
Please keep the following contact information on hand:
Crest Audio Customer Service Dept.
100 Eisenhower Drive
Paramus NJ 07652 USA
TEL [phone] FAX [phone]
http://www.crestaudio.com
Crest Audio Inc.
100 Eisenhower Dr., Paramus NJ 07652 USA
TEL: [phone] FAX: [phone]
http://www.crestaudio.com
Printed in USA

Feature Overview 2
A brief description of the LM design, features and functions.
System Connections 3
Contains diagrams illustrating conventional system connections.
Wiring Conventions 5
Contains diagrams indicating how connectors for Crest consoles are wired.
Power Supply 6
A description of the rack-mountable Century Series consoles power supply.
Power Connections 7
A description of Crest console power connections.
Console Cooling 7
A brief description of the dual-fan cooling setup.
LM-12 Input Module 8
Profiles the LM-12 input module. The module is illustrated and described.
LM-20 (LM-8+4) Input Module 10
Profiles the LM-20 (LM-8+4) input module. The module is illustrated and described.
LM-12 Output Module 13
Profiles the LM-12 ouput module. The module is illustrated and described.
LM 8+4 Output Module 15
Profiles the LM-8+4 output module. The module is illustrated and described.
LM-20 Output Module 17
Profiles the LM-20 ouput module. The module is illustrated and described.
Master Module A 19
Profiles the LM A-Master module. The module is illustrated and described.
Master Module B 21
Profiles the LM B-Master module. The module is illustrated and described.
Technical Information Appendix A
Includes dimensions, specifications, console access details,
user options, console block diagram, and rear panel layout.
Glossary Appendix B
The specific details of console operation are described here, alphabetically.
Schematics Appendix C
This appendix lists available LM console & power supply schematics.
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TABLE OF CONTENTS

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PAGE 2
CENTURY SERIES
Feature Overview
The Century Series was designed to have all the features and
functions demanded by the modern music professional. The
engineers at Crest Audio have delivered the finest combination
of function and sonic accuracy in an affordable intuitive con-
sole. The features listed below are common to all Century
Series LM Consoles.
• SSM/PMI High quality devices on balanced
microphone/line inputs and on all outputs for uncompro-
mised audio quality and reliability. All IC’s within the audio
path are socket mounted for easy upgrade or service.
• The signal path is completely free of electrolytic capaci-
tors and all internal audio connections are gold plated.
• Passive microphone splitters on every microphone input.
• 48 Volt switchable phantom power on all microphone
inputs.
• Optional transformers available on all microphone inputs
and primary outputs.
• Dynamic Signal Present and multiple-sample- point Peak
indicator LED’s are used on all input sections of the console
as well as on all primary outputs.
• Mono/Stereo PFL system. When a stereo module is used,
the signal is monitored in stereo while mono modules are mon-
itored in mono.
• Standard frame sizes include 32, 40, 44, 52 and 64 module
positions. Any frame size may be ordered short loaded for later
expansion.
• The three banks of four rotary send controls each have an
associated Pre switch. This switch can be internally selected to
operate as pre EQ or pre Fader; this selection applies to all
three Pre switches on the module.
• Each of the twelve send controls can be internally selected
to operate in one of three modes: follow its associated Pre
switch, always Pre or always Post.
• Mute system on input channels is designed to mute both pre
and post fader signals. When muted, PFL circuitry and, Peak
and Dynamic Signal Present LED indicators remain fully oper-
ational. This is a feature not available on many consoles at any
cost.
• Four scene (A-D) mute system
• The EQ section includes an EQ IN switch with LED and a
100Hz High Pass filter switch. The EQ itself offers four bands
(LF-40-800Hz, LMF-100Hz-2kHz, HMF-400Hz-8kHz, HF-
1.5k-20kHz) that are sweepable, providing full frequency con-
trol with generous overlap. The high and low frequency bands
are selectable between Peaking and Shelving via internal
jumpers.
• Each LM output Module (except those in the master mod-
ule) has a ten-segment LED array, three-band sweepable EQ,
EQ-In switch, variable high-pass filter, polarity reverse, Insert
switch, Talkback enable, Dim, Peak & dynamic Signal Present
LEDs, local Mute and PFL.
• Return level controls provide signal from Returns 1 and 2
found on the Master section. The Sub Input controls deliver
signal from outputs 11 and 12 which are selectable pre or post
fader. This feature allows mixes 11 and 12 to be cross-mixed
to all other outputs.
• Comprehensive Talkback section allows access to all pri-
mary console outputs. External signals can also be assigned
into the talkback system.
• The basis of every Century console is signal integrity.
From the input preamplifier's impressive EIN of -129 dBu, to
completely balanced primary busing, the Century LM delivers
one of the cleanest signals available at any cost. This signal
purity comes from using only the highest quality components
in its innovative design. All inputs and outputs are electronical-
ly balanced, the primary inputs and outputs have the option of
transformer isolation.
• UL/CE-approved external power supply over-designed
with ample current reserves. For the ultimate in fail-safe relia-
bility, a back-up power supply can be linked to the primary
supply with only an inexpensive jumper cable. External
switching is not needed.

LIVE MONITOR CONSOLE
PAGE 3
CENTURY SERIES LM
System Connections
The console is the nerve center of a sound system and controls
most of the variables within a system. Proper connection and
component relationships are vital to assure accurate operation
and results. The following diagrams illustrate conventional sys-
tem connections.
Signal Processors
In
Out
BAL INSERT RTN
DIR OUT
INSERT SEND
BAL MIC IN
BAL LINE IN
BAL INSERT RTN
DIR OUT
INSERT SEND
BAL MIC IN
BAL LINE IN
BAL INSERT RTN
DIR OUT
INSERT SEND
BAL MIC IN
BAL LINE IN
BAL INSERT RTN
DIR OUT
INSERT SEND
BAL MIC IN
BAL LINE IN
Front of House
Console
From
Stage
Microphones
Insert Send/Return Connection
Microphone Splitting

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CENTURY SERIES
Clip/Limit
Signal
Temp/DC
Active
Ch B
-1
0dB
-3
-6
-10
-15
-30
-80
6001 Professional Power Amplifier
Ch A
-1
0dB
-3
-6
-10
-15
-30
-80
Clip/Limit
Signal
Temp/DC
Active
Ch B
-1
0dB
-3
-6
-10
-15
-30
-80
6001 Professional Power Amplifier
Ch A
-1
0dB
-3
-6
-10
-15
-30
-80
Transmitters for
In-Ear Monitors
Receivers for
In-Ear Monitors
Floor Wedge Connection
Stereo In-Ear Monitor Connection

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CENTURY SERIES
1
2
3
PIN 1 = GROUND
PIN 2 = POSITIVE
PIN 3 = NEGATIVE
OUTPUT XLR
INPUT XLR
PIN 3
PIN 1
PIN 2 PIN 3
PIN 2
PIN 1
TIP - POSITIVE
RING - NEGATIVE
SLEEVE - GROUND
INPUT
TIP - SEND
RING - RETURN
SLEEVE - GROUND
INSERT
TIP - POSITIVE
RING - NEGATIVE
SLEEVE - GROUND
OUTPUT
Input Plug Polarities
Insert send & Insert return Polarities
Output Plug Polarities
Wiring Conventions
Since the same connectors are used throughout the professional audio industry, it is important to know how the connectors for
Crest’s Century Series are wired. The wiring is as follows.

LM
PAGE 6
CENTURY SERIES
Power Supply
Century Series Consoles use a separate rack-mountable power supply which provides the specific voltages used by each console.
Century Consoles make use of two different power supplies. The model and frame size of your particular console determines
which of the two supplies should be used.
Model
LM
Supply Model XCVA04
Frame Size 24,32
Supply Model XCVA06
Frame Size 40,44,52,64
Power Supply
C O N S O L E S
+20V
-20V
+48V
+24V
Press to Reset
4A
ON
Designed & manufactured in the USA by:
A division of Crest Audio Inc.
100 Eisenhower Dr.
Paramus, New Jersey 07652 USA
POWER OUT
POWER OUT
RISK OF ELECTRIC SHOCK
DO NOT OPEN
CAUTION
AVIS :RISQUE DE CHOC ÉLECTRIQUE—NE PAS OUVRIR
WARNING TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK DO NOT
EXPOSE THIS EQUIPMENTTO RAIN OR MOISTURE.
ATTENTION! POUR ÉVITER LE RISQUE D'INCENDIE OU DE CHOC
ÉLECTRIQUE, NE PLACEZ PAS CET APPAREIL SOUS LA PLUIE OU Á
L'HUMIDITÉ
6
7
21
4
53
Pin 1 +24V
Pin 2 +20V
Pin 3 Analog
Pin 4 Analog
Pin 5 Digital
Pin 6 +48V
Pin 7 -20V
CONSOLE
GROUND CHASSIS
GROUND
MAXIMUM AC IN:
XCVA04: 415WATTS
XCVA06: 825WATTS
+ 48V @ 1
+ 24V @ 6
±20V @ 6
Model XCVA06
Model XCVA04
±20V @ 4
+ 24V @ 4
S/N
Supply Identification
The type of power supply can be identified by the model num-
ber shown on the back of the chassis and panel label.
Power Requirements
The Century Series power supplies have certain electrical
requirements to operate properly. If possible the power supply
should be connected to a dedicated circuit. Should any other
appliance on the same circuit draw enough current to overload
the circuit, the breaker or fuse will trip causing loss of power
to the console. Note the maximum current draw specifications
at right. Be sure that the circuit to which you connect the sup-
ply can handle the draw.
The power switch on the supply front panel is also a circuit
breaker, there is no power fuse. Should the supply ever shut
down, or trip at start up, simply push the switch to the off posi-
tion and then on again.
Ground Linking
Safety Considerations - Each new power supply is shipped
with the AC third wire ground connected to the console chassis
ground. The connection is made at the rear of the power supply
unit. This is necessary for safety reasons so that exposed metal
parts are grounded. In the event of a live conductor making
contact with the console chassis or the power supply chassis
then the current will flow to ground without a safety hazard
arising. Note that when the console is disconnected from the
power supply the chassis ground connection to AC third wire
ground is broken and safety protection is lost. For uninterrupt-
ible grounding, in a fixed installation for example, make a con-
nection directly to the console chassis from the safety ground.
Disconnect the ground link on the rear of the power supply.
This disconnects console ground from power supply AC third
wire ground which would otherwise create a hum-loop.
Twin Supply Operation
When twin supplies are in use for automatic back-up, then the
ground links on both supplies should be fitted. In a situation
where the safety ground to the console chassis has been con-
nected and the ground path via the power supply is causing a
hum-loop, then disconnect the ground links on BOTH power
supplies.
Console and Power Supply Grounding
Console chassis ground is electrically connected to audio
ground, pin 1 of XLR connectors and 1/4" sockets and to the
terminal ‘CONSOLE GROUND’ at the rear of the power sup-
ply. The AC third wire connection in the power supply cable
connects the metal chassis of the power supply to safety
ground. This connection should never be disturbed. Hazardous
voltages exist inside the power supply which require the case
to be grounded. When rack-mounted, the power supply ground
may transfer to the rack case thru the front fixing screws,
though this connection is not reliable. When a console is con-
figured within a complete sound system the grounding require-
ments may call for the ground link to be disconnected. This is
permissible only when an alternative ground path has been
provided. If in doubt seek the
advice of an experienced elec-
trical engineer.
+48V @ 1A
+24V @ 6A
±20V @ 6A
Model XCVA06
Model XCPS-40
±20V @ 4
+24V @ 4
S/N
Power Supply Model
XCVA04
XCVA06
Max Current Draw 120V/230V
7A/4A
9A/5A

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PAGE 7
CENTURY SERIES
Designed & manufactured in the USA by:
A division of CrestAudio Inc.
100 Eisenhower Dr.
Paramus, New Jersey 07652 USA
POWER OUT
POWER OUT
RISK OF ELECTRIC SHOCK
DO NOT OPEN
CAUTION
AVIS : RISQUE DE CHOC ÉLECTRIQUE—NE PAS OUVRIR
WARNING TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK DO NOT
EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE.
ATTENTION! POUR ÉVITER LE RISQUE D'INCENDIE OU DE CHOC
ÉLECTRIQUE, NE PLACEZ PAS CETAPPAREIL SOUS LA PLUIE OU Á
L'HUMIDITÉ
6
7
21
4
53
Pin 1 +24V
Pin 2 +20V
Pin 3 Analog
Pin 4 Analog
Pin 5 Digital
Pin 6 +48V
Pin 7 -20V
CONSOLE
GROUND CHASSIS
GROUND
MAXIMUM AC IN:
XCVA04: 415 WATTS
XCVA06: 825 WATTS
+ 48V @ 1
+ 24V @ 6
±20V @ 6
Model XCVA06
Model XCVA04
±20V @ 4
+ 24V @ 4
S/N
Designed & manufactured in the USA by:
A division of CrestAudio Inc.
100 Eisenhower Dr.
Paramus, New Jersey 07652 USA
POWER OUT
POWER OUT
RISK OF ELECTRIC SHOCK
DO NOT OPEN
CAUTION
AVIS : RISQUE DE CHOC ÉLECTRIQUE—NE PAS OUVRIR
WARNING TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK DO NOT
EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE.
ATTENTION! POUR ÉVITER LE RISQUE D'INCENDIE OU DE CHOC
ÉLECTRIQUE, NE PLACEZ PAS CETAPPAREIL SOUS LA PLUIE OU Á
L'HUMIDITÉ
6
7
21
4
53
Pin 1 +24V
Pin 2 +20V
Pin 3 Analog
Pin 4 Analog
Pin 5 Digital
Pin 6 +48V
Pin 7 -20V
CONSOLE
GROUND CHASSIS
GROUND
MAXIMUM AC IN:
XCVA04: 415 WATTS
XCVA06: 825 WATTS
+ 48V @ 1
+ 24V @ 6
±20V @ 6
Model XCVA06
Model XCVA04
±20V @ 4
+ 24V @ 4
S/N
To AC Mains
To AC Mains
Interface Cable
To Console
Power Connections
The connections to and from the power supply vary depending on your specific configuration. Multiple power supplies can be
daisy-chained to provide fail-safe protection in the event of a supply failure. When two or more supplies are used, they may be
connected to the same mains voltage since only one of the supplies will actually be feeding the console at any given time.
The connectors on the power supply are “smart” so that either one can be used as the console or interface connection.
Console Cooling
A cooling fan configuration is included in all LM consoles except the LM-12 and the 32-chassis space LM Dual/Stereo models.
Two fans (one at each end of the console) draw air in through the sides of the chassis (under the sidebars). Air is distributed
through the chassis via a “vortex pan”, then proceeds up through the console modules, where the heated air exits the console
chassis.
Once the console is powered up, cooling fans remain on. A rear panel switch permits the fans to be set at low, medium or high
speeds.
There are no filters to change or clean. As with any console, use in dusty/unclean environments should be avoided.

LM
PAGE 8
CENTURY SERIES
LM-12 INPUT MODULE
The LM-12 input module is the primary input control for the LM-
12 monitor console. It differs from the LM-20 input module only
in the mix send section.
48V Phantom Power Switch
Turns on 48V Phantom Power as required by certain microphones
for proper operation.
LINE Switch
Selects between the Balanced XLR Microphone Input connector
and the Balanced Line Input 1/4" TRS connector.
PAD Switch
Introduces a -15 dB cut to the mic input signal.
GAIN Control
Adjusts input gain for proper signal level.
100Hz High Pass Switch
Reduces all low frequency content at a 12db per octave rate refer-
enced to 100Hz (-3db point).
Polarity Reverse Switch
Inverts the polarity of both the microphone and line inputs.
Four-Band Sweep Equalizer Controls
There are two knobs for each of the four bands. The inner knob
controls the boost or cut; while the outer knob controls the center
frequency. These center frequencies are printed on the chassis
around the outer knob.
EQ IN Switch
Inserts the EQ section into the input channel signal. An associated
LED illuminates when the switch is down.
PRE Switch 1-4
Toggles mix sends 1-4 between Post and the internally selected
Pre state.
Mix Sends 1-4
Adjusts signal level sent to output mixes 1-4
PRE Switch 5-8
Toggles mix sends 5-8 between Post and the internally selected
Pre state.
Mix Sends 5-8
Adjusts signal level sent to output mixes 5-8
PRE Switch 9-12
Toggles mix sends 9-12 between Post and the internally selected
Pre state.
Mix Sends 9-12
Adjusts signal level sent to output mixes 9-12
MUTE Switch with LED
Mutes the channel and all sends except the insert send. This
switch does not affect the PFL switch or the Peak and Signal
Present LED indicators, The LED illuminates when the channel is
muted either from the local mute switch or the scene mute system.
20
10
6
30
60
100
40
150 3
6
800
250
100
400
1
2K
1K
400
1.5 3
6
8K
3
2K
410
20K
+48V
100
EQ IN
HM
LM
PAD
LF
GAIN
HF
PRE
PRE
PRE
78
9
5
2
1
346
7
8
9
5
2
0
1
3
46
10
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
LINE
ø
5
6
7
8
1
2
3
4
9
MUTE
PFL
PEAK
SIG
0
5
10
30
40
20
PRE
PRE
78
9
5
2
0
1
346
10
78
9
5
2
0
1
346
10
78
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
7
8
9
2
0
1
3
10
SCENE
MUTE
SELECT
A
B
C
D
SAFE
7
8
9
5
2
0
1
346
10
5
6
7
8
4
9
10
11
12
BAL INSRT RTN
DIR OUT
INSRT SND
BAL MIC IN
BAL MIC OUT
PIN 1
LIFT
BAL LINE IN

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PAGE 9
CENTURY SERIES
PFL Switch
Samples the channel’s signal pre-fader and allows for monitor-
ing within the master section of the console. This signal is not
affected by the Mute Switch. When depressed, the signal level
can be seen on the output 12 meter, and heard via the mixer’s
headphone or local monitor output. When this PFL Switch is
depressed, the channel PEAK LED indicator illuminates at a
lower intensity. When used as a status indicator of switch posi-
tion, the Peak LED indicating circuit remains fully operational
by illuminating at a much higher intensity than when indicat-
ing PFL status.
PEAK LED Indicator
Illuminates RED when any of the points monitored come with-
in 3db of the clipping point. Signal is sampled after the input
preamplifier stage, after the EQ section, and after the fader.
This LED also serves as a PFL ON indicator, but at a much
lower intensity than when it is used to indicate clipping.
SIGNAL PRESENT LED
This green LED constantly displays level activity of the input
channel by varying in intensity.
100mm Fader
Used for control of all outputs of the channel except those
sends selected pre fader. (The Insert Output level is not affect-
ed by the fader position.)
Scene Mute Assignments
Assign the input channel to any of the four scene mute groups.
Scene mute combines with the module’s local mute button, and
actuates the local mute LED.
Scene Mute Safe Switch
Disables any selected scene mute assignments. An associated
green LED indicates that the channel is in a safe state.
Rear Panel Connections
Direct Out
This 1/4-inch TRS jack carries the direct output signal (post
fader & post mute) from the associated input channel.
Insert Send
This 1/4-inch TRS jack carries the send signal of the insert
loop to the external effect or signal processor.
Balanced Insert Return
This 1/4-inch TRS jack accepts the return signal of the insert
loop from the external effect or signal processor back into the
console.
Balanced Line In
This 1/4-inch TRS jack accepts balanced and unbalanced line
level inputs and delivers it into the associated input channel.
Lift Pin 1
This ground lift switch may be used to isolate pin1 of the mic
XLR from console ground.
Unpressed = pin 1 grounded
Pressed = pin 1 lifted
Balanced Mic In
This XLR connector accepts balanced microphone inputs for
the associated input channel.
Balanced Mic Out
This XLR connector is in parallel with the Balanced Mic In
connector and allows easy connection of the monitor board to
the FOH console.

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PAGE 10
CENTURY SERIES
LM-20 (LM-8+4) INPUT MODULE
This module serves as the input module for LM-20 and the now-
discontinued LM-8+4. The only difference between the two is
the factory default settings on the dual concentric sends.For the
LM-20 the sends are set for level/level operation. For an LM-
8+4 the sends are set for level/pan operation.
48V Phantom Power Switch
Turns on 48V Phantom Power as required by certain micro-
phones for proper operation.
LINE Switch
Selects between the Balanced XLR Microphone Input connector
and the Balanced Line Input 1/4" TRS connector.
PAD Switch
Introduces a -15 dB cut to the mic input signal.
GAIN Control
Adjusts input gain for proper signal level.
100Hz High Pass Switch
Reduces all low frequency content at a 12db per octave rate ref-
erenced to 100Hz (-3db point).
Polarity Reverse Switch
Inverts the polarity of both the microphone and line inputs.
Four-Band Sweep Equalizer Controls
There are two knobs for each of the four bands. The inner knob
controls the boost or cut; while the outer knob controls the cen-
ter frequency. These center frequencies are printed on the chas-
sis around the outer knob.
EQ IN Switch
Inserts the EQ section into the input channel signal. An associat-
ed LED illuminates when the switch is down.
PRE Switch 1-4
Toggles mix sends 1-4 between Post and the internally selected
Pre state.
Mix Sends 1-4
Adjusts signal level sent to stereo output mixes 1-4 or mono
mixes 1a through 4b.
PRE Switch 5-8
Toggles mix sends 5-8 between Post and the internally selected
Pre state.
Mix Sends 5-8
Adjusts signal level sent to stereo output mixes 5-8 or mono
mixes 5a through 8b.
PRE Switch 9-12
Toggles mix sends 9-12 between Post and the internally selected
Pre state.
Mix Sends 9-12
Adjusts signal level sent to stereo output mixes 9-12 or mono
mixes 9a through 12b.
20
10
6
30
60
100
40
150 3
6
800
250
100
400
1
2K
1K
400
1.5 3
6
8K
3
2K
410
20K
+48V
100
EQ IN
HM
LM
PAD
LF
GAIN
HF
PRE
PRE
4
PRE
7
8
9
5
2
1
346
7
8
9
5
2
0
1
3
46
10
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
LINE
ø
2
3
1
5
6
7
8
9
MUTE
PFL
PEAK
SIG
0
5
10
30
40
20
PRE
4
PRE
7
8
9
5
2
0
1
346
10
78
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
78
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
7
8
9
2
0
1
3
10
SCENE
MUTE
SELECT
A
B
C
D
SAFE
5
6
7
8
9
10
11
12
BAL INSRT RTN
DIR OUT
INSRT SND
BAL MIC IN
BAL MIC OUT
PIN 1
LIFT
BAL LINE IN

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PAGE 11
CENTURY SERIES
MUTE Switch with LED
Mutes the channel and all sends. This switch does not affect
the PFL switch or the Peak and Signal Present LED indicators,
The LED illuminates when the channel is muted either from
the local mute switch or the scene mute system.
PFL Switch
Samples the channel’s signal pre-fader and allows for monitor-
ing within the master section of the console. This signal is not
affected by the Mute Switch. When depressed, the signal level
can be seen on the output 12 meter, and heard via the mixer’s
headphone or local monitor output. When this PFL Switch is
depressed, the channel PEAK LED indicator illuminates at a
lower intensity. When used as a status indicator of switch posi-
tion, the Peak LED indicating circuit remains fully operation
by illuminating at a much higher intensity than its use as a PFL
status indicator.
PEAK LED Indicator
Illuminates RED when any of the points monitored come with-
in 3db of the clipping point. Signal is sampled after the input
preamplifier stage, after the EQ section, and after the fader.
This LED also serves as a PFL ON indicator, but at a much
lower intensity than when it is used to indicate clipping.
SIGNAL PRESENT LED
Constantly displays level activity of the input channel by vary-
ing in intensity.
100mm Fader
Used for control of all outputs of the channel except those Aux
output sections selected by switch to a pre fader position. (The
Insert Output level is not affected by the fader position.)
Scene Mute Assignments
Assign the input channel to any of the four scene mute groups.
Scene mute combines with the module’s local mute button, and
actuates the local mute LED.
Scene Mute Safe Switch
Disables any selected scene mute assignments. An associated
green LED indicates the channel is in a safe state.
Rear Panel Connections
Direct Out
This 1/4-inch TRS jack carries the direct output signal (post
fader & post mute) from the associated input channel.
Insert Send
This 1/4-inch TRS jack carries the send signal of the insert
loop to the external effect or signal processor.
Balanced Insert Return
This 1/4-inch TRS jack accepts the return signal of the insert
loop from the external effect or signal processor back into the
console.
Balanced Line In
This 1/4-inch TRS jack accepts balanced and unbalanced line
level inputs and delivers it into the associated input channel.
Lift Pin 1
This ground lift switch may be used to isolate pin1 of the mic
XLR from console ground.
Unpressed = pin 1 grounded
Pressed = pin 1 lifted
Balanced Mic In
This XLR connector accepts balanced microphone inputs for
the associated input channel.
Balanced Mic Out
This XLR connector is in parallel with the Balanced Mic In
connector and allows easy connection of the monitor board to
the FOH console.

LM
PAGE 12
CENTURY SERIES
OUTPUT
+9
+6
+3
0
-3
-6
-9
-12
-15
-18
11
88
O+
11
88
O+
SUB
INPUT
1
1
HF
LF
10
4
15 30
6
1
60
30
13
5
8
7
8
9
5
2
0
1
346
1
7
8
9
5
2
0
1
3
46
1
3
1
51
1
20
11
88
O+ MID
ø
EQ IN
HPF
4
2
810
20
40
RETURN
1
2
7
8
9
5
2
0
1
346
1
7
8
9
5
2
0
1
3
46
1
MUTE
PFL
PEAK
SIG
DIM
TB ENB
INSERT
ON
SUB
INPUT
1
1
1
0
5
10
30
40
5
20
7
8
9
5
2
0
1
346
1
7
8
9
5
2
0
1
3
46
1
ø
4
2
20
40
RETURN
1
2
7
8
9
5
2
0
1
346
1
7
8
9
5
2
0
1
3
46
1
BAL OUT
INSERT RTN
INSERT SEND

LM
PAGE 13
CENTURY SERIES
LM-12 Output Module
The LM-Mono Group output module is the primary output
module on the LM-12 and the secondary output module on the
LM-8+4 and the LM-20
Output Meter
Monitors the post-fader output signal via a ten-segment LED
array.
Output EQ
Controls the the equalization of the output mix signal through
three bands, via six controls. The upper knob of each band
determines the center frequency (high-1kHz-20kHz, mid-
300Hz-8kHz, low-40Hz, 1kHz), while the lower knob adjusts
the amount of boost or cut.
EQ IN Switch
Inserts the EQ section into the output channel signal. An asso-
ciated LED illuminates when the switch is down.
High Pass Filter Switch
Inserts the High Pass Filter into the output signal.
HPF Frequency Control
This knob adjusts the high pass filter frequency from 20Hz to
400Hz. The filter operates at a -12 dB per octave rate.
Return Level Controls
Adjusts the level of return signals 1 and 2 in the output. These
signals come from the Master Section. See Returns 1 & 2 on
the Master Section description for more information.
Sub Input Controls
Adjusts the level of cross-mix in the output from mono outputs
11 and 12.
Polarity Reverse Switch
Inverts the polarity of the output.
Insert On Switch
Turns on the insert loop for the output signal. If a complete
insert loop is not present depressing this switch will mute the
output.
TB Enable Switch
Injects the talkback signal from the master section into the
group output.
DIM Switch
Introduces a -6dB drop to the output signal. This is a push
on/push off switch, not momentary.
MUTE Switch with LED
Mutes the output. This switch does not affect the PFL switch
or the Peak and Signal Present LED indicators.
Output PFL
Enables Pre Fader Listening of the output signal. (this signal
can be internally selected post fader)
Output PEAK & Signal LEDs
The red LED indicates that the output is within 3dB of the clip-
ping point.
The green LED constantly displays the level of signal activity
by varying in intensity.
Output Fader
Controls the final output signal level.
Rear Panel Connections
Balanced Out
This XLR connector carries the post-fader output signal from
the associated output module.
Output Insert Send
This 1/4-inch TRS balanced jack carries the send signal of the
output insert loop to the external effect or signal processor.
Output Insert Return
This 1/4-inch TRS balanced jack accepts the return signal of
the output insert loop from the external effect or signal proces-
sor.

LM
PAGE 14
CENTURY SERIES
MONO
OUTPUT
+9
+6
+3
0
-3
-6
-9
-12
-15
-18
16 16
88
O+
16 16
88
O+
SUB
INPUT
11
12
HF
LF
100
40
150 300
6
1K
600
300
1K 3
5
8K
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
3
1K
510
15
20K
16 16
88
O+ MID
Ø
EQ IN
HPF
40
20
80 100
200
400
RETURN
1
2
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
MONO
MUTE
PFL
PEAK
SIG
DIM
TB ENB
INSERT
ON
SUB
INPUT
11
12
0
5
10
30
40
5
20
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
Ø
40
20
100
200
400
RETURN
1
2
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
INSERT RETURN
BAL OUT LEFT
INSERT SEND
INSERT RETURN
BAL OUT RIGHT
INSERT SEND

LM
PAGE 15
CENTURY SERIES
LM-8+4 Output Module
The LM-Stereo group output module is the primary output
module on the discontinued LM-8+4.
Output Meters
Monitors the post-fader output signal via two ten-segment
LED arrays.
Output EQ
Controls the the equalization of the output mix signal through
three bands, via six controls. The upper knob of each band
determines the center frequency (high-1kHz-20kHz, mid-
300Hz-8kHz, low-40Hz, 1kHz), while the lower knob adjusts
the amount of boost or cut.
EQ IN Switch
Inserts the EQ section into the output channel signal. An asso-
ciated LED illuminates when the switch is down.
High Pass Filter Switch
Inserts the High Pass Filter into the output signal.
HPF Frequency Control
This knob adjusts the high pass filter frequency from 20Hz to
400Hz. The filter operates at a -12 dB per octave rate.
Return Level Controls
Adjusts the level of return signals 1 and 2 in the output. These
signals come from the Master Section. The center knob adjusts
level while the outer knob adjusts panning within the stereo
image. See Returns 1 & 2 on the Master Section description for
more information.
Sub Input Controls
Adjusts the level of cross-mix in the output from mono outputs
11 and 12. The center knob adjusts while the outer knob
adjusts panning within the stereo image.
Mono Switch
Depressing this switch mixes the left and right pre-insert sig-
nals together onto the Left Insert Send jack. The Left Insert
Return is switched to both Left and Right Returns. This allows
for a mono processor to be used, but affect both channels.
Polarity Reverse Switch
Inverts the polarity of the output.
Insert On Switch
Turns on the insert loop for the output signal. If a complete
insert loop is not present depressing this switch will mute the
output.
TB Enable Switch
Injects the talkback signal from the master section into the
group output.
DIM Switch
Introduces a -6dB drop to the output signal. This is a push
on/push off switch, not momentary.
MUTE Switch with LED
Mutes the output. This switch does not affect the PFL switch
or the Peak and Signal Present LED indicators.
Output PFL
Enables Pre Fader Listening of the output signal. (this send can
be internally selected post fader)
Output PEAK & Signal LEDs
The red LED indicates that the output is within 3dB of the clip-
ping point.
The green LED constantly displays the level of signal activity
by varying in intensity.
Output Fader
Controls the final output signal level
Rear Panel Connections (L & R)
Balanced Out
This XLR connector carries the post-fader output signal from
the associated output module.
Output Insert Send
This 1/4-inch TRS balanced jack carries the send signal of the
output insert loop to the external effect or signal processor.
Output Insert Return
This 1/4-inch TRS balanced jack accepts the return signal of
the output insert loop from the external effect or signal proces-
sor.

LM
PAGE 16
CENTURY SERIES
OUTPUT
+9
+6
+3
0
-3
-6
-9
-12
-15
-18
16 16
88
O+
16 16
88
O+
SUB
INPUT
11
12
HF
LF
100
40
150 300
6
1K
600
300
1K 3
5
8K
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
3
1K
510
15
20K
16 16
88
O+ MID
Ø
EQ IN
HPF
40
20
80 100
200
400
RETURN
1
2
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
AB
MUTE
PEAK
SIG
DIM
TB ENB
INSERT ON
SUB
INPUT
11
12
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
Ø
40
20
200
400
RETURN
1
2
7
8
9
5
2
0
1
346
10
7
8
9
5
2
0
1
346
10
AB
PFL
0
5
10
30
40
5
20
INSERT RETURN
BAL OUT LEFT
INSERT SEND
INSERT RETURN
BAL OUT RIGHT
INSERT SEND

LM
PAGE 17
CENTURY SERIES
LM-20 Output Module
The LM-Dual group output module is the primary output mod-
ule on the LM-20.
Output Meter
Monitors the post-fader output signal via two ten-segment
LED arrays.
Output EQ
Controls the the equalization of the output mix signal through
three bands, via six controls. The upper knob of each band
determines the center frequency (high-1kHz-20kHz, mid-
300Hz-8kHz, low-40Hz, 1kHz), while the lower knob adjusts
the amount of gain or cut. This single set of knobs controls
both channels A & B.
EQ IN Switch
Inserts the EQ section into the output channel signal. An asso-
ciated LED illuminates when the switch is down.
High Pass Filter Switch
Inserts the High Pass Filter into the output signal.
HPF Frequency Control
This knob adjusts the high pass filter frequency from 20Hz to
400Hz. The filter operates at a -12 dB per octave rate. This sin-
gle knob controls both channels A & B.
Return Level Controls
Adjusts the level of return signals 1 and 2 in the output. These
signals come from the Master Section. The center knob adjusts
“level A” while the outer knob adjusts “level B.” See Returns 1
& 2 on the Master Section description for more information.
Sub Input Controls
Adjusts the level of cross-mix in the output from mono outputs
11 and 12. The center knob adjusts “level a” while the outer
knob adjusts “level b.”
Polarity Reverse Switch
Inverts the polarity of the output.
Insert On Switch
Turns on the insert loop for the output signal. If a complete
insert loop is not present depressing this switch will mute the
output.
TB Enable Switch
Injects the talkback signal from the master section into the
group output.
DIM Switch
Introduces a -6dB drop to the output signal. This is a push
on/push off switch, not momentary.
MUTE Switch with LED
Mutes the output. This switch does not affect the PFL switch
or the Peak and Signal Present LED indicators.
Output PFL
Enables Pre Fader Listening of the output signal. (This send
can be internally selected post fader)
Output PEAK & Signal LEDs
The red LED indicates that the output is within 3dB of the clip-
ping point.
The green LED constantly displays the level of signal activity
by varying in intensity.
Output Faders
Controls the final output level of each signal (a & b).
Rear Panel Connections (L & R)
Balanced Out
This XLR connector carries the post-fader output signal from
the associated output module.
Output Insert Send
This 1/4-inch TRS balanced jack carries the send signal of the
output insert loop to the external effect or signal processor.
Output Insert Return
This 1/4-inch TRS balanced jack accepts the return signal of
the output insert loop from the external effect or signal proces-
sor.

LM
PAGE 18
CENTURY SERIES
OUTPUT
MONITOR A LEFT
MONITOR A RIGHT
BAL OUT
EXT TB IN
INSERT RTN
INSERT SEND