User's Manual
S-12
12-CHANNEL MIXING CONSOLE
R
LTO
www.altoproaudio.com
Version 2.3 August 2005
English
SAFETY RELATED SYMBOLS
CAUTION
RISK OFELECTRIC SHOCK
DO NOTOPEN
This symbol, wherever used, alerts you to the presence of un-insulated and dangerous voltages within the product enclosure. These are voltages that
may be sufficient to constitute the risk of electric
shock or death.
This symbol, wherever used, alerts you to important operating and maintenance instructions.
Please read.
Fuse
To prevent fire and damage to the product, use only
the recommended fuse type as indicated in this
manual. Do not short-circuit the fuse holder. Before
replacing the fuse, make sure that the product is
OFF and disconnected from the AC outlet.
Protective Ground
Before turning the product ON, make sure that it is
connected to Ground. This is to prevent the risk of
electric shock.
Never cut internal or external Ground wires. Likewise,
never remove Ground wiring from the Protective
Ground Terminal.
Protective Ground Terminal
AC mains (Alternating Current)
Hazardous Live Terminal
ON: Denotes the product is turned on.
OFF: Denotes the product is turned off.
WARNING
Describes precautions that should be observed to
prevent the possibility of death or injury to the user.
CAUTION
Describes precautions that should be observed to
prevent damage to the product.
Disposing of this product should not be
placed in municipal waste and should be
Separate collection.
WARNING
Power Supply
Ensure that the mains source voltage (AC outlet)
matches the voltage rating of the product. Failure
to do so could result in damage to the product and
possibly the user.
Unplug the product before electrical storms occur
and when unused for long periods of time to reduce
the risk of electric shock or fire.
External Connection
Always use proper ready-made insulated mains
cabling (power cord). Failure to do so could result
in shock/death or fire. If in doubt, seek advice from
a registered electrician.
Do Not Remove Any Covers
Within the product are areas where high voltages
may present. To reduce the risk of electric shock do
not remove any covers unless the AC mains power
cord is removed.
Covers should be removed by qualified service
personnel only.
No user serviceable parts inside.
Operating Conditions
Always install in accordance with the manufacturer's
instructions.
To avoid the risk of electric shock and damage, do
not subject this product to any liquid/rain or moisture.
Do not use this product when in close proximity to
water.
Do not install this product near any direct heat source.
Do not block areas of ventilation. Failure to do so
could result in fire.
Keep product away from naked flames.
IMPORTANT SAFETY INSTRUCTIONS
Read these instructions
Follow all instructions
Keep these instructions. Do not discard.
Heed all warnings.
Only use attachments/accessories specified by the
manufacturer.
Power Cord and Plug
Do not tamper with the power cord or plug. These are
designed for your safety.
Do not remove Ground connections!
If the plug does not fit your AC outlet seek advice from
a qualified electrician.
Protect the power cord and plug from any physical
stress to avoid risk of electric shock.
Do not place heavy objects on the power cord. This
could cause electric shock or fire.
Cleaning
When required, either blow off dust from the product
or use a dry cloth.
Do not use any solvents such as Benzol or Alcohol.
For safety, keep product clean and free from dust.
Servicing
Refer all servicing to qualified service personnel only.
Do not perform any servicing other than those instructions contained within the User's Manual.
1
PREFACE
Dear Customer:
Thank you for choosing the LTO S-12 12-Channel Mixing Console, which is the result of our LTO AUDIO TEAM's
endeavours.
For the LTO AUDIO TEAM, music and audio is more than a profession, it is a passion and an obsession!
We have, in fact, been designing professional audio products for a number of years in cooperation with many of the
world's major brands.
The LTO line represents unparalleled analogue and digital products made by musicians, for musicians. With our
design centres in Italy, the Netherlands, and the United Kingdom we provide you with world-class designs, while our
software development teams continue to develop an impressive range of audio specific algorithms.
By purchasing our LTO products you become the most important member of our LTO AUDIO TEAM. We would
like to share with you our passion for what we design and invite you to make suggestions, which will aid us in developIng future products for you. We guarantee you our commitment for quality, continual research and development,
and of course the best prices.
The LTO S-12 is an extremely flexible, ultra-low noise 12-channel console, configured with 4 mono and 4 stereo input
channels, each channel is equipped with a variety of key features including a warm, natural sounding EQ, Peak LEDs
MUTE/ALT3-4, SOLO-in-place and high quality fader.
We would like to thank all the people who made the LTO S-12 12-Channel Mixing Console possible, especially to
our designers and LTO staff. It is their passion for music and professional audio that has made it possible for us to
offer you, our most important team member, our continued support.
Thank you very much
LTO AUDIO TEAM
2
TABLE OF CONTENTS
1.INTRODUCTION........................................................................................................................................................4
2.FEATURES................................................................................................................................................................5
3.GETTING STARTED...................................................................................................................................................6
4.CONTROL ELEMENTS.............................................................................................................................................7
4.1 The mono MIC/LINE channels..........................................................................................................................8
4.2 INPUT LEVEL setting......................................................................................................................................8
4.3 LOW CUT FILTER............................................................................................................................................8
4.4 STEREO INPUTS.............................................................................................................................................9
4.5 +4dBu / -10dBV................................................................................................................................................9
4.6 PHONES..........................................................................................................................................................9
4.7 The 3 BANDS EQUALISER...............................................................................................................................9
4.8 AUX SEND .....................................................................................................................................................10
4.9 PAN..................................................................................................................................................................10
4.10 MUTE / ALT 3-4 .............................................................................................................................................10
4.11 SOLO ............................................................................................................................................................10
4.12 SOLO LED .....................................................................................................................................................10
4.13 PEAK..............................................................................................................................................................10
4.14 FADER...........................................................................................................................................................10
4.15 INSERT...........................................................................................................................................................11
4.16 MAIN SECTION.............................................................................................................................................11
4.17 REAR PANEL ................................................................................................................................................14
5.INSTALLATION & CONNECTION...............................................................................................................................15
6.FOR THE EXPERTS WHO WANT TO KNOW MORE.................................................................................................18
7.SYSTEM BLOCK DIAGRAMS...................................................................................................................................19
8.TECHNICAL SPECIFICATIONS..................................................................................................................................20
9.WARRANTY................................................................................................................................................................21
3
1.INTRODUCTION
Your S-12 is a 12-channel mixer and it is one of the most popular compact mixing consoles in the world. In fact it has
been sold already in terms of thousands of units worldwide. Despite its compact dimensions, great performances and
sound quality are insured thanks to the specification of the components used and the building quality.
Your S-12 is packed with features that can not be found in other consoles of its size: 4 Mono (these are provided with
Ultra Low Noise microphone preamplifiers and Phantom Power at +48 Volt) and 4 stereo input channels are provided,
and each of them is provided with a 3 bands graphic equaliser for HI, MID and LOW controls, MUTE/ALT 3-4, SOLOin-place and high quality fader etc..
Your S-12 is very easy to operate but we advise you to go through each Section of this Manual carefully. In this way
you will get the best out of your S-12.
4
2. FEATURES
The S-12 12-Channel Mixing Console is designed for the professional application, and presents with the following specific
features:
-. Ultra-low noise 12-channel 2+2-bus mixing console
-. 4 MIC input channels with gold plated XLRs and balanced Line inputs
-. 4 stereo input channels with balanced TRS jacks
-. 2 additional multi-functional stereo AUX Returns
-. Ultra-low noise discrete MIC preamps with +48V Phantom power
-. Low noise, high headroom
-. Peak LEDs on each channel
-. TRS and XLR outputs, Phones / Control Room output and Alt output.
-. 2 Aux Sends per channel for external effects and monitoring
-. 2-Track inputs assignable to Main Mix, outputs
-. Mute / Alt 3-4, Solo function on each channel
-. Highly accurate 12-segment Bar-graph meters
-. +4dBu / -10dBV on each stereo channel
-. Switchable Low Cut filter on each mono channel
-. Inserts on MIC channels
-. High quality faders and potentiometers
Phones / Control Room
5
3. GETTING STARTED
3.1 Please check the AC Voltage available in your Country before connecting your S-12 to the AC socket.
3.2 Be sure that the main power switch is turned off before connecting the Mixer to the AC socket. Also, you should
make sure that all Input and Output Controls are turned down. This will avoid damages to your speakers and avoid
excessive noise.
3.3 Before turning on the S-12 you shall connect it to a power amplifier and turn-on the mixer BEFORE the power amp-
lifier. Once you have finished your working session you shall turn the mixer off AFTER the power amplifier.
3.4 Before disconnecting the S-12 always turn-off the Power switch.
3.5 Do not use solvents to clean your S-12. A dry and clean cloth will be OK.
6
4. CONTROL ELEMENTS
MIC 1
LINE IN 1
TRIM
+15dB 45dB
0dB 60dB
15 +15
12 +12
15 +15
1
8
2
8
RIGHTLEFT
12
3
BAL OR
UNBAL
L NE
MIC
LOW CUT
75Hz
18dB/Oct
EQ
HI
12kHz
MID
2 5kHz
LOW
80Hz
AUX
POST
PRE
+15
POST
(PRE)
+15
PAN
MUTE/
ALT 3 4
PEAK
10
dB
5
0
-5
-10
-20
-25
-30
-40
-60
MIC 2 MIC 3 MIC 4
LINE IN 2
TRIM
+15dB 45dB
0dB 60dB
15 +15
12 +12
15 +15
1
8
2
8
RIGHTLEFT
12
3
BAL OR
UNBAL
LINE
MIC
LOW CUT
75Hz
18dB/Oct
EQ
HI
12kHz
MID
2 5kHz
LOW
80Hz
AUX
POST
PRE
+15
POST
(PRE)
+15
PAN
MUTE/
ALT 3 4
10
dB
5
0
-5
-10
-20
-25
-30
-40
-60
LINE IN 3
TRIM
+15dB 45dB
0dB 60dB
15 +15
12 +12
15 +15
1
8
2
8
RIGHTLEFT
12
3
BAL OR
UNBAL
LINE
MIC
LOW CUT
75Hz
18dB/Oct
EQ
HI
12kHz
MID
2 5kHz
LOW
80Hz
AUX
POST
PRE
+15
POST
(PRE)
+15
PAN
MUTE/
ALT 3 4
10
dB
5
0
-5
-10
-20
-25
-30
-40
-60
LINE IN 4
TRIM
+15dB 45dB
0dB 60dB
15 +15
12 +12
15 +15
1
8
2
8
RIGHTLEFT
12
3
BAL OR
UNBAL
LINE
MIC
LOW CUT
75Hz
18dB/Oct
EQ
HI
12kHz
MID
2 5kHz
LOW
80Hz
AUX
POST
PRE
+15
POST
(PRE)
+15
PAN
MUTE/
ALT 3 4
10
dB
5
0
-5
-10
-20
-25
-30
-40
-60
STEREO AUX RETURN AUX SEND 2-TRACK IN/OUT
LEFT(MONO)
LEFT
RIGHT
1
2
1
RIGHT
2
CTRL ROOM
OUTPUT
L
R
L
R
TAPE IN TAPE OUT
3
MIC (MONO)
LINE IN 5/6 LINE IN 7/8
12
LEFT(MONO)
LEFT (MONO)
LINE IN 9/10
LEFT (MONO)
LINE IN 11/12
LEFT (MONO)
TRIM
0dB 60dB MIC
15 +15
12 +12
15 +15
1
8
2
8
EQ
12kHz
MID
2 5kHz
LOW
80Hz
AUX
+15
POST
(PRE)
+15
BAL
RIGHTLEFT
MUTE/
ALT 3 4
10
dB
5
0
-5
-10
-20
-25
-30
-40
-60
HI
POST
PRE
1
2
RIGHT RIGHT
LEVEL
+4dBu
10dBV
EQ
HI
12kHz
15 +15
MID
2 5kHz
12 +12
LOW
80Hz
15 +15
AUX
POST
PRE
8
+15
POST
(PRE)
8
+15
BAL
RIGHTLEFT
MUTE/
ALT 3 4
10
dB
5
0
-5
-10
-20
-25
-30
-40
-60
1
2
LEVEL
15 +15
12 +12
15 +15
8
8
+4dBu
10dBV
EQ
HI
12kHz
MID
2 5kHz
LOW
80Hz
AUX
+15
POST
(PRE)
+15
BAL
RIGHTLEFT
MUTE/
ALT 3 4
10
dB
5
0
-5
-10
-20
-25
-30
-40
-60
RIGHT
POST
PRE
LEVEL
15 +15
12 +12
15 +15
1
2
+4dBu
10dBV
8
8
RIGHT
+15
+15
RIGHTLEFT
EQ
12kHz
MID
2 5kHz
LOW
80Hz
AUX
POST
(PRE)
BAL
MUTE/
ALT 3 4
PEAKPEAKPEAKPEAKPEAKPEAKPEAK
10
dB
5
0
-5
-10
-20
-25
-30
-40
-60
HI
SOLOSOLOSOLOSOLOSOLOSOLOSOLOSOLO
POST
PRE
PHONES
LEVEL
+4dBu
10dBV
2
8
EFX TO AUX1
1
8
2
8
-+15
AUX SEND
SOLO
ACTIVE
SOLO MODE
LTO
12-CHANNEL MIXING CONSOLE
1
AUX
RETURN
LEVEL
SET
PFL
AFL
10
dB
5
0
-5
-10
-20
-25
-30
-40
-60
8
+15
PHANTOM PWR
CLIP
10
7
4
2
0
-2
-4
-7
-10
-20
-30
LR
OUTPUT LEVEL
CTRL ROOM
+15
+15
R
TO
8
-
ALT 3-4
ALT 3 4
TO MAIN MIX
TO MAIN MIX
MA N MIX
ALT 3 4
2TK
2TK IN
+15
10
dB
5
0
-5
-10
-20
-25
-30
-40
-60
1
2
3
4 5/6 7/8
9/10 11/12
LEFT RIGHT
MAIN MIX LEVEL
PHONES/
CONTROL ROOM
7
4.1 The mono MIC/LINE channels
1
These are Channel 1 through Channel 4. You can connect balanced, low impedance microphones to the XLR socket. On the 1/4" phone jack you can
connect either a microphone or a line level instrument. You shall never connect
an unbalanced microphone to the XLR socket if you do not want to damage
both the Microphone and the Mixer.
MIC 1
12
3
48 Volt phantom power
2
It is available only to the XLR Mic sockets. Never plug in a microphone when
phantom power is already on. Before turning phantom power on, make sure
that all faders are all the way down. In this way you will protect your Stage
Monitors and Main Loudspeakers.
4.2 INPUT LEVEL setting
3
This Control is provided with 2 different indication rings: One is
for the Microphone and the other for the Line levels. When you
use a microphone you shall read the OUTSIDE ring (0-60 dB),
When you use a Line level instrument you shall read the INSIDE
ring (+15~-45 dB). For optimum operation you shall set this control
in a way that the peak LED will blink also occasionally in order to
avoid distortion on the input channel.
LINE IN 1
TRIM
+15dB -45dB
0dB 60dB
BAL OR
UNBAL
LINE
MIC
LOW CUT
75Hz
18dB/Oct
1
3
4
POWER PHANTOM
ON
OFF
4.3 LOW-CUT FILTER
4
By pressing this button you will activate a 75 Hz low frequency filter with a slope of 18 dB per octave. You can use
this function to reduce hum and stage rumble when using microphones.
2
8
4.4 STEREO INPUTS
5
5
These are Channel 5 through 12. They are
organised in stereo pair and they are provided
with 1/4" TRS phone sockets.
If you connect only the left jack, the input will
operate in mono mode.
4.5 +4dB / -10dBuV
6
This switch adjusts the input sensitivity of
the on the stereo channels CH 5line inputs
~ CH 12. Engaging the switch is used to suit
for "-10dBV" sound source. If you are unsure,
leave the switch up.
4.6 PHONES
7
The 1/4" TRS socket will send out the signal
mix to a pair of headphones
12
3
MIC (MONO)
TRIM
0dB 60dB MIC
LINE IN 5/6 LINE IN 7/8
LEVEL
+4dBu
10dBV
LEFT (MONO)
LEFT(MONO)
RIGHT RIGHT
LEVEL
6
+4dBu
10dBV
15 +15
LINE IN 9/10
LEFT (MONO)
RIGHT
EQ
HI
12kHz
LINE IN 11/12
LEFT (MONO)
LEVEL
+4dBu
10dBV
RIGHT
LEVEL
+4dBu
10dBV
PHONES
7
8
4.5 The 3 BANDS EQUALISER
A 3-band equaliser is provided for all input channels with a wide
range of frequency adjustment.
4.5.1 HI
8
This is the Treble control. You can use it to get rid of high frequency
noises or to boost the sound of cymbals or the high harmonics of
the human voice. The gain range goes from -15dB to +15dB with
a center frequency of 12 kHz.
4.5.2 MID
9
This is the Midrange control. It can affect most fundamental frequencies of all musical instruments and human voice. An attentive
use of this control will give you very wide panorama of sound effects.
The gain range goes from -12dB to +12dB and the center frequency
is 2.5 kHz.
4.5.3 LOW
10
This is the Bass control. Boost male voice or kickdrum and bass
guitar. Your system will sound much bigger than what it is. The gain
range goes from -15dB to +15dB and the center frequency is 80 Hz.
12 +12
15 +15
1
8
2
8
MID
2.5kHz
LOW
80Hz
AUX
POST
PRE
+15
POST
(PRE)
+15
PAN
RIGHTLEFT
MUTE/
ALT 3 4
SOLO
PEAK
10
dB
5
0
-5
-10
-20
-25
-30
-40
-60
9
10
1
9
4.8 AUX SEND
11
These two controls will send the audio signal out to Auxiliary busses.
AUX 1 can be configured as PRE/POST Fader via the PRE/POST switch:
Up for POST Fader, the audio signal will be affected by the main Channel
Fader; Down for PRE Fader, the signal is sent out before reaching the
main fader. AUX 2 is configured as POST-Fader; However, AUX 2 can
also be configure as PRE-Fader through any internal modification.
(Please see "MODIFICATIONS" later in this Manual.)
4.9 PAN
12
This is the PANORAMA control, or balance control. You can adjust
the stereo image of the signal via this Control. Keep this control in
center position and your signal will be positioned in the middle of
stage. Turn this control fully counterclockwise and the signal will be
present only on the left speaker and vice-versa. Of course a wide
number of intermediate positions is available.
4.10 MUTE / ALT 3-4
13
Each channel is equipped with the MUTE / ALT 3-4 switch. Pressing
this switch is used to route the channel signal to ALT 3-4 output
instead of the main mix and the LED beside MUTE/ ALT 3-4 will
illuminate.
4.11 SOLO
14
Pressing this switch allows you to monitor the signals through your
headphone or CONTROL ROOM, then the SOLO signal will replace
other signals, and be also sent to the CONTROL ROOM, PHONES
and METERs. Usually use the solo in live work to preview channels
before they are let into the mix.
15 +15
12 +12
15 +15
1
2
8
8
EQ
HI
12kHz
MID
2.5kHz
LOW
80Hz
AUX
+15
POST
(PRE)
+15
PAN
RIGHTLEFT
MUTE/
ALT 3 4
SOLO
PEAK
10
dB
5
0
-5
-10
-20
-25
-30
-40
-60
POST
PRE
11
12
13
15
14
16
17
It is useful to set instruments's input level and EQ, and you canan
also solo any channel that you want to. The SOLO switch never affects
1
any mix other than the CONTROL ROOM mix.
4.12 SOLO LED
15
Each channel is equipped with the SOLO LED display. When the SOLO button was engaged, the LED on corresponding channel will illuminate.
4.13 PEAK
16
Inside your S-12 the audio signal is monitored in several different stages and then sent to the PEAK Led. When this
Led blinks, it warns you that you are reaching signal saturation and possible distortion. The PEAK Led will blink with
a level that is 6dB before actual clipping.
4.14 FADER
17
This Fader will adjust the overall level of this channel and set the amount of signal sent to the Main output.
10
4.15 INSERT
18
Insert points are provided for the Mono Mic Channels.
When you insert a jack in the insert socket, the signal
will be taken out after the Input Gain Control (Trim),
sent to an external processor such a compressorlimiter, and returned into the channel strip immediately
before the EQ section. Of course, these jacks used must
be stereo (Tip Send/Ring Return).
4.16 MAIN SECTION
-. STEREO AUX RETURN
19
Use these stereo 1/4" phone socket to return the
sound of an effect unit or sound processor to the
Main Mix.
Alternatively you can use them as an extra auxiliary
input.
-.AUXSEND1&2
20
CHANNEL INSERT
(P -FADER/PRE-EQ TIP SEND/RING RETURN)RE
CH4 CH3 CH2 CH1
19 20 21 22
STEREO AUX RETURN AUX SEND
LEFT(MONO)
RIGHT
1
1
18
CTRL ROOM
OUTPUT
L
2-TRACK IN/OUT
L
This 1/4" phone socket is used to send out the
signal from the AUX Bus to external devices such
as effects and sound processors.
-. CONTROL ROOM OUTPUT
21
LEFT
RIGHT
2
2
R
R
TAPE IN TAPE OUT
These two unbalanced TRS jacks should be connected to the input of your control room amplifier.
-. 2-TRACK IN / OUT
22
Input
Use the Tape input if you wish to listen to your Mix from a Taper Recorder or DAT, You can assign the signal coming
form the Taper Recorder either to a pair of studio monitor using the Control Room assignment on the front panel or
you can also send the signal directly to the Main Mix.
Output
These 1/4" TRS sockets will route the main mix into a tape recorder.
11
-. AUX SEND
23
The both switches are used to determine the master AUX
SEND levels. The adjustable range is from - to +15dB.
When the effect unit connected to mixer has
no input gain
control, you can get a further +15dB gain available from
these AUX SEND outputs.
-. AUX RETURN
24
The Auxiliary Returns 1 and 2 are in fact two additional
stereo Line inputs. AUX RETURN 1 is configured to be
assigned permanently to the Main Mix. (It operates in
Mono Mode if you connect only the left jack).
The EFX TO AUX1 button is used to switch the signal
from AUX RETURN 2 between MAIN MIX and AUX
SEND 1.
If a signal is routed to AUX RETURN 1 and no signal
is connected to AUX RETURN 2, depressing the EFX
TO AUX 1 will route the signal to AUX SEND 1, which
evel will be controlled by AUX RETURN 2.
Without doubt, this feature will be very useful to you.
-. MAIN MIX LEVEL
25
These faders set the amount of signal sent either to
the Main Out socket or to the Tape Output.
-. LED METER
26
This stereo 12 segments Led Meter will indicate the level
of the overall output signal.
23
27
2
8
+15
RETURN
EFX TO AUX1
1
8
+15
2
8
-+15
AUX SEND
SOLO
ACTIVE
SOLO MODE
LEFT RIGHT
MAIN MIX LEVEL
24
AUX
LEVEL
SET
PFL
AFL
10
dB
5
0
-5
-10
-20
-25
-30
-40
-60
1
8
+15
PHANTOM PWR
CLIP
10
7
4
2
0
-2
-4
-7
-10
-20
-30
LR
OUTPUT LEVEL
-
TO
CTRL ROOM
CONTROL ROOM
8
+15
ALT 3-4
ALT 3 4
TO MAIN MIX
2TK
TO MAIN MIX
MAIN MIX
ALT 3 4
2TK IN
PHONES/
28
30
29
31
32
26
34
10
dB
5
0
33
-5
-10
-20
-25
-30
-40
-60
25
-. SOLO MODE
This button provides two modes: up for PFL (Pre-Fader-Listen) mode, down for AFL (After-Fader-Listen) mode.
Engage the button, the output signal of soloed channel will follow the TRIM, EQ, FADER and PAN/BAL control,
and the SOLO ACTIVE LED illuminates.
Release the button to enter into PFL mode, the output signal of soloed channel is unaffected by the PAN/BAL
and FADER control.
Please note that the SOLO function can never affect the mix at main recording output, and also can't be affected
by channel's MUTE/ALT 3-4 switch.
27
12
-. ALT 3-4
This switch is used to adjust the level of the ALT output, and the adjustable range is from - to +15dB. This is another
way to offer you an extra independent stereo submix with its own level adjustment knob.
28
-. POWER
This LED indicates when the Power is on in your S-12.
-. PHANTOM
This LED indicates when the Phantom Power is switched on.
-. ALT 3-4 TO MAIN MIX
Engaging this switch allows you to combine the ALT 3-4 output with the MAIN MIX, and feeds ALT 3 - 4 signals
into MAIN L / R output.
-. 2 TK TO MAIN MIX
Engaging this switch allows you to combine the 2 TRACK Output with the MAIN MIX, in other words, feeds
the 2 TRACK IN signals into MAIN L / R output.
-. PHONES / CONTROL ROOM
This Control sets the amount of signal sent to the Control Room and headphone.
29
30
31
32
33
-. CONTROL ROOM SOURCE
You can choose to monitor any combination of MAIN MIX, ALT 3-4 and 2 TK IN via these MATRIX switches. The
ALT 3-4 is the additional stereo mix bus; 2 TK IN is the stereo signal coming from the TAPE IN RCA jacks.
These stereo signals will be delivered to the PHONES / CONTROL ROOM and METERS display via engaging
these switches. If no switches engaged, there will be no signal at these outputs.
Note: When the channel's SOLO switch was engaged, then, the SOLO signal will replace other signals, and also
be sent to the CONTROL ROOM, PHONES and METERS.
34
13
4.17 REAR PANEL
-. AC INLET & FUSE HOLDER
35
Use it to connect your S-12 to the Main AC with the supplied AC
cord. Please check the Voltage available in your Country and
how the Voltage for your S-12 is configured before attempting to
connect your S-12 to the Main AC.
-. POWER
36
This switch is used to turn the Main Power ON and OFF.
-. PHANTOM
2
This switch will apply +48 Volt Phantom Power only to the 5 XLR
microphone inputs. Never connect microphones when the Phantom
Power is on already.
CAUTION
RISK OF ELECTRIC SHOCK
WARNING: SHOCK HAZARD
AVIS: RISQUE DE CHOC ELECTRIQUE
DO NOT OPEN
DO NOT OPEN
CAUTION:
REPLACE WITH THE SAME TYPE FUSE AND RAT NG
DISCONNECT SUPPLY CORD BEFORE CHANGING FUSE
NE PASOUVR R
MODEL
SERIAL
36
POWER PHANTOM
ON
OFF
f
USA / Canada
100-120V 60Hz
Fuse:T500mAL
2
Apparaten skall anslutas
U o
till jordat uttag nar den
ansluts till ett natverk
AC INPUT
EUROPE
210 240V 50Hz
Fuse:T250mAL
RATED POWER CONSUMPTION: 23W
35
UK / Aust
240V 50Hz
Fuse:T250mAL
MAIN
-. MAIN MIX OUTPUT
12
3
37
OUTMIX PUT (BALANCED)
LEFT
12
3
37
OUTPUT
+4dBu
MIC
MAIN
LEVEL
39
MAIN OUTPUT
RIGHT LEFT
ALT OUTPUT
RIGHT(4) LEFT(3)
38
This stereo output is supplied both with XLR and 1/4" jack socket and it is controlled by the Main Mix Level on
the front panel. It will send the audio signal to an amplifier. The output level can be varied from - to +10dB.
-. ALT OUTPUT
38
These 1/4" sockets are unbalanced outputs. They are capable of delivering +22dBu into the load.
Level to the ALT OUTPUT is adjusted by ALT 3-4 rotary knob on the front panel.
-. MAIN OUTPUT LEVEL
39
When depress the switch, the output level from MAIN MIX OUTPUT will be reduced 30dB.
14
5. INSTALLATION & CONNECTION
Ok, you have got to this point you are now in the position to successfully operate your S-12. However, we advise you
to read carefully the following section to be the real Master of your own Mix. Not paying attention enough to the Input
signal level, to the routing of the signal and the assignment of the signal will result in unwanted distortion, a corrupted
signal or no sound at all. So you should follow this procedure for every single channel:
Turn down all Input and Output Gain Controls.
Connect phantom powered microphones before switching on the +48Volt Phantom Power switch.
If you have a power amplifier connected to your S-12 set the Level of the amplifier at no more than 70%.
Now, set the CONTROL ROOM/PHONES level at no more than 50%. In this way you will be able to hear later
what you are doing connecting a pair of headphones or a pair of powered studio monitor speakers.
Position EQ controls on middle position.
Position panoramic (PAN) control on center position.
With a headphone or studio monitor speakers connected apply a Line Level input signal so that the PEAK Led
does not light up.
At this point increase the input gain so that the PEAK led will blink occasionally. In this way you will maintain
good headroom and ideal dynamic range.
Now connect a microphone and ask the singer to sing loud into the microphone. Turn slowly the Gain Control
clockwise and have the PEAK Led blink only occasionally.
Now repeat the same sequence for all input channels. The Main Led Meter could move up into the red section.
In this case you can adjust the overall output level through the MAIN MIX control.
15
B. Wiring Configuration
You can connect unbalanced equipment to balanced inputs and outputs. Simply follow these schematics.
Strain Clamp
Strain Clamp
Sleeve
Tip
Ring
Sleeve=Ground/Screen
Use for Headphone, Stereo Return
Ring=Right Signal
1/4" Stereo (TRS) Jack Plug
Sleeve
Use for Mono Line In, Mono 1/4"Jack Plugs
Tip
Sleeve=Ground/Screen
1/4" Mono (TS) Jack Plug
Tip=Left Signal
Tip=Signal
Strain Clamp
2
2=Hot(+)
3=Cold( )
Use for Balanced Mic Inputs
(For unbalanced use, connect pin 1 to 3)
1
3
Sleeve
Tip
Ring
Sleeve=Ground/Screen
Use for Pre Gain Channel Inserts
Ring=Return Signal
1/4" Stereo (TRS) Jack Plug
1=Ground/Screen
2=Hot(+)
(For unbalanced use, leave pin 3 unconnected)
Tip=Send Signal
2
1
3
3=Cold( )
Use for Main output
1=Ground/Screen
3-pin XLR Male Plug
(seen from soldering side)
3-pin XLR Line Socket
(seen from soldering side)
16
Ring=Return Signal (Connected together)
Sleeve=Ground/Screen
Tip=Signal
Sleeve=Ground/Screen
'Tapped' Connection Direct Output Lead
(Enables the Insert to be used as a Direct Output
while maintaining the channel signal flow)
To Channel Insert
To Tape or FX Input
To Processor Input
Sleeve=Ground/Screen
Tip
Tip=Send Signal
To Channel Insert
Sleeve
Ring
Ring=Return Signal
To Processor Output
-Stereo lead for insert Connection
(To be used when the processor does not employ a
single jack connection for the In/Out Connections)
17
6. FOR THE EXPERTS WHO WANT TO KNOW MORE
As we have told you previously in this Manual, the Aux Send 2 Control both on Mono and stereo channels is factory
wired as POST-FADER. If you have some skill in electronic components soldering you can modify this setting and have
all your AUX sends configured as PRE-FADER.
(PRE)
POST
Aux
Disconnect
the POST route
Before
Modification on mono and stereo channels
(PRE)
POST
Aux
Solder the PRE route
After
18
7. SYSTEM BLOCK DIAGRAMS
D
8
LEFT
RIGHT
TAPEOUT
R
LEVEL
MA NOUT
R
AUX SEND2
T
S
LEVEL
MAIN MIX
2TK
7
AUX SEND1
AUXSEND
R
T
S
6
AUX1
AUX2
LEVEL
MAIN MIX LEFT
213
T
S
R
+4dB/MIC
MAIN MIXRIGHT
213
T
S
+4dB/MIC
ALT3-4OUT
LEVEL
ALT3-4
C
LEFT
RIGHT
ALT-3(L)
R
T
S
TAPEIN
ALT-4(R)
2TK
R
T
S
2TK
ALT 3-4
SOLO ACTIVE
SOLO CTRL
B
PHONES
R
T
LEFTMETER
SOLO MODE
RIGHTMETER
AFL
( )
PFL LED
(LEVEL SET)
PFL
( )
S
PHONES OUTPUT
LEFT
R
T
S
CONTROL ROOM OUTPUT
A
VER020825
11of
KEV N LIN.
Rev son
8
Sheet
Drawn By:
RIGHT
S-12 BLOCK DIAGRAM
ALTO MIXINGCONSOLE
R
T
S
CONTROL ROOM
&PHONES
24-Dec-2002
S12-MAP.Sch
Mode No:
A3
T te
Sze
Date:
F e:
7
6
2TK TO MIX
MAIN MIX
5
ALT 3-4 TO MIX
CONTROL ROOM SOURCE
AFL L
AFL R
SOLO(PFL)
5
LEFT-BUS
AUX-1
LOGIC
EFX SEND
SOLO(PFL)
AFL R
AFL L
AUX 2
AUX 1
ALT4(R)
ALT3(L)
RIGHT BUS
LEFT BUS
4
3
HI
MID
LO
2
GAIN
AUX-2
RIGHT-BUS
ALT-4
LEFT-BUS
ALT-3
MA N/ALT
PAN
LEVEL
2
LO CUT
1
3
12K2.5K80
+/-15db
3-BANDEQ
+
-
AFL-L
AFL-R
LEFT-BUS
SOLO(PFL)
SOLO
AUX2
RIGHT-BUS
AUX-2
ON
( )
PRE
POST
121
ALT-3(L)
ALT-4(R)
LEFT-BUS
ALT-4
MA N/ALT
BALANCE
ALT-3
RIGHT-BUS
AUX-1
AUX1
2
PRE
POST
LEVEL
75Hz
HIPASS
R
3c5e1a4d2b
SG/OL
HI
12K2.5K80
MID
+/-15db
3-BANDEQ
LO
T
S
RN
TN
INSERT
-
+
LEFT-BUS
RIGHT-BUS
RIGHT-BUS
AUX-2
121
AUX2
PRE
AUX-1
AUX1
2
PRE
POST
RIGHT-BUS
LEFT-BUS
LEFT-BUS
1
EFX TO AUX-1
RETURN
AUX2 /DSP
AUX-1
AUX-1
RIGHT-BUS
3
1
3
2
2
AUX2 /DSP
AFL-L
AFL-R
SOLO(PFL)
SOLO
ON
( )
POST
EFX SEND
SOLO(PFL)
SIP R
SIP L
AUX 2
AUX 1
ALT4(R)
ALT3(L)
RIGHT BUS
LEFT BUS
4
3
AUX1 RETURN
12K2.5K80
EQ
-
-
-
+
SG/OL
GA N
-
+
CHANNEL 5,6 ONLY
+
-
+
-
+
+
2
T
T
S
R
R
RN
RN
TN
213
T
T
S
LEFT(MONO)
C
R
3c5e1a4d2b
S
RN
TN
RIGHT
PHANTOM
+48V
POWER
213
M C5N
R
RN
PHANTOM
+48V
POWER
MIC GAIN:0~60dB
MICIN
LINEIN
LINE IN TRIM:+15dB~-45dB
1
3c5e1a4d2b
TN
MONO INPUT CHANNELS ( 1-4 )
STEREO INPUT CHANNELS (5-12)
D
3c5e1a4d2b
STEREO AUX RETURN 1
B
3c5e1a4d2b
LEFT(MONO)
TN
T
T
RIGHT
S
R
RN
TN
3c5e1a4d2b
STEREO AUX RETURN 2
S
R
RN
TN
3c5e1a4d2b
LEFT
RIGHT
A
1
S
19
8. TECHNICAL SPECIFICATIONS
Mono input channels
Microphone input
Frequency response
Distortion (THD&N)
Gain range 0dB to 60dB(MIC),
SNR (Signal Noise Rated)
Line input
Frequency response
Distortion (THD&N)
Sensitivity range
Stereo input channels
Line input
Frequency response
Distortion (THD&N)
Impedances
Microphone input
Channel Insert return
All other inputs
Tape out
All other output
Equalization
Hi shelving
Mid bell
Low shelving
Low Cut filter
Main Mix Section
Noise (Bus noise)
Max output
AUX Return gain range
AUX Sends max out
Power supply
Main voltage
Power Consumption
Main connection
Physical
Dimension (W D H)XX
Net weight
Fuse
electronically balanced, discrete input configuration
10Hz to 55kHz, +/-3dB
0.005% at +4dBu, 1kHz
115dB
electronically balanced
10Hz to 55kHz, +/-3dB
0.005% at +4dBu, 1kHz
+15dBu to 45dBu-
Balanced
10Hz to 55kHz, +/-3dB
0.005% at +4dBu, 1kHz
1.4Kohm.
2.5Kohm.
10Kohm or greater.
1Kohm.
120ohm.
+/-15dB @12kHz
+/-12dB @2.5kHz
+/-15dB @80Hz
75Hz, 18dB/oct.
Fader 0 dB, channels muted:-100.0dBr (ref.:+4dBu)
Fader 0dB, all input channels assigned
and set to UNITY gain:-90dBr (ref.:+4dBu)
+22dBu balanced XLR,
+22dBu unbalanced, 1/4" jacks
- to +15dB
+22dBu
USA/Canada100-120V~, 60Hz
Europe210-240V~, 50Hz
U.K./Australia240V~, 50Hz
23watts
100-120V~ : T500mAL
210-240V~ : T250mAL
Standard IEC receptacle
300mmX355mmX28/80mm (11.8"x14.0"x0.8"/3.1")
4.04Kg (8.908lb)
20
9. WARRANTY
1. WARRANTY REGISTRATION CARD
To obtain Warranty Service, the buyer should first fill out and return the enclosed Warranty Registration Card within
10 days of the Purchase Date.
All the information presented in this Warranty Registration Card gives the manufacturer a better understanding of
the sales status, so as to purport a more effective and efficient after-sales warranty service.
Please fill out all the information carefully and genuinely, miswriting or absence of this card will void your warranty
service.
2. RETURN NOTICE
2.1 In case of return for any warranty service, please make sure that the product is well packed in its original shipping
carton, and it can protect your unit from any other extra damage.
2.2 Please provide a copy of your sales receipt or other proof of purchase with the returned machine, and give detail
information about your return address and contact telephone number.
2.3 A brief description of the defect will be appreciated.
2.4 Please prepay all the costs involved in the return shipping, handling and insurance.
3. TERMS AND CONDITIONS
3.1 warrants that this product will be free from any defects in materials and/or workmanship for a period
LTO
of 1 year from the purchase date if you have completed the Warranty Registration Card in time.
3.2 The warranty service is only available to the original consumer, who purchased this product directly from the
retail dealer, and it can not be transferred.
3.3 During the warranty service, may repair or replace this product at its own option at no charge to you for
LTO
parts or for labor in accordance with the right side of this limited warranty.
3.4 This warranty does not apply to the damages to this product that occurred as the following conditions:
Instead of operating in accordance with the user's manual thoroughly, any abuse or misuse of this product.
Normal tear and wear.
The product has been altered or modified in any way.
Damage which may have been caused either directly or indirectly by another product / force / etc.
Abnormal service or repairing by anyone other than the qualified personnel or technician.
And in such cases, all the expenses will be charged to the buyer.
3.5 In no event shall be liable for any incidental or consequential damages. Some states do not allow the exclu-
LTO
sion or limitation of incidental or consequential damages, so the above exclusion or limitation may not apply to you.
3.6 This warranty gives you the specific rights, and these rights are compatible with the state laws, you may also
have other statutory rights that may vary from state to state.
21
SEIKAKU TECHNICAL GROUP LIMITED
SEKAKU ELECTRON INDUSTRY CO., LTD.
No. 1, Lane 17, Sec. 2, Han Shi West Road, Taichung 40151, Taiwan
http://www.altoproaudio.com Tel: 886-4-22313737
email: alto@altoproaudio.com Fax: 886-4-22346757
All rights reserved to ALTO. All features and content might be changed
without prior notice. Any photocopy, translation, or reproduction of part of this
manual without written permission is forbidden. Copyright 2005 SEIKAKU GROUP
c
NF01109 2.3
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