Alto L-6 User manual

www.altoproaudio.com
Version1.0
MODEL: L-6

CONTENTS
1. Introduction…………………………………………………………….2
2. Specification…………………………………………………………....3
3. Black Diagram………………………………………………………….4
4. Schematic Diagram……………………………………………………5
5. Wiring Diagram………………………………………………………..10
6. PCB Layout…………………………………………………………….11
7. Test Procedure………………………………………………………..16
8. BOM……………………………………………………………………..22

1. Introduction
The L-6 is 2 mono MIC/LINE channels with MIC PREAMPS plus 2 stereo channels perfect for keyboards, MIDI
equipment or other stereo sound sources and a 2-track input/output for recording and playback in a mixer small enough
to carry in your board luggage: you can find great 3-band equalizers in each chhannel,one AUX sends,one stereo returns,
phantom power and accurate peak LED and level meters. Plus of course our ultra low noise circuitry and exceptional
build quality.
- 2 MIC Input Channels with gold plated XLRs and balanced Line Inputs.
- 2 Stereo Input Channels with balanced TRS Jacks.
- Ultra-low noise discrete MIC Preamps with +48 V Phantom Power.
- Extremely high headroom –offering more dynamic range.
- Balanced Inputs for highest signal integrity.
- Warm , natural 3-band EQ on each channels.
- Peak LEDs on each mono Channels and each stereo Channels.
- Adjusts the input sensitivity on each stereo channels.
- 1 AUX Sends per channel for external effects and monitoring.
- Balanced TRS and XLR outputs, Control Room and Headphone Outputs.
- 2-Track Inputs assignable to Main Mix, Control Room / Headphone Outputs.
- Highly accurate 6 segment Bar graph Meters.
- Performance and excellent noise figures
- Rugged construction ensures long life even under the most demanding conditions
- Manufactured under ISO9001 certified management system

Mono input channels
Microphone input Electronically balanced, discrete input configuration
Frequency response 10Hz to 55kHz, +3dB
Distortion(THD & N) 0.005% at +4dBu, 1kHz
Gain range 0dB to 60dB (MIC)
SNR (Signal to Noise Ratio) 115dB
Line input Electronically balanced
Frequency response 10Hz to 55kHz, +3dB
Distortion (THD & N) 0.005% at +4dBu,1kHz
Stereo input channels
Line input Unbalanced
Frequency response 10Hz to 55kHz,+3dB
Distortion (THD & N) 0.005% at +4dBu,1kHz
Impedance
Microphone input 1.4kOhm
All other inputs 10kOhm or greater
Tape out 1kOhm
All other output 120Ohm
Equalization
Hi shelving +15dB @ 12kHz
Mid bell +12dB @ 2.5kHz
Low shelving +15dB @ 80Hz
Main Mix Section
Noise (Bus noise) Fader 0dB, channels muted:100dBr (ref.:+4dBu)
Fader 0dB, all input channels assigned and set to
UNITY gain: (ref.: +4dBu)
Max output +22dBu balanced XLR
+22dBu unbalanced , 1/4” jacks
AUX return gain range OFF to 15dB
AUX send max out +22dBu
DSP section
A/D and D/A converters 24 bit
DSP resolution 24bit
Type of Vibraflange, Funky, Rockabilly, bigstage, vibrato 1-
4, Flanger1-4, Chorus 1-4
Presets 16
Presets 16-positon preset bank selector
Controls FX level, reverb level Clip LED
Power supply (AC/AC adapter)
Main Voltage USA/Canada 100 12V~, 60Hz
Europe 210 230V~,50Hz
U.K./Australia 240V~, 50Hz
Power consumption 15Watts
Physical
Net weight 1.4kg (xxxlb)
Shipping weight Xxx kg (xxxlb)
Dimension (W*D*H) 185m
m
×230mm×35/55m
m

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Titel Size File Date Drawn By
Sheet
RevisionModel No
8-Sep-2003 KEVIN LIN
ALTO MIXING CONSOLE
11of
L-6 BLOCK DIAGRAM VER030701
A2(C)
MONO INPUT CHANNELS ( 1-2 )
2 1 3
MIC IN
+48V
3-BAND EQ
12K2.5K80
SG/OL
LEFT-BUS
RIGHT-BUS
AUX-1
RIGHT BUS LEFT BUS
AUX 1
STEREO INPUT CHANNELS (3-6)
EQ 12K2.5K80
LEFT BUS
RIGHT BUS
AUX 1
STEREO AUX RETURN 1
RIGHT BUS LEFT BUS
AUX 1 AUX SEND
MAIN OUT
LEFT BUS
RIGHT BUS
2
1 3
2TK TO MIX
2
1 3RIGHT BUS
LEFT BUS
TAPE IN
RIGHT
2-TRACK
21
3
2TK TO CTRL ROOM
21
3
PHONES OUTPUT
LEFT METER
RIGHT METER
+/ 15db
3-BAND EQ
12K2.5K80
+/ 15db
3c 5e 1a 4d 2b
LEFT 3c
5e 1a 4d 2b
RIGHT
MAIN MIX
AUX SEND1
T R S
MAIN MIX LEFT
T R S
MAIN MIX RIGHT
T R S
CONTROL ROOM OUTPUT
LEFT
T R S
RIGHT
T R S
PHONES
T R S
& PHONES
CONTROL ROOM
LEFT
TAPE OUT
LEVEL
AUX RETURN1
T
R
S
RN TN
T
R
S
RN TN
PAN
PHANTOM
LINE IN
GAIN
-
+
POWER
-
+
-
+
LO MID HI
1 2 1 2
AUX1
LEVEL
POST
PRE
BALANCE
AUX1
LEVEL
LO MID HI
SG/OL
3c 5e 1a 4d 2b
LEFT(MONO)3c
5e 1a 4d 2b
RIGHT
T
R
S
RN TN
T
R
S
RN TN
-
+
-
+
MIC GAIN:0~60dB LINE IN TRIM:+15dB~-45dB
EFX SEND
DSP BOARD
PRESETS
FX LEVEL
REVERB LEVEL
EFX SEND
LEFT-BUS
RIGHT-BUS
AUX-1
EFX SEND
AUX 1
AUX1
1 2 1 2
POST
PRE