LTO L-8 Service Manual
Service Manual
www.altoproaudio.com
Version: 1.1
Model: L-8 (8-CHANNEL MIXING CONSOLE
WITH DIGITEL EFFECTS)
CONTENTS
1. Specification
2. Block Diagram
3. Schematic Diagram
4. Printed Circuit Board
5. Wiring Diagram
6. Test Procedure
7. Electrical Parts List
8. Exploded Views & Mechanical Parts List
9. Notes
8. TECHNICAL SPECIFICATION
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
Sensitivity range +15dBu to 45dBu
Stereo input channels
Line input unbalanced
Frequency response 10Hz to 55kHz, 3dB
+
Distortion (THD & N) 0.005% at +4dBu, 1kHz
Impedances
Microphone input 1.4kOhm
Channel Insert return 2.5kOhm
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
Low Cut filter 75Hz, 18dB/oct.
Main Mix Section
Noise (Bus noise) Fader 0 dB, channels muted: 100dBr (ref.:+4dBu)
Fader 0dB, all input channels assigned
and set to UNITY gain: 90dBr (ref.:+4dBu)
Max output +22dBu balanced XLR,
+22dBu unbalanced, 1/4" jacks
AUX Return gain range OFF to +20dB
AUX Sends max out +22dBu
DSP SECTION
A/D and D/A converters 24 bit
DSP resolution 24 bit
Type of effects Hall, Room, Vocal & Plate REVERBS
Mono & Stereo DELAY (max DELAY TIME 500ms)
Chorus, Flanger & Vibrato MODULATIONS
REV+DELAY, REV+CHORUS, REV+FLANGER, REV+VIBRATO combinations
Presets 256
Controls 16-position PRESET BANK Selector
16-position VARIATION selector
CLIP LED
MUTE SWITCH with LED indicator
Power supply
Main voltage USA/Canada 100 120V~, 60Hz
Europe 210 230V~, 50Hz
U.K./Australia 240V~, 50Hz
Power Consumption 25watts
Fuse 100 120V~ : T500mAL
210 240V~ : T250mAL
Main connection Standard IEC receptacle
Physical
Net weight 2.4Kg (5.29lb)
Shipping weight 3.5Kg (7.72lb)
Dimension (W D H) 245mm 268mm 24/73mm (9.64" 10.54" 0.94"/2.87")
1 2 3 4 5 6 78
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KEVIN LIN.
ALTO MIXING CONSOLE
11of
L-8 BLOCK DIAGRAM
VER030118
A2(C)
MONO INPUT CHANNELS ( 1-4 )
213
MIC IN
+48V
3-BAND EQ
12K2.5K80
HI PASS
2
1
3
LO CUT
SG/OL
LEFT-BUS
RIGHT-BUS
AUX-1
AUX-2
RIGHT-BUS
LEFT-BUS
AUX-1
AUX-2
STEREO INPUT CHANNELS (5-8)
EQ
12K2.5K80
LEFT-BUS
RIGHT-BUS
AUX-1
AUX-2
LEFT-BUS
RIGHT-BUS
STEREO AUX RETURN 2
RIGHT-BUS
LEFT-BUS
AUX-1
AUX SEND
AUX-2
MAIN OUT
LEFT-BUS
RIGHT-BUS
2
1
3
2TK TO MIX
2
1
3RIGHT-BUS
LEFT-BUS
TAPE IN
RIGHT
2-TRACK
2
1
3
2TK TO CTRL ROOM
2
1
3
PHONES OUTPUT
LEFT METER
RIGHT METER
75Hz
+/-15db
3-BAND EQ
12K2.5K80
+/-15db
3c5e1a4d2b
LEFT
3c5e1a4d2b
RIGHT
MAIN MIX
AUX SEND1
TRS
AUX SEND2
TRS
MAIN MIX LEFT
TRS
MAIN MIX RIGHT
TRS
CONTROL ROOM OUTPUT
LEFT
TRS
RIGHT
TRS
PHONES
TRS
& PHONES
CONTROL ROOM
LEFT
TAPE OUT
213
213
LEVEL
AUX RETURN2
STEREO AUX RETURN 1
3c5e1a4d2b
LEFT(MONO)
3c5e1a4d2b
RIGHT
AUX RETURN1
-
+
T
RSRN
TN
T
RSRN
TN
T
RSRN
TN
T
RSRN
TN
PAN
PHANTOM
LINE IN
GAIN
-
+
POWER
-
+
-
+
-
+
LO MID HI
1 2
1 2
AUX1
AUX2
LEVEL
POST
PRE
BALANCE
AUX1
AUX2
LEVEL
LO MID HI
SG/OL
3c5e1a4d2b
LEFT(MONO)
3c5e1a4d2b
RIGHT
T
RSRN
TNTRSRN
TN
-
+
-
+
213
MIC5 IN
+48V
PHANTOM
GAIN
-
+
POWER
CHANNEL 5,6 ONLY
3c5e1a4d2b
INSERT
T
RSRN
TN
MIC GAIN:0~60dB
LINE IN TRIM:+15dB~-45dB
EFX SEND
DSP BOARD
PRESETS
VARIATIONS
MUTE
DSP FOOTSWITCH
EFX SEND
LEFT-BUS
RIGHT-BUS
AUX-1
AUX-2
EFX SEND
AUX-1
AUX1
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KEVIN LIN.
INPUT STAGE
41of
ALTO L-8
VER030113
A2
EQ HI
12KHZ
C131
18n(M)
VR2
B50K
R151
6K8
VR4
B50K
R150
6K8
LO
R47
10K
C87
47u/25V
5
6
7
U3B
4580M
R220
1M
C179
22P
R212
1K1
VR3
B50K
R137
1K3
MID
R196
910R
C155
12n(M)
R197
910R
C139
33n(M)
C140
33n(M)
C171
12n(M)
C163
18n(M)
C88
47u/25V
R285
5K1
VR6
W50K
AUX-1
R228
68K
R248
4K7
C195
2.2u/50V
R152
6K8
TR2
BR
TR1
BR
R264
1K5
+VCC
LD1
RED
R236
30K
3
2
1
U3A
4580M
VR8
W50K
PEAK
C89
47u/25V
R256
3K9
R270
36K
C180
22P
VR5
W50K
C90
47u/25V
R284
5K1
AUX-2
LEVEL
AUX-POST
VR7A
JQ10K
VR7B
JQ10K
R287
5K1
R286
5K1
LEFT-BUS
RIGHT-BUS
PAN
PGND
AUX-PRE
80HZ
2.5K
EQ HI
12KHZ
C132
18n(M)
VR10
B50K
R155
6K8
VR12
B50K
R154
6K8
LO
R55
10K
C94
47u/25V
5
6
7
U6B
4580M
R221
1M
C181
22P
R213
1K1
VR11
B50K
R139
1K3
MID
R198
910R
C156
12n(M)
R199
910R
C141
33n(M)
C142
33n(M)
C172
12n(M)
C164
18n(M)
C95
47u/25V
R289
5K1
VR14
W50K
AUX-1
R229
68K
R249
4K7
C196
2.2u/50V
R156
6K8
TR4
BR
TR3
BR
R265
1K5
+VCC
LD2
RED
R237
30K
3
2
1
U6A
4580M
VR16
W50K
PEAK
C96
47u/25V
R257
3K9
R271
36K
C183
22P
VR13
W50K
C98
47u/25V
R288
5K1
AUX-2
LEVEL
AUX-POST
VR15A
JQ10K
VR15B
JQ10K
R291
5K1
R290
5K1
LEFT-BUS
RIGHT-BUS
PAN
PGND
AUX-PRE
80HZ
2.5K
EQ HI
12KHZ
C133
18n(M)
VR18
B50K
R159
6K8
VR20
B50K
R158
6K8
LO
R63
10K
C101
47u/25V
5
6
7
U9B
4580M
R222
1M
C182
22P
R214
1K1
VR19
B50K
R141
1K3
MID
R200
910R
C157
12n(M)
R201
910R
C143
33n(M)
C144
33n(M)
C173
12n(M)
C165
18n(M)
C103
47u/25V
R293
5K1
VR22
W50K
AUX-1
R230
68K
R250
4K7
C197
2.2u/50V
R160
6K8
TR6
BR
TR5
BR
R266
1K5
+VCC
LD3
RED
R238
30K
3
2
1
U9A
4580M
VR24
W50K
PEAK
C97
47u/25V
R258
3K9
R272
36K
C184
22P
VR21
W50K
C106
47u/25V
R292
5K1
AUX-2
LEVEL
AUX-POST
VR23A
JQ10K
VR23B
JQ10K
R295
5K1
R294
5K1
LEFT-BUS
RIGHT-BUS
PAN
PGND
AUX-PRE
80HZ
2.5K
EQ HI
12KHZ
C134
18n(M)
VR26
B50K
R163
6K8
VR28
B50K
R162
6K8
LO
R71
10K
C102
47u/25V
5
6
7
U12B
4580M
R223
1M
C185
22P
R215
1K1
VR27
B50K
R143
1K3
MID
R202
910R
C158
12n(M)
R203
910R
C145
33n(M)
C146
33n(M)
C174
12n(M)
C166
18n(M)
C104
47u/25V
R298
5K1
VR30
W50K
AUX-1
R231
68K
R251
4K7
C198
2.2u/50V
R164
6K8
TR8
BR
TR7
BR
R267
1K5
+VCC
LD4
RED
R239
30K
3
2
1
U12A
4580M
VR32
W50K
PEAK
C105
47u/25V
R259
3K9
R273
36K
C186
22P
VR29
W50K
C107
47u/25V
R297
5K1
AUX-2
LEVEL
AUX-POST
VR31A
JQ10K
VR31B
JQ10K
R296
5K1
R299
5K1
LEFT-BUS
RIGHT-BUS
PAN
PGND
AUX-PRE
80HZ
2.5K
84
U3C
4580M
84
U6C
4580M
C205
100n
C206
100n
+VCC
-VCC
C289
100n
C290
100n
84
U12C
4580M
84
U9C
4580M
J2
POST
(PRE)
J1
POST
(PRE)
J3
POST
(PRE)
J4
POST
(PRE)
C295
100n
C296
100n
C297
100n
C298
100n
(SOLTON 1K2)用
C319
47u/25V
C318
47u/25V
C320
47u/25V
C321
47u/25V
EQ HI
C135
18n(M)
VR34A
B50K
R167
6K8
VR36A
B50K
R166
6K8
LO
R96
10K
C111
47u/25V
3
2
1
U16A
4580M
R224
1M
C187
22P
R216
1K1
VR35A
B50K
R145
1K3
MID
R204
910R
C159
12n(M)
R205
910R
C147
33n(M)
C148
33n(M)
C175
12n(M)
C167
18n(M)
C112
47u/25V
R312
5K1
VR38
W50K
AUX-1
R232
47K
R254
4K7
C199
2.2u/50V
R170
6K8
TR10
BR
TR9
BR
R268
1K5
+VCC
LD5
RED
R244
22K
3
2
1
U17A
4580M
VR40A
W50K
PEAK
C113
47u/25V
R260
3K9
R281
36K
C188
22P
VR37
W50K
C116
47u/25V
R313
5K1
AUX-2
LEVEL
AUX-POST
VR39A
JQ10K
VR39B
JQ10K
R311
5K1
R310
5K1
LEFT-BUS
RIGHT-BUS
BAL
PGND
AUX-PRE
80HZ
2.5K
EQ HI
C136
18n(M)
VR34B
B50K
R169
6K8
VR36B
B50K
R168
6K8
LO
R111
10K
C119
47u/25V
5
6
7
U16B
4580M
R225
1M
C190
22P
R217
1K1
VR35B
B50K
R146
1K3
MID
R206
910R
C160
12n(M)
R207
910R
C149
33n(M)
C150
33n(M)
C176
12n(M)
C168
18n(M)
C120
47u/25V
80HZ
2.5K
R97
10K
R98
10K
R233
47K
R245
22K
5
6
7
U17B
4580M
VR40B
W50K
C114
47u/25V
R261
3K9
R280
36K
C189
22P
C115
47u/25V
LEVEL
R100
10K
R99
10K
J5
POST
(PRE)
EQ HI
12KHZ
C137
18n(M)
VR41A
B50K
R172
6K8
VR43A
B50K
R171
6K8
LO
R120
10K
C124
47u/25V
3
2
1
U19A
4580M
R226
1M
C191
22P
R218
1K1
VR42A
B50K
R147
1K3
MID
R208
910R
C161
12n(M)
R209
910R
C151
33n(M)
C152
33n(M)
C177
12n(M)
C169
18n(M)
C127
47u/25V
R317
5K1
VR45
W50K
AUX-1
R235
47K
R255
4K7
C200
2.2u/50V
R173
6K8
TR12
BR
TR11
BR
R269
1K5
+VCC
LD6
RED
R246
22K
3
2
1
U20A
4580M
VR47A
W50K
PEAK
C121
47u/25V
R262
3K9
R283
36K
C192
22P
VR44
W50K
C130
47u/25V
R314
5K1
AUX-2
LEVEL
AUX-POST
VR46A
JQ10K
VR46B
JQ10K
R316
5K1
R315
5K1
LEFT-BUS
RIGHT-BUS
BAL
PGND
AUX-PRE
80HZ
2.5K
EQ HI
12KHZ
C138
18n(M)
VR41B
B50K
R175
6K8
VR43B
B50K
R174
6K8
LO
R125
10K
C125
47u/25V
5
6
7
U19B
4580M
R227
1M
C193
22P
R219
1K1
VR42B
B50K
R148
1K3
MID
R210
910R
C162
12n(M)
R211
910R
C153
33n(M)
C154
33n(M)
C178
12n(M)
C170
18n(M)
C126
47u/25V
80HZ
2.5K
R121
10K
R122
10K
R234
47K
R247
22K
5
6
7
U20B
4580M
VR47B
W50K
C128
47u/25V
R263
3K9
R282
36K
C194
22P
C129
47u/25V
LEVEL
R124
10K
R123
10K
J6
POST
(PRE)
PCB# L8MN1.PCB
RTN-CH1
RTN-CH2
RTN-CH3
RTN-CH4
PRE-CH5
PRE-CH6
PRE-CH7
PRE-CH8
84
U16C
4580M
84
U17C
4580M
C217
100n
C218
100n
C219
100n
C220
100n
84
U20C
4580M
84
U19C
4580M
C207
100n
C208
100n
C201
100n
C202
100n
MAIN IN-OUTPUT
L8MN1.S01
LED DISPLAY
L8MN1.S02
L8MN1 (1/3)
UDASP IN-OUT SECTION
L8MN1.S03
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KEVIN LIN.
STEREO AUX & SENDS & MAIN OUT & 2TK & CTRL R & PHONES
32of
ALTO L-8
VER030120
A2(C)
C265
100P
C241
47u/25V
R77
8K2
R241
22K
C266
100P
C239
47u/25V
R78
8K2
R240
22K
VR48B
W50K
VR48A
W50K
3
2
1
U21A
4580M
5
6
7
U21B
4580M
84
U23C
4580M
R318
56K
C223
22P
C243
47u/25V
R302
5K1
R320
56K
C269
22P
C245
47u/25V
R304
5K1
5
6
7
U25B
4580M
3
2
1
U25A
4580M
84
U26C
4580M
R15
5K1
C13
22P
LEFT-BUS
RIGHT-BUS
C260
22P
R306
5K1
R305
5K1
84
U21C
4580M
R301
5K1
C234
47u/25V
C233
47u/25V
5
6
7
U26B
4580M
3
2
1
U26A
4580M
84
U27C
4580M
R277
36K
C264
22P
R16
3K9
C8
47u/25V
VR51B
W50K
MAIN MIX
VR51A
W50K
R276
36K
C263
22P
R339
3K9
C236
47u/25V
C237
47u/25V
C238
47u/25V
R76
10K
R75
10K
84
U24C
4580M
C203
100n
C204
100n
+VCC
-VCC
C211
100n
C212
100n
C251
47u/25V
R188
20K
3
2
1
U23A
4580M
R189
20K
C282
22P
C252
47u/25V
R85
10K
R309
5K1
C246
47u/25V
R186
20K
5
6
7
U23B
4580M
R187
20K
C281
22P
C248
47u/25V
R81
10K
R308
5K1
LEFT-BUS
RIGHT-BUS
2TK TO MIX
R348
27K
2TK TO
R349
27K
3
2
1
U27A
4580M
5
6
7
U27B
4580M
VR50B
W50K
VR50A
W50K
C249
47u/25V
C255
47u/25V
R344
3K9
R345
3K9
R278
36K
R279
36K
C225
22P
C226
22P
C250
47u/25V
C256
47u/25V
R82
10K
R86
10K
84
U25C
4580M
AUX RETURN 1
R-METER
EFX TO AUX1
R184
20K
C231
47u/25V
3
2
1
U24A
4580M
R275
36K
C222
22P
L-METER
AUX-1
R185
20K
C232
47u/25V
5
6
7
U24B
4580M
R274
36K
C221
22P
AUX-2
C271
100P
C272
100P
MAIN MIX
ROOM
LEFT-BUS
RIGHT-BUS
LEFT
RIGHT
R73
39K
R74
39K
CONTROL
PHONES/
CTRL ROOM
C14
100P
C19
47u/25V
R7
10K
C20
100P
C5
47u/25V
R8
10K
VR49B
W50K
VR49A
W50K
3
2
1
U1A
4580M
5
6
7
U1B
4580M
R319
36K
C224
22P
C244
47u/25V
R27
10K
R321
36K
C270
22P
C247
47u/25V
AUX RETURN 2
C22
22P
C45
47u/25V
R39
5K1
R72
10K
R38
5K1
5
6
7
U31B
4580M
C24
22P
C286
47u/25V
R375
5K1
R41
51K
R93
5K1
1
2
3
4
5
6
7
8
CN0
2.5-8P
PGND
+VCC-VCCPH PWR
C305
100n
C306
100n
C307
100n
C308
100n
C309
100n
C310
100n
C311
100n
C312
100n
MAIN-L-2
MAIN-R-2
LEFT-BUS
RIGHT-BUS
AUX-1
AUX-2
AUX-SEND1
AUX-SEND2
AUX-RTN1-L
AUX-RTN1-R
AUX-RTN2-L
AUX-RTN2-R
2TK-IN-L
2TK-IN-R
2TK TO CR-R
2TK TO CR-L
SW9A
PS-22E85L
SW9B
PS-22E85L
RIGHT-BUS
LEFT-BUS
MAIN-L-3
MAIN-R-3
SW10B
PS-22E85L
MAIN-R-2
2TK TO CR-R
2TK TO CR-L
MAIN-L-2
SW10A
PS-22E85L
CTRL-R-L
CTRL-R-R
CTRL-R-L
CTRL-R-R
1
2
3
4
5
6
7
8
9
10
11
12
CN3
2.5-12P-B24
(TO L8MN1)
RTN-CH1
RTN-CH2
RTN-CH3
RTN-CH4
PRE-CH5
PRE-CH6
PRE-CH7
PRE-CH8
1
2
3
4
5
6
7
8
9
10
11
12
CN4
2.5-12P-B24
(TO L8MN1)
MAIN-R-2
MAIN-R-3
MAIN-L-2
MAIN-L-3
+VCC
-VCC
1
2
3
4
5
6
7
8
CN5
2.5-8P-B24A
(TO L8MN1)
AUX-RTN1-L
AUX-SEND1
AUX-RTN1-R
AUX-SEND2
AUX-RTN2-L
CTRL-R-L
AUX-RTN2-R
CTRL-R-R
2TK-IN-L
2TK-IN-R
PH PWR
FOOTSW
+VCC
-VCC
EFXRTN-L
EFXRTN-R
AUX-SEND2
AUX-SEND1
MAIN-L-2
MAIN-L-3
MAIN-R-2
MAIN-R-3
2TK-IN-L
2TK-IN-R
+5VD
L8MN1 (2/4)
DGND
3
2
1
U31A
4580M
3
2
1
U2A
4580M
C6
47u/25V
C7
47u/25V
5
6
7
U2B
4580M
R10
10K
C12
22P
R9
10K
C11
22P
R11
10K
R12
5K1
R13
27K
R14
27K
R26
3K9
C10
47u/25V
R25
3K9
C9
47u/25V
AUX-1
84
U1C
4580M
84
U2C
4580M
C15
100n
C16
100n
C17
100n
C18
100n
VR9
W50K
(AUX RETURN2)
84
U31C
4580M
C340
100n
C341
100n
1 2 34
A
B
C
D
4
321
D
C
B
A
L8MN1.S02
Titel
Size
File:
Date:
Drawn By:
Sheet
RevisionModel No:
5-Oct-2003
KEVIN LIN.
DISPLAY STAGE
43of
ALTO L-8
VER030120
A4
8
9
14
U35C
LM339
1
6
7
U35B
LM339
1
6
7
U38B
LM339
8
9
14
U38C
LM339
8
9
14
U36C
LM339
1
6
7
U36B
LM339
1
6
7
U39B
LM339
8
9
14
U39C
LM339
LD10
GR
LD11
GR
LD12
GR
LD13
GR
LD14
GR
LD15
GR
LD16
GR
LD17
GR
R350
120R
R355
120R
R356
470R
R359
330R
R357
470R
R360
330R
R358
470R
R361
510R
R362
620R
+VCC
R354
56R
-VCC
PGND
10
11
13
U35D
LM339
5
4
2
U35A
LM339
5
4
2
U38A
LM339
10
11
13
U38D
LM339
10
11
13
U36D
LM339
5
4
2
U36A
LM339
5
4
2
U39A
LM339
10
11
13
U39D
LM339
LD22
GR
LD23
GR
LD24
GR
LD25
GR
LD26
GR
LD27
GR
LD28
GR
LD29
GR
-VCC
LEFT METER
(-30) (-20) (-10) (-7) (-4) (-2) (0) (+2)
3
2
1
U30A
4580M
R367
100K
R371
0R0
R369
100K
C283
47u/25V
PGND
10
11
13
U37D
LM339
5
4
2
U37A
LM339
5
4
2
U40A
LM339
10
11
13
U40D
LM339
LD30
GR
LD31
GR
LD32
YEL
LD33
RED
8
9
14
U37C
LM339
1
6
7
U37B
LM339
1
6
7
U40B
LM339
8
9
14
U40C
LM339
LD18
GR
LD19
GR
LD20
YEL
LD21
RED
R363
1K3
R364
2K
R365
5K6
R366
27K
TR13
HR
+VCC
D1A
DA204K
D1B
DA204K
TR14
HR
R353
120R
R351
470R
R352
470R
R87
10K
PGND
5
6
7
U30B
4580M
R368
100K
R372
0R0
R370
100K
C284
47u/25V
PGND
L-METER
R-METER
312
U36E
LM339
312
U37E
LM339
312
U35E
LM339
312
U38E
LM339
312
U39E
LM339
84
U30C
4580M
C213
100n
C214
100n
R373
47R
R374
47R
C257
47u/25V
C258
47u/25V
+VCC
-VCC
PGND
LD8
RED
LD7
GR
R253
4K7
R252
2K
PGND
PGND
PH PWR
31
D3A
DA204K
D3B
DA204K
31
D2A
DA204K
D2B
DA204K
(+4) (+7) (+10) (+18)
PWR ON
PHANTOM
+VCC
312
U40E
LM339
R428
10K
R427
10K
PGNDPGND
L8MN1 (3/4)
C342
47P
C343
47P
1 2 3 4 5 6 78
A
B
C
D
8
7654321
D
C
B
A
L8MN1.S03
Titel
Size
File:
Date:
Drawn By:
Sheet
RevisionModel No:
5-Oct-2003
KEVIN LIN.
UDASP IN/OUT SECTION
44of
ALTO L-8
VER030217
A2(C)
C39
22P
C61
1.5nF 2.5%
C50
4.7uF
5
6
7
U44B
4580M
R24
10K
R68
68R
R17
3K3
R19
10K
R22
10K
3
2
1
U44A
4580M
R1
10K
C40
22P
C62
1.5nF 2.5%
C52
4.7uF
5
6
7
U45B
4580M
R46
10K
R6
68R
R18
3K3
R20
10K
R23
10K
3
2
1
U45A
4580M
R48
10K
3
5
7
RL1B
RY-5W-K
4
6
8
RL1C
RY-5W-K
EFXRTN-L
EFXRTN-R
C59
4.7uF
5
6
7
U46B
4580M
3
2
1
U46A
4580M
C60
1.5nF 2.5%
R21
10K
R2
10K
C49
22P
R56
10K
C38
22P
R54
2K2
R53
10K
EFXRTN-L
EFXRTN-R
AUX-SEND2
(MUTE)
(MUTE)
12
34
56
78
910
1112
1314
1516
CN6
HEADER 8X2
1
2
3
4
COM
EN2
SDB161PVB15FS
1
2
3
4
COM
EN1
SDB161PVB15FS
1 2
3 4
5 6
7 8
AR1
680R*4
1 2
3 4
5 6
7 8
AR2
680R*4
DGND DGND
+5VD
DGND
+5VD
CLK
4
J
2
S5R
1
Q
6
Q7K
3
U48A
74HC109
+5VD
R50
10K
D7
BAS316
12
U49A
74HC14
C3
1uF
DGND
+5VD
R52
10K
D15
BAS316
C4
1uF
DGND
R80
220R
R79
220R
SW1
PS-22E85NL
DGND
(MUTE)
R67
10K
R66
10K
TR16
BR
DGNDDGND
12
RL1A
RY-5W-K
+5VD
C51
100N
D9
RLS4148
R65
220R
R49
7K5
LD54
RED
FOOTSW
84
U44C
4580M
84
U46C
4580M
84
U45C
4580M
C29
100N
C30
100N
C31
100N
C32
100N
+VCC
-VCC
3 4
U49B
74HC14
5 6
U49C
74HC14
8 9
U49D
74HC14
12 13
U49F
74HC14
147
U49G
74HC14
DGND
CLK
12
J
14
S11R
15
Q
10
Q9K
13
U48B
74HC109
DGND
168
U48C
74HC109
C36
100N
C35
100N
+5VD
DGND
C86
10uF
UDASP IN/OUT SECTION
JP1
PGND
1
2
4
8
1
2
4
8
DGND
3
2
1
U47A
LM393
5
6
7
U47B
LM393
R90
4K7
+VCC
R114
1K
C37
100N
R112
1M
R113
2M2
R5
820K
D10A
RB400D
PEAK(FLICKER)
MUTE(GLOW)
PRESETVARIATION
84
U47C
LM393
TR17
BR
DGND
R118
10K
R3
10K
DGND
OUT3RS
4
TG
2
TH
6
CTR5DS
7
U43A
NE555
C1
100N
DGND
+5VD
R4
47K
C118
10uF
DGND
81
U43B
NE555
C117
33P
C2
33P
10K CHANGE TO 3K3
L8MN1 (4/4)
EFX-SEED
D16
DA202K
1 2 3 4 5 6 7 8
A
B
C
D
8
7654321
D
C
B
A
L8PU2.Sch
Titel
Size
File:
Date:
Drawn By:
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RevisionModel No:
5-Oct-2003
KEVIN LIN.
INPUT/OUTPUT STAGE
11of
ALTO L-8 VER030120A2(C)
R13
4R7
R14
4R7
C6
1n
C5
1n
C51
1000u/10V
R11
4R7
VR1
2C10K
R12
1K50
R50
2K49
3
2
1
U2A
4580M
R46
5K11
C49
22P
C85
47u/25V
5
6
7
U2B
4580M
R131
62K
R136
1K3
R177
20K
R176
20K
C86
47u/25V
C70
0.22u/50V
C71
0.22u/50V
C72
0.22u/50V
R149
6K8
LO CUT
2
1
3
4
X5
JY-5042-030G
3c
5e
1a
4d
2b
X6
JY-6351G-02-250
T
R
S
RN
TN
C1
330P
C15
10n
R388
470R
R45
2K49
C29
47u/63V
C30
47u/63V
R29
6K34
R30
6K34
C20
22u/35V
C19
22u/35V
R2
6K81
R1
6K81
3
2
1
U5A
4580M
R54
5K11
C54
22P
C91
47u/25V
5
6
7
U5B
4580M
R132
62K
R138
1K3
R179
20K
R178
20K
C93
47u/25V
C73
0.22u/50V
C74
0.22u/50V
C75
0.22u/50V
R153
6K8
2
1
3
4
X7
JY-5042-030G
3c
5e
1a
4d
2b
X8
JY-6351G-02-250
T
R
S
RN
TN
3
2
1
U8A
4580M
R62
5K11
C58
22P
C92
47u/25V
5
6
7
U8B
4580M
R133
62K
R140
1K3
R182
20K
R180
20K
C100
47u/25V
C76
0.22u/50V
C77
0.22u/50V
C78
0.22u/50V
R157
6K8
2
1
3
4
X9
JY-5042-030G
3c
5e
1a
4d
2b
X10
JY-6351G-02-250
T
R
S
RN
TN
3
2
1
U11A
4580M
R67
5K11
C59
22P
C99
47u/25V
5
6
7
U11B
4580M
R134
62K
R142
1K3
R183
20K
R181
20K
C108
47u/25V
C79
0.22u/50V
C80
0.22u/50V
C81
0.22u/50V
R161
6K8
2
1
3
4
X11
JY-5042-030G
3c
5e
1a
4d
2b
X12
JY-6351G-02-250
T
R
S
RN
TN
LINE IN1
LINE IN2
LINE IN3
LINE IN4
MIC 1
MIC 2
MIC 3
MIC 4
84
U2C
4580M
C203
100n
C201
100n
C204
100n
C202
100n
+VCC
-VCC
C205
100n
C206
100n
84
U5C
4580M
84
U8C
4580M
84
U11C
4580M
PH PWR
C287
100n
C288
100n
C289
100n
C290
100n
C291
100n
C292
100n
C293
100n
C294
100n
C295
100n
C296
100n
C297
100n
C298
100n
C299
100n
C300
100n
C301
100n
C302
100n
C43
100n
C45
100n
TR15
HR
TR16
A1316
R15
1K50
-VCC
+VCC
R52
2K49
R51
2K49
C16
10n
R389
470R
TR25
HR
TR26
A1316
-VCC
+VCC
3
2
1
U1A
4580M
5
6
7
U1B
4580M
C48
22P
C50
22P
R403
5K11
R402
5K11
R58
2K49
-VCC
R57
2K49
TR35
HR
+VCC
R53
2K49
D4
BAS316
+VCC
R28
20K
-VCC
R417
10K0
R418
10K0
R404
5K11
C57
22P
84
U1C
4580M
84
U4C
4580M
84
U7C
4580M
84
U10C
4580M
R48
4R7
R49
4R7
C8
1n
C7
1n
C52
1000u/10V
R398
4R7
VR9
2C10K
R16
1K50
R60
2K49
C2
330P
C17
10n
R390
470R
R59
2K49
C32
47u/63V
C33
47u/63V
R31
6K34
R32
6K34
C23
22u/35V
C21
22u/35V
R4
6K81
R3
6K81
PH PWR
TR17
HR
TR18
A1316
R17
1K50
-VCC
+VCC
R65
2K49
R64
2K49
C35
10n
R391
470R
TR27
HR
TR28
A1316
-VCC
+VCC
3
2
1
U4A
4580M
5
6
7
U4B
4580M
C60
22P
C61
22P
R406
5K11
R405
5K11
R94
2K49
-VCC
R91
2K49
TR36
HR
+VCC
R56
2K49
D5
BAS316
+VCC
R40
20K
-VCC
R419
10K0
R420
10K0
R407
5K11
C62
22P
R19
4R7
R20
4R7
C10
1n
C9
1n
C53
1000u/10V
R399
4R7
VR17
2C10K
R18
1K50
R61
2K49
C3
330P
C31
10n
R392
470R
R127
2K49
C34
47u/63V
C36
47u/63V
R33
6K34
R34
6K34
C26
22u/35V
C25
22u/35V
R6
6K81
R5
6K81
PH PWR
TR19
HR
TR20
A1316
R21
1K50
-VCC
+VCC
R66
2K49
R129
2K49
C38
10n
R393
470R
TR29
HR
TR30
A1316
-VCC
+VCC
3
2
1
U7A
4580M
5
6
7
U7B
4580M
C64
22P
C82
22P
R409
5K11
R408
5K11
R144
2K49
-VCC
R126
2K49
TR37
HR
+VCC
R90
2K49
D6
BAS316
+VCC
R42
20K
-VCC
R421
10K0
R422
10K0
R410
5K11
C63
22P
R24
4R7
R25
4R7
C12
1n
C11
1n
C55
1000u/10V
R400
4R7
VR25
2C10K
R22
1K50
R128
2K49
C4
330P
C40
10n
R394
470R
R191
2K49
C37
47u/63V
C39
47u/63V
R35
6K34
R36
6K34
C28
22u/35V
C27
22u/35V
R8
6K81
R7
6K81
PH PWR
TR21
HR
TR22
A1316
R23
1K50
-VCC
+VCC
R130
2K49
R379
2K49
C44
10n
R395
470R
TR31
HR
TR32
A1316
-VCC
+VCC
3
2
1
U10A
4580M
5
6
7
U10B
4580M
C84
22P
C110
22P
R413
5K11
R412
5K11
R380
2K49
-VCC
R165
2K49
TR38
HR
+VCC
R135
2K49
D7
BAS316
+VCC
R43
20K
-VCC
R423
10K0
R424
10K0
R411
5K11
C83
22P
MIC GAIN=0~-60dB
LINE IN GAIN=+15~-45dB
INS-CH1
2
1
3
4
X13
JY-5042-030G
3c
5e
1a
4d
2b
X14
JY-6351G-02-250
T
R
S
RN
TN
LINE IN 5/6
MIC 5
3c
5e
1a
4d
2b
X15
JY-6351G-02-250
T
R
S
RN
TN
LEFT(MONO)
RIGHT
3
2
1
U15A
4580M
R108
10K
C66
22P
C117
47u/25V
R105
10K
C227
22P
R101
10K
C275
100P
R102
10K
C273
100P
5
6
7
U15B
4580M
R109
10K
C67
22P
C118
47u/25V
R106
10K
C228
22P
R103
10K
C276
100P
R104
10K
C274
100P
R107
10K
R110
10K
R88
4R7
R89
4R7
C14
1n
C13
1n
C56
1000u/10V
R401
4R7
VR33
2C10K
R26
1K50
R382
2K49
3
2
1
U14A
4580M
R95
5K11
C65
22P
C109
47u/25V
R190
20K
C18
330P
C46
10n
R396
470R
R381
2K49
C41
47u/63V
C42
47u/63V
R10
6K81
R9
6K81
PH PWR
TR23
HR
TR24
A1316
R27
1K50
-VCC
+VCC
R384
2K49
R383
2K49
C47
10n
R397
470R
TR33
HR
TR34
A1316
-VCC
+VCC
3
2
1
U13A
4580M
5
6
7
U13B
4580M
C315
22P
C316
22P
R415
5K11
R414
5K11
R387
2K49
-VCC
R386
2K49
TR39
HR
+VCC
R385
2K49
D8
BAS316
+VCC
R44
20K
-VCC
R425
10K0
R426
10K0
R416
5K11
C317
22P
R192
20K
R193
20K
TP7
TP8
3
2
1
U16A
4580M
5
6
7
U16B
4580M
R38
10K
R37
10K
C22
47u/25V
C24
47u/25V
PRE-CH5
PRE-CH6
3c
5e
1a
4d
2b
X16
JY-6351G-02-250
T
S
RN
TN
LINE IN 7/8
3c
5e
1a
4d
2b
X17
JY-6351G-02-250
T
R
S
RN
TN
LEFT(MONO)
RIGHT
3
2
1
U18A
4580M
R118
10K
C68
22P
C122
47u/25V
R116
10K
C229
22P
R112
10K
C279
100P
R113
10K
C277
100P
5
6
7
U18B
4580M
R119
10K
C69
22P
C123
47u/25V
R117
10K
C230
22P
R114
10K
C280
100P
R115
10K
C278
100P
R194
20K
R195
20K
84
U15C
4580M
84
U16C
4580M
84
U14C
4580M
84
U13C
4580M
+VCC
-VCC
3c
5e
1a
4d
2b
X18
JY-6351G-02-250
STEREO AUX
LEFT 1
3c
5e
1a
4d
2b
X19
JY-6351G-02-250
RIGHT 1
RETURN2
STEREO AUX
RETURN1
3c
5e
1a
4d
2b
X20
JY-6351G-02-250
3c
5e
1a
4d
2b
X21
JY-6351G-02-250
RIGHT 2
LEFT 2
(MONO / MASTER)
EFXRTN-L
EFXRTN-R
AUX-RTN2-L
AUX-RTN2-R
AUX-RTN1-R
AUX-RTN1-L
3c
5e
1a
4d
2b
X22
JY-6351G-02-250
AUX SEND1
R324
120R
R323
120R
3c
5e
1a
4d
2b
X23
JY-6351G-02-250
AUX SEND2
R322
120R
R325
120R
T
R
S
RN
TN
T
R
S
RN
TN
AUX-SEND1
AUX-SEND2
R342
1K
R343
1K
L(WHITE)
R(RED)
TAPE IN TAPE OUT
1 4
2 5
3
6
X31
SCP6873NS3232
MAIN-L-2
MAIN-R-2
2TK-IN-L
2TK-IN-R
3
2
1
U29A
BA15218N
5
6
7
U29B
BA15218N
C262
22P
R83
10K
R332
120R
3c
5e
1a
4d
2b
X28
JY-6351G-02-250
R334
120R
PHONES
R331
120R
R330
120R
3
2
1
U28A
BA15218N
5
6
7
U28B
BA15218N
R84
10K
C261
22P
CTRL-R-R
CTRL-R-L
84
U28C
BA15218N
84
U29C
BA15218N
R347
47R
R346
47R
C253
47u/25V
C254
47u/25V
C313
100n
C314
100n
+VCC
-VCC
1
2
3
4
5
6
7
CN2
7P-2.0
(TO L8PU1)
MAIN-R-2
MAIN-L-2
MAIN-R-3
MAIN-L-3
1
2
3
4
5
6
7
8
9
10
11
12
CN3
2.5-12P-B24
(TO L8MN1)
RTN-CH1
RTN-CH2
RTN-CH3
RTN-CH4
PRE-CH5
PRE-CH6
PRE-CH7
PRE-CH8
1
2
3
4
5
6
7
8
9
10
11
12
CN4
2.5-12P-B24
(TO L8MN1)
MAIN-R-2
MAIN-R-3
MAIN-L-2
MAIN-L-3
+VCC
-VCC
1
2
3
4
5
6
7
8
CN5
2.5-8P-B24A
(TO L8MN1)
AUX-RTN1-L
AUX-SEND1
AUX-RTN1-R
AUX-SEND2
AUX-RTN2-L
CTRL-R-L
AUX-RTN2-R
CTRL-R-R
2TK-IN-L
2TK-IN-R
PH PWR
CTRL-R-L
CTRL-R-R
FOOTSW
+VCC
-VCC
EFXRTN-L
EFXRTN-R
3c
5e
1a
4d
2b
X25
JY-6351G-02-250
FOOTSWITCH
FOOTSW
1
2
3
4
5
6
7
8
9
CN1
9P-2.0
(TO L8PU1)
INS-CH1
INS-CH2
INS-CH3
INS-CH4
RTN-CH4
RTN-CH3
RTN-CH2
RTN-CH1
L8PU2
PCB# L8PU2.PCB
SW1A
PS-22E85L
SW1B
PS-22E85L
LO CUT
INS-CH2
SW2A
PS-22E85L
SW2B
PS-22E85L
LO CUT
INS-CH4
SW4A
PS-22E85L
SW4B
PS-22E85L
LO CUT
INS-CH3
SW3A
PS-22E85L
SW3B
PS-22E85L
PRE-CH7
PRE-CH8
C303
100n
C304
100n
84
U18C
4580M
1 2 34
A
B
C
D
4
321
D
C
B
A
3c5e1a
4d
2b
X1
JY-6351G-02-250
T
RSRN
TN
GND-INS
INSERT1
L8PU1.Sch
Titel
Size
File:
Date:
Drawn By:
Sheet
RevisionModel No:
5-Oct-2003
KEVIN LIN.
OUTPUT STAGE (INSERT & MAIN OUTPUT)
11of
ALTO L-8
VER021103
A4
INS1
RTN1
3c5e1a
4d
2b
X2
JY-6351G-02-250
T
RSRN
TN
GND-INS
INSERT2
INS2
RTN2
3c5e1a
4d
2b
X3
JY-6351G-02-250
T
RSRN
TN
GND-INS
INSERT3
INS3
RTN3
3c5e1a
4d
2b
X4
JY-6351G-02-250
T
RSRN
TN
GND-INS
INSERT4
INS4
RTN4
3c5e1a
4d
2b
X8
JY-6351G-02-250
T
RSRN
TN
MAIN R (UNBAL)
3c5e1a
4d
2b
X7
JY-6351G-02-250
T
RSRN
TN
MAIN L (UNBAL)
R7
120R
R6
120R
R11
120R
R5
120R
3c5e1a
4d
2b
X5
JY-6351G-02-250
T
RSRN
TN
CTRL ROOM R
3c5e1a
4d
2b
X6
JY-6351G-02-250
T
RSRN
TN
CTRL ROOM L
R4
120R
R3
120R
R10
120R
R2
120R
(BALANCED)
213
X10
JY-5030-030G
213
X9
JY-5030-030G
R14
120R
MAIN OUT
RIGHT
R21
5K1
LEFT
R13
120R
R23
5K1
R16
120R
R22
5K1
R15
120R
R24
5K1
MAIN-R-2
MAIN-R-3
MAIN-L-2
MAIN-L-3
123456789
CN1
9P-2.0
GND-INS
1234567
CN2
7P-2.0
PCB# L8PU1.PCB
R1
120R
R8
120R
R9
120R
R12
120R
L8PU1
4. PRINTED CIRCUIT DIAGRAM
PCB : L8MN1 Top Overlay
PCB : L8MN1 Top Layer
PCB : L8MN1 Bottom Layer
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