Alto L-8 Service Manual
Service Manual
Model: L-8 (8-CHANNEL MIXING CONSOLE
WITH DIGITEL EFFECTS)
www.altoproaudio.com
Version: 1.1
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.
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
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
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
Dimension (W D H) 245mm 268mm 24/73mm (9.64" 10.54" 0.94"/2.87")
Net weight 2.4Kg (5.29lb)
Shipping weight 3.5Kg (7.72lb)
D
8
AUX SEND
TRS
AUX SEND1
AUX SEND2
TRS
MAIN OUT
TRS
MAIN MIX LEFT
213
TRS
C
LEFT
RIGHT
TAPE OUT
MAIN MIX RIGHT
213
2-TRACK
TAPE IN
B
PHONES
TRS
PHONES OUTPUT
CONTROL ROOM OUTPUT
LEFT
RIGHT
TRS
TRS
A
VER030118
11of
KEVIN LIN
RevisionModel No
Drawn By
Sheet
L-8 BLOCK DIAGRAM
ALTO MIXING CONSOLE
5-Oct-2003
L8MAP Sch
7654321
2
LEVEL
MAIN MIX
AUX-1
AUX-2
EFX SEND
AUX-2
AUX-1
RIGHT-BUS
LEFT-BUS
RIGHT-BUS
LEFT-BUS
PAN
LEVEL
LO CUT
3
AUX1
2
1
12K2.5K80
+/-15db
LO MID HI
3-BAND EQ
LEFT-BUS
EFX SEND
AUX-1
AUX-2
AUX2
PRE
POST
1 2
1 2
RIGHT-BUS
LEFT-BUS
BALANCE
LEVEL
75Hz
SG/OL
HI PASS
12K2.5K80
+/-15db
LO MID HI
3-BAND EQ
2TK TO MIX
1
RIGHT-BUS
12K2.5K80
EQ
3
LEFT-BUS
2
1
AUX2
3RIGHT-BUS
AUX-2
1
3
1
2
2TK TO CTRL ROOM
2
AUX-1
AUX1
SG/OL
3
LEFT-BUS
RIGHT-BUS
& PHONES
CONTROL ROOM
LEFT METER
LEFT-BUS
RIGHT METER
AUX-1
RIGHT-BUS
AUX1
AUX RETURN2
AUX RETURN1
A2(C)
Ttel
Size
Fle
Date
EFX SEND
AUX-2
AUX-1
RIGHT-BUS
LEFT-BUS
GAIN
+
-
213
+48V
POWER
PHANTOM
MONO INPUT CHANNELS ( 1-4 )
MIC IN
LINE N
D
RSRN
3c5e1a4d2b
T
TN
-
CHANNEL 56 ONLY
+
INSERT
MIC GAIN:0~60dB
LINE IN TRIM: 15dB~-45dB
-
T
RSRN
TN
3c5e1a4d2b
STEREO INPUT CHANNELS (5-8)
-
RSRN
3c5e1a4d2b
LEFT(MONO)
C
GAIN
T
TN
RIGHT
PHANTOM
-
RSRN
TN
213
+48V
POWER
MIC5 IN
3c5e1a4d2b
STEREO AUX RETURN 1
-
T
RSRN
3c5e1a4d2b
LEFT(MONO)
B
T
TN
-
RSRN
3c5e1a4d2b
RIGHT
STEREO AUX RETURN 2
-
T
TN
T
RSRN
TN
3c5e1a4d2b
LEFT
DSP BOARD
MUTE
PRESETS
VARIATIONS
RIGHT
A
DSP FOOTSWITCH
1 2 3 4 5 6 78
R311
5K1
R310
5K1
AUX-POST
VR38
W50K
AUX-PRE
R316
5K1
R315
5K1
AUX-POST
VR45
W50K
AUX-PRE
VR37
W50K
VR44
W50K
Sheet
Drawn By:
8
LEFT-BUS
RIGHT-BUS
LEFT-BUS
RIGHT-BUS
AUX-2
AUX-1
AUX-2
AUX-1
RevisionModel No:
VER030113
41of
KEVIN LIN.
D
C
B
A
7654321
VR2
C131
18n(M)
EQ HI
12KHZ
C318
47u/25V
RTN-CH1
D
RTN-CH2
C
RTN-CH3
B
RTN-CH4
A
MID
2.5K
LO
80HZ
EQ HI
12KHZ
C319
47u/25V
MID
2.5K
LO
80HZ
EQ HI
12KHZ
C320
47u/25V
MID
2.5K
LO
80HZ
EQ HI
12KHZ
C321
47u/25V
MID
2.5K
LO
80HZ
1 2 3 4 5 6 78
R212
1K1
R137
1K3
R196
910R
R150
6K8
C139
33n(M)
C132
18n(M)
R213
1K1
(SOLTON 1K2)用
R139
1K3
R198
910R
R154
6K8
C141
33n(M)
C133
18n(M)
R214
1K1
R141
1K3
R200
910R
R158
6K8
C143
33n(M)
C134
18n(M)
R215
1K1
R143
1K3
R202
910R
R162
6K8
C145
33n(M)
MAIN IN-OUTPUT
L8MN1.S01
B50K
VR4
B50K
VR10
B50K
VR12
B50K
VR18
B50K
VR20
B50K
VR26
B50K
VR28
B50K
VR3
B50K
C155
12n(M)
VR11
B50K
C156
12n(M)
VR19
B50K
C157
12n(M)
VR27
B50K
C158
12n(M)
C163
18n(M)
C171
12n(M)
R197
910R
R151
6K8
C140
33n(M)
R47
10K
C164
18n(M)
C172
12n(M)
R199
910R
R155
6K8
C142
33n(M)
R55
10K
C165
18n(M)
C173
12n(M)
R201
910R
R159
6K8
C144
33n(M)
R63
10K
C166
18n(M)
C174
12n(M)
R203
910R
R163
6K8
C146
33n(M)
R71
10K
C87
47u/25V
C94
47u/25V
C101
47u/25V
C102
47u/25V
6
5
4580M
R228
68K
6
5
4580M
R229
68K
6
5
4580M
R230
68K
6
5
4580M
R231
68K
LED DISPLAY
L8MN1.S02
R220
U3B
C195
2.2u/50V
R248
4K7
R221
U6B
C196
2.2u/50V
R249
4K7
R222
U9B
C197
2.2u/50V
R250
4K7
U12B
C198
2.2u/50V
R251
4K7
C179
22P
1M
C181
22P
1M
C182
22P
1M
C185
C89
47u/25V
7
C88
R152
6K8
LEVEL
47u/25V
VR8
W50K
R236
R256
3K9
30K
R264
+VCC
1K5
C180
22P
R270
4580M
U3A
36K
47u/25V
1
2
3
PEAK
LD1
TR2
RED
BR
TR1
BR
PGND
C96
C95
47u/25V
7
R156
6K8
LEVEL
47u/25V
VR16
W50K
R237
R257
3K9
30K
R265
+VCC
1K5
C183
22P
R271
4580M
36K
1
U6A
2
3
PEAK
LD2
TR4
RED
BR
TR3
BR
PGND
C97
C103
47u/25V
7
R160
6K8
LEVEL
47u/25V
VR24
W50K
R238
30K
R266
1K5
R258
3K9
+VCC
C184
22P
R272
4580M
36K
1
U9A
2
3
PEAK
LD3
TR6
RED
BR
TR5
BR
PGND
C105
R259
47u/25V
VR32
W50K
R239
30K
R267
1K5
3K9
+VCC
22P
LEVEL
R223
1M
7
C104
47u/25V
R164
6K8
C186
22P
R273
4580M
36K
1
U12A
2
3
PEAK
LD4
TR8
RED
BR
TR7
BR
PGND
UDASP IN-OUT SECTION
L8MN1.S03
C90
J1
C98
47u/25V
J2
C106
47u/25V
J3
C107
47u/25V
J4
POST
(PRE)
POST
(PRE)
POST
(PRE)
POST
(PRE)
VR7A
JQ10K
VR7B
JQ10K
R284
5K1
R285
5K1
VR15A
JQ10K
VR15B
JQ10K
R288
5K1
R289
5K1
VR23A
JQ10K
VR23B
JQ10K
R292
5K1
R293
5K1
VR31A
JQ10K
VR31B
JQ10K
R297
5K1
R298
5K1
PAN
PAN
PAN
PAN
R287
5K1
R286
5K1
AUX-POST
VR6
W50K
AUX-PRE
VR5
W50K
R291
5K1
R290
5K1
AUX-POST
VR14
W50K
AUX-PRE
VR13
W50K
R295
5K1
R294
5K1
AUX-POST
VR22
W50K
AUX-PRE
VR21
W50K
R296
5K1
R299
5K1
AUX-POST
VR30
W50K
AUX-PRE
VR29
W50K
LEFT-BUS
RIGHT-BUS
AUX-2
AUX-1
LEFT-BUS
RIGHT-BUS
AUX-2
AUX-1
LEFT-BUS
RIGHT-BUS
AUX-2
AUX-1
LEFT-BUS
RIGHT-BUS
AUX-2
AUX-1
+VCC
-VCC
U3C
4580M
L8MN1 (1/3)
BAL
VR39A
JQ10K
VR39B
JQ10K
J5
POST
(PRE)
R313
R312
5K1
BAL
VR46A
JQ10K
VR46B
JQ10K
J6
POST
(PRE)
R314
R317
5K1
ALTO L-8
5-Oct-2003
L8MN1.Sch
5K1
5K1
84
VR35A
B50K
C159
12n(M)
VR35B
B50K
C160
12n(M)
VR42A
B50K
C161
12n(M)
VR42B
B50K
C162
12n(M)
C295
100n
C296
100n
18n(M)
C175
12n(M)
R205
910R
R167
6K8
C148
33n(M)
R96
10K
C176
12n(M)
R207
910R
R169
6K8
C150
33n(M)
R111
10K
C169
18n(M)
C177
12n(M)
R209
910R
R172
6K8
C152
33n(M)
R120
10K
C170
18n(M)
C178
12n(M)
R211
910R
R175
6K8
C154
33n(M)
R125
10K
C167
C168
18n(M)
4580M
U12C
84
C111
47u/25V
C119
47u/25V
C124
47u/25V
C125
47u/25V
C297
100n
C298
100n
C113
C187
22P
R224
U16A
U16B
U19A
U19B
U16C
1M
1
C112
47u/25V
R97
10K
R98
10K
C190
22P
R225
1M
7
C120
47u/25V
C191
22P
R226
1M
1
C127
47u/25V
R121
10K
R122
10K
C193
22P
R227
1M
7
C126
47u/25V
C217
100n
84
C218
100n
U17C
4580M
C219
100n
84
C220
100n
2
3
4580M
6
5
4580M
2
3
4580M
6
5
4580M
4580M
R244
R245
R233
47K
R246
22K
R247
U19C
4580M
LEVEL
22K
LEVEL
22K
R254
4K7
R232
47K
LEVEL
LEVEL
22K
R255
R234
4K7
47K
R235
47K
C207
100n
84
C208
100n
47u/25V
VR40A
W50K
C114
47u/25V
VR40B
W50K
2.2u/50V
C121
47u/25V
VR47A
W50K
C128
47u/25V
VR47B
W50K
2.2u/50V
C199
C200
U20C
4580M
R260
3K9
R261
3K9
R262
3K9
R263
3K9
C201
100n
84
C202
100n
TR9
BR
TR11
BR
2
3
6
5
R170
6K8
2
3
6
5
R173
6K8
4580M
4580M
4580M
U17B
TR10
BR
4580M
U20B
TR12
BR
C188
22P
C189
22P
C192
22P
C194
22P
U17A
PGND
U20A
PGND
R281
36K
1
R280
36K
7
R268
1K5
R283
36K
1
R282
36K
7
R269
47u/25V
LD5
RED
1K5
LD6
RED
R99
10K
C115
R123
10K
C129
47u/25V
C116
47u/25V
+VCC
PEAK
C130
47u/25V
+VCC
PEAK
Titel
Size
Date:
File:
R100
10K
R124
10K
INPUT STAGE
PCB# L8MN1.PCB
A2
VR34A
C135
B50K
18n(M)
EQ HI
R216
1K1
R145
1K3
R204
MID
2.5K
80HZ
910R
VR36A
R166
B50K
6K8
LO
C147
33n(M)
VR34B
C136
18n(M)
B50K
PRE-CH5
EQ HI
R217
1K1
R146
1K3
R206
MID
2.5K
LO
80HZ
EQ HI
12KHZ
MID
2.5K
LO
80HZ
EQ HI
12KHZ
MID
2.5K
LO
80HZ
4580M
U6C
910R
VR36B
R168
B50K
6K8
C149
33n(M)
C137
18n(M)
C151
33n(M)
C138
18n(M)
C153
33n(M)
84
R208
910R
R171
6K8
R210
910R
R174
6K8
C289
100n
C290
100n
R218
R147
R219
R148
VR41A
B50K
1K1
1K3
VR43A
B50K
VR41B
B50K
1K1
1K3
VR43B
B50K
U9C
4580M
PRE-CH6
PRE-CH7
PRE-CH8
C205
100n
84
C206
100n
7654321
C223
VR49B
W50K
U21A
4580M
U21B
4580M
47u/25V
47u/25V
22P
C269
22P
C9
VR49A
W50K
C10
1
7
R318
56K
C243
47u/25V
R320
56K
C245
47u/25V
R25
3K9
R26
3K9
L8MN1 (2/4)
CTRL-R-L
CTRL-R-R
SW9A
PS-22E85L
CTRL-R-L
CTRL-R-R
2TK TO CR-L
2TK TO MIX
LEFT-BUS
L-METER
C255
R-METER
C246
47u/25V
C271
100P
CONTROL
ROOM
C249
47u/25V
VR50B
W50K
VR50A
W50K
R186
20K
R187
20K
R345
3K9
6
5
R344
3K9
2
3
6
5
4580M
C226
U23B
22P
U27B
4580M
4580M
C225
22P
U27A
C281
22P
C248
47u/25V
7
47u/25V
R81
10K
1
7
C256
R278
36K
C250
47u/25V
R82
10K
R279
36K
R308
5K1
R86
10K
PHONES/
R302
5K1
LEFT-BUS
LEFT-BUS
2TK TO
CTRL ROOM
SW10A
SW10B
2TK- N-L
R348
27K
47u/25V
R349
27K
MAIN-L-2
2TK TO CR-L
R304
5K1
C224
22P
2
3
4580M
C270
22P
6
5
4580M
U1A
U1B
RIGHT-BUS
R319
36K
1
C244
47u/25V
R321
36K
7
C247
47u/25V
R305
5K1
R306
5K1
RIGHT-BUS
MAIN-R-2
2TK TO CR-R
LEFT-BUS
EFX TO AUX1
(AUX RETURN2)
2TK-IN-L
RIGHT-BUS
PS-22E85L
PS-22E85L
AUX RETURN 1
C241
C11
22P
R9
10K
U2A
4580M
C12
22P
R10
10K
U2B
4580M
47u/25V
C265
100P
C239
47u/25V
C266
100P
1
7
C6
47u/25V
C7
47u/25V
AUX-RTN1-L
D
AUX-RTN1-R
C19
R7
10K
2
3
C5
R8
10K
6
5
C14
100P
C20
100P
47u/25V
47u/25V
AUX-RTN2-L
C
AUX-RTN2-R
VR48A
R77
W50K
8K2
R241
22K
R78
VR48B
8K2
W50K
R240
22K
AUX RETURN 2
R11
10K
R12
5K1
R27
10K
AUX-1
VR9
W50K
2
3
6
5
R13
27K
R14
27K
8
D
C
SW9B
PS-22E85L
C232
47u/25V
7
5-Oct-2003
L8MN1.S01
2TK TO CR-R
RIGHT-BUS
AUX-SEND2
R185
20K
ALTO L-8
AUX-SEND2
+VCC-VCCPH PWR
+5VD
Sheet
Drawn By:
PGND
DGND
RevisionModel No:
KEVIN LIN.
CN0
2.5-8P
1
2
3
4
5
6
7
8
VER030120
32of
B
A
C282
U23A
4580M
CTRL-R-L
CTRL-R-R
2TK-IN-L
2TK-IN-R
AUX-SEND1
AUX-SEND2
FOOTSW
22P
C252
47u/25V
1
R274
36K
AUX-2
R85
10K
C221
22P
6
5
R309
5K1
U24B
4580M
CN5
2.5-8P-B24A
(TO L8MN1)
1
2
3
4
5
6
7
8
Titel
STEREO AUX & SENDS & MAIN OUT & 2TK & CTRL R & PHONES
Size
A2(C)
Date:
File:
C13
22P
R15
6
LEFT-BUS
B
RIGHT-BUS
5K1
5
U25B
4580M
C260
22P
2
3
U25A
4580M
C203
100n
+VCC
A
-VCC
84
U21C
4580M
C204
100n
1 2 3 4 5 6 78
84
U23C
4580M
C211
100n
C212
100n
7
C234
47u/25V
R301
5K1
1
C233
47u/25V
84
U24C
4580M
MAIN MIX
LEFT
R73
39K
MAIN MIX
RIGHT
R74
39K
C305
100n
C306
100n
47u/25V
47u/25V
U25C
4580M
C236
84
C8
VR51B
W50K
VR51A
W50K
C307
100n
C308
100n
3K9
R339
3K9
2
3
2
3
U26C
4580M
C264
22P
C311
100n
C312
100n
6
5
C24
22P
6
5
C22
22P
R277
36K
R38
5K1
1
U26A
4580M
C263
22P
R276
36K
R93
5K1
1
U31A
4580M
C309
100n
84
C310
100n
U27C
4580M
84
U26B
4580M
U31B
4580M
U1C
4580M
84
C237
47u/25V
7
C238
47u/25V
7
C15
100n
C16
100n
R39
5K1
47u/25V
R375
47u/25V
C45
5K1
C286
U2C
4580M
R76
10K
R72
10K
R75
10K
R41
51K
84
MAIN-L-2
MAIN-L-3
MAIN-R-2
MAIN-R-3
C17
100n
C18
100n
MAIN-L-2
MAIN-L-3
MAIN-R-2
MAIN-R-3
84
U31C
4580M
C340
100n
C341
100n
+VCC
-VCC
PH PWR
AUX-1
RTN-CH1
RTN-CH2
RTN-CH3
RTN-CH4
PRE-CH5
PRE-CH6
PRE-CH7
PRE-CH8
+VCC
-VCC
R275
36K
AUX-1
CN3
2.5-12P-B24
(TO L8MN1)
C251
47u/25V
C272
100P
AUX-SEND1
CN4
2.5-12P-B24
(TO L8MN1)
C231
47u/25V
1
2TK- N-R
AUX-SEND1
R184
20K
MAIN-R-2
MAIN-R-3
MAIN-L-2
MAIN-L-3
AUX-RTN1-L
AUX-RTN1-R
AUX-RTN2-L
EFXRTN-L
AUX-RTN2-R
EFXRTN-R
2TK-IN-R
C222
22P
2
3
U24A
4580M
1
2
3
4
5
6
7
8
9
10
11
12
R189
20K
2
R188
3
20K
AUX-2
1
2
3
4
5
6
7
8
9
10
11
12
R16
D
C
B
A
C257
HR
RED
YEL
GR
GR
GR
GR
GR
GR
GR
GR
GR
GR
+VCC
R373
C213
47R
100n
C342
C343
47P
312
312
312
312
312
312
84
31
47P
31
+VCC
2K
R252
U37C
14
U37B
1
U40C
14
U40B
1
U36C
14
U36B
1
U39C
14
U39B
1
U35C
14
U35B
1
U38C
14
U38B
1
LD7
LM339
LM339
LM339
LM339
LM339
LM339
LM339
LM339
LM339
LM339
LM339
LM339
4
L8MN1 (3/4)
-VCC
LD21
RED
YEL
LD20
GR
LD19
GR
(+4) (+7) (+10) (+18)
LD18
GR
LD17
321
GR
LD16
LEFT METER
GR
LD15
GR
LD14
GR
LD13
GR
LD12
GR
LD11
GR
(-30) (-20) (-10) (-7) (-4) (-2) (0) (+2)
LD10
HR
TR13
GR
PWR ON
8
9
6
7
8
9
6
7
8
9
6
7
8
9
6
7
8
9
6
7
8
9
6
7
R351
470R
PGND
+VCC
PH PWR
R366
R365
R364
R363
R362
R361
R358
R360
R357
R359
R356
R355
R354
PGND
27K
5K6
2K
1K3
620R
510R
470R
330R
470R
330R
470R
120R
56R
R253
4K7
10
11
4
5
10
11
4
5
10
11
4
5
10
11
4
5
10
11
4
5
10
11
4
5
R352
470R
R87
10K
LD8
RED
PHANTOM
U37D
LM339
13
U37A
LM339
U40D
LM339
13
U40A
LM339
U36D
LM339
13
U36A
LM339
U39D
LM339
13
U39A
LM339
U35D
LM339
13
U35A
LM339
U38D
LM339
13
U38A
LM339
PGND
PGND
-VCC
LD33
LD32
2
LD31
LD30
2
LD29
LD28
2
LD27
LD26
2
LD25
LD24
2
LD23
LD22
2
TR14
D1B
R353
R350
+VCC
120R
D1A
DA204K
DA204K
120R
47u/25V
R367
U40E
U39E
U38E
U37E
U36E
U35E
U30C
D3A
D2A
100K
C258
PGND
LM339
LM339
LM339
LM339
LM339
LM339
4580M
7
DA204K
DA204K
6
1
DA204K
DA204K
2
L-METER
D3B
5
3
47u/25V
D2B
R372
U30B
4580M
R371
U30A
4580M
R374
C214
0R0
0R0
-VCC
47R
100n
R428
C284
R370
100K
R427
R369
100K
10K
47u/25V
10K
C283
47u/25V
Titel
DISPLAY STAGE
PGNDPGND
PGND
PGND
R368
RevisionModel No:
Size
100K
R-METER
VER030120
ALTO L-8
A4
43of
KEV N L N.
Drawn By:
Sheet
5-Oct-2003
L8MN1.S02
File:
Date:
1 2 34
D
C
B
A
7654321
8
L8MN1 (4/4)
+5VD
D
EFXRTN-L
EFXRTN-R
C
AUX-SEND2
B
EFXRTN-L
EFXRTN-R
EFX-SEED
10K CHANGE TO 3K3
C50
4.7uF
3
RL1B
RY-5W-K
(MUTE)
5
7
C52
4.7uF
4
RL1C
RY-5W-K
(MUTE)
6
8
C59
4.7uF
MUTE(GLOW)
PEAK(FLICKER)
R68
68R
R6
68R
R53
10K
+VCC
R90
4K7
1
1
U44A
4580M
1
U45A
4580M
6
5
LD54
RED
U47A
LM393
R17
3K3
R18
3K3
C39
22P
C40
22P
C38
22P
R54
2K2
U46B
4580M
2
3
2
3
C60
1.5nF 2.5%
7
C37
100N
3
2
R19
10K
R20
10K
R114
1K
1.5nF 2.5%
7
1.5nF 2.5%
7
R21
10K
R2
10K
R112
1M
7
C61
R22
10K
U44B
4580M
C62
R23
10K
U45B
4580M
R113
2M2
U47B
LM393
D
C
B
1 2
3 4
AR1
680R*4
5 6
7 8
5 6
+5VD
12
EN1
SDB161PVB15FS
1
1
2
2
3
4
4
8
U49C
74HC14
100N
100N
D9
RLS4148
R66
10K
DGNDDGND
COM
DGND DGND
U43A
NE555
OUT3RS
CTR5DS
C1
DGND
DGND
C51
R24
10K
D16
DA202K
+5VD
DGND
R1
R56
10K
U46A
R49
7K5
1
R65
220R
C2
33P
C117
33P
10K
R48
10K
R5
820K
D10A
RB400D
6
5
R46
10K
6
5
C49
22P
2
3
4580M
5
6
CN6
HEADER 8X2
12
34
56
78
910
1112
1314
1516
3 4
U49B
74HC14
RL1A
RY-5W-K
TR16
BR
AR2
680R*4
U48B
5 6
7 8
SDB161PVB15FS
1
1
2
2
3
4
4
8
COM
1 2
3 4
EN2
PRESETVARIATION
+5VD
R4
47K
4
2
TG
6
TH
7
C118
10uF
DGND
DGND
R118
10K
R3
CLK
1
+5VD
2
J
4
3
K
DGND
TR17
BR
R67
10K
10K
6
7
U48A
74HC109
Q
Q
S5R
10
R50
10K
9
74HC109
Q
Q
S11R
D7
BAS316
C3
1uF
DGND
CLK
15
14
J
12
13
K
DGND
U49A
74HC14
U49D
74HC14
8 9
U49F
74HC14
12 13
+5VD
R52
10K
12
C4
1uF
DGND
DGND
D15
BAS316
R80
220R
R79
220R
FOOTSW
DGND
SW1
PS-22E85NL
(MUTE)
C29
100N
+VCC
-VCC
A
1 2 3 4 5 6 78
84
U44C
4580M
C30
100N
84
U45C
4580M
C31
100N
C32
100N
84
U46C
4580M
84
U47C
LM393
U43B
NE555
U48C
74HC109
81
168
DGND
C35
100N
147
U49G
74HC14
C36
100N
+5VD
C86
10uF
JP1
PGND
UDASP IN/OUT SECTION
Titel
Size
Date:
File:
A2(C)
5-Oct-2003
L8MN1.S03
UDASP IN/OUT SECTION
ALTO L-8
Sheet
Drawn By:
RevisionModel No:
KEVIN LIN.
A
VER030217
44of
7654321
8
PH PWR
R1
R2
6K81
330P
C19
22u/35V
C20
22u/35V
R3
6K81
330P
C21
22u/35V
C23
22u/35V
PH PWR
C18
C1
PH PWR
C2
R10
6K81
C42
47u/63V
6K81
C30
47u/63V
6K34
R30
6K34
R4
6K81
C33
47u/63V
6K34
R32
6K34
C41
47u/63V
R26
1K50
C275
100P
C273
100P
C276
100P
C274
100P
R29
1K50
R31
1K50
C29
47u/63V
R12
C32
47u/63V
R16
R101
10K
C227
R103
10K
C228
R13
1
MIC 1
D
LINE IN1
MIC GAIN=0~-60dB
MIC 2
LINE IN2
C
3
2
4
X5
JY-5042-030G
3c
4d
2b
1a
5e
X6
JY-6351G-02-250
LINE IN GAIN=+15~-45dB
1
3
2
4
X7
JY-5042-030G
3c
4d
2b
1a
5e
X8
JY-6351G-02-250
MIC 5
1
3
2
4
X13
JY-5042-030G
X14
JY-6351G-02-250
X15
JY-6351G-02-250
3c
4d
2b
1a
5e
3c
4d
2b
1a
5e
B
LINE IN 5/6
LEFT(MONO)
RIGHT
4R7
R14
4R7
R
RN
TN
T
S
R48
4R7
R49
4R7
R
RN
TN
T
S
R9
6K81
R88
4R7
330P
R89
4R7
R
RN
TN
T
S
R
RN
TN
T
S
-VCC
R102
10K
22P
R104
10K
22P
1n
C46
10n
R44
20K
C13
R381
2K49
-VCC
-VCC
1n
1n
C15
10n
R28
20K
C5
2K49
C17
10n
R40
20K
C7
2K49
-VCC
R45
R59
VCC
-VCC
-VCC
R382
2K49
TR23
R396
470R
TR24
A1316
R27
1K50
2
3
6
5
VCC
VCC
HR
TR16
A1316
TR18
A1316
R105
10K
R106
10K
R50
2K49
TR15
R388
470R
R15
1K50
R60
2K49
TR17
R390
470R
R17
1K50
C66
22P
C67
22P
VCC
C16
10n
HR
R389
470R
TR26
A1316
C6
1n
-VCC
VCC
C35
10n
HR
R391
470R
TR28
A1316
C8
1n
-VCC
VCC
C47
R384
10n
2K49
TR33
HR
R397
470R
TR34
A1316
R383
C14
2K49
1n
-VCC
R108
10K
1
U15A
4580M
R109
10K
7
U15B
4580M
R52
2K49
TR25
HR
R51
2K49
R65
2K49
TR27
HR
R64
2K49
1000u/10V
C117
47u/25V
C118
47u/25V
C51
1000u/10V
C52
1000u/10V
VCC
C56
VR33
2C10K
R401
4R7
VCC
BAS316
VR1
2C10K
R11
4R7
VCC
BAS316
VR9
2C10K
R398
4R7
R385
2K49
D8
BAS316
R107
10K
R37
10K
R110
10K
R38
10K
R53
2K49
D4
R56
2K49
D5
-VCC
2
3
6
5
VCC
R57
2K49
TR35
U1A
HR
4580M
3
2
C48
22P
5
6
R58
C50
2K49
22P
R402
-VCC
5K11
VCC
R91
2K49
TR36
U4A
HR
4580M
3
2
C60
22P
5
6
R94
C61
2K49
22P
R405
-VCC
5K11
VCC
R386
2K49
TR39
U13A
HR
4580M
3
2
R415
C315
5K11
22P
U13B
4580M
5
6
R387
C316
2K49
22P
R414
5K11
C22
47u/25V
1
U16A
4580M
C24
47u/25V
7
U16B
4580M
R403
5K11
U1B
4580M
R406
5K11
U4B
4580M
1
7
1
7
1
7
TP7
TP8
R416
5K11
R425
10K0
R426
10K0
R404
5K11
R417
10K0
R418
10K0
R407
5K11
R419
10K0
R420
10K0
0.22u/50V
C317
22P
R192
20K
R193
20K
C57
22P
C62
22P
C73
PRE-CH5
PRE-CH6
3
2
R136
1K3
C70
0.22u/50V
R131
62K
3
2
R138
1K3
R132
62K
3
2
R190
20K
4580M
0.22u/50V
4580M
0.22u/50V
U14A
4580M
U2A
C71
6
5
U5A
6
5
C65
22P
R95
5K11
5K11
C74
47u/25V
1
C49
22P
R46
5K11
U2B
4580M
47u/25V
1
C54
22P
R54
U5B
4580M
1
C109
47u/25V
LINE IN 7/8
LEFT(MONO)
RIGHT
C85
R176
20K
C72
0.22u/50V
R149
6K8
47u/25V
7
C91
R178
20K
C75
0.22u/50V
R153
6K8
47u/25V
7
C86
R177
20K
C93
R179
20K
VCC
-VCC
VCC
-VCC
X16
JY-6351G-02-250
X17
JY-6351G-02-250
LO CUT
SW1A
PS-22E85L
SW1B
PS-22E85L
LO CUT
SW2A
PS-22E85L
SW2B
PS-22E85L
3c
4d
RN
2b
TN
1a
T
5e
S
3c
R
4d
RN
2b
TN
1a
T
5e
S
U1C
4580M
U13C
4580M
INS-CH1
INS-CH2
84
84
C201
100n
C202
100n
C297
100n
C298
100n
U2C
4580M
U14C
4580M
C279
100P
C277
100P
C280
100P
C278
100P
1
X9
JY-5042-030G
X10
JY-6351G-02-250
X11
JY-5042-030G
X12
JY-6351G-02-250
C205
100n
C206
100n
C301
100n
C302
100n
C68
22P
2
3
R116
10K
C69
22P
6
5
R117
10K
3
2
4
3c
4d
2b
1a
5e
1
3
2
4
3c
4d
2b
1a
5e
U5C
4580M
U16C
4580M
R118
10K
U18A
4580M
R119
10K
R
RN
TN
T
S
R
RN
TN
T
S
84
84
1
7
U18B
4580M
MIC 3
LINE IN3
MIC 4
LINE IN4
C203
100n
84
84
C204
100n
C299
100n
C300
100n
R112
10K
C229
C230
R113
10K
22P
R114
10K
R115
10K
22P
U4C
4580M
U15C
4580M
84
84
C287
100n
C288
100n
C43
100n
C45
100n
C122
47u/25V
C123
47u/25V
R5
6K81
R19
4R7
R20
4R7
22u/35V
C26
22u/35V
6K81
R24
4R7
R25
4R7
22u/35V
C28
22u/35V
PH PWR
C3
330P
C25
PH PWR
R7
C4
330P
C27
U7C
4580M
U18C
4580M
84
84
PRE-CH7
R194
20K
PRE-CH8
R195
20K
R6
6K81
C36
47u/63V
R34
6K34
R8
6K81
C39
47u/63V
R36
6K34
C289
100n
C290
100n
C303
100n
C304
100n
R33
6K34
R35
6K34
47u/63V
R18
1K50
47u/63V
R22
1K50
C34
C37
U8C
4580M
84
VCC
C31
10n
R42
20K
-VCC
C9
1n
R127
2K49
-VCC
VCC
C40
10n
R43
20K
-VCC
C11
1n
R191
2K49
-VCC
C291
100n
C292
100n
STEREO AUX
RETURN1
(MONO / MASTER)
STEREO AUX
RETURN2
R61
2K49
TR19
R392
470R
TR20
A1316
R21
1K50
R128
2K49
TR21
R394
470R
TR22
A1316
R23
1K50
U10C
4580M
LEFT 1
RIGHT 1
LEFT 2
RIGHT 2
HR
HR
TR30
A1316
TR32
A1316
C293
100n
84
C294
100n
JY-6351G-02-250
JY-6351G-02-250
JY-6351G-02-250
JY-6351G-02-250
C38
10n
10n
R393
470R
C44
R395
470R
VCC
VCC
R66
C53
BAS316
2K49
1000u/10V
TR29
HR
VR17
2C10K
R399
4R7
R129
C10
2K49
1n
-VCC
VCC
VCC
R130
C55
BAS316
2K49
1000u/10V
TR31
HR
VR25
2C10K
R400
4R7
R379
C12
2K49
1n
-VCC
C295
100n
84
U11C
4580M
C296
100n
3c
4d
2b
1a
5e
X18
3c
4d
2b
1a
5e
X19
3c
4d
2b
1a
5e
X20
3c
4d
2b
1a
5e
X21
R90
2K49
D6
R135
2K49
D7
AUX-RTN1-L
AUX-RTN1-R
EFXRTN-L
AUX-RTN2-L
EFXRTN-R
AUX-RTN2-R
-VCC
-VCC
VCC
-VCC
VCC
R126
2K49
TR37
U7A
HR
4580M
3
2
C64
22P
5
6
R144
C82
2K49
22P
R408
5K11
VCC
R165
2K49
TR38
U10A
HR
4580M
3
2
C84
22P
5
6
R380
C110
2K49
22P
R412
5K11
R347
47R
R346
47R
AUX-SEND1
R409
5K11
U7B
4580M
R413
5K11
U10B
4580M
84
U28C
BA15218N
1
7
1
7
R324
120R
R323
120R
R322
120R
C63
22P
R410
5K11
R421
10K0
R422
10K0
C76
0.22u/50V
C83
22P
R411
5K11
R423
10K0
R424
10K0
C79
0.22u/50V
84
U29C
BA15218N
AUX-SEND2
R325
120R
TAPE IN TAPE OUT
X31
SCP6873NS3232
L(WHITE)
R(RED)
1 4
2 5
3
3
2
R140
1K3
R133
62K
3
2
R142
1K3
R134
62K
C253
C313
47u/25V
100n
C254
C314
47u/25V
100n
3c
R
4d
RN
2b
TN
1a
T
5e
S
X22
JY-6351G-02-250
3c
R
4d
RN
2b
TN
1a
T
5e
S
X23
JY-6351G-02-250
6
U8A
4580M
5K11
C77
0.22u/50V
6
5
U11A
4580M
5K11
C80
0.22u/50V
6
5
R342
C92
47u/25V
1
C58
22P
R62
U8B
4580M
C99
47u/25V
1
C59
22P
R67
U11B
4580M
AUX SEND1
AUX SEND2
MAIN-L-2
1K
MAIN-R-2
R343
1K
2TK-IN-L
R180
20K
C78
0.22u/50V
R157
6K8
C100
47u/25V
7
R181
20K
C81
0.22u/50V
R161
6K8
C108
47u/25V
7
R182
20K
R183
20K
LO CUT
SW3A
PS-22E85L
PS-22E85L
LO CUT
SW4A
PS-22E85L
PS-22E85L
SW3B
SW4B
FOOTSW
L8PU2
INS-CH3
INS-CH4
FOOTSWITCH
3c
4d
2b
1a
5e
X25
JY-6351G-02-250
D
C
B
2TK-IN-R
C261
CTRL-R-R
CTRL-R-L
22P
R84
10K
C262
22P
R83
10K
2
3
2
3
U28A
BA15218N
U29A
BA15218N
R330
U28B
BA15218N
U29B
BA15218N
120R
7
R331
120R
R332
120R
7
R334
120R
6
1
5
6
1
5
CN1
9P-2.0
RTN-CH1
A
INS-CH1
RTN-CH2
INS-CH2
RTN-CH3
INS-CH3
RTN-CH4
INS-CH4
1 2 3 4 5 6 7 8
(TO L8PU1)
1
2
3
4
5
6
7
8
9
CTRL-R-R
CTRL-R-L
MAIN-R-2
MAIN-R-3
MAIN-L-2
MAIN-L-3
CN2
7P-2.0
(TO L8PU1)
1
2
3
4
5
6
7
-VCC
PH PWR
RTN-CH1
RTN-CH2
RTN-CH3
RTN-CH4
PRE-CH5
PRE-CH6
PRE-CH7
PRE-CH8
+VCC
VCC
-VCC
CN3
2.5-12P-B24
(TO L8MN1)
1
2
3
4
5
6
7
8
9
10
11
12
MAIN-R-2
MAIN-R-3
MAIN-L-2
MAIN-L-3
AUX-RTN1-L
AUX-RTN1-R
AUX-RTN2-L
EFXRTN-L
AUX-RTN2-R
EFXRTN-R
CN4
2.5-12P-B24
(TO L8MN1)
1
2
3
4
5
6
7
8
9
10
11
12
CTRL-R-L
CTRL-R-R
2TK-IN-L
2TK-IN-R
AUX-SEND1
AUX-SEND2
FOOTSW
CN5
2.5-8P-B24A
(TO L8MN1)
1
2
3
4
5
6
7
8
3c
4d
2b
1a
5e
X28
JY-6351G-02-250
PHONES
Titel
Size
Date
File
INPUT/OUTPUT STAGE
PCB# L8PU2.PCB
ALTO L-8 VER030120A2(C)
5-Oct-2003
L8PU2.Sch
Sheet
Drawn By
RevisionModel No
KEVIN LIN.
A
11of
D
4
L8PU1
MAIN R (UNBAL)
C
MAIN OUT
(BALANCED)
MAIN L (UNBAL)
B
RIGHT
LEFT
A
11of
VER021103
KEVIN LIN.
RevisionModel No:
Drawn By:
Sheet
R16
120R
X9
JY-5030-030G
R24
5K1
R23
5K1
OUTPUT STAGE (INSERT & MAIN OUTPUT)
Titel
PCB# L8PU1 PCB
ALTO L-8
5-Oct-2003
L8PU1.Sch
A4
Size
File:
Date:
X8
JY-6351G-02-250
3c5e1a
4d
2b
T
RSRN
TN
R6
120R
321
R7
120R
X5
JY-6351G-02-250
3c5e1a
4d
CTRL ROOM R
RSRN
R3
120R
2b
TN
T
R4
120R
3c5e1a
4d
CTRL ROOM L
RSRN
R2
120R
2b
TN
3c5e1a
4d
2b
RSRN
TN
R5
120R
X6
JY-6351G-02-250
T
R10
120R
T
X7
R11
120R
MAIN-R-2
MAIN-R-3
JY-6351G-02-250
MAIN-L-2
MAIN-L-3
R13
213
120R
R14
120R
X10
JY-5030-030G
R22
5K1
R21
5K1
R15
213
120R
INSERT1
3c5e1a
4d
2b
T
RSRN
TN
NS1
RTN1
CN1
9P-2.0
123456789
R1
X1
120R
JY-6351G-02-250
INSERT2
3c5e1a
4d
RSRN
GND-INS
NS2
RTN2
GND-INS
1234567
X2
2b
T
TN
R8
120R
CN2
7P-2.0
JY-6351G-02-250
INSERT3
3c5e1a
4d
RSRN
GND-INS
NS3
RTN3
2b
TN
X3
JY-6351G-02-250
INSERT4
3c5e1a
4d
2b
T
GND-INS
R9
120R
RSRN
NS4
RTN4
TN
X4
JY-6351G-02-250
T
GND-INS
R12
120R
1 2 34
D
C
B
A
4. PRINTED CIRCUIT DIAGRAM
PCB : L8MN1 Top Overlay
PCB : L8MN1 Top Lay e r
PCB : L8MN1 Bottom Layer
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