Alto OEX-400 Service Manual page 9

1 2
C115 22P
MN-EQ-SOURCE
R41
22K
R172
2
MAIN-IN-EQ
1
5K6
D 3
R42
R175
22K
6K8 U23A
4580M
MN-EQ-OOL-1
C198
MN-EQ-OOL-2
R178
C197
10P
39K
10P
6
7 U15B 2
5
4580M
3
+VCC6 -30DB
R155
2 3
E C
120R
GR
Q1
D10
PNP +VCC6 -VCC6
C
LM339
U21A
3 12
R191
470R
1N4148 1N4148
D1 D2
R194 R195
R247
43R 510R
10K
R192
470R
3 12
U22A
Q2
+VCC6 LM339 -VCC6
PNP
D12
R156
GR
120R
2 3
E C
-30DB
R213
C58
C81
47u/25V 8K2
22P
B
R137
36K
VR22
2
C59
W50K
47u/25V
2
R207
1
27K
3
U17A
MONITOR OUT
4580M
R255
27K
R255 IS NOT USED
R46
6
22K
7
5
C61
R84
U17B 47u/25V
10K
4580M
-VCC -VCC6 C190
R148
10
C152 47UF/25V
A
0.1u
C153 C191
0.1u 47UF/25V
R149
10
+VCC U20C +VCC6
4580M
1 2
3
C116
C55
22P R184
C117
680R
47u/25V R120
22P
R173
8K2
5K6
2
1
3
R189
R176 2 6
2K7
6K8
VR21
U16A 5
W50K
4580M
R177 4580M
39K
MASTER(VOLUMES)
1
U15A
4580M
-10DB 0DB +10DB
-VCC6
GR YE RED
C57
47u/25V
D11 D14 D16
U21B U21C U21D
LM339 LM339 LM339
R82
10K
R196 R197 R198
+VCC6
1.2K 2.7K 22K
U22B U22C U22D
LM339 LM339 LM339 R83
10K
D13 D15 D17
GR YE RED
-VCC6 C60
-10DB 0DB +10DB 47u/25V
MO-OUT-L
C118
HP-OUT-L
22P
R157
R217
120R
10K0
R214
2 6
1 7
100R 1/4W
3 5
R158
U18A
U18B
120R
BA15218N
BA15218N
R45
22K
C119
HP-OUT-R
22P
R159
120R
R216
10K0
2 6
1 7
3 5
R160
U19A U19B
120R
R215
BA15218N BA15218N
100R 1/4W
MO-OUT-R
3
4 5
CI00185
C238
100nF
R264
27.0K
R43
22K
6
C56 C237
7 5
47u/25V R44 0.22u/50V
22K
U16B
R262 R265
15.0K 12.0K
TAPE-OUT
D20
4148
R200
2
1
100K
3
U20A
4580M
MN VMETER
D19
R199
4148
100K
D21
MO VMETER
4148
R201
6
7
100K
5
U20B
4580M
D22
R202
4148
100K
-VCC1 -VCC8
C166
0.1u
C167
0.1u
U14C +VCC1 U15C +VCC8
4580M 4580M
4 5
- 7 -
6 7
7
U10B
4580M
C239
47u/25V
TO AMP IN
J13
R248
4
1K
3
2
1
R249
10K NC CON4
R254
4.7K
R253
4.7K
-VCC
R150
10
C168 C170 C172 C174
0.1u 0.1u 0.1u 0.1u
C169 C171 C173 C175
0.1u 0.1u 0.1u 0.1u
U16C U17C U18C
R151
4580M 4580M 4580M 4580M
10
+VCC
6 7
8
D
C
B
C188
C164 47UF/25V
0.1u
C165 C189
0.1u 47UF/25V
A
U19C
8