McIntosh C8AC Service Manual

19 20
AMPLIFIER 751377 SCH
3
150k
R58
150k
R57
12AT7A
5
9
4
V6:3
100k
R33
12AX7A
8
6
7
V5:2
10k
R42
100k
R38
12AT7A
8
6
7
V6:2
1000µF
C27
15k
R72
1M
R76
1M
R75
200V
D8
12AX7A
5
9
4
V5:3
12AT7A
5
9
4
V7:3
12AX7A
3
2
1
V5:1
12AT7A
3
2
1
V6:1
15k
R71
.047µF
C25
475
R41
100µF
C19
.047µF
C24
10k
R31
1M
R50
200V
D11
12AT7A
8
6
7
V7:2
.047µF
C30
1M
R48
100pF
C15
.047µF
C31
12AT7A
3
2
1
V7:1
+350V
+350V
100k
R37
100k
R34
47.5k
R52
22pF
C11
100µF
C21
2.21M
R46
150k
R54
12AX7A
8
6
7
V4:2
2.21K
R8
100µF
C2
12AX7A
5
9
4
V4:3
+12.6V
2 1
3
Q1
221k
R9
+200V
10k
R11
221k
R6
+200V
100k
R5
.1µF
C17
100k
R10
22.1k
R21
22.1k
R20
V11 CATH
V11 CATH
150k
R56
150k
R55
12AT7A
5
9
4
V2:3
AGND
100k
R35
12AX7A
8
6
7
V3:2
10k
R40
100k
R44
30k
R62
12AT7A
8
6
7
V2:2
1000µF
C26
15k
R70
100k
R68
1M
R74
1M
R73
200V
D9
12AX7A
5
9
4
V3:3
12AT7A
5
9
4
V1:3
12AX7A
3
2
1
V3:1
12AT7A
3
2
1
V2:1
15k
R69
.047µF
C23
475
R39
100µF
C18
.047µF
C22
10k
R29
1M
R49
200V
D10
12AT7A
8
6
7
V1:2
.047µF
C28
1M
R47
100pF
C14
.047µF
C29
12AT7A
3
2
1
V1:1
+350V
+350V
100k
R43
100k
R36
47.5k
R51
100µF
C20
2.21M
R45
150k
R53
12AX7A
3
2
1
V4:1
2.21K
R14
100µF
C3
2
1
3
Q2
221k
R16
+200V
10k
R22
221k
R12
+200V
100k
R4
.1µF
C16
100k
R17
22.1k
R24
22.1k
R23
V8 CATH
V8 CATH
J1:1
MAIN - LEFT
MAIN - RIGHT
J5:13
J5:2
J5:6
J5:9
J5:10
J5:7
J5:11
J6:4
J6:12
J6:10
J6:9
J6:5
J6:6
J6:7
J6:3
J6:8
R OUT 16
R OUT 16
L OUT 16
L OUT 16
+350V
D3
D2
3.32K
R13
3.32K
R7
1µF
C6
1µF
C4
10µF
C1
+200V
200V
D1
+350V
10k
R30
10k
R32
1
2
3
G
D
S
Q4
1 2
3
G
D
S
Q3
2.21M
R27
2.21M
R28
J1:3
J1:5
1µF
C32
30k
R61
+700V
+700V
100k
R66
1µF
C33
100k
R65
1µF
C34
30k
R63
+700V
100k
R67
1µF
C35
30k
R64
+700V
+12.6V
+700V
J5:1
100pF
C8
AGND
100pF
C7
+12.6V
+12.6V
J5:14
J5:3
J5:5
J5:8
J6:11
BIAS
BIAS
J6:1
J6:2
J4:7
INP SW
MODE SW
ON
OFF/STBY
POWER SW
J2:1
J2:2
PWR SW
MUTE
MAIN
J4:10
J4:1
J4:12
J4:9
J4:6
J4:3
L BAL+
L BAL-
R BAL-
L UNBAL
R UNBAL
46.4k
R3
22pF
C10
22pF
C12
22pF
C13
J3:1
J3:2
2.21K
R1
STANDBY LED
1
5 8
7
6
2 3 4
K2
1
5 8
7 6
2 3
4
K1
J4:4
10K
R19
10K
R18
J1:4
J1:2
J1:6
J1:7
BAL INPUT
J6:13
J6:14
.1µF
C9
+12.6V
100
R15
220µF
C5
1K
R25
1K
R26
22.1K
R59
22.1K
R60
200V
D7
200V
D6
200V
D5
200V
D4
1
1
1
1
2
2
2
2
2
R BAL+
5
5
5
5
5
5
5
PWR SW
+5V
MODE SW
MUTE
INP SW
L UNBAL
GND
R UNBAL
R BAL+
R BAL-
L BAL+
L BAL-
V9 PLT
V8 CATH
V8 GRID
FIL C
FIL A
+12.6V
GND
V9 GRID
L OUT 16
V9 PLT
V10 PLT
V11 CATH
V11 GRID
FIL C
FIL B
BIAS
+700V
V10 GRID
R OUT 16
V11 PLT
+350V
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
GND
PWR SW
GND
STBY LED

McIntosh C8AC Specifications

General

Brand	McIntosh
Model	C8AC
Category	Amplifier
Language	English