© 2002-11 PRINTED IN JAPAN
B53-0007-00 (N) 3379
POWER AMPLIFIER
KAC-6401
SERVICE MANUAL
SPEAKER OUTPUT SIDE
LINE INPUT SIDE
25
Accessory
(W01-1606-05)
Screw set
(N99-1587-05)
Fuse
(F52-0014-05)
Connecting cord assy
(E30-6144-05)
Dressing panel
(A21-4267-02)
Heat sink
(F01-1726-01)
KAC-6401
2
ADJUSTMENT
No.
ITEM
INPUT
OUTPUT
RECEIVER
ALIGNMENT
ALIGN
FIG.
SETTINGS
SETTINGS
SETTINGS
POINTS
FOR
Connect a cassette receiver or CD receiver.
IDLE
Connect a DC
(A)
1
CURRENT
-voltmeter across
VOLUME : 0
VR3 (L ch)
2.5mV
(a)
each resistor
VR4 (R ch)
R189 (A-Lch)
(B)
R192 (A-Rch)
VR5 (L ch)
R193 (B-Lch)
VR6 (R ch)
R196 (B-Rch)
VR6
(B-Rch)
VR5
(B-Lch)
VR3
(A-Lch)
VR4
(A-Rch)
J3
SP. OUT
Lch
Ach
Bch
Rch
DC Voltmeter
(a) 2.5mV
R189
R192
R193
R196
+
-
4
3
A
B
C
D
E
F
G
H
I
J
1
2
3
4
5
6
7
PC BOARD (FOIL SIDE VIEW)
X09-5660-10
IC
Q
Address
16C
25C
33C
44C
54G
14D
24D
34E
44E
54D
64D
74E
84F
94D
10
4D
11
4E
12
4F
13
5D
14
3D
15
4D
16
3E
17
4F
18
2B
19
2D
20
2E
21
2F
22
3C
23
3C
24
3D
25
3E
26
3F
27
3E
28
3G
29
3G
R75
R38
C106
6
10
1
5
R35
R10
R97
R7
R244
R111
W304
W320
W319
W321
R85
R79
C89
R239
R174
R139
R106
C107
R51
R52
R50
R49
R245
R8
R9
C31
R19
R15
R16
R20
C127
C27
C28
R46
R34
R24
C11
C32
R22
R18
R17
R21
C130
C30
C29
R47
R39
R29
C16
R58
C35
R57
C40
R62
C36
R60
C34
R56
C38
C39
R55
C37
R59
R61
R37
R28
R27
R36
R40
R30
R25
R26
R33
R23
R138
W306
C119 C118
R140
R175
C120
C121
R249
R248
R247
R246
R243
R242
R84
R66
R65
C122
C42
R68
C44
R74
R87
R78
R86
C47
C116
C117
R77
R67
R73
C43
C41
R64
R63
C123
R179
C90
W305
R159
R238
C33
R162
C108
R163
C91
R182
R143
C86
R164
C94
R166
R161
R178
R144
W324
C62
W312
C84
R146
R82
R117
R118
R76
C85
W307
W318
R148
R141
C110
R212
R142
R160
R222
R5
R6
C93
W323
C92
R187
R183
R147
R201
R218
R221
R217
R216
R235
C65
R240
R198
R213
R208
R207
R215
R533
R202
R214
R241
R205
R197
R199
R200
R206
R150
R137
W322
R149
C96
C133
W314
R80
C48
R88
W313
W317
C95
C63
R114
R120
R116
R119
R115
C64
R110
W311
C83
R113
W309
W308
W310
R107
R165
R42
R45
C128
C129
R48
R145
R41
R43
R44
R186
B
E
B
BE
B
E
B
BE
B
E
B
E
BB
E
B
BE
EE
E
E
R254
9
8
1
16
4
1
5
8
1
4
5
8
1
7
14
8
14
1
7
8
W59
W64
W102
W76
W75
W63
W115
W74
W77
W103
W94
W79
W39
W44
W52
W42
W43
W170
W147
W105
W104
W214
W218
W27
W26
W167
W143
W135
W9
S
D
GS
D
G
W53
W54
W55
W5
W10
W6
W11
W21
W213
W18
W4
W3
W72
W23
W58
W137
W67
W66
W65
W70
W34
W33
W32
W35
W48
W51
W40
W118
W68
W166
W46
W130
W69
W15
W117
W36
W37
W16
W113
W127
W112
W129
W119
W198
W41
W116
W121
W148
W92
W163
W142
W141
W139
W150
W144
W206
W215
W196
W195
W207
W128
W197
W107
W83
W47
W57
W111
W193
W189
W192
W184
W188
W185
W159
W160
W194
W191
W179
W187
W171
W190
W182
W186
W177
W134
W161
W174
W158
W169
W168
W178
W173
W86
W93
W97
W110
W200
W181
W201
W176
W175
W154
W125
W122
W152
W162
W165
W183
W90
W91
W95
W164
W149
W146
W157
W156
W155
W145
W120
W89
W109
W99
W114
W100
W56
W82
W81
L1
C7
C8
TH1
R169
R219
R231
R224
R14
R13
W61
R11
R12
W29
C1
C5
C2
C6
C3
C71
VR3
R90
C4
C114
C113
R132
W239
VR2
VR1
L2
R170
R171
C73
VR5
C109
R98
R99
C25
C26
C24
C23
C51
C52
C22
C21
C20
C19
W1
W87
R176
C45
C46
C98
C97
W73
W238
W138
W71
W133
W80
R173
R189
W220
W101
R91
R93
W401
R96
C112
W14
R225
R232
R220
W60
W240
R236
R237
R105
W13
W219
R125
C75
W20
W25
C99
R204
C9
C10
R126
W131
R31
R71
W132
C17
W88
R72
R32
C18
W172
R69
R70
W17
W50
W49
R4
R3
W221
C78
W7
VR4
R177
R190
W236
W30
W31
R1
W45
R2
W38
W202
C50
R92
R81
C49
R83
W62
R108
R180
R191
W217
W216
C74
W402
R192
W230
R122
R136
W2
R172
R184
R181
R194
W211
W212
W226
W84
VR6
R185
W228
W227
R188
W208
W85
W209
W222
R196
W224
W235
R101
C54
C58
W28
R89
C67
C53
C66
R100
R195
W223
W225
W210
W229
R121
C57
R193
R152
C79
R129
R151
R153
C80
R154
R167
W231
W232
W233
R130
C70
W96
W234
W237
W403
W199
W78
W19
W22
W12
R156
C81
R155
R157
C82
R158
R134
C72
R131
R104
R210
R203
R209
C111
R234
C100
R211
C115
R223
R133
R135
R228
R227
C104
C103
C105
C102
R94
R53
R54
R127
W106
C59
C55
R109
C68
R102
R123
R168
R253
W153
C76
R95
C56
C60
R103
R124
C69
R251
R112
C77
R128
W108
W136
C61
R250
W140
R252
W123
C126
C125
C101
C87
C88
W126
W98
W8
W24
R230
C124
R229
W124
W151
Q52
Q23
Q22
Q24
Q25
Q27
Q26
Q28
Q29
Q48
Q53
Q46
Q62
Q63
X09-5660-10
(J74-1547-01)
AUDIO UNIT
D41
Q31
D15
S3
S1
S5
S2
S4
Q32
Q38
Q35
Q39
D34
D11
D9
J1
J2
E1
D31
D32
D44
D38
D39
E2
D43
Q57
Q54
Q55
D14
Q30
D12
D51
Q58
Q21
D53
D2
D54
D6
D4
D52
D8
D49
D3
D7
D10
D1
D5
CN3
Q41
Q40
D21
D22
Q33
D24
D23
Q36
Q42
Q43
D13
D45
D46
Q34
Q45
Q44
D25
D26
D48
Q37
D47
Q10
Q6
Q15
Q2
Q5
Q1
Q9
Q14
Q20
D17
Q18
D18
D55
Q19
D28
D27
Q56
D19
D20
D16
D33
D30
D35
D40
Q47
D36
D37
Q49
D42
D60
D29
D57
Q4
Q3
Q13
Q11
Q7
D58
Q16
Q12
Q8
Q17
Q60
Q59
Q61
Q50
Q51
D56
D59
ST/MONO
A
HPF/OFF/LPF
A
INPUT
SENS.
A
HPF/OFF/LPF
B
ST/MONO
B
INPUT
SENS.
B
AB/A
A
IN
B
IN
A+B
OUT
D50
BE
BE
BE
BE
B
E
B
E
B
E
BE
BE
BE
B
E
B
E
BE
B
E
B
E
B
E
B
B
E
E
B
E
B
E
B
E
E
B
E
B
E
B
B
E
E
B
E
B
E
B
E
B
B
E
B
E
E
B
B
E
B
E
B
E
E
B
E
B
E
B
E
B
B
E
E
B
E
B
E
B
E
B
B
E
E
B
E
B
E
B
E
B
IC4
IC3
IC1
IC2
IC5
IC
Q
Address
30
2C
31
2C
32
2D
33
2E
34
2F
35
2E
36
2G
37
2G
38
2C
39
2C
40
2D
41
2D
42
2F
43
2E
44
2F
45
2G
46
4G
47
5F
48
4F
49
4F
50
7F
51
7F
52
4F
53
4F
54
5D
55
5D
56
6E
57
6E
58
4C
59
4E
60
3E
61
4F
62
3F
63
3F
Refer to the schematic diagram for the values of resistors and capacitors.
A
B
C
D
E
F
G
H
I
J
1
2
3
4
5
6
7
15.4V
15.4V
-15.4V
15.4V
-15.4V
15.4V
-15.4V
15.4V
-15.4V
-22.2V
22.2V
-15.4V
AUDIO UNIT (X09-5660-10)
IC1(4/4)
IC1(1/4)
D10
D49
D12
IC3(1/2)
S5
D50
D7
D5
IC1(3/4)
IC1(2/4)
D3
D1
FILTER SW
INPUT
SENSITIVITY
S1
S2
S3
OPERATION
SW
INPUT
SW
SELECTOR
OPERATION
SW
CN3
L
R
LINE IN A
J2
LINE OUT
R
L
LINE IN B
R
L
D46
D45
D47 D48
D52
D54
D6
D8
IC2(4/4)
IC2(1/4)
SENSITIVITY
INPUT
FILTER SW
D2
D4
D53
D51
IC2(3/4)
IC2(2/4)
S4
IC4(1/2)
IC4(2/2)
IC3(2/2)
D11
D9
Q54
Q55
Q1
D14
D13
D55
D60
Q5
Q9
D16
D15
Q13
Q58
Q14
Q18
D22
D21
D17
Q22
Q23
Q30
Q31
Q39
Q38
IDLE. ADJ.
D56
Q2
Q6
Q10
Q15
Q59
IDLE. ADJ.
D23
Q24
D18
Q32
Q25
Q40
Q19
D24
Q33
Q41
Q4
Q8
Q12
D58
D57
Q3
Q7
Q11
IDLE. ADJ.
Q21
D28
Q29
Q37
Q45
Q61
Q17
D27
Q28
D20
Q36
Q16
Q60
IDLE. ADJ.
Q27
D26
D19
Q35
Q26
Q44
Q43
Q20
D25
Q34
Q42
D29
D30
Q53
Q46
D31
D32
DIFFERENTIAL
AMPLIFIER
MUTE
RIPPLE
FILTER
MUTE
DIFFERENTIAL
AMPLIFIER
AMPLIFIER
DIFFERENTIAL
DIFFERENTIAL
AMPLIFIER
TEMPERATURE
COMPENSATION
TEMPERATURE
COMPENSATION
OVER-CURRENT
PROTECTION
OVER-CURRENT
PROTECTION
POWER
DRIVER
AMPLIFIER
DRIVER
AMPLIFIER
POWER
POWER
STAGE
STAGE
POWER
P.
D
OVER-VO
PROTEC
CONSTANT
POWER SUPPLY
VOLTAGE
INPUT BUFFER /
ISOLATION AMPLIFIER
ISOLATION AMPLIFIER
INPUT BUFFER /
LPF
INVERTER
LPF
INVERTER
E2
D59
Q62
SPEAKER
LEVEL INPUT
47K
1000P
R6
C107
C106
1000P
47K
R5
300
R212
R222
300
12
13
4
14
1200P
C1
15P
C120
9.1K
R7
18K
R15
1K
R1
10u16
+
C5
5.6K
R33
18K
R19
5.6K
R34
2
3
1
15P
C27
5.6K
R41
51K
R23
68P
C127
5.6K
R45
0.33
C37
0.47
C33
18K
R55
100K
R59
0.047
C45
43K
R73
43K
R67
68K
R63
0.047
C41
3K
R77
0.022
C43
5
7
6
8
10u16
+
C49
6.8K
R85
47K
R83
62K
R75
1K
R31
1K
R2
R56
R20
18K
C121
9
9.1K
1200P
C2
R8
R16
18K
15P
C6
+
10u16
10
7
0.47
1000P
C17
5.6K
R42
5.6K
R35
C28
68P
C128
6
15P
5.6K
R46
R36
5.6K
8
5
C34
68K
0.33
100K
R60
18K
C38
R64
51K
R26
51K
R25
51K
R24
11
10K(A)
VR1
R70 560
R69 560
3
2
1
4
15K
R86
22P
C47
7.5K
R81
15K
R78
0.01
C116
0.1
C11
0.01
C117
0.1
C31
HPF
OFF
LPF
S5
22u16
+
C10
22u16
+
C9
2.2K
R52
2.2K
R51
2.2K
R49
2.2K
R50
MO
ST
A
AB
ST
MO
5
4
3
2
1
AL+
9
8
7
6
10
BL-
AL-
AR-
BR-
AR+
BR+
BL-
AL-
AR-
AR+
BR-
BR+
2.2K
R11
12K
R243
10u16
+
C20
12K
R242
10u16
+
C19
2.2K
R12
+
C22
10u16
+
12K
R245
C21
10u16
R244
12K
2.2K
2.2K
R14
R13
+
47K 10u16
10u16
C26
R249
47K
+
+
C25
C24
10u16
R248
+
47K
R247
C23
10u16
R246
47K
BL+
BL-
AL-
BR-
AR-
BR+
AR+
10u16
C8
R10
C7
10u16
R9
R4
1K
C4
1200P
1200P
C3
R3
1K
C18
C36
0.47
+
9.1K
18K
12
15P
C123
13
14
R18
18K
R22
C32
0.1
C30
5.6K
R40
R39
5.6K
1000P
R44
5.6K
15P
2
11
3
1
R48
5.6K
C130
68P
R62
100K
0.33
C40
18K
R58
S4
HPF
R66
68K
OFF
C119
0.01
LPF
R80
15K
R72 560
R82
7.5K
R88
C48
22P
15K
2
4
3
1
C35
0.47
C122
9
9.1K
R17
18K
15P
18K
R21
+
10
8
4
C16
0.1
7
R32
1K
R43
5.6K
R38
5.6K
C29
68P
C129
6
15P
5.6K
R47
R37
5.6K
5
VR2
10K(A)
0.022
R65
R68
0.33
R57
18K
100K
R61
0.047
C42
68K
43K
C39
C44
5
R74
47K
R71 560
R84
R79
43K
C46
0.047
3K
R76
62K
10u16
C50
+
R87
6
8
6.8K
7
C118
0.01
16K
R30
R29
16K
R28
16K
R27
16K
22u16
C52
+
150K
R97
10
R99
2.2K
R54
10u35
C126
+
10u35
C125
+
22u16
C51
+
2.2K
R53
10
R98
3.3K
R89
4.7K
R90
18K
R100
10u16
+
C57
680P
C53
10u35
C70
+
3.3K
R130
100
R113
820
R106
8.2K
R105
4700P
C62
47u25
C61
+
620
R121
47u25
C66
+
820
R117
18K
R125
6P
C74
470
R104
3.3K
R129
220
VR3
100P
C83
620
R139
2.2K
R138
10K
R137
100
R150
100u25
C78
+
82
R146
10u16
C79
+
100
R151
220
R169
3.6K
R160
3.6K
R159
470P
C90
470P
C89
1.8K
R174
0.1
R190
1.8K
R175
2.2
R176
0.1
R189
2.2
R173
100
R152
820
R118
C67
47u25
R107
820
8.2K
C54
4.7K
R91
680P
R101
18K
R92
3.3K
10u16
+
C58
R108
C75
R122
C63
4700P
R114
100
620
+
6P
10u35
R126
18K
C71
+
C80
10u16
1.8K
R179
R178
1.8K
2.2
R177
82
R147
100P
C84
R140
220
620
VR4
470P
3.6K
R161
C91
R153
100
R162
R170
470P
C92
3.6K
220
R191
0.1
R192
0.1
2.2
R180
R141
+
2.2K
100
R154
220u25
C87
+
R167
10
3.3K
R131
3.3K
R132
2W
2W
2W
2W
8.2K
R112
47u25
R110
18K
R103
680P
C56
4.7K
R96
3.3K
R95
C60
10u16
+
R111
820
R124
C65
4700P
R116
100
R128
6P
18K
C77
620
C69
R120
820
+
47u25
8.2K
C55
R94
4.7K
680P
18K
R102
820
3.3K
R93
C59
+
10u16
R109
6P
R115
C64
C68
R123
820
R119
4700P
100
620
+
C76
R127
18K
10u35
C72
+
3.3K
R133
R134
3.3K
R196
R172
C96
R166
3.6K
470P
R188
2.2
R187
1.8K
C82
10u16
R135
3.3K
R136
3.3K
10u35
C73
+
R144
620
R145
+
2.2K
VR6
220
100
R158
220
2W
0.1
620
R182
10u16
R143
R186
R185
2.2
1.8K
1.8K
R183
1.8K
2.2
R184
C88
220u25
+
C86
100P
82
R149
R165
470P
C95
3.6K
R157
100
82
R148
100P
C85
220
VR5
470P
3.6K
R164
C94
R156
100
R168
10
R163
R171
470P
C93
3.6K
220
R195
2W
0.1
2W
R194
0.1
2W
R193
0.1
2.2
R181
R142
C81
+
2.2K
R155
100
33K
R533
3.3K
R241
3.3K
R201
3.3K
R198
10u16
C115
3.3K
R200
3.3K
R199
47K
R197
33K
R202
W401
3300u25
C98
+
10
R204
3300u25
C97
+
2200P
C99
1/2W
Q5,6,9,10
Q1,2
Q3,4
Q7,8,11,12
Q16,17,60,61
Q14,15,58,59
Q18,19
Q20,21
Q22-25
Q26-29
Q30-33
Q34-37
Q38-41
Q42-45
Q54,55
IC1
IC2
B
B
B
+B
+B
+B
B
B
B
+B
+B
+B
B
+B
B
B
B
B
+B
+B
B
B
+B
B
B
B
+B
B
B
+B
B
B
B
+B
+B
+B
+B
B
+B
+B
B
B
+B
+B
+B
+B
B
+B
B
B
+B
+B
+B
+B
+B
+B
+B
100u6.3
C124
+
R254
47K
R253
47K
R252
R250
0.1
C133
+B
+B
O
N
M
L
K
1
2
3
4
5
6
7
0.5V
0.1V
3.8V
2.5V
0V
3.8V
14.3V
5.0V
14.3V
14.3V
0V
5.0V
5.0V
IC5
KAC-6401
D30
D42
Q47
Q46
D34
D37
D35
D36
Q49
Q48
D40
D33
Q52
J1
SP OUT
D41
D44
D39
Q51
Q57
D38
Q50
D43
Q56
P. CON.
DETECTION
POWER
SWITCH
MUTE
ON/OFF
MUTE
DRIVER
SWITCHING
STAGE
POWER
OVER-CURRENT
PROTECTION
OVER-VOLTAGE
PROTECTION
SWITCHING
DRIVER
SWITCHING
REGULATOR
IC1,2
: NJM2060M
IC3,4
: NJM4565MD
IC5
: UPC494GS
Q1-4,13-17,58-61
: 2SC945(A)(Q,P)
Q5-12,49,56,57
: 2SA733(A)(Q,P)
Q18-21
: 2SC4137(V,W)
Q22,25,26,29,46,48,52,53
: 2SC2412K
Q23,24,27,28,62,63 : 2SA1037K
Q30,33,34,37,54
: 2SC1627A
Q31,32,35,36,47,55 : 2SA817A
Q38,41,42,45
: 2SC4511
B
Q39,40,43,44
: 2SA1725
B
Q50,51
: FKV550T
B
D1-8,10,12,15-28,30,
33,35,36,38-40,43,44,
49-60
: 1SS133
D9,11,42
: RD16JS(B)
D13,14
: RD8. 2JS(B)
D29
: RD7. 5JS(B)
D31
: FMU22S
A
D32
: FMU22R
A
D34
: B30-1460-05
D37
: RD10JS(B)
D41
: 1N5406-M
D45-48
: RD5. 1JS(B)
GND LINE
SIGNAL LINE
B LINE
B LINE
E1
D59
Q62
Q63
3.3K
R241
3.3K
R201
3.3K
R240
10u16
C115
+
3
.3K
3
.3K
33K
R202
1.8K
R203
1.2K
R209
1.2K
R210
47u10
C100
+
100
R207
4.7K
R211
2.2K
R206
1K
R205
47K
R208
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
OSCILLATOR
REGULATOR
REFERENCE
AMP
ERROR
27K
R214
2.7K
R216
10K
TH1
2K
R217
27K
R215
1000P
C108
1u50
C101
+
680K
R213
6.8K
R234
16K
R235
1000P
C110
10K
R223
100u25
C112
+
680
R238
6.8K
R239
10u16
+
C111
100u10
C109
+
22K
R218
10K
R221
L+(A)
F1(25A)
L+(B)
L-(B)
L-(A)
R+(B)
R+(A)
R-(B)
R-(A)
BATT
GND
P-CON
10
R227
0.047
C103
10
R228
0.047
C102
0.047
C105
10
R230
0.047
C104
10
R229
10u16
C114
+
C113
3300u16
+
L2
W403
1.5K
R237
4.7K
R220
10
R232
150
R225
W402
4.7K
R219
R231
10
R224
150
1.5K
R236
L1
10
R204
2200P
C99
1/2W
Q50,51
Q56,57
+B
+B
+B
+B
+B
+B
+B
B
+B
(F52-0014-05)
+B
+B
+B
+B
+B
+B
B
+B
+B
+B
+B
+B
+B
+B
100u6.3
C124
+
R254
5.6K
47K
R253
47K
R252
47K
R250
R251
47K
+B
+B
+B
2SA733(A)
2SA817A
2SC1627A
2SC945(A)
B
C
E
2SC2412K
2SC4137
B
E C
2SA1725]B
2SC4511]B
2SA1037K
NJM4565MD
UPC494GS
NJM2060M
CAUTION : For continued safety, replace
safety critical components only with
manufacturer's recommended parts (re-
fer to parts list).
Indicates safety critical components.
To reduce the risk of electric shock, leak-
age-current or resistance measurements
shall be carried out (exposed parts are
acceptably insulated from the supply cir-
cuit) before the appliance is returned to
the customer.
· DC voltages are as measured with a
high impedance voltmeter. Values may
vary slightly due to variations between
individual instruments or/and units.