© 2005-5 PRINTED IN JAPAN
B53-0285-00 (N) 1708
POWER AMPLIFIER
KAC-6402
SERVICE MANUAL
Accessory
(W01-1606-05)
190mm
Screw set
(N99-1587-05)
Fuse
(F52-0014-05)
Connecting cord assy
(E30-6144-05)
4/3/2channel
Power Amplifier
Powe Amplifie
MAXIMUMPOWER
4/3/2channel
KAC-6402 (E type,M type)
KAC-6402 (K type)
This product uses Lead Free solder.
KAC-6402
2
BLOCK DIAGRAM
+6dB
0dB
+29.5dB
ISOLATION
AMPLIFIER
LINE IN
AL
ST/MONO
Ach
INPUT
GAIN
CONT.
LINE IN
AR
AMPLIFIER
ISOLATION
ISOLATION
AMPLIFIER
ST/MONO
AMPLIFIER
ISOLATION
SPEAKER
INPUT
GAIN
CONT.
Bch
INPUT
BR
LINE IN
LINE IN
BL
LPF+6dB
HPF
HPF
LPF+6dB
LPF+6dB
HPF
LPF+6dB
HPF
MUTE
AMPLIFIER
POWER
POWER
AMPLIFIER
AMPLIFIER
POWER
POWER
AMPLIFIER
OUT BR
SPEAKER
SPEAKER
OUT BL
OUT AR
SPEAKER
OUT AL
SPEAKER
CONVERTER
DC/DC
AVR
15V
OVER ROAD PROTECTION
DC DETECT AND
THERMAL
PROTECTION
PROTECTION
OVER VOLTAGE
P CON CIRCUIT
P CON
BATTERY
A-AB
+1
-1
+1
-1
FREQ. CONT.
FREQ. CONT.
COMPONENTS DESCRIPTION
AUDIO UNIT (X09-5890-10)
Ref. No.
Application / Function
Operation / Condition / Compatibility
IC1,3
Buffer amplifier
Lowers impedance and amplify by 6dB
IC2,4
Isolation amplifier
Reduces common mode noise
IC5,9
Buffer amplifier
Rch operates as reverse amplifier
IC6,10
Reverse buffer amplifier
Reverse amplifier operation of 6dB
IC7,8,11,12
LPF/HPF
LPF and HPF with variable cut off
IC13
DC-DC converter
Oscillation and control of DC-DC converter
Q3,4
Constant voltage power supply
Constant voltage control of
±15V
Q5,6
DC-DC converter
Switching FET
Q7,8,9,10
DC-DC converter
Gate driver for Q5,6
Q11,12
DC-DC converter
ON/OFF of IC13 output
Q101,102,201,202
Input mute circuit
Shock noise absorption at power ON/OFF
Q103~106,203~206
Power amplifier
First step differential absorption
Q107~110,207~210
Power amplifier
Second step differential absorption
Q111,112,211,212
Power amplifier
Second step current mirror load
Q113,114,213,214
Power amplifier
Power amplification circuit bias temperature compensation
Q115~118,215~218
Power amplifier
Excess current detection
Q119~122,219~222
Power amplifier
Power amplification step darlington driver
Q123~126,223~226
Power amplifier
Power amplification step darlington output transistor
Q601
B-class step mute
Mute signal generation circuit: Normally ON
Q602
Mute circuit
Mute signal generation circuit: Normally OFF
Q603
Input mute
Mute signal generation circuit: Normally OFF
Q604
Power ON/OFF
Primary power supply control transistor: Normally ON
Q605
Power ON/OFF
Power control circuit
Q606
Power ON/OFF
Excess voltage protection circuit: Goes OFF when primary input voltage of 16V or less
Q610
Excess current detection
Goes ON when detecting excess current and turns OFF DC-DC converter
Q611,612
DC output voltage detection
Goes ON when detecting DC output voltage from power amplifier
KAC-6402
3
COMPONENTS DESCRIPTION
ADJUSTMENT
No.
Item
Alignment point
Method
Align for
Note
VR5 (ALch)
1
IDLE
VR6 (ARch)
Connect a DC voltmeter
2.5mV
After Power on
CURRENT
VR7 (BLch)
between emitter resister
5 minutes
VR8 (BRch)
Q226
Q224
Q225
Q223
Q124
Q126
Q123
Q125
VR5
AL
AR
VR6
BR
VR8
BL
VR7
DC voltmeter
BRch 2.5mV
R456
DC voltmeter
BLch 2.5mV
R455
DC voltmeter
ALch 2.5mV
DC voltmeter
ARch 2.5mV
R255
R256
Ref. No.
Application / Function
Operation / Condition / Compatibility
Q613,614
DC output voltage detection
Latch circuit at DC detection
Q615,616
B-class step mute transistor
Circuit for turning OFF input of power amplification step
Q617,618
B-class step mute transistor
Driver for Q615,616: Normally ON
D1
Reverse connection protection
Melts off fuse when primary power supply is inversely connected
for primary power supply
D2,3
AVR reference voltage
Control Q3,4 by Zenner voltage generated at D2,3
D4,5
Secondary power supply rectifier
D6~9
Switching
Reverse flow prevention
D22,201,101,102
Temperature compensation
Makes 2nd step deferential transistor
Vbe current constant
D32~37
Static protection
Prevents ope amp destruction by static
D103,104,203,204
Current mirror
2nd step deferential amplifier current mirror load
D105,106,205,206
B-class step mute
Reverse flow prevention
D107~110,207~210
Excess current detection
Reverse flow prevention
D229,430
Input mute
Reverse flow prevention of signal current
D601
LED control
D610 power indicator control
D602,603
Mute control
Reverse flow prevention
D604
AVR for mute
10V
D605
Power control
Reverse flow prevention
D606
Primary power supply excess
Level shift
voltage detectoin
D607
Power control
Level shift
KAC-6402
4
A
B
C
D
E
1
2
3
4
5
6
7
PC BOARD (FOIL SIDE VIEW)
W412
R636
R613
R614
R637
R633
C610
C607
R605
R604
R610
R608
R607
R611
R609
R612
R606
R602
R635
C609
R632
R634
R617
R621
R620
R629
R623
R622
R668
R662
R664
W416
R671
R666
R670
R661
R667
R669
R13
W417
W421
R12
W420
W419
R14
R10
R19
R25
R24
R22
C13
W413
W414
R26
R21
C11
W415
R23
R16
R17
R8
R15
R11
W418
W402
W407
W406
R663
R665
W409
W410
W411
W408
R237
R251
C217
R233
R241
C221
R229
W388
W395
W394
W387
R243
R235
W396
W397
W400
W398
W399
W401
R27
R18
R2
R1
R221
R231
W389
W392
W390
W391
W393
R225
R223
R219
W385
W381
R213
R209
W384
W383
W382
R425
R423
R465
W404
R421
R466
R413
W379
R431
W380
R419
TH1
R443
R449
C419
R439
R437
W405
R435
W403
R451
C421
R441
R429
R433
C417
W386
R9
1
8
16
9
BE
BE
B
E
BE
BE
B
E
B
E
BE
B
E
B
E
B
E
B
E
B
E
B
E
B
E
BE
BE
B
E
B
E
B
E
B
E
C6
C7
L2
L3
W601
C606
R261
R461
C14
R618
C461
C903
C907
C1
11
10
9
7
8
3
4
5
6
1
2
C8
C12
C211
C223
C224
C411
C423
C424
C601
C602
C603
C608
C617
R7
R245
R247
R255
R257
R258
R445
R453
R455
R457
R458
R603
R615
R616
VR5
VR7
C15
W174
W167
W166
W172
SD
G
S
D
G
W175
W173
W170
W176
W171
W181
W178
W179
W177
W180
W182
W112
W113
W131
W123
W163
W161
W68
W127
W99
W100
W106
W102
W101
W137
W144
W151
W147
W143
W146
W150
W136
W104
W103
W142
W156
W165
W152
W138
W140
W80
W79
W78
W71
W75
W76
W77
W135
W124
W164
W157
W141
W94
W74
W162
W155
W107
W139
W120
W125
W126
W128
W129
W133
W132
W118
W116
W115
W114
W134
W117
W149
W148
W109
W105
W70
W72
W73
W92
W108
W121
W122
W85
W96
W69
W91
W86
W87
W88
W98
W90
W93
W83
W82
W97
W119
W89
W81
W95
W84
W145
W154
W110
W111
W153
W130
W158
W160
BL
AL
C9
EB
E
B
BE
EB
E
E
BE
BE
B
E
B
B
E
B
E
B
E
B
B
BE
B
E
E
E
B
E
B
E
C10
Q615
D616
Q605
Q606
D607
D606
D614
Q614
Q602
D602
D603
D605
D604
D601
Q603
Q601
Q612
Q611
D613
Q613
Q610
Q616
Q618
Q617
Q12
Q7
Q8
Q9
Q11 D6
D9
D8
D7
Q10
D109
D111
D
D103
D101
D430
D206
D203
D
D207
D209
D4
Q123
Q223
D5
Q125
Q225
D1
J9
P1
Q5
Q6
Q113
Q213
Q119
Q219
Q121
Q221
Q604
Q107
Q109
Q111
Q117
Q207
Q211
Q215
Q217
IC13
AUDIO UNIT
X09-5890-10
(J76-0087-11)
Refer to the schematic diagram for the values of
resistors and capacitors.
X09-5890-10
Ref. No. Address
IC1
3I
IC2
3H
IC3
2I
IC4
2H
IC5
3I
IC6
3I
IC7
3H
Ref. No. Address
IC8
3H
IC9
4I
IC10
4I
IC11
4H
IC12
4H
IC13
4C
Q3
6I
Ref. No. Address
Q4
6H
Q5
2C
Q6
2B
Q7
3B
Q8
3C
Q9
3B
Q10
3C
Q11
4B
Q12
4C
Q101
4F
Q102
4F
Ref. No. Address
Q103
4F
Q104
4F
Q105
4F
Q106
4G
Q107
4E
Q108
5G
Q109
5F
Q110
5G
Q111
4E
Q112
4G
Q113
6E
KAC-6402
5
J
I
H
G
F
1
2
3
4
5
6
7
R417
R201
R235
R249
R219
5
W377
R217
R211
C901
W381
R213
R209
R421
R413
R411
R409
W379
R431
W380
W376
R419
C905
W378
R119
R115
C117
C31
R128
R240
C220
R232
C222
R242
R239
C219
W375
W372
W371
W370
R252
R238
W369
W367
W360
R234
C218
R230
R244
R236
R250
W364
R660
R659
W374
R216
R202
R204
C204
R208
R215
C259
R227
C260
R228
R205
R203
C203
R207
R206
R210
R212
R214
W368
R218
C902
R220
R266
R265
R408
R404
C404
R401
R405
R407
R403
C403
W373
R406
C459
R415
R427
C460
R428
R414
R410
R402
W365
R418
R416
R412
W366
C906
R420
W357
R178
R224
R222
R226
R174
W363
R176
C37
R170
R172
C38
R173
C154
C152
R166
W353
R168
R164
R177
W358
R422
R424
R426
R378
R374
W362
W361
R432
W359
C352
C354
R376
C41
R372
C42 R370
R375
R377
R373
R366
W354
W355
W356
R368
R364
W351
W350
W352
R6
W343
R5
W319
W312
W308
W318
W317
W322
W310
W309
W315
W306
W311
W305
W303
R353
W324
W327
R381
W323
R181
R161
R169
R171
W339
W333
W334
C153
C151
R165
W347
R175
W337
R167
R163
W338
R179
C35
C36
R158
R162
R160
R180
W325
R154
C150
R157
W332
R159
W328
W330
R116
R361
R360
W348
C351
C353
R371
R369
W342
W336
W340
W335
R118
C110
W346
C32
W345
R130
R365
R120
W341
R367
R363
C108
C40
C39
R359
R358
R362
R379
R352
R380
R354
C350
C118
R357
R110
R108
R114
R112
W331
R106
C106
R153
R152
R182
W321
R155
R151
R156
W313
R351
R356
R355
R382
W320
W316
C101
C102
R100
R104
W30
W302
W301
W304
C324
C128
R450
R440
C420
R436
R444
R442
C422
R452
R438
C418
R434
R430
R303
R304
C317
C318
R312
R327
R313
R311
R328
R314
C33
R319
C109
R320
C34
R330
C308
R318
C310
C107
R316
R129
R117
R329
R317
C309
C307
R315
C306
R109
R107
R306
R310
R308
R127
R113
R111
R300
C105
W329
R105
C305
R305
R309
R307
W326
W344
W349
R126
R323
R123
R103
C129
R125
R145
R326
R324
R325
C301
R321
R121
W314
R322
R122
R124
C302
BE
BE
B
E
B
E
BE
B
E
B
E
BE
BE
B
E
B
E
BE
VR1
VR2
VR3
VR4
2
5
6
7
1
4
3
1
2
9
10
C2
C3
C616
C4
C5
C100
C207
C208
C209
C210
C261
C300
C407
C408
C409
C410
C461
C904
C908
C103
C104
C111
C112
C113
C114
C115
C116
C155
C156
C157
C158
C159
C160
C201
C202
C205
C206
C
211
C212
C213
C214
C215
C216
C303
C304
C311
C312
C313
C314
C315
C316
C355
C356
C357
C358
C359
C360
C401
C402
C405
C406
C411
C412
C413
C414
C415
C416
R101
R102
R246
R248
R253
R254
R256
R301
R302
R446
R447
R448
R454
R456
VR6
VR8
W55
W12
W8
W22
W2
W3
W11
W14
W59
W62
W16
W68
W18
W20
W159
W19
W60
W23
W21
W17
W25
W24
W38
W36
W33
W31
W30
W27
W35
W32
W29
W34
W37
W39
W28
W40
W13
W10
W4
W54
W41
W52
W64
W71
W53
W47
W58
W67
W5
W7
W6
W26
W15
W48
W63
W57
W70
W46
W45
W1
W61
W69
W66
W65
W56
W44
W51
W43
W42
W50
W49
W9
BR
AR
14
85
4
1
5
8
4
1
5
8
4
1
5
8
4
1
5
8
4
1
5
8
4
1
5
8
4
1
5
8
4
1
5
8
4
1
5
8
4
1
5
8
4
1
5
8
4
1
5
8
E
B
BE
BE
BE
B
E
B
E
B
E
B
E
B
E
B
E
B
B
E
B
E
B
B
B
EE
B
E
EE
B
B
E
B
E
B
E
B
E
E
B
B
E
B
E
B
E
B
E
B
E
E
B
E
B
E
B
Q205
D107
1
D105
D101
Q105
D201
D108
D110
D106
Q104
Q103
Q101
Q102
Q106
D229
D102
Q202
Q204
Q203
Q201
Q206
D22
D104
D204
D3
D2
D610
D34
D32
D33
D208
D205
D211
D210
D37
D35
D36
Q3
Q123
Q124
Q224
Q4
Q126
Q225
Q226
S4
S5
J2
Q114
Q214
S1
S2
S3
J1
AB-A
S1.INPUT
VR2.Bc
h
SENS
ST
-MONO
S2.Bc
h
VR1.Ac
h
SENS
ST
-MONO
VR3.Ac
h
FREQ
UENCY
HPF-OFF-LPF
S4.Ac
h
HPF-OFF-LPF
S5.Bc
h
VR4.Bc
h
FREQ
UENCY
Ac
h
B
c
h
Q119
Q120
Q220
Q122
Q221
Q222
Q107
Q108
Q109
Q110
Q112
Q115
Q116
Q118
Q207
Q208
Q209
Q210
Q212
Q216
Q218
S3.Ac
h
IC12
IC8
IC11
IC10
IC9
IC7
IC2
IC6
IC5
IC1
IC4
IC3
Ref. No. Address
Q114
6G
Q115
5F
Q116
5H
Q117
5E
Q118
5G
Q119
5E
Q120
5H
Q121
5D
Q122
5G
Ref. No. Address
Q123
5F
Q124
5H
Q125
5D
Q126
5G
Q201
4F
Q202
4F
Q203
3F
Q204
3F
Q205
3F
Ref. No. Address
Q206
3G
Q207
3E
Q208
3G
Q209
3F
Q210
3G
Q211
3E
Q212
3G
Q213
2E
Q214
2G
Ref. No. Address
Q215
3E
Q216
2F
Q217
3E
Q218
2G
Q219
2D
Q220
2G
Q221
2F
Q222
2H
Q223
2D
Ref. No. Address
Q224
2G
Q225
2E
Q226
2H
Q601
5B
Q602
5B
Q603
5B
Q604
6B
Q605
6B
Q606
6B
Ref. No. Address
Q610
6C
Q611
6C
Q612
6C
Q613
6C
Q614
6C
Q615
6D
Q616
6C
Q617
6D
Q618
6C