Kenwood KAC-8402-D, KAC-8452-D Service manual
POWER AMPLIFIER
KAC-8402/8452
SERVICE MANUAL
KAC-8452
(E type,M type)
CONTROL SYSTEM
© 2005-3 PRINTED IN JAPAN
B53-0250-00 (N) 1708
channel
Powe
Amplifie
Dressing Panel
(A21-4464-02)
Fuse (40A)
(F52-0016-05)
Accessories
(W01-1606-05)
Screw set
(N99-1759-05)
Connecting cord assy
(E30-6144-05)
Dressing Panel
(A21-4469-02)
: KAC-8452(K type)
(A21-4470-02)
: KAC-8402
(A21-4524-02)
: KAC-8452(E type),
KAC-8452(M type)
KAC-8452
KAC-8402
(K type)
19cm
This product uses Lead Free solder.
KA C-8402/8452
BLOCK DIAGRAM
L
LINE IN
(A)
R
L
LINE IN
(B)
R
L
LINE OUT
(A+B)
R
SPK
AL
ISOLATION
AMPLIFIER
ISOLATION
AMPLIFIER
SPK
AL
SPK
BL
IC2
ISOLATION
AMPLIFIER
ISOLATION
AMPLIFIER
SPK
BR
OUTPUT LEVEL
INPUT SENS
Q241,242
INPUT SENS
Q443,444
IC1 (X08)
INVERT
ST/MONO
SW0
AB/A
ST/MONO
SW1
SW2
IC5 (X08)IC1
FREQ
IC7,8 (X08)
B.B
B.B
HPF
12dB
SW3
HPF/OFF
HPF
HPF
IC1 (X08)
INVERT
12dB
18dB
12dB
SW4
HPF/OFF/LPF
HPF
12dB
IC4 (X08) Q401-426
IC6 (X08)
SW
LPF
SW
X08X09 X09
DC/DC
15V
AVR
CONVERTER
Q201-225
MUTE
MUTE
MUTE
MUTE
POWER AMP
POWER AMP
POWER AMP
POWER AMP
DC DETECTOP
OVERLOAD PROTECTOR
P CON
CIRCUIT
OVER VOLTA GE
CIRCUIT
THERMAL
PROTECTION
SPEAKER
OUTPUT
SPEAKER
OUTPUT
SPEAKER
OUTPUT
SPEAKER
OUTPUT
P-CON
BATTERY
6dB 0dB
0dB
32.5dB
2
KA C-8402/8452
COMPONENTS DESCRIPTION
● PREAMPLIFIER UNIT (X08-4200-10)
Ref. No. Application / Function
IC1 (2/2) ARch reversal buffer
IC1 (1/2) BRch reversal buffer
IC4 Bch HPF
IC5 Ach HPF
IC6 Bch LPF
IC7,8 Bch Bass boost filter
● AUDIO UNIT (X09-5840-1x)
Ref. No. Application / Function
IC1,2 Input isolation amp
IC4 Switching regulator controller
IC6
Q1 For +15.6V AVR
Q2 For -15.6V AVR
Q3~8 DC/DC converter FET
Q9~12 For FET driving
Q13,14 FET drive low start SW
Q201~210
Q211 For temperature compensation bias
Q212
Q213 For temperature compensation bias
Q214~219
For temperature protection and -3dB attenuator
comparators
For ACH voltage amplifying step differential amplifying
For ACH voltage amplifying step differential amplifying
For ACH voltage amplifying step differential amplifying
Ref. No. Application / Function
Q220 For ACH final current amplifying
Q221
Q222,223 For ACH final current amplifying
Q225 For ACH final current amplifying
Q241,242 Mute
Q280 -3dB Attenuator circuit
Q282 -3dB Attenuator circuit
Q401~410
Q411,412 For temperature compensation bias
Q415~422
Q423~426 For BCH final current amplifying
Q443,444 Mute
Q481,482 -3dB Attenuator circuit
Q601 For shock noise prevention
Q602 P-CON ON/OFF processing
Q603 Mute driver
Q604 +B SW
Q605 P-CON ON/OFF processing
Q606 For BU excess voltage detection
Q610
Q611~614 For output DC abnormal voltage detection
Q615~618 For shock noise prevention
Q619,620 Logo LED power supply
Q621~628 For temperature detection
For ACH voltage amplifying step differential amplifying
For BCH voltage amplifying step differential amplifying
For BCH voltage amplifying step differential amplifying
For excess current detection and excess current
protection
ADJUSTMENT
No. ITEM ALIGNMENT POINT METHOD ALIGN FOR NOTE
VR1 (ALch)
IDLE VR2 (ARch)
1
CURRENT VR3 (BLch)
VR4 (BRch)
Connect a DC voltmeter
between check land 2.5mV
(Refer to PC BOARD)
After Power on
5 minutes
3
A B C D E
R671
W
C
D
K
KAC-8402/8452
1
PC BOARD (FOIL SIDE VIEW)
AUDIO UNIT
BLch 2.5mV
ARch 2.5mV
X09-5840-1x A/2
(J76-0074-11)
2
TH602
BE
Q626
W562
R437
W575
EB
R441
Q419
Q415
EB
Q417
EB
Q421
R442
EB
R436
W357
R454
W358
R434
EB
R444
W362
W361
W365
R433
W355
R459
W356
R435
R443
W360
W352
D403
3
BRch 2.5mV
4
D405
D408
DC voltmeter
EB
EB
EB
Q422
Q418
Q416
D404
Q420
5
CN1
216
117
W363
W359
6
W342
C300
W351
W341
W350
W346
W347
W348
W349
C371
R300
W344
W345
C316
C107
C422
C420
R430
R438
C315
W343
W571
R371
D107
R440
R432
W565W566W567
W568
W569
W570
C156
R439
R198
R429
C419
C421
R431
W563
D461
D459
W564
D460
W561
TH601
C332
R326
R325
C331
R395
C150
C326
R196
C126
R396
R398
W340
C356
C324
LINE OUT
Q425
Q426
C334
14 8
R312
R311
C333
C313
C350
R195
DC voltmeter
C3
W325
Q423
W318
EB
R445
Q622
BE
R639
E
B
BEBEB
E
EB
W558
R324
C314
IC2
R323
W559
C303
D300
R394
R194
Q424
C338
C337
R303
C301
Q411
W335
W336
Q412
W556
W557
R301
W319
W326
W333
W323
R473
W334
W327
W313
W328
W324
W331
R448
W329
W337
R460
W322
W315
W330
R418
R416
W338
C306
R308
R310
R372
R306
W554
W555
71
R305
D301
W311
C305
R307
R309
W314
W321
W316
W317
W320
R304
C302
R302
W332
C304
J1
BA+B A
LINE IN
R2
R447
W303
W312
C415
C908
W540
R457
C910
R421
W553
R413
R474
C409
W550
R446
W551
R426
BR
R458
VR4
C911
R414
C410
Q410
EB
D463
W304
W307
W308
D302
W309
R370
W305
W310
W306
W552
W301
W298
W299
C103
R103
C171
C101
R101
R171
D100
C5
W296
W548
EB EB
W293
W294
R214
R425
VR3
R417
R453
W549
C416
C909
R420
C115
R104
C102
W300
W572
D4
-VCC +VCC
Q2
W290
W291
R274
BL
E
W302
C116
134679
C913
C210
Q409
D462
R419
C412
R422
C132
R126
R125
C131
R102
C212
Q206
B
E
W289
C264
R264
R212
C208
Q405
B
B
Q407
C411
R455
C407
C463
W295
EB
EB
Q406
R424
C408
C464
W297
R464
W547
C134
C34
R124
C114
14 8
R112
IC1
17
R111
C33
C113
R123
C133
W287
C309
W292
R313
R317
C104
R321
9
10
C124
SPEAKER
R222
Q208
EB
R224
E
W576
EB
R256
W288
E
E
R423
R407
R411
R463
C414
Q408
R408
R412
C106
W545
C105
W546
W282
R315
R319
J2
LEVEL
INPUT
Q1
Q204
Q202
C413
B
EB
EB
W544
R108
R106
R105
R107
W285
D3
R208
C206
W541
W542
W277
D457
C405
Q403
C406
R452
Q404
W543
R110
R109
C310
R320
1
2
R322
B
C218
C204
W539
R451
C417
W115
R172
D101
C4
R1
R206
R204
R405
W260
W537
D458
EB
C418
W286
R170
W538
R316
R318
C214
D152
EB
W573
W269
W270
W271
W272
R220
R210
R280
R409
Q401
Q402
C404
R314
R118
C202
R410
W280
R261
W276
R213
R228
C403
R406
R428
W284
D102
C311
C912
C209
C401
W253
C402
R120
W535
W283
R427
R403
D430
R404
C312
C112
W275
Q443
R465
R466
R628
R119
W278
W536
R480
C100
R100
R114
R121R122
Q205
W281
W268
BE
C211
C261
BEBE
Q444
W265
Q614
D614
R116
R117
C2
C263
R401
Q481
BE
W273
W274
W261
C207
R486
W258
W267
R637
R633
C610
BE
Q623
W264
EB
R263
W266
R488
Q482
W534
C607
R636
C111
W244
W245
W532
BE
R640
Q627
W516
TH603
EB EB
Q220
W246
W247
W241
R221
Q207
EB
R223
R207
EB
R255
Q203
R211
C217
C201
R461
R284
D295
R481
D495
W533
W254
R484
W255
BE
W256
W242
W263
W262
W259
W257
D613
R632
R634
Q613
BE
BE BE
C609
Q611
R115
R113
C109
C110
R246
W224
R219
C213
D251
R205
C205
EB
R209
Q201
C203
R203
R227
W249
Q241
R285
BE BE
Q280
R282
W227
W228
W232
W240
W234
W235
W236
W238
W230
W243
W233
W251
W248
W252
Q610
R629
R617
BE
Q612
R635
C451
R266
W214
R201
Q242
W531
Q282
W231
R622
BEBE
W528
W529
W530
R471
D229
W239
R623
W220
W221
C606
R620
C608
W226
W527
R287
R265
W225
W223
W229
R621
BR
W370
J8
SPEAKER OUTPUT B
W219
W217
Q621
R638
W222
W216
W218
W215
R258
W339
BE
C450
W213
R248
W209
W353
EB
W210
W211
W212
DC voltmeter
W524
W525
R260
EB
Q213
W193
W208
W522
W205
W526
R273
C461
W104
Q625
W204
W207
W166
W206
W203
W250
BL
R470
W195
W197
W198
W199
W190
W202
W194
W523
W201
W191
W200
R238
Q222
W196
R244
R230
W192
W279
W185
W189
C220
W520
W521
W187
W173
Q212
C222
W186
W188
EB
W178
W118
R232
R234
W184
W177
R240
W182
W183
W181
-B
D204
W519
W179
W180
R216
W517
BE
W171
W172
W518
W161
W167
D261
D618
R656
W163
Q216
Q210
R657
W175
W176
BE
W174
AR
R262
C7
R4
R654
Q225
R218
W168
W169
R625
W170
C251
SPEA
W149
C902
R905
W158
VR2
AR
D617
W560
R655
W165
Q218
W164
W162
R271
7
4
Q210
ALch 2.5mV
JIHGF
KAC-8402/8452
1
DC voltmeter
D254
W135
R609
C603
W141
W113
R6
R606
BEBE
W134
R251
C6
D605
R607
Q602
W506
R245
C8
R615
Q620
C215
D603
BE
D61
R243
R5
R612
W133
R611
W114
BE
W112
BE
EB
TH604
W129
W136
Q604
W138
Q608
J3
Q221
C906
W128
W125
EB
EB
R235
W505
W515
Q223
EB
BE
Q628
C605
W132
D609
C922
D205
Q624
R239
GND
R231
Q217
C221
C219
L3
R259
W131
R229
C1
R237
W126
EB
D203
R233
Q215
W120
W121
TH605
W122
W123
W124
L2 L1
W137
Q219
C10
W354
R241
W116
L4
D6
W3
C11
W237
W2
W117
W111
W108
W109
W368
W369
W110
W367
D5
W364
W366
Q3
SDGSDGSDGSDGSDGSDG
Q7
Q5
Q4
Q8
Q6
W13
W14
D2
D1
BU
Q218
R262
Q225
W149
71
72
W158
18
167
BE
VR2
AR
R218
C7
R4
C611
D617
W560
R657
R654
R655
R671
W174
W168
D615
R658
W164
7
W574
W169
W175
R625
C902
R905
W170
W176
W162
W165
163
W157
AR
R271
C251
61
Q214
D206
EB
EB EB
W154
W155
C617
R643
R903
P1
W160
R247
W153
C216
R226
R668
BE
R662
R670
W159
R624
85
IC6
14
R904
R907
C903
W147
R236
W151
C250
Q618
BE
W156
R648
R906
W150
W513
Q616
R644
R642
W152
W514
C616
R666
R669
R667
R664
R649
W148
C907
EB
W512
D616
R659
W511
W145
R902
R270
R641
BE
R661
R608
R660
R215
+B
R3
BE
W144
R242
W510
Q617
BE
W146
Q603
R604
R603
D260
Q615
C601
W509
R665
D604
R605
D601
AL
Q209
R663
W127
C602
R613
EB
D602
W140
W508
W142
BE
D610
Q601
D253
R257
W130
W143
Q211
R225
R217
Q606
Q605
Q619
R602
R618
R616
D255
C604
R627
D606
BE
D607
W139
W507
VR1
BE
EB
AL
C9
R610
R614
X09 B/2
D600
13
WH1
C600
2
X09-5840-1x
Ref. No. Address
IC1 5C
IC2 5B
IC4 5I
IC6 5F
Q1 2C
Q2 2C
Q3 3H
Q4 4H
Q5 4H
Q6 5H
Q7 4H
Q8 4H
Q9 4I
R7R8
W577
R14
R12
BE BE
W504
Q12
W503
Q13
BE BE
Q9
W502
Q11
R10
D10
BE
BE
Q14
W103
R13
R11
Q10
R9
Q10 4I
Q11 4I
Q12 4I
Q13 4I
Q14 4I
Q201 4D
Q202 3C
Q203 4D
Q204 3C
Q205 3D
Q206 3C
Q207 3D
Q208 3C
Q209 3F
Q210 3E
Q211 2F
Q212 2E
Q213 2D
Q214 2F
Q215 2G
Q216 2E
Q217 2G
Q218 2F
Q219 2H
Q220 2D
Q221 2G
Q222 2E
Q223 2G
Q225 2F
Q241 4D
W106
R15
D9
C13
R23
W105
D8
R19
C14
W101
W102
16 9
IC4
18
R24
W501
C17
C16
R25
R22
C15
R20
D7
R16
R17
R18
R21
Q242 4D
Q280 4D
Q282 4D
Q401 4C
Q402 5C
Q403 4C
Q404 5C
Ref. No. Address
Q405 4C
Q406 5C
Q407 4C
Q408 4C
Q409 4C
Q410 5C
Q411 3B
Q412 4B
Q415 3A
Q416 4A
Q417 3A
Q418 4A
Q419 3A
Q420 4A
Q421 3A
Q422 4A
Q423 2B
Q424 5B
Q425 3B
Q426 4B
Q443 4C
Q444 5C
Q481 4D
Q482 5D
Q601 5F
Q602 5G
Q603 5F
Q604 5G
Q605 5F
Q606 5F
Q608 5G
Q610 6D
Q611 6D
Q612 6D
Q613 6D
Q614 6C
Q615 4F
Q616 4F
Q617 4F
Q618 4F
Q619 5F
Q620 5G
Q621 5D
Q622 2B
Q623 2D
Q624 3G
Q625 5D
Q626 2B
Q627 2D
Q628 3G
3
4
5
6
SPEAKER OUTPUT A POWER IN
Refer to the schematic diagram for the values
of resistors and capacitors.
7
5
K L M N O
KAC-8402/8452
1
PC BOARD (FOIL SIDE VIEW)
PREAMPLIFIER UNIT X08-4200-10 (J76-0070-02)
CN1
TP15
TP186
AMP-BL
ISO-BR
W62
W130
B.B.
W51
S2
S4
W57
W60
R138
R137
AMP BR
TP176
A-ISO GND-2
B-ISO-GND-2
TP7
TP175
TP5
ISO-AR
ISO-AL
W59
W44
200mV
5V
W45
W49
W46
W41
200Hz
50Hz
W38
W42
W43
200Hz
50Hz
W50
200mV
W129
5V
W52
W128
W61
W58
W55
200Hz
50Hz
C112
R124
W53
W54
TP6
ISO-BL
TP4
A-ISO-GND-1
2
S3S5
3
W65
OFF ON
Bch
W134
LPF
S6
W69
4
AB A
S1
ST MONO
W70
Ach
5
1
2
B-ISO-GND-1
W131
W63
W66
W67
W64
MONOST
31
64
R227
46
13
R226
W68
OFF HPF
610
5
W133
1
31
64
W132
31
64
HPFOFF
46
13
C111
R123
6
W56
W33
TP177
+15V
17
16
LOGO-LED
W34
TP9
AMP-AR
W48
36524136425136425136425136425
1
VR4
VR1 VR2
VR3
W47
VR5
W32
W40
TP179
FAN+B
TP181
D-GND
TP180
TP187
AMP-AL
W39
W36
R243
R244
W27
Bch LOW PASS
R121
R127
R128
Ach HI PASS
W35
W37
W29
W127
W126
W125
W31
TP178
R239
W123
R126
W30
15V
C229
W124
C129
W28
W122
R240
W121
C132
C221
R601
W117
Bch INPUT SENS
R220
W116
W118
Bch HI PASS
W119
R233
C222
TP300
Ach INPUT SENS
W120
R203
C230
R246
TP270
14
IC1
85
TP255
C124
R130
R122
W20
W21
W22
W23
R218
W17
W18
R234
W19
C224
W15
W16
R208
R219
R229
R228
TP266
C201
TP267
R207
TP262
C213
IC4
C214
R248
C232
C210
C206
41
IC8
58
TP269
C205
R209
R217
C211
R241
14
C223
85
C218
TP263
R242
C212
R222
C220
R133
TP253
W113
W14
W13
R224
R210
TP268
C209
C217
C103
R129
R237
R247
W110
W111
W8
R147
C122
W12
R134
W10
W107
R216
R202
W11
C202
W4
W108
W106
C228
R225
R204
C208
C219
W105
TP256
C113
TP301
C114
R135
C104
TP264
R238
TP265
R215
TP258
W7
R141
IC5
W5
R206
C226
41
IC7
58
R205
C225
C215
W104
R258
R259
TP259
14
IC6
85
TP302
R213
C204
R221
R214
W6
14
85
C123
R142
TP251
C118
C216
W3
C117
W102
C227
TP257
R211
C207
W2
R148
W1
R212
C203
W101
TP234
13
CN3
R604
X08-4200-10
Ref. No. Address
IC1 6M
IC4 4M
IC5 6N
IC6 4N
IC7 3N
IC8 3M
7
Refer to the schematic diagram for the values of resistors and capacitors.
6
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