Kenwood KAC-8404 Service manual
POWER AMPLIFIER
KAC-8404
SERVICE MANUAL
© 2007-11 PRINTED IN JA PA N
B53-0600-00 (N) 519
Fuse (40A)
(F52-0016-05)
FUSE[40A] P.CON
4/3/2 Channel
4/3/2 Channel
POWER IN
LEFT
BRIDGED
SPEAKER OUTPUT
RIGHT LEFT
BRIDGED
SPEAKER OUTPUT
Dressing Panel
(A21-6635-02): (E,K type)
(A21-6636-02): (M type)
E,K type
M type
RIGHT
SP LEVEL INPUT
SIGNAL SENSING
LINE IN
TURN-ON
Accessories
(W01-1606-05)
Screw & wrench key set
(N99-1820-05)
This product complies with the
Connecting cord assy
(E30-6144-05)
19cm
This product uses Lead Free solder.
RoHS directive for the European market.
2
KAC-8404
X09-874 X08-443
F.P.H
F.P.L
F.P.H
F.P.L
F.P.H
F.P.L
F.P.H
F.P.L
Q710
F
Q301,315
SENS.
VOL
IC4
Q302,316
Q401,415
SENS.
IC4
RETLIF CL
NAF
RVA
NAF
VOL
Q402,416
POWER
INDI.
TTA
TTA
TTA
TTA
P- CON
BATT.
GND
Q303
Q304
Q403
Q404
ETUM
ETUM
ETUM
ETUM
POWER AMP
POWER AMP
POWER AMP
POWER AMP
50W x4c h / 4
75W x4 ch / 2
AL
(INV)
BL
(INV)
AR
BR
SP
OUTPUT
BLOCK DIAGRAM
SP
OUTPUT
(0.2V~5.0V )
LINE IN
SPEAKER LEVEL INPUT
L..P.F / OFF/ H.P.
)Bd21-( zH002zH05 F.P.L
)Bd21-( zH002
B.Boost SEL.
TESFFO-CD
IC5
Q703
DAOLREVO
zH05 F.P.H
IC5,7
IC5,7
Q701-704
Q707,708
ssaB
tsooB
40Hz
+18dB
ssaB
tsooB
TED
B
LANGIS
ROTCETED
IC3,4
LA
RA
LB
RB
+L
-L
-R
+R
+L
-L
-R
+R
PMA
-OSI
IC3,4
-OSI
PMA
IC1,2
IC1,2
ST /
MONO
SEL
PMA-OSI
PMA-OSI
ST /
MONO
SEL
Q709
TED
Q11,12
15V
RVA
IC2
IC3
IC2
IC3
IC8
IC9
IC8
IC9
LAMREHT
TED
TH1
CD/CD
NOC
REWOP
FFO/NO
NOC-P
YTIROIRP
X08-443
KAC-8404
COMPONENTS DESCRIPTION
PREAMPLIFIER UNIT (X08-4430-10)
●
Ref. No. Application/Function
IC1-3 HPF, LPF
IC4 Reverse circuit
IC5,7 Bass Boost
IC6,8,9 HPF, LPF
IC10 Attenuator circuit
Q301,302,315,316,
Q401,402,415,416
Q303,304,403,404 Mute circuit
Q305-308,Q405-408 Differential circuit (First stage)
Q309,310,313,314,
Q409,410,413,414
Q311,312,411,412 Current mirror
Q701-704 DC protection
Q705-708 Shock noise mute
Q709 Over current detection
Q710 Stabilized power supply
Attenuator circuit
Differential circuit (Second stage)
AUDIO UNIT (X09-8740-10)
●
Ref. No. Application/Function
IC1-4 Isolation circuit
IC5 DC-DC IC
Q1,2 Switch
Q3-6 Gate driver
Q7-10 DC/DC comparator
Q11,12 Constant voltage circuit
Q301,302,401,402 Temperature compensation
Q303-306,Q403-406 Over current detection
Q307-310,Q407-410 Darlington
Q311-314,Q411-414 Final stage
Q701 Voltage supply
Q702 Over voltage detection
Q703 P-CON
Q704,705 Mute driver
Q706 Shock noise mute driver
Q707,708 Auto P-CON driver
ADJUSTMENT
No. ITEM ALIGNMENT POINT METHOD ALIGN FOR NOTE
1 IDEL CURRENT
B-Lch 2.5mV
DC voltmeter
-
+
Q413
Q411
Q412
Q414
VR5 (A-Lch)
VR6 (A-Rch)
VR7 (B-Lch)
VR8 (B-Rch)
B-Rch
W8
R419
R420
Connet a DC voltmeter
between check land
(Refer to a fi gure)
A-Rch
B-Lch
VR7
VR8
X08-443 (B/2)
VR6
A-Lch
VR5
Q314
W83
A-Rch 2.5mV
DC voltmeter
Q312
R320
W98
R319
2.5mV After Power on 5minutes
+-
Q313
Q311
A-Lch 2.5mV
-
+
DC voltmeter
B-Rch 2.5mV
DC voltmeter
+
-
W45
3
A B C D E
3
KAC-8404
1
PC BOARD (FOIL SIDE VIEW)
AUDIO UNIT
X09-8740-10 (J76-0471-01)
2
R313
Q313
EBEB
EB
Q309
E
C301
Q301
B
R309
E
Q307
R311
3
Q311
R303
B
R301
W31
W98
R319
R321
Q305
BE
R307
R317
D303
C305
C12
W90
D304
D302
Q308
W89
R302
BE
BE
W88
Q312
EB EB
R320
Q304
W87
R315
R305
C303
Q303
D301
BE
W95
W77
C13
D6
W103
W91
W92
W100
4
D7
R20
Q8
R22
C7
C8
TH1
L2
W81
W82
Q10
Q7
R23
C9
5
Q5Q6
R16
R14
R18
R15
BE
W313
BEBEBE
Q3
6
Q4
Q2
BE
W2
R19
R21
SDG SDG SDG SDG
Q9
R13
BE
Q1
W312
C2
W104
R17
D5
W99
W101
W102
W309
W97
C4
W906
W94
C6
R5
D4
C3
R4
W306
W308
18
IC5
169
R1
R7
C5
C1
R28
W307
D3
D1
W299
W291
R8
W292
R10
W298
W293
R9
D2
R11
W294
R2
R704
W297
W295
W300
R12
W301
W302
R3
W303
W305
W304
W296
BE BE
Q703
R707
D701
D705
R711
W289 W288
W290
Q702
R706
R710
D704
D703
BE
R708
W1
Q704
W287
W285
W286
R702
W284
W282
R709
D706
R713
W283
W280
W281
D702
W278
W279
Q705
D707
BE
R712
R703
Q302
Q310
BE
W79
W80
R306
W84
W85
W268
W269
C302
W76
W265
R304
W310
BE
W78
W266
W264
W263
122
111
R312
W93
W83
R310
R316
C304
W271
R332
CN33
W270
R331
W262
81
WH5
R25
W74
C11
C10
R24
W75
R715
W277
EB
R701
R705
L3
W273
W274
W276
W275
R716
R714
R724
C706
W272
Q701
D713
R723
Q707
R722
BE
BE
Q708
R726
R725
W267
BE
C702
Q706
C703
R323
D708
W70
W258
C704
C701
W71
W261
W72
C705
C307
W67
W68
W259
W64
W73
W260
R721
W69
R322
W256
W257
W254
W255
W66
W65
W63
P1
R324
Q314
W60
W61
W62
R717
W58
W59
R719
W56
W57
C308
R718
R308
W54
W55
C306
W253
R720
R314
R318
W52
W106
W86
D710
W50
W48
W105
W53
W51
W49
W47
Q306
BE
W40
C16
W249
W41
W42
W43
W44
W247
W246
W252
W248
W245
C211
R215
C207
R217
C209
14
IC4
58
C208
R216
C210
R220
C218
W250
W45
R423 R424
R219
W251
W46
C217
R218
C212
W244
W238
C14
W242
W239
W240
R727
W243
C216
C214
J3
W38
R213
D8
D709
C407
W241
R214
R26
W39
W37
W236
Q11
W36
W237
EB
C17
W234
W235
7
W231
W232
CN1
J4
W35
W23
28
7
4
W235
EB EB
R27
W34
W35
C17
W233
W234
CN1
28
17
W231
W232
C206
R424
J4
D9
W33
R205
C205
1
4
IC3
58
R210
R206
C408
C15
R209
C215
C213
R211
R212
R207
R208
W32
Q12
W230
W31
R431
W30
W227
W228
W229
C100
CN44
W226
W29
W225
D201
D202
R100
W28
28
W25
C204
W24
W19
W20
W22
17
W21
W27
W224
W223
W26
D101
D102
R204
R432
R106
C115
C202
R202
J1
W23
W221
R108
C106
IC1
58
C105
R105
R203
C201
W222
D103
R201
R112
R110
R109
C203
C122
JIHGF
KAC-8404
1
X09-8740-10
Ref. No. Address
IC1 6G
IC2 5G
IC3 6F
IC4 6E
C405
R407
EBEBEBEB
W9
R417
BE
Q405
Q409
D403
W8
W11
W15
R405
C403
EB
Q403
EB
Q407
R411
R409
W16
W12
W10
EB
Q404
Q408
BE
R402
W217
D404
EB
W218
C406
R408
W13
W17
EB
Q410
R414
R410
W18
C118
W220
R120
R118
C112
W14
R114
C110
W215
W216
14
W214
R107
C104
W219
C113
R104
C102
IC2
W213
58
C107
R115
R113
R111
C125
W211
R103
C101
W212
R102
D203
R117
C111
C109
W210
R101
14
C103
C222
R421
R406
R404
R403
R401
R422
D402
Q406
C123
R419
R420
C404
D401
W207
R418
C114
W209
R125
C401
R416
C402
W7
C116
R119
W208
EB
C223
R129
R415
R116
Q413
R413
BE
Q401
Q411
Q412
R412
BE
Q402
Q414
W6
C108
R127
C117
W206
C225
R227
R225
C226
W205
W4
W5
W204
W3
W202
W203
C126
C224
D711
D712
C124
R228
R230
R226
R126
W201
R128
R130
R229
J2
IC5 6B
Q1 6B
Q2 6A
Q3 6A
Q4 6A
Q5 6B
Q6 6A
Q7 5B
Q8 4B
Q9 6B
Q10 5B
Q11 2E
Q12 2F
Q301 3B
Q302 2D
Q303 3C
Q304 2C
Q305 2B
Q306 2E
Q307 3B
Q308 2C
Q309 2B
Q310 2D
Q311 3B
Q312 2C
Q313 2B
Q314 2D
Q401 3G
Q402 4G
Q403 3G
Q404 4G
Q405 2G
Q406 4G
Q407 3G
Q408 4G
Q409 2G
Q410 5G
Q411 3G
Q412 4G
Q413 2G
Q414 5G
Q701 5D
Q702 6C
Q703 6C
Q704 5C
Q705 5C
Q706 6C
Q707 5C
Q708 5C
2
3
4
5
6
Refer to the schematic diagram for the values of resistors and capacitors.
7
5
K L M N O
KAC-8404
1
PC BOARD (FOIL SIDE VIEW)
PREAMPLIFIER UNIT X08-4430-10 B/2 (J76-0468-02)
X08-4430-10 B/2
Ref. No. Address
IC10 6N
CN7
2
1
VR5
A-L
VR6
A-R
VR7
B-L
2
R334
C302
C301
BE
R712
R717
R433
W267
R306
Q304
R302
BEBE
R344
R304
R339
R343
Q301
R719
Q706
W87
R342
W88
R708
BE
R308
W86
R303
BE
BE
Q311
R711
R715
W945
W99
Q316
W82
W83
R307
Q315
R713
Q708
W97
R721
W89
W96
R341
R301
C706
Q710
R434
C707
VR8
W85
W265
W75
W76
W77
R722
EB
B-R
W946
W84
W262
W81
W263
W264
W72
W80
R441
R401
W121
D704
W261
W260
C714
W78
R407
W74
R406
R402
R442
Q416
R403
W73
W71
R408
W70
W259
Q402
R404
R443
BE
Q401
R405
W69
BEBE
R444
C402
R438
R437
Q415
W256
W257
1
28
D305
D306
BEBE
Q404
Q414
C418
C423
C404
R410
R409
C403
C401
BE
Q403
BE
C422
C417
W68
W258
C711
C708
CN4
W254
W255
R416
Q406
BE
C406
C906
C905
C405
R415
BE
R724
W253
W66
W67
D406
EB
BE
Q413
W65
C710
7
R430
R414
Q405
R413
R429
R735
W251
D405
Q410
D404
R418
C408
W63
Q408
R412
R411
Q407
R417
Q409
D403
R730
R736
W252
Q412
BE
C908
C907
BE
C407
BE
BE
Q411
R725
R729
R731
W120
EB
R426
BE
C414
R422
C412
R420
R419
C411
R421
C415
C413
R425
R728
41
IC10
58
R733
R732
W61
C416
C410
W248
R726
R727
R428
R424
D402
C409
R423
R427
W60
1
2
D401
R734
CN6
W64
C709
R723
D705
W62
C712
C713
W936
R333
W119
3
CN22
W274
W118
W275
82212
711
C3
W272
W273
W115
W271
11
W117
C5
W114
CN3
4
W250
W44
8
CN5
5
1
W122
R701
D701
W276
C701
Q704
BE
BE
C702
R703
R702
C704
6
R705
C703
Q701 Q702
R706
BE
Q703
BE
R704
W116
W107
C310
W270
D702
C4
C309
W935
W111
W109
W110
W112
W108
W106
C6
R337
C319
R328
R324
D302
R326
Q310
D304
EB
C316
R322
C308
R321
W19
C312
C311
R318
R320
Q308
BE
C904
C903
W104
BE
R319
Q307
C307
Q309
BE
C315
R317
C313 C314
D303
R325
W103
D301
W105
R707
R718
R720
BE BE
Q707
W102
R330
R314
R316
Q306
BE
R312
C902
C306
C901
C305
R311
Q305
R315
R313
R329
Q313
W101
C705
R716
Q314
BE
BE
R323
BE
Q705
R709
R714
W94
W100
Q312
C318
C323
C304
R310
R309
C303
R327
R710
W90
W91
W92
W93
W95
EB
C322
C317
W98
BE
Q302
R338
Q303
R305
BE
Q709
BE
D703
Q301 5M
Q302 4L
Q303 5L
Q304 4L
Q305 5L
Q306 4L
Q307 5L
Q308 4L
Q309 5L
Q310 4L
Q311 5M
Q312 4L
Q313 5L
Q314 4L
Q315 5M
Q316 4M
Q401 5M
Q402 4M
Q403 5M
Q404 4M
Q405 5N
Q406 4N
Q407 5N
Q408 4N
Q409 5N
Q410 4N
Q411 5N
Q412 4N
Q413 5N
Q414 4M
Q415 5M
Q416 4M
Q701 6K
Q702 6K
Q703 6K
Q704 6L
Q705 6L
Q706 6M
Q707 6L
Q708 6M
Q709 6L
Q710 6M
7
Refer to the schematic diagram for the values of resistors and capacitors.
6
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