Kenwood KAC-819 Service manual
POWER AMPLIFIER
KAC-819
SERVICE MANUAL
Heat sink
(F01-1655-01)
C
2001-1 PRINTED IN JAPAN
B51-7691-00 (4) 3376
Accessory
(W01-1515-05)
Screw set
(N99-1587-05)
KAC-819
SP P-CON Switching Circuit
When the SP output from the head unit is connected to SP IN, the power can be switched ON/OFF based on the
DC voltage of the SP output. However, As certain haed unit models output DC permanently or generate a click
during switching OFF, it is required to provide the capability of previous P-CON switching. A circuit which can
perform the switching without using a switch is described below.
This circuit performs switching by inhibiting the operation of the S-P-CON circuit when a voltage is applied to the
P-CON pin.
Circuit operation description
When the head unit is connected to SP-IN, the DC component in the SP output turns Q38 ON through D32 and
R158.
When a voltage is applied to the P-CON pin under this condition, Q45 is turned ON via R188, positive feedback is
applied by combination of Q45 and Q46, Q45 and Q46 are held at ON, so the voltage at point (A) is almost 0V and
the SP-P-CON circuit is not activated.
This circuit holds the ON status while the DC voltage from SP is present.
Therefore, in this condition, the P-CON circuit continues functioning. To cancel the functioning, the voltage at the
SP-IN pin should go 0V.
to P-CON terminal
from SP-P-CON
CIRCUIT DESCRIPTION
D29
7.5V
Q46
A
+
10u35
R158
4.7K
D32
R188
100K
power control
Q38
3.3K
Q45
ADJUSTMENT
No. ITEM FIG.
INPUT
SETTINGS
OUTPUT
SETTINGS
Connect a cassette receiver or other receiver.
1
IDEL
CURRENT
Connect a DC
voltmeter to CN3
TUNER
(RECEIVER)
SETTINGS
Volume : 0
ALIGNMENT
POINTS
VR3
ALIGN FOR
After sufficient aging
adjust to 2mV
--
2
B CA D E F G H I J
R3
R1
W74
W75
R12
R20
C46
C52
R194
E
C51
L1
W123
S
D
G
W202
W201
W118
R136
S
R138
G
D
R134
SDG
W122
R133
C55
W114
W115
W113
R159
TH2
R188
R153
R152
R154
E
B
W95
W89
E
R158
R155
R156
R151
B
W85
R193
R169
C56
W91
W94
C70
C69
W93
W90
R226
E
W83
E
B
R227
B
B
E
W78
C79
W77
W88
R228
C68
W105
W120
W124
R139
SDG
R137
R135
W125
W121
W102
W109
W110
W107
W108
W106
R132 R131
C54
W101
C53
R143
R114
R112
W100
R116
W119
R141
BE
W103
W104
R157
R140
BE
EB
EB
8
W112
W117
C59
C58
R144
W116
9
C8
W99
BE
R113
R111
R115
BE
R117
C67
R119
EB
R118
R120
BE
W35
1
C57
R142
16
C10
B
BE
E
R179
R160
L2
W86
R170
R173
C75
W97
W92
EB
EB
R172
R174
EB
B
R176
W84
W82
C35
C34R18
R67
R62
R63
R68
EB
C76
R183
W81
R181
R177
BE
BE
R180
EB
C31
W79
C32
R61
R16
C11
R182
W98
C65
R171
C66
R175
R178
R229
R24
R22
R21
C7
C9
R23
W96
R2
W87
R186
R185
R184
C4
W80
C2
R7
R4
R6
R5
R101
W15
W27
E
W17
R103
R73
W7
R187
R164
W28
W34
R162
W40
W48
W46
R224
C44
R95
R225
C45
C78R96
C42
C77
K1
R109
B
C63
E
R108
W32
8
R107
C71
C72
R163
R161
R75
R72
W62
C43
W63
W66
W65
R17
W70
W69
W73
W76
W68
R79
R93
R74
BE
W41
W30
W47
W45
R19
W33
B
C48
R71
EB
R81
EB
R80
W29
W31
W16
EB
R110
C64
C74
R168
R167
C73
R165
B
R166
1
E
TH1
R85
R87
W6
W8
R89
W5
BE
W2
W3
W20
W25
W22
W13
B
R90
E
R51
C24
C25
W24
R83
W71
R10 W53
R70
C33
W67
R64
R65
C37
R69
W54
W55
C36
E
C39
B
R29
R26
R66
R14
R15
W72
R11
R25
R13
R28
R8
C12
C47
W52
W51
W44
C38
EB
C61
R105
C62
R106
EB
EEB
B
R82
W36
W39
R78
W49
W50
R27
C6
R9
R44
R52
R43
C21
41
W58
C5
C13
W64
W61
W59
W60
C1
R30
7
8
C15
R35
R34
C14
R36
C3
VR1
W57
R40
W56
R39
R32
R31
W37
14
W42
1
C19
R33
C18
R38
R41
R485R45
8
C17
R37
C16
W43
R47
W38
VR2
R49
R50
R86
W1
R104
W21
VR3
C40
B
R77
E
R76
W11
W12
W10
W9
EB
R92
R102
W14
R91
W23
W26
R84
W19
W18
R88
BE
R46
W4
R42
C20
C23
C22
X09 B/4
X09 C/4
J2
E2
CN4
Q36
D31
Q34
D28
Q35
Q38
J3
D30
Q37
J4
D29
D32
Q39
Q45
Q46
E1
J1
WH1
X09 D/4
D101
D40
Q33
D27
D25
IC3
D26
Q31
D33
Q30
Q32
Q29
Q18
Q17
Q19
Q20
Q23
Q44
D34
D100
Q22
Q40
Q25
D21
D37
Q2
D24
Q26
Q21
Q1
Q24
D36
D35
CN2
D22
D23
D38
CN1
CN5
E3
D7
D11
Q28
J5
Q27
D14
D13
D15
D17
D16
D20
D18
D19
IC4
Q5
D12
D6
Q7
D9
Q8
Q41
X09-5360-10 A/4
(J74-1030-21)
CN3
Q12Q11
Q3
D5
Q4
D10
Q15
Q16
Q9
D3
D4
Q10
IC2
IC1
D1
D2
S2
Q6
D8
Q13
Q14
S1
OFF/6dB/12dB
BASS BOOSTINFRASONIC
OFF/15Hz/25Hz
PC BOARD (Component side view)
1
2
3
4
5
6
AUDIO UNIT (X09-5360-10)
X09-5360-10 A/4
(J74-1030-21)
Q41
R168
EB
W16
C64
R110
Q28
R165
EB
R164
C72C73
R108
W32
Q27
R163
EB
C63
R109
R107
D13
D14
D17
R96
J5
R225
J4
R151
R153
D30
R152
J3
W201
CN4
C74
W8
R167
18
IC4
C71
D16
D15
C42
C77
C78
C44
R95
R156
D29
Q38
BE
EB
R154
Q37
R166
D19
C45
D31
W202
Q36
R224
R155
R187
R161
D20
D18
R193
W85
W89
W95
DSG
W34
R162
W40
W46
W48
R158
L1
R169
CN3
C70
R87
C43
R188
BE
Q39
D32
W123
X09 C/4
W7
R227
C69
C56
W6
C46
Q46
EB
W83
Q34
BE
BE
EB
W115
W73
W76
R77
D7
BE
C61
R105
D11
W55
C51
BE
Q15
L2
W51
W52
W53
W54
Q33
R194
VR3
R106
W44
C37
SDG
W21
Q16
R69
R18
C34
D100
R104
C62
R70
C35
R135
D10
C36
R139
R76
C40
R68
BE
C33
W84
D27
D5
R90
R101
W15
W17
W20
W22
W25
W27
W29
W31
R103
EB
D9
R73
R75
R20
C52
Q44
W90
W113
W114
W122
EBBE
R85
R89
R19
W45
W47
D12
W63
W65
W66
W78
C79
R226
BE
Q45
W91
W93
W94
W118
SDG
R138
W77
W33
K1
D28
W30
R17
W28
W62
TH1
W5
R159
TH2
W41
R136
W2
W3
W13
R81
R80
Q8
Q7
C48
R71
D6
R72
Q5
R74
R79
R93
W70
W69
W68
W88
R133
C55
R134
SDG
Q35
X09 B/4
E2
J2
R67
Q6
C38
R64
R137
C47
EB
Q2
R63
W86
Q40
BE
BE
R65
W1
R83
R82
W82
C39
D34
EB
EB
Q4
Q3
W67
R62
R176
R86
EB
Q1
D24
R132
R131
W110
Q13Q11Q12
W11
C21
W50
EB
R177
W121
W125
R44
R43
R61
R52
W49
R12
C31
W101
W102
C25
R10
R13
D4
R27
R8
R11
EB
Q22
EB
Q25
W108
R92
R14
R15
W97
R16
C76
D25
R102
41
W39
D3
R25
R180
R172
W107
W10
R26
C11
R183
R174
D8
R179
IC2
R9
C6
C12
R28
R181
D37
R173
C75
W106
W72
W9
W42
R29
Q23
EB
C68
W105
W120
R88
R84
W18
W19
C24
8
R48
5
17
IC1
C13
R30
W61
W64
W71
W75
W80
R186
R184
R185
R182
R178
D23
R175
BE
Q24
C65
R171
D36
D35
C67
Q19
W104
W103
W124
D26
BE BE
W12
W24
Q10
Q9
W36
R78
R66
W79
C32
W81
Q21
Q26
EB
D21
W92
R160
EB
R170
C54
C53
W109
X09 D/4
E1
J1
WH1
R51
R45
W99
W60
W74
R119
Q17
W23
W26
R41
814
C66
W100
D101
W59
D1
EB
EB
R38
D22
R117
D33
R115
D2
W98
R35
R34
CN1
R120
R141
(X09-5360-10)
Ref. No.
Q14
C22
W4
R91
R37
C17
C18
C19
R33
C14
R36
C15
C1
C2
C4
R229
D40
R118
EB
EB
Q18
R113
R111
R116
R157
W119
BE
Q31
C20
W14
R42
R46
C23
C16
R49
R50
VR2
R32
R31
R47
W37
W38
W43
VR1
W57
W58
R40
C3
C5
R1
R5
R7
R4R3
R2
R6
W87
C9
C7
W96
R23
R22
CN2
C8
Q20
R228
R114
C59
EB
Q29
D38
R21
R24
C10
W35
C57
1
R112
R142
R143
C58
R144
8
W117
W112
EB
EB
Q32
Q30
W56
CN5
IC3
W116
R140
S2S1
R39
E3
16
9
OFF/15Hz/25Hz
OFF/6dB/12dB
BASS BOOSTINFRASONIC
IC1
IC2
IC3
IC4
Q1
Q2
Q3
Q4
Q5
Q6
Q7
Q8
Q9
Q10
Q11
Q12
Q13
Q14
Q15
Q16
Q17
Q18
Q19
Q20
Q21
Q22
Q23
Q24
Q25
Q26
Q27
Q28
Q29
Q30
Q31
Q32
Q33
Q34
Q35
Q36
Q37
Q38
Q39
Q40
Q41
Q44
Q45
Q46
Address
3D
2D
5E
2B
3C
3C
3C
3C
3C
2C
2C
2C
2C
2C
2C
2B
2D
2D
2C
2C
5D
5D
5D
5D
4C
4D
4D
4D
4D
4C
2A
2A
6D
6E
6D
6D
6C
6B
6C
6B
4B
4B
4B
4C
2B
4C
4B
3B
PC BOARD (Foil side view)
AUDIO UNIT (X09-5360-10)
(X09-5360-10)
Ref. No.
Address
IC1
3G
IC2
2G
IC3
5F
IC4
2I
Q1
3G
Q2
3G
Q3
3G
Q4
3G
Q5
3H
Q6
2G
Q7
2H
Q8
2H
Q9
2G
Q10
2G
Q11
2H
Q12
2H
Q13
2G
Q14
2F
Q15
2H
2H
Q16
5G
Q17
5F
Q18
5G
Q19
5F
Q20
4G
Q21
4G
Q22
4G
Q23
4G
Q24
4G
Q25
4G
Q26
Q27
Q28
Q29
Q30
Q31
Q32
Q33
Q34
Q35
Q36
Q37
Q38
Q39
Q40
Q41
Q44
Q45
Q46
2I
2I
6F
6F
6F
6F
6H
6I
6H
6I
4I
4I
4I
4G
2I
4H
4I
3H
7
Refer to the schematic diagram for the values of resistors and capacitors.
Refer to the schematic diagram for the values of resistors and capacitors.
3
4
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