Text preview for : KAC-819.pdf part of Kenwood KAC-819 Kenwood Power Amplifier Car Power Amplifier Car Kenwood KAC-819 KAC-819.pdf
Back to : KAC-819.pdf | Home
POWER AMPLIFIER
KAC-819
SERVICE MANUAL
C 2001-1 PRINTED IN JAPAN
B51-7691-00 (4) 3376
Heat sink
(F01-1655-01)
Accessory Screw set
(W01-1515-05) (N99-1587-05)
KAC-819
CIRCUIT DESCRIPTION
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.
D29
7.5V power control
to P-CON terminal
A
D32 R158 Q38
from SP-P-CON
10u35
4.7K
3.3K
+
Q46
R188
100K
Q45
ADJUSTMENT
TUNER
INPUT OUTPUT ALIGNMENT
No. ITEM (RECEIVER) ALIGN FOR FIG.
SETTINGS SETTINGS POINTS
SETTINGS
Connect a cassette receiver or other receiver.
IDEL Connect a DC After sufficient aging
1 - Volume : 0 VR3 -
CURRENT voltmeter to CN3 adjust to 2mV
2
A B C D E F G H I J
PC BOARD (Component side view) PC BOARD (Foil side view)
1 AUDIO UNIT (X09-5360-10) AUDIO UNIT (X09-5360-10)
X09-5360-10 A/4 X09-5360-10 A/4
(J74-1030-21) (X09-5360-10) (J74-1030-21) (X09-5360-10)
Q12 Q11 Q6 Q13
Ref. No. Address Q13 Q11 Q12
Ref. No. Address
Q14 Q14
IC1 3D D8 IC1 3G
OFF/15Hz/25Hz
OFF/15Hz/25Hz
R77
C22
R77 D8 Q6
Q41 E B
Q41 E B
E B E B E B E B
INFRASONIC
INFRASONIC
C22
B E B E D7 B E
B E B E IC2 2D R102 E B D7 IC2 2G
R92
R102 R88 R88
R90
R168 TH1 IC3 5E IC3 5F
R86
W1
R86
R168
R76 R76 TH1
W3
W2
C74
C74
R84
W4
R101 R101
W2
W3
W4
R90
W5
C20
C20
W16 W16
W8
W8
C40 C40
W9
IC4 2B IC4 2I
W14
R91
W10
R84
W14
R92
W15 W15
R91
R167
R167
W18
R85
W12
R85
W12
W11
W1
W18
S1
S1
C64 W17 W17
R87
R87
VR3 W19 VR3 C64
W5
Q1 3C R42 Q1 3G
W13
R42
W9
W13
W10
W19
C73
C73
R166
R166
CN3
W20 W20
CN3
R110 R46 R46 R110
W21
Q2 3C Q2 3G
W21
W11
R89
R89
W23 W23
C23
C23
W22 W22
W6
R165
2 R165
OFF/6dB/12dB
OFF/6dB/12dB
Q28