Kenwood KAC-PS811D, KAC-X811D Service Manual

POWER AMPLIFIER

KA C-PS8 11D
KA C-X8 11D

SERVICE MANUAL

© 2004-2 PRINTED IN JAPAN
B53-0138-00 (N) 2704

Heat sink
(F01-1751-01)

Screw
(N07-0003-08)

25

25

25

POWER IN

Fuse (25A)
(F52-0014-05)

Cover
(F07-1136-12): KAC-X811D
(F07-1137-12): KAC-PS811D

Subwoofer Power Amplifier

Screw
(N09-4214-08)

5

6

4

3

2

1

0

VOLTFAN

CURRTEMP

7

8

9

MENU

RESETREMOTETO H/UID NUMBER

Screw set
(N99-1752-05)

Screw set
(N99-1577-15)

Accessory
(W01-1606-05)

KA C-PS811D/X8 11D

BLOCK DIAGRAM

LINE IN

LINE
OUT

to H/U

REMOTE

(X09-5790-10)

IC15

I2C
BUFFER

(X08-4170-10)

IC1

ISO I.F.S B.R.F INV

15/25Hz FREQ

ED1

LCD

BACK
LIGHT

IC6

LCD
DRIVER

IC16

COMPARATOR

Q1-4

ISOLATOR

IC10

IC11

RESET

THERMAL
PROTECT

CORRECTIC

IC2 IC2IC1

ON/OFF OFF/6/12 NOR/REV

FREQ

IC5

L.P.F

ACCRESSROM
SWITCH

IC4

IC3

AMP
CONT.

ON/OFFLEVEL

LED

FAN

AVR 5V SW5V 15V

Q20 84,110

+5V
SWITCH

Q106-108

AVR

IND

FAN

Q10 IC2,3 IC4,5

COMPARATOR

CURRENT
DET.

D.D CONu-COM

IC2Q9

TRIANGLE
WAVE

INPUT
VOLTAGE
MEASURE DET.

MUTE
DRIVER

Q80 IC14 Q63 Q66

POWER
SWITCH

IC13

15V

+5V
AVR

IC3

Q25,26,

29,30,

Q83

FAN
CONTROL

DEAD
TIME
CONT

Q52-55

Q15,18,19,21,22,27,

28,37-40,42-45,48-51

AMPMUTE

OVER

IC6

LOAD
DET. DET.

OVER
VOLTAGE

Q73,

D PWR

Q62

78
DC

OFFSET

P CON
DET.
DOWN
VOLTAGE
DET.

SP OUT

P CON
BATT
GND

COMPONENTS DESCRIPTION

● PREAMPLIFIER UNIT (X08-4170-10)

Ref. No Application / Function Operation / Condition / Compatibility

IC1 ISF Cutting super-low range of audio signal
IC2 (1/4~3/4) BRF Cutting bandwidth of audio signal
IC2 (4/4) INV Phase reversal of audio signal
IC3 OP amplifier Voltage amplification, Buffer
IC4 E-VOL Electronic volume
IC5 LPF Cutting high-range of audio signal
IC6 LCD driver LCD driver

● AUDIO UNIT (X09-5790-10)

Ref. No Application / Function Operation / Condition / Compatibility

IC1 Isolation amplifier Prevent noise from GND potential difference
IC2 (1/2) Triangular wave generation Reference signal for digitizing analog signal
IC2 (2/2) Error amplifier Error is compensated by the feedback from output
IC3 Comparator, Triangular wave generation Digitizing by comparison of analog signal and triangular wave

2

KA C-PS811D/X8 11D

COMPONENTS DESCRIPTION

Ref. No Application / Function Operation / Condition / Compatibility

IC4,5 NAND D class section reverse wave, deadtime, generation and rectification
IC6 Comparator Short circuit detection of SP output
IC7 Signal amplification For SP output short-circuit detection, send the output to comparator
IC10 Element operation control Communication, display, protection, etc. control
IC11 Reset Reset signal is output when voltage goes below standard voltage

IC13 DC/DC converter

IC14 Signal amplification To have µcom display current value, amplify potential differences of GND
IC15 Bi-directional buffer Send/Receive data and clock between AMP
IC16 Comparator Receive from H/U data and clock
Q1,2,5,7 Digital signal transmission Send LX-REQ-M signal to H/U
Q3,4,6,8 Digital signal transmission Send LX-DATA-S signal to H/U
Q9 Mute Mute drive signal generation
Q10 Mute Turn audio signal OFF
Q15,18,19,21,22,27,
Q28,37~40,42~45
Q16,17 Voltage control Match the beginning of the fall to +15V when -15V power supply is OFF
Q20 Voltage control 5V power supply ON/OFF
Q23,24,35,36,41,83
Q25,29,84 AVR +15V
Q26,30,110 AVR -15V
Q31,33,46,109 Voltage control D class section predrive stage power supply ON/OFF
Q47 AVR D class section first stage supplementary power supply
Q52-55 Voltage current converter Over current detection when SP is shorted
Q57,58,60,61,
Q64,65,67~70
Q59,63 Voltage control
Q62 Voltage detection Pcon detection
Q66 Voltage detection Pcon over voltage detection
Q71,72 Waveform shaping For SP output short-circuit detection, send the output to comparator
Q73,78 Voltage detection DC detection of output
Q74-77 Current amplification Switching FET drive current amplification
Q79,80 Voltage control DC/DC converter power supply ON/OFF
Q81,82 Voltage control DC/DC converter drive waveform ON/OFF
Q88,89,98,99 Voltage control 5L digital signal reception
Q95,96 Voltage control
Q97 Voltage control Normally 15V power supply and over voltage control
Q102,111 Voltage control
Q103,104 Voltage control LCD backlight and illumination LED control
Q106-108 AVR µcom system 5V power supply.

Signal amplification, switching D class section voltage or current amplification

Voltage control Fan voltage ON/OFF and limiting over voltage

Switching DC/DC converter switching

Voltage on secondary side, which produces the drive signal for switching
element, will be limited to below standard voltage

In order to have µcom display voltage value, send voltage to it only when 5V SW ON

When Comm-SW of µcom is ON, turn communication system power supply ON

When Comm-SW of µcom is ON, turn communication system 5V power supply ON

3