Kenwood KAC-8101D, KAC-8151D Service Manual

POWER AMPLIFIER

KAC-8101D/8151D

SERVICE MANUAL

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© 2003-2 PRINTED IN JAPAN
B53-0040-00 (N) 3114

Heat sink
(F01-1729-11)

Dressing panel
(A21-4271-03) : KAC-8151D
(A21-4288-03) : KAC-8101D

Connecting cord assy
(E30-6145-05)

Screw set
(N99-1740-05)

Accessory
(W01-1606-05)

Screw set
(N99-1587-05)

Dressing plate
(B03-5024-14)

Panel

5

KAC-8151D only

Control assy

Knob
(K23-1076-03)

KAC-8151D only.

(A64-3054-02)
: KAC-8151D

(A64-3094-02)
: KAC-8101D

Rear panel
(A84-0348-02)

Modular cable
(E30-6240-15)

KAC-8101D/8151 D

WIRED
REMOTE
CONTROL

+0/+6/+9/+12dB

BLOCK DIAGRAM

INPUT

BATT

P. CON

GND

ISO AMP

+

VOL BOOST

0.2-5.0V

CONVERTER
SW

COMPONENTS DESCRIPTION

BASS LOWPASS INFRASONICINPUT

+12dB/OFF 50-200Hz

-15V AVR +15V AVR

TRANSFORMER

FILTER FILTER

THERMAL
PROTECTION PROTECTION

OFF/15/25Hz

D CLASS AMP

COMPEARATE

++

AMP
(DEA T TIME)

EXPANDER
ON/OFF MUTE

TRIANGLE
WAVE

OVELOAD DC OFFSET

POWER
AMP

PWMMIX

PROTECTION

OUTPUT

OUTPUT

AUDIO UNIT (X09-5480-1x)

Ref No. Application / Function

IC1 Isolation amplifier
IC2 Bus boost amplifier

IC3

IC4 Expander amplifier
IC5 DC detection rectification amplifier
IC6 Expander detection and difference output

IC7

IC8

IC9

IC10,11 Dead time generator
IC12 Bus boost level changer
IC15 DC/DC converter
Q1 Mute
Q3~5 Output FET control (current amplifier)
Q7~10 Output FET control (current amplifier)
Q11~14 Output FET driver

(1/2) : Lowpass filter amplifier
(2/2) : Infrasonic amplifier

(1/2) : Triangular waveform generation
(2/2) : Summing amplifier
(1/2) : ASO (current, voltage comparison) detection
(2/2) : DC converter control
(1/2) : Triangular waveform generation
(2/2) : PWM waveform generator

Ref No. Application / Function

Q15,16 Output FET
Q17~20 Speaker output current detection
Q21,22 Output FET control power supply and control
Q23~25 DC protection
Q26,27 ASO DC detection
Q28 IC8 (2/2) output logic invert
Q31 Reduced voltage protection
Q32 Over voltage protection
Q34 DC/DC converter power supply
Q36 DC/DC converter control
Q37~40 Power FET driver
Q41~46 Power FET
Q47~50 Small-signal ± power supply

Q51,52

Q53 Power FET control power supply
Q55 Mute, LED and protection control
Q61~64 Power FET driver
Q65,66 Power FET

When OFF, quick break in a circuit of – power
supply for small-signal circuit

2