Components Description; Preamplifier Unit (X08-4180-1X); Audio Unit (X09-5820-1X) - Kenwood KAC-8102D Service Manual

PREAMPLIFIER UNIT (X08-4180-1x)

Ref. No. Application / Function
IC11 (1/2) INFRA SONIC FILTER
IC11 (2/2) INVERTER
IC12 (1/2) OP AMP
IC12 (2/2) BASS BOOST
IC14,15 BASS BOOST
IC13 LOW PASS FILTER

AUDIO UNIT (X09-5820-1x)

Ref. No. Application / Function
IC1 DC/DC converter IC
IC2 (1/2) Differential amplifier
IC2 (2/2) Differential amplifier
IC11 Isolation amplifier
IC12,13 NAND
IC31 Comparator
IC32 (1/2) Triangular wave generation
IC32(2/2) Error amplifier
IC51~53 OP amp, electronic volume
IC61,62 Comparator
Q1-3 PCON switch
Q4,5 Mute
Q8~11 Gate drive
Q12-20 DC/DC converter
Q25,26,28 AVR
Tracking when ±15V AVR is OFF
Q29,30
Q36 DC/DC converter ON/OFF control
Q37~38 DC/DC converter pulse ON/OFF control
Q41 4.4V AVR
Q42 AVR
Q43 DC/DC converter ON/OFF control
Q151 Mute
Q187~190 Electric power amplification
Q401~415 Pulse amplification and rectifying
Q416 15V AVR
Control of ON/OFF of electric
Q417,418
power amplification section
Q501 Emitter follower
Q601,602 Comparator
Q603 DC/DC converter control
Q604~607 Electric current and voltage conversion
Q608~611 Latch circuit

COMPONENTS DESCRIPTION

Cutting super-low area of voice signals
Reversing voice signal phase
Voltage amplification, buffer
High-boost (variable levels)
High-boost (variable levels)
Cutting high range of voice signal
Create drive signal for switching element
Detection of temperature, DC, and excess current and hold protection for a certain time
Containing excess voltage of ±B
Prevention of noise by the electric potential difference of GND
Generation and forming of Dclass section reversal waveform and dead time
Digitalize signal by comparing analog signal and triangular wave
Reference signal generation for converting analog signals to digital signals
Error compensation by feedback from output
Frequency, variable level BASS BOOST
Detection of short-circuiting of SP output and determine excess current for triggering protection
Turns on the circuit when ON-signal is impressed on PCON
Mute drive signal generation, Turn LED off
DC/DC converter FET gate drive
DC/DC converter switching
±15V AVR
Adjusts -15V' AVR falling to '+15V' AVR falling
Stops DC/DC converter switching when protection is triggered
ON/OFF of DC/DC converter drive waveform
Vref 5V reference AVR
±15V AVR
Stops DC/DC converter switching when protection is triggered
Turning off voice signal
Dclass large current switching
Generation of signal for driving Dclass final FET
Integration AVR for obtaining Dclass High+B
Makes the electric power amplification section non-operative for 1.2 seconds when the
power is turned on and when protection is triggered
Generation of temperature compensation reference voltage for control of electronic volume
Detection of short-circuiting of SP output and determine excess current for triggering protection
Convey IC62 u pin output, result of excess current detection, to IC2 and stop the DC/DC converter
Conversion of current to voltage of the current flowing to final
Detection and holding of output excess voltage
KAC-8102D/8152D
KAC-9102D/9152D
Operation / Condition / Compatibility
Operation / Condition / Compatibility
3