Kenwood KAC-X40 Service Manual page 3

AUDIO UNIT (X09-8580-10)
Ref. No.
IC1 Rch input buffer at side A and isolation
IC2 Lch input buffer at side A and isolation
IC3 L/Rch input buffer at side B
IC4 L/Rch isolation at side B
IC5 DC/DC control
IC6 ATT
Q1,15,17 +15VAVR
Q2,16 -15VAVR
Q3~8 DC/DC
Q9~12 DC/DC driver
Q13,14 DC/DC delay start circuit
Q201~204,401~404 ACLASS initial stage
Q205~210,407~410 ACLASS second stage
Q211,212,411,412 Constant current circuit
Q215,216,415,416 Over current limiter
Q217,218,417,418,610 Over current protection
Q220,222,223,225,423,
AMP final stage
Q425,426,428
Q241,242,443,444 AUDIO MUTE
Q280,282,283,290,
ATT
Q481~484
Q601~606 P-CON control
Q611~614 DC protection
Q615~618 POP MUTE
Q619,620 LED driver
Q621 Power switch for thermistor
Q684,685 FAN AVR
NO. ITEM
IDEL
1
CURRENT
COMPONENTS DESCRIPTION
Application / Function
ADJUSTMENT
ALIGNMENT
METHOD
POINT
VR1 (A Lch) Connect a DC
VR2 (A Rch) voltmeter between
VR3 (B Lch) check land
VR4 (B Rch) (Refer to PC BOARD)
Operation / Condition / Compatibility
Rch input signal amplification (+6dB) and noise reduction in transmission
quality at side A
Lch input signal amplification (+6dB) and noise reduction in transmission
quality at side A
Input signal amplification (+6dB) at side B
Noise reduction in input signal transmission quality at side B
Controlled by P-CON & protection circuit
Detects inside temperature and makes the necessary ATT.
Operation while P-CON is turned on.
Operation while P-CON is turned on.
Controlled by IC5.
Controlled by IC5.
Delays the start of DC/DC when P-CON is turned on.
Voltage amplification of small signal
Voltage amplification of small signal
Makes current in ACLASS initial stage constant.
Operation under the over current condition
Operation under the over current condition
Current amplification of small signal
Controlled by Q603.
Controlled by IC6. Takes the level of -1.5dB or 3dB in response to
changes in temperature (TH601-605)
Operates when P-CON is turned on/off.
Operates when DC is detected in the SP output.
Operation while P-CON is turned on.
Operation while P-CON is turned on.
Operation while P-CON is turned on.
Operation while P-CON is turned on.
ALIGN FOR
2.0mV
KAC-X40
NOTE
After Power on 5minutes
3