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POWER AMPLIFIER (IC201: LA4663)
The power amplifier is a two-channel amplifier with standby switch.
+
–
STAND BY
VCC1 VCC2
+
OUT1
–
OUT1
–
OUT2
+
OUT2
PER
GND1
PWR
GND2
Output amplifier
+
–
Output amplifier
Input amplifier
Input amplifier
CH 1
CH 2
Ripple Filter/
Starting Time
Vcc/ground shorting
protection circuit
Load shorting protection circuit
Thermal protection circuit
Protection circuits
Ri=
20k
Ω
Ri=
20k
Ω
IN2
IN1
PRE
GND
SIGNAL
MUTE
3
8
7
5
6
2
3
4
1
13
12
9
10
11
Summary of Contents for WK-1800
Page 30: ...29 PRINTED CIRCUIT BOARD Main PCB JCM733 MA1M Top View Bottom View 1 6 5 4 3 2 9 10...
Page 31: ...30 Sub PCB JCM733 MA2M 7 8 Sub PCB JCM733 MA3M Top View Top View...
Page 32: ...31 Console PCBs JCM733 CN1M Top View Top View Console PCBs JCM733 CN2M...
Page 33: ...32 Display PCB JCM733 LCD1M Top View Bottom View...
Page 34: ...33 Keyboard PCBs JCM763T KY1M Top View Top View Keyboard PCBs JCM763T KY2M...
Page 40: ...39 SubPCB JCM733 MA2M MA3M 7 8 Regulator IC Power Amp...
Page 41: ...40 Console PCBs JCM733 CN1M CN2M S Register S Register...
Page 42: ...41 LCD Driver PCB JCM733 LCD1M LCD Driver Back Light Circuit...
