Cambridge Audio Azur 740A Amplifier
AP19784/3 F
ront P
anel Circuit Diagram (Microcontroller & LCD)
PGD
2.
PGC
1.
M
C
LR
/VPP
1
RA
0/
A
N
0
2
RA
1/
A
N
1
3
R
A
2/AN2/Vr
ef-
/CVr
ef
4
R
A
3/AN3/VR
EF+
5
R
A
4/T0CKI/C1OUT
6
R
A
5/AN4/S
S/C2OUT
7
RE
0/
RD/
A
N
5
8
RE
1/
WR/
AN6
9
RB
4
37
RB
3/
PG
M
36
RB
2
35
RB
0/
IN
T
33
VD
D
32
VS
S
31
R
D
7/PS
P7
30
R
D
6/PS
P6
29
RB
1
34
R
D
5/PS
P5
28
R
D
4/PS
P4
27
R
C7/R
X
/DT
26
RC
5/
SDO
24
RC
4/
SDI
/SDA
23
R
D
3/PS
P3
22
R
D
2/PS
P2
21
R
C6/TX/CK
25
VD
D
11
VS
S
12
OS
C1/CLKIN
13
OS
C2/CLKOUT
14
R
C
O/T1OS
O/T1CKI
15
R
C
1/T1OS
I/CCP2
16
R
C2/CCP1
17
R
C
3/S
CK/S
CL
18
R
D
0/PS
P0
19
RE
2/
C
S/
A
N
7
10
R
D
1/PS
P1
20
RB
5
38
RB
6/
PG
C
39
R
B7/PG
D
40
U1
PIC16F877A-I/P
PROGRAMMED
_WITH=AP20357/x
SW1
KPT-1105A
SW2
KPT-1105A
SW3
KPT-1105A
SW4
KPT-1105A
SW7
KPT-1105A
SW8
KPT-1105A
SW9
KPT-1105A
INPUT
1
INPUT
2
INPUT
3
INPUT
4
INPUT
5
TAPE
MON
MODE
+5V
LCD DISPLAY
C
ONN
C1
100nF
50V
Mo
no
Ceramic
C2
100nF
50V
Mo
no
Ceramic
SERIAL
D
A
TA
SERIAL CLO
CK
INPUT
STROBE
VI/
SHORT
CLIP
D
ETECT
MAINS
FAIL
D
C
O
FFSET
PHO
NES
D
ETECT
C4
100nF
50V
Mo
no
Ceramic
ON/STB
Y
ROW
3
ROW
2
COL
1
C
OL
2
C
OL
3
X1
Strip Cut Crystal
4MHz
C5
22pF
50V
NP0 Ceramic
C6
22pF
50V
NP0 Ceramic
Vss
1
Vd
d
2
Vo
3
R
S 4
R/
W
5
E 6
D0
7
D1
8
D2
9
D3
10
D4
11
D5
12
D6
13
D7
14
LED
A
15
LED
K
16
CG
N
D
3
AS
W
1
BS
W
2
FI
X
2
5
FI
X
1
4
ROT1
No
ble
Ro
tary Encoder
C7
10uF
16V
Electrolytic
C8
10uF
16V
Electrolytic
C9
100nF
50V
Mo
no
Ceramic
PREAMP
RELAY
VOL
U
M
E
ST
ROBE
+5V
+5V
O
V
ER
TEMP
D
2
CLK
3
ST
B
1
OE
15
Q0
4
Q1
5
Q2
6
Q3
7
Q4
14
Q5
13
Q6
12
Q7
11
QS
9
QS
10
VCC
16
GND
8
U2
M74H
C4094B
1R
O
V
ER
TEMP
VI/
SHORT
D
C
O
FFSET
LCD
DECOUPLE
2
1
15
16
1
2
3
4
5
6
1a
2a
3a
4a
5a
6a
7
8
7a
8a
CN1
2x8
Way
D
IL
B
o
tto
m Entry Header
RS
E
2
1
16
15
LCD
CONN
ORIEN
TA
TION
FROM
FRON
T
CLIP
D
ETECT
ON/OFF
BRIGHT
CONTROLBUS
IR
+5V
SERIAL CLO
CK
SERIAL
D
A
TA
INPUT
STROBE
ABUS
IR
PO
WER
AMP
RELAY
LCD
STR
.
SW6
KPT-1105A
SW5
KPT-1105A
1
P5
C11
10nF
50V
Ceramic
1
P2
C12
10nF
50V
Ceramic
1
P3
C13
10nF
50V
Ceramic
1
P4
C14
10nF
50V
Ceramic
1
P1
C15
10nF
50V
Ceramic
V
O
LUME
STR
O
B
E
SPEAKER
ABUS
IR
+5V
SPEAKER
A
RELAY
RC5
BL
OCK
RC5 TX
C16
100nF
50V
Mo
no
Ceramic
+5V
C17
10uF
16V
Electrolytic
PHO
NES
D
ETECT
CONTROL
BUS
IR
PREAMP
RELAY
SPEAKER
A
RELAY
SPEAKER
B
RELAY
SP
EA
K
ERBR
EL
A
Y
TO
POWER
AMP
PCB
TO
PRE
AMP
PCB
MAINS
FAIL
RC5
BL
OCK
RC5 TX
POWER
AMP
RELAY
+5V
D1
Blue
Azur
LED
PO
WER
AMP
RELAY
DIRECT REL
AY
DIRECT REL
AY
SW10
KPT-1105A
DIRECT
ROW
4
+5V
R19
100R
1/4W
Metal
Film
R3
1K2
1/4W
Metal
Film
R6
300R
1/4W
Metal
Film
R1
56R
1/4W
Metal
Film
R2
56R
1/4W
Metal
Film
R5
10K
1/4W
Metal
Film
R10
10K
1/4W
Metal
Film
R11
10K
1/4W
Metal
Film
R15
220R
1/4W
Metal
Film
R12
220R
1/4W
Metal
Film
R14
47R
1/4W
Metal
Film
R8
10R
1/4W
Metal
Film
R9
10R
1/4W
Metal
Film
R16
1K
1/8W
Metal
Film
R17
1K
1/8W
Metal
Film
R4
10K
1/4W
Metal
Film
R7
10K
1/4W
Metal
Film
1
2
3
4
5
6
7
8
9
10
CN9
10
Way
R
ight Angle Header
+5V
3
OPT
1
GND
2
U3
TSO
P34836
36KHz
1
2
3
4
5
6
CN2
6W
ay
R
ight Angle Header
PIC IR
ON/OFF
+5V
MCLR
+5V
+5V
PIC IRON/OFF
+5V
1
2
3
4
5
6
CN11
6W
ay
+5V
C3
47nF
50V
Ceramic
C22
47nF
50V
Ceramic
+5V
D4
1N4148
Signal D
io
d
e
MCLR
LK2
24
AWG
LK3
24
AWG
+5V
+5V
LK4
24
AWG
LK6
24
AWG
LK7
24
AWG
+5V
+5V
LK9
24
AWG
CONTROL
BUS
IR
CONTROL
BUS
IR
LK10
24
AWG
+5V
+5V
LK12
24
AWG
LK13
24
AWG
LK14
24
AWG
LK15
24
AWG
LK16
24
AWG
LK17
24
AWG
LK20
24
AWG
LK21
24
AWG
LK22
24
AWG
LK23
24
AWG
LK24
24
AWG
LK25
24
AWG
LK26
24
AWG
LK27
24
AWG
LK28
24
AWG
LK29
24
AWG
LK30
24
AWG
LK31
24
AWG
LK33
24
AWG
LK34
24
AWG
LK32
24
AWG
LK35
24
AWG
LK36
24
AWG
LK8
24
AWG
2
3
1
U4:A
VCC=+5V
M74H
C02
GND
=GND
5
6
4
U4:B
VCC=+5V
M74H
C02
GND
=GND
8
9
10
U4:C
VCC=+5V
M74H
C02
GND
=GND
11
12
13
U4:D
VCC=+5V
M74H
C02
GND
=GND
LK5
24
AWG
LK11
24
AWG
R36
10K
1/4W
Metal
Film
R39
1K
1/8W
Metal
Film
R28
47K
1/4W
Metal
Film
R34
10K
1/4W
Metal
Film
R35
47K
1/8W
Metal
Film
R27
47K
1/4W
Metal
Film
R29
47K
1/4W
Metal
Film
R30
47K
1/4W
Metal
Film
R31
47K
1/4W
Metal
Film
R32
100K
1/4W
Metal
Film
R33
10K
1/4W
Metal
Film
PGD
PGC
Q3
B
C
337-25
NPN Signal
Q1
B
C
337-25
NPN Signal
Q2
B
C
337-25
NPN Signal
1
2
3
4
5
6
7
8
9
CN3
9W
ay
R
ight Angle Header
R13
47K
1/8W
Metal
Film
LCD
STR
LCD
STR
.
LCD
STR
BRIGHT
ON/OFF
+5V
LK18
24
AWG
2
CCW
1
CW
3
PR1
Multiturn
500R
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11