AP222671 Cambridge Azur 740A Amplifier Service Manual 1

sharonn

Cambridge-740A-pwr-sm

Cambridge Audio Schematics & Service Manuals

PDF preview unavailable. Download the PDF instead.

Cambridge-740A-pwr-sm
Issue Date: 8th August 2007
SERVICE MANUAL

740A

SPECIFICATIONS:
Power Output THD (unweighted)
Frequency Response S/N Ratio (ref 1W/8 Ohms) Input Impedances Power Amp Damping Factor Max Power Consumption Minimum Power Consumption Bass & Treble Controls
Dimensions Weight

100W RMS into 8 Ohms 150W RMS into 4 Ohms
< 0.001% 1 kHz At 80% of rated power
< 0.01% 20 Hz ­ 20 kHz At 80% of rated power
10 Hz ­ 50 kHz +/- 1 dB
> 96 dB
Inputs 1-6 47 kOhm
> 110 at 1 kHz
750W
Active (no signal) 45W Standby 6W
Shelving Type
Max bass boost/cut +/-10 dB at 10 Hz
Max treble boost/cut +/- 7.5 dB at 20 kHz
115 x 430 x 350mm (4.5 x 16.9 x 13.8")
10.7kg (23.5Lbs)

Gallery Court Hankey Place London SE1 4BB UK Tel: +44 (0)20 7940 2200 Fax: +44 (0)20 7940 2233

AP22267/1 1

740A SERVICE MANUAL

TABLE OF CONTENTS

Safety Precautions & Important Notes Exploded Diagrams Exploded Diagram Parts List Front Panel PCB Schematic (Tone Control) Front Panel PCB Schematic (Microcontroller & LCD) Front Panel PCB Layout (Top Side) Front Panel PCB Layout (Bottom Side) Front Panel PCB BOM Preamp PCB Schematic (Tone Control) Preamp PCB Schematic (Protection Circuitry) Preamp PCB Schematic (Power Supply) Preamp PCB Schematic (Headphone Driver) Preamp PCB Schematic (Buffers & Switches) Preamp PCB Board Layout (Top Side) Preamp PCB Board Layout (Bottom Side) Preamp PCB BOM Amplifier Schematic (Speaker PCB) Amplifier Schematic (Right Channel) Amplifier Schematic (Left Channel) Amplifier Schematic (Protection) Amplifier Schematic (Power Supply) Amplifier PCB Board Layout (Top Side) Amplifier PCB Board Layout (Bottom Side) Amplifier PCB BOM Abus Schematic Abus PCB Board Layout (Top Side) Abus PCB Board Layout (Bottom Side) Abus PCB BOM Mains Schematic (Mains) Mains PCB Board Layout (Top Side) Mains PCB Board Layout (Bottom Side) Mains PCB BOM

4 5-8

9 10 11 12 13 14-15

16 17 18

19 20

21 22 23-26 27 28 29

30

31

32

33

34-36

37

38

39

40-41

42

43

44

2

45

IC Pin Layout Details____________________________________________ 46-51 Service Mode Instructions________________________________________52 Procedure to Upgrade Software___________________________________ 53 Kanda PIC Hand Held Programmer Modification Instructions____________54-58 Revised Front Panel Schematic­to improve encoder reliability: (see Service Bulletin TNBC-0035)__________________________________ 59-60

SAFETY PRECAUTIONS & IMPORTANT NOTES
1. Check that the rear of the product indicates the correct supply voltage for your area.
2. The lighting flash with the arrowhead within an equilateral triangle is intended to alert the user or service agent to the presence of dangerous voltages within the product enclosure that may be of sufficient magnitude to constitute a risk of electric shock to persons.
3. The exclamation point within an equilateral triangle is intended to alert the user or service agent to the presence of important operating and maintenance (Servicing) instructions in the literature accompanying the appliance.
4. This product complies with EEC Low Voltage (73/23/EEC) and Electromagnetic Compatibility (89/336/EEC) Directives when used and serviced in accordance with this manual. For continued compliance all components marked safety and EMC critical must only be replaced by Cambridge Audio approved parts.
5. Any unauthorised design alterations or additions will void the manufacturer's warranty; furthermore the manufacturer cannot accept responsibility for personal injury or property damage resulting therefrom.
6. When servicing, care should be taken to observe the original routing and dressing of the leads and it should be confirmed that they have been returned to normal after re-assembly.
Notes on chip component replacement Never reuse a component that has been removed from a PCB Notice that the minus side of a tantalum capacitor may be damaged by heat
COPYRIGHT NOTICE.
© 2007 Audio Partnership PLC. All rights reserved.
Cambridge Audio and Azur are registered trademarks for Audio Partnership PLC. This document may not be reproduced, distributed, transmitted, displayed, published, or broadcast without the express written prior permission of Audio Partnership PLC. Alteration or removal of any trademark, copyright, or other notice from this content is prohibited. Information provided in this document is provided solely for the use of official service agents in repairing and servicing Audio Partnership PLC products.
4

Cambridge Audio Azur 740A Amplifier

2 3

15 3

To enhance viewing, please print to A3

Exploded Diagram (Complete Unit)

5

10 8

Cambridge Audio Azur 740A Amplifier
13
9
1

16

To enhance viewing, please print to A3

Exploded Diagram (Chassis Assembley)

6

Cambridge Audio Azur 740A Amplifier

5 6
7 4

To enhance viewing, please print to A3

Exploded Diagram (Front Panel Assembley)

7

Cambridge Audio Azur 740A Amplifier

11

12 14

To enhance viewing, please print to A3

Exploded Diagram (Rear Panel Assembley)

8

Cambridge Audio Azur 740A Amplifier

Drawing Ref Part N umber

Factory Designation

1

PY1237 3200-063073E000

-

PY1242 3200-063074E000

2

PY1338 6574-150018E000-02

-

PY1339 6574-150018E000-01

3

PY1340 6574-150020E000-02

-

PY1341 6574-150020E000-01

4

PY1342 8574-015010E301

-

PY1343 8574-015020E301

5

PY1344 6574-150029E000A01

-

PY1345 6574-150029E000-01

6

PY1346 9474-015000E041

7

PY1138 2409-010200E001

8

PY1347 9474-015000E091

9

PY1348 9474-015000E001

10

PY1349 9474-015000E101

11

PY1350 9474-015000E331

12

PY1351 2404-040100E001

13

PY1352 9474-015000E341

14

PY1322 2333-008919E003

15

PY1165 9805-084000E001

16

PY1122 6074-150004E000

-

PY1125 6074-150004E000A01

D escr iption Azur-740A 230V Transformer TI-063073D For EU Version Azur-740A 110V Transformer For CU (USA) Version Azur 740A Top Panel-S (With Painted) Azur 740A Top Panel-B (With Painted) Azur-740A Side Panel-S (With Painted) Azur-740A Side Panel-B (With Painted) Azur-740A Front Panel-S Assy Rev A (Metal plus PCB) Azur-740A Front Panel-B Assy Rev A Azur-740A Front Panel Artwork-S (AP200931) (metal) Azur-740A Front Panel Artwork-B Azur-740A Control PCBA Rev A Rotary Encoder Switch REB161(9*7)PVB20FHINB1-2-24E Azur-740A Amp Power PCBA (AP19797/A) Rev A <T Type> Azur-740A Protection Circuitry PCB-A Assy Rev A Azur-740A Protection Circuitry PCB-B Assy Rev A Azur-740A A-Bus Hub PCBA REV A Piano DIP Switch 4P DPL-04K Series Azur-740A Input PCBA Rev A <T-Type Resistor> WP8-22 8 Way SPK Terminal 4Blk/4Red Gold Plating for 740A Azur-740/840/A/C Remote Control Assy Rev A Plastic foot black Plastic foot silver

Exploded Diagram Parts List

9

Cambridge Audio Azur 740A Amplifier

CN6 6 Way Right Angle Header

1

2

3

4

5

6

RC

RBB

RTB

RA

R

RA

RC

RTB

RIGHT LK38

24 AWG +15V

-15V

CN5

8

R

7

6

SHIELD_SUPPLY

RA

5

4

3

2

1

8 Way Right Angle Header

L LA

RBB

C101
1.5nF 63V Met. Polyester
R103
4K7 1/4W Metal Film
RC
LC

LTB

C201
1.5nF 63V Met. Polyester LEFT
R203
4K7 1/4W Metal Film

LBB

LA

LC

LC

LBB

LTB

LA

1

2

3

4

5

6

L
CN7
6 Way Right Angle Header

-15V

C104

CA2
1 2 3 4 5 6

47nF 63V Met. Polyester
R
C103
10pF 50V NP0 Ceramic

See AP20043/1 6 Way to 4 Way Screened Audio cable
U100:B
NE5532P Audio Op Amp 6
7 5

U100:A

4

NE5532P

Audio Op Amp

3

R106

1

2

2K2

R R107
2K2 1/4W Metal Film

1/4W Metal Film

C107

8

R

C106

10pF 50V NP0 Ceramic

47nF 63V Met. Polyester +15V
R
-15V
C204

LK39

24 AWG

R

R

LK40

47nF 63V Met. Polyester
L
C203
10pF 50V NP0 Ceramic

L
6 5

24 AWG
U200:B L
NE5532P Audio Op Amp
7

U200:A

4

NE5532P

L R207

Audio Op Amp

3

R206

1

2

2k2

1/4W Metal Film

2K2 1/4W Metal Film
C207

8

L

C206

10pF 50V NP0 Ceramic

L

47nF 63V Met. Polyester +15V

CA1
1 2 3 4 5 6
See AP20044/1 6 Way to 5 Way Screened Audio cable

4 Way
CN10 Straight Header
1 2 3 4

1

2

3

4

R18
1K1 1/8W Metal Film

R20
1K1 1/8W Metal Film

R24
R23 2K2 1/8W Metal Film 2K2 1/8W Metal Film

SHIELD_R2

CN4
4 3 2 1
4 Way Right Angle Header

SHIELD_L2

LK37
24 AWG

VR1:A
5k Push Action Linear Pot

VR2:B
5k Push Action Linear Pot
C10
680nF 63V Met. Polyester

VR1:B
5k Push Action Linear Pot

C18
680nF 63V Met. Polyester
5k VR2:A
Push Action Linear Pot

R21
1K1 1/8W Metal Film

R22
1K1 1/8W Metal Film

R25
2K2 1/8W Metal Film
LK1
24 AWG

R26
2K2 1/8W Metal Film

1

2

3

4

5

1 2 3 4 5

GUARD

CN8 5 Way Straight Header

To enhance viewing, please print to A3 AP19784/3 Front Panel Circuit Diagram (Tone Control)

10

Cambridge Audio Azur 740A Amplifier

Vss 1 Vdd 2 Vo 3 RS 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

+5V

+5V

LK7

L2K4 A1W4G

24 AWG
LK25
24LAKW3G6

24LAKW1G2

LK424 AWG

24 AWG

+5V

+5V

LK11

24LAKW3G2

24 AWG

+5V

+5V

LK3

2L4KA3W1G

24 AWG

CN11
1 2 3 4 5 6 6 Way

+5V PGC PGD MCLR
+5V

COL 1 SW1

COL 2 SW2

KPT-1105A
INPUT 1
SW4

KPT-1105A
INPUT 2
1.
SW5

ROW 2

KPT-1105A
INPUT 4
SW7 LK15

KPT-1105A
INPUT 5
SW8

LCD STR.

LK24 LK13

LCD STR

24 AWG 24 AWG

+5V LCD DECOUPLE

R27
47K 1/4W Metal Film
+5V

R29
47K 1/4W Metal Film

ROW 3 R30
47K 1/4W Metal Film
ROW 4

KPT-1105A
ON/STBY SW10
KPT-1105A
DIRECT

R19
100R 1/4W Metal Film

C9
100nF 50V Mono Ceramic

C4
100nF 50V Mono Ceramic

C7 C22
10uF 16V 47nF 50V Electrolytic Ceramic

LK35

24 AWG

1

CN1

2

1a

1

2a

2

U2

3a

3

4

4a

4

LK33

Q0 5

5a

5 LK34

Q1 6

6a

6

24 ALWKG30 7 Q2

Q3

7a

7 24 AWG

14

8a

8

Q4 24 AWG 13

Q5

15

16

12 Q6

2x8 Way

11

DIL Bottom Entry HeaLdKer26

Q7

LK29 LK27 24 AWG

9 QS
10

24 AWG LK28

QS

2 D
3 CLK
1 STB
15 OE VCC
16
8 GND

24 AWG 24 AWG

M74HC4094B1R

LCD DISPLAY CONN

RS E LCD STR.
+5V

LK23 C5
24 AWG

LK20
24 AWG

22pF 50V NP0 Ceramic
C6

X1
Strip Cut Crystal 4MHz

C11
10nF 50V Ceramic

22pF 50V NP0 Ceramic

1

R7

P5

10K

1/4W Metal Film

2. 24 AWG KPT-1105A
SPEAKER

LK9

L2K41A7WG

24 AWG

1

2

3

4

LCD STR

5

6

BRIGHT

7

ON/OFF

8

9

10

11

12

13

14

15

16

17

18

19

LK16

20

24 AWG +5V

R12
220R 1/4W Metal Film

ON/OFF

R3
1K2 1/4W Metal Film

Q1
BC337-25 NPN Signal

D1
Blue Azur LED

1

CCW

PR1

Multiturn

2

500R

R1

R2

56R

56R

CW

1/4W Metal Film

1/4W Metal Film

POWER AMP RELAY
LK18
24 AWG

R11
10K 1/4W Metal Film

Q3
BC337-25 NPN Signal

R15
220R 1/4W Metal Film

3

2

16

1

15

LCD CONN ORIENTATION FROM FRONT

R6
300R 1/4W Metal Film

Q2
BC337-25 NPN Signal

R5
10K 1/4W Metal Film

BRIGHT
R10
10K 1/4W Metal Film

+5V TO POWER AMP PCB

COL 3 SW3

KPT-1105A
INPUT 3
SW6

R31
47K 1/4W Metal Film

+5V

SPEAKER B RELAY SPEAKER A RELAY
PREAMP RELAY VI/SHORT
CLIP DETECT MAINS FAIL DC OFFSET OVER TEMP

CN9
1 2 3 4 5 6 7 8 9 10

RC5 BLOCK RC5 TX
PHONES DETECT DIRECT RELAY
PIC IR ON/OFF

1 2 3 4 5 6
LK2
24 AWG

CN2
6 Way Right Angle Header

TO PRE AMP PCB

KPT-1105A
TAPE MON
SW9

KPT-1105A

+5V

+5V
MODE

10K

10 Way Right Angle Header
R32

100K 1/4W Metal Film

CONTROL BUS IR VOLUME STROBE POWER AMP RELAY
ABUS IR INPUT STROBE

SERIAL DATA SERIAL CLOCK

CN3
1 2 3 4 5 6 7 8 9

1/4W Metal Film

9 Way

R4
MCLR

LK6

U1 24 AWG

MCLR/VPP

RB7/PGD

RA0/AN0

RB6/PGC

RA1/AN1

RB5

RA2/AN2/Vref-/CVref

RB4

RA3/AN3/VREF+

RB3/PGM

RA4/T0CKI/C1OUT

RB2

RA5/AN4/SS/C2OUT

RB1

RE0/RD/AN5

RB0/INT

RE1/WR/AN6

VDD

RE2/CS/AN7

VSS

VDD

RD7/PSP7

VSS

RD6/PSP6

OSC1/CLKIN

RD5/PSP5

OSC2/CLKOUT

RD4/PSP4

RCO/T1OSO/T1CKI RC7/RX/DT

RC1/T1OSI/CCP2 RC6/TX/CK

RC2/CCP1

RC5/SDO

RC3/SCK/SCL

RC4/SDI/SDA

RD0/PSP0

RD3/PSP3

RD1/PSP1

RD2/PSP2

PGD 40 PGC 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21

PIC16F877A-I/P

PROGRAMMED_WITH=AP20357/x
R28

R13
47K 1/8W Metal Film
R39
1K 1/8W Metal Film

D4
1N4148 Signal Diode
DIRECT RELAY
PHONES DETECT
RC5 TX RC5 BLOCK OVER TEMP DC OFFSET MAINS FAIL CLIP DETECT

CONTROL BUS IR

+5V

C1

100nF 50V

Mono Ceramic

1K 1/8W Metal Film
R16

VI/SHORT PREAMP RELAY SPEAKER A RELAY SPEAKER B RELAY
SERIAL CLOCK

C3
47nF 50V Ceramic
+5V

R17
SERIAL DATA

1K 1/8W Metal Film INPUT STROBE
ABUS IR
POWER AMP RELAY VOLUME STROBE

R33

R36

10K

1/4W Metal Film

10K

1/4W Metal Film
R34

C8
10uF 16V Electrolytic

PIC IR ON/OFF

Right Angle Header

LK10
24 AWG
R8 10R
1/4W Metal Film
R9
10R 1/4W Metal Film
C2
100nF 50V Mono Ceramic

CONTROL BUS IR
ROT1
1 A SW
2 B SW
3 C GND
4 FIX1
5 FIX2
Noble Rotary Encoder

+5V
R14
47R 1/4W Metal Film
U3

47K 1/4W Metal Film
U4:D LK8 13

10K 1/4W Metal Film
U4:B
6
12 LK5 4
5

OPT 1
GND 2
+5V 3
TSOP34836 36KHz

C16
100nF 50V Mono Ceramic

C17
10uF 16V Electrolytic

11

24 AWG

24 AWG

VCC=+5V

+5V

VCC=+5V

M74HC02

M74HC02

GND=GND

GND=GND

P2

P3

P4

P1

LK22

U4:C
+5V 9 10 8
VCC=+5V M74HC02 GND=GND

U4:A
3 1
2
VCC=+5V M74HC02 GND=GND

R35
47K 1/8W Metal Film

C12
10nF 50V Ceramic

C13
10nF 50V Ceramic

C14
10nF 50V Ceramic

C15
10nF 50V Ceramic

CONTROL BUS IR 1 1 1 1

L24KA2W1G

24 AWG

To enhance viewing, please print to AA3P19784/3 Front Panel Circuit Diagram (Microcontroller & LCD)

11

Cambridge Audio Azur 740A Amplifier

To enhance viewing, please print to A3 AP19784/3 Front Panel Board Layout (Top Side)

12

Cambridge Audio Azur 740A Amplifier

To enhance viewing, please print to A3 AP19784/3 Front Panel Board Layout (Bottom Side)

13

Cambridge Azur 740A Front Panel PCB Assembly BOM

AP Part No

Value

Description/Type

Qty Component Ident Type

RESISTORS

10R

1/4W Metal Film

2

R8, R9

47R

1/4W Metal Film

1

R14

56R

1/4W Metal Film

2

R1, R2

100R

1/4W Metal Film

1

R19

220R

1/4W Metal Film

2

R12, R15

300R

1/4W Metal Film

1

R6

1K

1/8W Metal Film

3

R16, R17, R39

1K1

1/8W Metal Film

4

R18, R20-R22

1K2

1/4W Metal Film

1

R3

2K2

1/8W Metal Film

4

R23-R26

2K2

1/4W Metal Film

4

R106, R107, R206,

R207

4K7

1/4W Metal Film

2

R103, R203

10K

1/4W Metal Film

8

R4, R5, R7, R10, R11, R33, R34, R36

47K

1/8W Metal Film

2

R13, R35

47K

1/4W Metal Film

5

R27-R31

100K

1/4W Metal Film

1

R32

RESISTORS VARIABLE

500R

Multiturn

1

PR1

5k

Push Action Linear Pot 2

VR1, VR2

CAPACITORS

10pF 50V

NP0 Ceramic

4

C103, C107, C203,

C207

22pF 50V

NP0 Ceramic

2

C5, C6

1.5nF 63V

Met. Polyester

2

C101, C201

10nF 50V

Ceramic

5

C11-C15

47nF 50V

Ceramic

2

C3, C22

47nF 63V

Met. Polyester

4

C104, C106, C204,

C206

100nF 50V

Mono Ceramic

5 C1, C2, C4, C9, C16

680nF 63V 10uF 16V

Met. Polyester Electrolytic

2

C10, C18

3

C7, C8, C17

CONNECTORS

2x8 Way

DIL Bottom Entry Header

1

CN1

6 Way 9 Way 4 Way 8 Way 5 Way 10 Way 4 Way
6 Way
4MHz
Blue Azur LED 75V 150mA

Right Angle Header Right Angle Header Right Angle Header Right Angle Header
Straight Header Right Angle Header
Straight Header IDC Programming
Header
Strip Cut Crystal
3mm Signal Diode

3

CN2, CN6, CN7

1

CN3

1

CN4

1

CN5

1

CN8

1

CN9

1

CN10

1

CN11

CRYSTALS

1

X1

DIODES

1

D1

1

D4

Tolerance

Factory P/N

AP19787/4
Notes

1% 1% 1% 1% 1% 1% 1% 1% 1% 1%
1%
1%
1%
1% 1% 1%
10% 1065-002500E120

5%

1181-100042-000

5%

1181-220042-000

10%

1117-152052-900

10%

1100-103043-000

10%

1100-473044-000

10%

1117-473053-000

10%

1100-104043-000

10%

1117-684053E000

20%

1102-100014-000

2350-016300-001 2300-006010-000

Please mount on track side of PCB

2300-004010-000

2300-005000-000

2300-002000-001

3100-000030-003 1401-141480-000

Note: resistors, capaciotrs and other 'generic' electronic components are

not usually stocked by the manufacturer. Please obtain these locally.

14

Cambridge Azur 740A Front Panel PCB Assembly BOM

AP Part No

Value

Description/Type

Qty Component Ident Type

INTEGRATED CIRCUITS

Tolerance

Factory P/N

40 Pin

Flash Microcontroller

1

U1

PIC16F877AI/P

PY524 M74HC4094B

8 Bit Shift Register

1

U2

M74HC4094

B1R

PY755

36KHz

IR Receiver IC

1

U3

TSOP34836

PY471 PY108
PY214

Quad 2 Input Dual
45V 300mA

NOR Gate Audio Op Amp
NPN Signal

1

U4

M74HC02

2

U100, U200

NE5532P

TRANSISTORS

3

Q1-Q3

BC337-25

4174-409052-600 3001-348360-000 4155-320052-900 1300-337000-100

AP19787/4
Notes
Program with software: AP20357/x Please add
version label!

Note: resistors, capaciotrs and other 'generic' electronic components are

not usually stocked by the manufacturer. Please obtain these locally.

15

Cambridge Audio Azur 740A Amplifier

RCh In
STAR LCh In
+15V
STAR -15V

R L

+15V -15V

L

R

CN12
1 2 3 4 5 6 7 8 9
9 Way Straight Header

CN13
1 2 3 4
4 Way Straight Header

R L

U8
LM317T Adj Regulator
3 VI

2 VO

1 ADJ

C3
47nF 63V Met. Polyester

C13
47uF 35V Electrolytic

R11
3k 1/8W Metal Film

R16
220R 1/8W Metal Film
R12
1k8 1/8W Metal Film

C16
100uF 25V Electrolytic

STAR

C12

47uF 35V

C11

Electrolytic

47nF 63V

Met. Polyester

R13
620R 1/8W Metal Film

1 ADJ

VI 2

VO 3

U7 LM337T
Adj Regulator

R14
10k 1/8W Metal Film

C15

R15
120R 1/8W Metal Film

100uF 25V Electrolytic

+6.6VA
C17
47nF 63V Met. Polyester
C14
47nF 63V Met. Polyester
-6.6VA -15V

4 RL1:B
3 5
ME2-5S 2P2T Relay

R46
1/4W Metal Film 330R

R47
1/4W Metal Film 330R

C48

Polypropylene 100nF 100V

C47

NP Electrolytic 100uF 25V

STAR

+15V
C78
100uF 25V Electrolytic
C77
100uF 25V Electrolytic

RCh Out
R L
LCh Out

CN5
1 2 3 4 5 6
6 Way Straight Header TO POWER AMP

R36
220R
1/8W Metal Film

-6.6VA

R35

+6.6VA

220R
R34 1/8W Metal Film
220R 1/8W Metal Film

220R 1/8W Metal Film
R33

8 RL1:C
6 7
ME2-5S 2P2T Relay

R45
1/4W Metal Film 330R

47nF 63V

47nF 63V

Met. Polyester Met. Polyester

L

C37 C40

C38
Electrolytic 470uF 10V

Electrolytic

L

470uF 10V

C39

RCh Out

Electrolytic 470uF 10V
C56

LCh Out
C42
Electrolytic 470uF 10V

C55 C41

47nF 63V

47nF 63V

Met. Polyester Met. Polyester

R

C49

R44
1/4W Metal Film 330R
R

NP Electrolytic 100uF 25V
C50
Polypropylene 100nF 100V

U2
IN1 24
REF1A 23
REF1B 22
OUT1 21
AVDD1 20
AVSS1 19
AVSS2 18
AVDD2 17
OUT2 16
REF2B 15
REF2A 14
IN2 13
YAC526 Volume IC

-15V
R129

10k

1

1/8W Metal Film

ZCEN

2

ZCEN2

3 CSN

Volume Strobe

4 SDATAI

Data

5

DGND

6

REF

7 DVSS

-6.6VD

8 SCLK

Clock

9 SDATAO
10 TE1

C35

C36
Mono Ceramic

11 TE2

47uF 35V

100nF 100V

12 TE3

Electrolytic

5 RL2:B
3 4
ME2-5S 2P2T Relay
8 RL2:C
6 7
ME2-5S 2P2T Relay
HP

Q14
BC327-25 PNP Signal
RL2:A
1

LK1
24 AWG 12.5mm Pitch
R49
1206 Thick Film 10k
R105
1206 Thick Film 1k

+5V RC5 Block

DGND

C8
47uF 35V Electrolytic
C9
Mono Ceramic 100nF 100V

R141
620R 1/8W Metal Film

1 ADJ

VI 2

VO 3

U6 LM337T
Adj Regulator

R140
10k 1/8W Metal Film
R142
120R 1/8W Metal Film

C34
47uF 35V Electrolytic

FB3
On 24AWG Wire 1uH Ferrite
C120
Mono Ceramic 100nF 100V
R130
220R 1/8W Metal Film

C119
Electrolytic 470uF 10V

C10
Mono Ceramic 100nF 100V
-6.6VD

2 ME2-5S 2P2T Relay
HP
RL1:A
1
2 ME2-5S 2P2T Relay
MPSA14 NPN Darlington

D13
1N4004 Rectifier Diode

+5V
D1
1N4004 Rectifier Diode

Q13

R19
1k
R131 1/4W Metal Film
10k 1/8W Metal Film

Tone Defeat Relay

MAIN

To enhance viewing, please print to A3AP19799/6 Preamp PCB Circuit Diagram (Tone Control)

16

Cambridge Audio Azur 740A Amplifier

L Speaker Test R Speaker Test

Temp Sense

6SHDNHU&DEOH6KRUW&LUFXLW'HWHFWRU
Senses a DC resistance of 2 ohms or less

+5V

R80
1k 1/8W Metal Film For 1mA

R81
10k 1/8W Metal Film

D10
Rectifier Diode 1N4004

R75
100R 1/8W Metal Film

R73
4.7R 1/8W Metal Film

4

8

U13:A
LM393AP Dual Comparator 3
1 2
C112
100nF 50V Mono Ceramic

+5V
R82
1k 1/8W Metal Film For 1mA

D9
Rectifier Diode 1N4004

R71
100R 1/8W Metal Film

U13:B
LM393AP Dual Comparator 5
7 6

DGND

R72
4k7 1/8W Metal Film

R74
10k 1/8W Metal Film
3
2

8

U14:A
LM393AP Dual Comparator
1

4

R65

R69
100k 1/8W Metal Film

R68
4k7 1/8W Metal Film Open Collector Output
PIC Temp

R64
4k7 1/8W Metal Film (Open Collector Output)
D8

C51
100uF 16V Electrolytic

1N4148 Signal Diode

PIC VI/Short

R29

4k7

DGND

1/8W Metal Film

(Open Collector Output)

C54
100uF 16V Electrolytic

D14
1N4148 Signal Diode

PIC VI/Short

DGND

+5V

+5V +5V

C21
100uF 16V Electrolytic

RC5 Block RC5 TX
Head Phones Detect Tone Defeat Relay
Head Phones Detect Gnd PIC IR on/off
C63
10nF 50V Ceramic

CN1
1 2 3 4 5 6

3,& 6LJQDOV

6 Way Straight Header

DGND

UNREG

PIC GND

L Speaker Test R Speaker Test Speaker A Relay
Speaker B Relay
R70
2W Carbon 220R

1 2 3 Clean Gnd 4 5 6 Relay Gnd 7
DGND

CN9
6SHDNHU 3&% 6LJQDOV
7 Way Straight Header

C6
Mono Ceramic 100nF 100V

Speaker B Relay Speaker A Relay Preamp Standby
PIC VI/Short

C7
100uF 16V Electrolytic

+5V PIC Clip Mains Fail PIC DC PIC Temp

DGND

CN3
1 2 3 4 5 6 7 8 9 10

3,& 6LJQDOV

DGND

10 Way Straight Header To PIC

+5V

C58
Mono Ceramic 100nF 100V
U14:B
LM393AP Dual Comparator 5
7 6

0DLQV 3&% 6LJQDOV

CN8
3 2 1
3 Way Straight Header

POWER AMP STANDBY UNREG

DGND

Temp Sense PIC VI/Short
PIC DC PIC CLIP

R144
1/4W Metal Film
10k CN7
1 2 3 4 5

3URWHFWLRQ 6LJQDOV 7R$PS

5 Way Straight Header

DGND

910R 1/8W Metal Film 910 / (910 + 10k) with ZP221A501E voltage gives 100deg C cutout

DGND

To enhance viewing, please printAtoPA139799/6 Preamp PCB Circuit Diagram (Protection Circuitry )

17

Cambridge Audio Azur 740A Amplifier

AC Sense 2 AC Sense 1

D2

Rectifier Diode 1N4004
D3

Rectifier Diode 1N4004

R132
10k 1/8W Metal Film

1N4148

+5V
D15

Signal Diode

R67

4k7
1/8W Metal Film
C31
Mono Ceramic
330nF 100V

R66
4k7 1/8W Metal Film

Q12
BC327-25 PNP Signal
Mains Fail

C22
47uF 35V Electrolytic

U5 L7805

Regulator

1 VI

3 VO

2 GND

C52
100nF 50V Mono Ceramic

+5V
C53
100nF 50V Mono Ceramic

AC Sense 1

Main

C30

C28

UNREG

No Fit Mono Ceramic
D4

No Fit Mono Ceramic
D5

MBR1100

MBR1100

Schottky Rectifier Schottky Rectifier

CN6
1 2 3

3 Way Straight Header

Main

C29
Met. Polyester 39nF 250V

D6

D7

Main

MBR1100 Schottky Rectifier
C27

MBR1100 Schottky Rectifier

C32

C57

2200uF 35V Electrolytic

AC Sense 2

No fit Mono Ceramic

No Fit Mono Ceramic

Q11
BC327-25 PNP Signal

R30
47R 2W Carbon

DGND

U3 L7815 Regulator

1 VI

3 VO

2 GND

R127

C26
2200uF 35V Electrolytic

1/4W Metal Film

4k7

Q8

22.5V 240V BC337-25

NPN Signal

R137
10k 1/8W Metal Film
R139

Preamp Standby

+5V
Q9

R126
100k 1/8W Metal Film
R48

BC327-25 PNP Signal
R128

6k2 1/8W Metal Film

7k5 1/4W Metal Film 28V 240V

Q10
BC337-25 NPN Signal

10k 1/8W Metal Film

R136
10k 1/8W Metal Film
BC337-25 NPN Signal

Q7 R138
10k 1/8W Metal Film

Main -Unreg

C25
47nF 63V Met. Polyester
C33
47nF 63V Met. Polyester
VI 2
U4
L7915 Regulator

1 GND

100uF 25V Electrolytic 105

C24
Met. Polyester 47nF 63V

C19

D11
Rectifier Diode 1N4004

C23
Met. Polyester 47nF 63V

C18
100uF 25V Electrolytic 105

D12
Rectifier Diode 1N4004

VO 3

+15V -15V

W5 WIRE1
A
FB5
On 24AWG Wire 1uH Ferrite
DGND

W6
A STAR

To enhance viewing, please print to A3AP19799/6 Preamp PCB Circuit Diagram (Power Supply)

18

Cambridge Audio Azur 740A Amplifier

RCh HP Out
5FK2XW

R32
1/4W Metal Film 100R

LCh HP Out
/FK2XW

R27
1/4W Metal Film 100R

C117
100pF 50V NP0 Ceramic

R20
1/4W Metal Film 1k5

U1:B

5 6
R31
1/4W Metal Film 1k5

7
NE5532P Audio Op Amp

HP

R39
1/4W Metal Film 5k6

Q6
BD139 NPN Power

R43

Q4
1/4W Metal Film

560R

BD139

R42 NPN Power

1/4W Metal Film 560R

R40
1/4W Metal Film 3k3

R8
1/4W Metal Film 1R

R41
1/4W Metal Film 2k7

R6
1/4W Metal Film 1R

Q5
BD140 PNP Power
R7
1/4W Metal Film 5k6

R9
1/4W Metal Film 180R
C2
10nF 63V Polyester

R10
360R 1/4W Metal Film

+15V

R38
10R 1/4W Metal Film

C43

Electrolytic 470uF 25V

C44

C118
100pF 50V NP0 Ceramic

8

R26 Met. Polyester 1/4W Metal Film
47nF 63V 1k5
HP
U1:A
2
1
3

R28

NE5532P

4

Audio Op Amp

1/4W Metal Film

1k5

R21
1/4W Metal Film 5k6

Q3
BD139 NPN Power

R25 Q2
1/4W Metal Film 560R
BD139
R24 NPN Power
1/4W Metal Film 560R

R22
1/4W Metal Film 3k3
R23
1/4W Metal Film 2k7

R3
1/4W Metal Film 1R
R1
1/4W Metal Film 1R

HP
R37

CE4le6ctrolytic
470uF 25V

C45

-15V

47nF 63V

10R

Met. Polyester

1/4W Metal Film

R2
1/4W Metal Film 5k6

Q1
BD140 PNP Power

R4
1/4W Metal Film 180R
C1
10nF 63V Polyester

R5
360R 1/4W Metal Film

Head Phones Detect

Head Phones Detect Gnd
R17

10R 2W Carbon

R18

10R
2W CarboCn4
680pF 50V NP0 Ceramic

C5
680pF 50V NP0 Ceramic

W3
C

W1
B Main

HP

CN2
8 7
3
2

RSW1 RSW2
R
L

1 CK-6.35-08A Headphone Jack

GND

W4 WIRE3

C HP

WIRE2

W2
B HP

To enhance viewing, please print tAo AP319799/6 Preamp PCB Circuit Diagram (Headphone Driver)

19

Cambridge Audio Azur 740A Amplifier

+15V

5 7
6 -15V

3 6 3 6 3 STAR 6 3 6 3

L

R124

J2

No Fit
1/4W Metal Film
C116

Screw Terminal

CN18:B
AV2-8.4-9

CN17:D AVC4-18.04-29

CN17:B
AV4-8.4-9

CN16:D CAV140-80.4-9

CN16:B
AV4-8.4-9

CN15:D
AV4-8.4-9

CN15:B
AV4-8.4-9

Ceramic No Fit

PreOut Left

220pF 50V
NP0 Ceramic R87

NP0 Ceramic
R89 220pF 50V

R121
47k 1/8W Metal Film

C104 R50

47uF 16V NP Electrolytic
R92

STAR
C97 47uF 16V

220R 1/8W Metal Film

NP Electrolytic

220R 1/8W Metal Film

C89

C105

1206 Thick Film 47k
1k 1/8W Metal Film

R96 R51
1206 Thick4F7ilkm

C93 NP Electrolytic
47uF 16V
R100

NP Electrolytic 47uF 16V
R104

100pF 50V NP0 Ceramic
STAR

C95

1k

STAR

100pF 50V NP0 Ceramic

1/8W Metal Film
C91

R83

47k

1206 Thick Film1/8W Metal Film

1k

C85

47k

R84

1/8W Metal Film

1206 Thick Film

1k

C69

STAR

100pF 50V NP0 Ceramic

100pF 50V

100pF 50V

NP0 Ceramic

NP0 Ceramic

U20:B

U15:B

STAR
U16:B

STAR
U17:B

U18:B

R60

U11:A

R62

R

70

72

72

0'

'9'

'$%

&'

1/4W Metal Film

1/4W Metal Film

47R

47R

U11:B

1
32

$X[

3 1
2

CN14:D CN14:B

4

8

C62

C61

1

STAR

STAR

4

1

4

1

4

1

4

CN17:C

STAR

CN14:C CN15:A CN15:C

CN16:A

CN16:C CN17:A

CN18:A

AV4-8.4-9

AV4-8.4-9

47nF 63V Met. Polyester
NE5532P Audio Op Amp

47nF 63V Met. Polyester NE5532P Audio Op Amp

STAR

STAR

2

AV4-8.4-9
CN14:A
C72
NP Electrolytic 47uF 16V

5

2

AV4-8.4-9

AV4-8.4-9

AV4-8.4-9

5

2

AV4-8.4C-999

NP Electrolytic 47uF 16V
C113

NP Electrolytic 47uF 16V
C88

NP Electrolytic 47uF 16V
C92
STAR

220pF 50V NP0 Ceramic
C96
NP Electrolytic 47uF 16V

5

AV4-8.4-9

2

CAV140-81.4-9

5

AV4-8.4-9

AV2-8.4-9

2 PreOut Right

R90
220R 1/8W Metal Film

NP0 Ceramic 220pF 50V

STAR

R88

C103

220R

NP Electrolytic

1/8W Metal Film 47uF 16V

C87

NP Electrolytic
C71 47uF 16V

R109

NP Electrolytic
47uF 16V
R108

47k 1/8W Metal Film

47k
R85 1/8W Metal Film

STAR
R91

C74

1206 Thick Film

1k

C73

1206 Thick Film

1k

100pF 50V

NP0 Ceramic

4 100pF 50V

NP0 Ceramic
STAR
U19:B

C76

47nF 63V Met. Polyester

R106

R102

R98

R94

R86

R93

47k 1/8W Metal Film

1206 Thick Film

1k 100pF 50V

NP0 Ceramic

U19:A STAR

C70

-15V +15V

8

4

C75

C67

R95

47k 1/8W Metal Film

1206 Thick Film

1k

STAR

C86

U18:A
+15V 8

100pF 50V NP0 Ceramic
-15V
4

47k

R97

1/8W Metal Film

1206 Thick Film

1k

100pF 50V

NP0 Ceramic

C90
STAR

U17:A +15V
-15V

8

4

R99

47k 1/8W Metal Film

1206 Thick Film

1k

STAR 100pF 50V

NP0 Ceramic

U16:A
+15V
8

C94
-15V 4

47k

R101

1/8W Metal Film

1206 Thick Film 100pF 50V

1k

STAR NP0 Ceramic

C98

U15:A

-15V

+15V

R103
1206 Thick Film 1k
U20:A
+15V

8

4

8

C68 C83

C84

C111

C110

C109 C108

C106

C107

3 1
2 3 1 2 3 1 2 3 1 2

3 1
2

47nF 63V Met. Polyester

47nF 63V

47nF 63V

Met. Polyester Met. Polyester

Met. Polyester 47nF 63V

Met. Polyester 47nF 63V

47nF 63V Met. Polyester

Met. Polyester 47nF 63V

Met. Polyester Met. Polyester Met. Polyester Met. Polyester

47nF 63V

47nF 63V

47nF 63V

47nF 63V

5 7
6 -15V 3
1 2

5 7
6 5 7 6

5 7
6 5 7 6

5 7
6

LCh Out RCh Out

NE5532P Audio Op Amp

NE5532P Audio Op Amp

NE5532P Audio Op Amp

NE5532P Audio Op Amp

LCh HP Out
R76
5
Wire Link 6
R79
No Fit

STAR +15V

R63

U12:B
7
NE5532P Audio Op Amp

R123
220R 1/8W Metal Film

C59

PreOut Left
C115
220pF 50V NP0 Ceramic

STAR

RCh HP Out
R77

Wire Link

R78
No Fit

47R 1/4W Metal Film
3
2

8

4

47nF 63V
U12:A Met. Polyester R122
1

NE5532P

220R

STAR

PreOut Right

Audio Op Amp 1/8W Metal Film

C114

R61

C60
47nF 63V Met. Polyester

220pF 50V NP0 Ceramic

-15V STAR

STAR

47R 1/4W Metal Film

STAR

NE5532P Audio Op Amp

NE5532P Audio Op Amp

STAR

STAR

NE5532P

-15V

Audio Op Amp +15V

STAR

STAR NE5532P Audio Op Amp

R133
100R 1/4W Metal Film
C20

R134
100R 1/4W Metal Film

STAR

Switch Strobe PIC GND

Mono Ceramic
U10 100nF 100V

1 Vss
2 L-S1
3 L-S2
4 L-S3
5 L-COM1
6 L-S4
7 L-S5
8 L-S6
9 L-COM2
10 L-S7
11 L-S8
12 L-COM3
13 ST
14 GND

Vdd 28
R-S1 27
R-S2 26
R-S3 25
R-COM1 24
R-S4 23
R-S5 22
R-S6 21
R-COM2 20
R-S7 19
R-S8 18
R-COM3 17
DATA 16
CLK 15

TC9163AF

CN10

&RQWURO%XV,5

1

$%863&%'*QG

2

$%86,5

3

$%866WDWXV

4

$%863&%9

5

6

7

8

9

10

STAR
CBUS IR
ABUS IR Preamp Standby +5V RC5 Block RC5 Tx
PIC IR On/Off C64

FFC Connector ABUS Control Signals ABUS Control Signals

PIC GND

Ceramic 1nF 50V

Data Clock

CBUS IR Volume Strobe POWER AMP STANDBY
ABUS IR Switch Strobe

Data

S1

Clock

Screw Terminal

STAR

STAR STAR NE5532P Audio Op Amp

NE5532P Audio Op Amp

STAR

STAR

STAR STAR
NE5532P Audio Op Amp

STAR
NE5532P Audio Op Amp

CN4

1

2

&RQWURO%XV,5

3

4

9ROXPH6WUREH

3RZHUDPS6WDQGE\

5

$%86,5

6

,QSXW6WUREH

7

'*QGIURP3,&

8

'DWD

9

&ORFN

9 Way Straight Header PIC GND To PIC

R56
470k 1/4W Metal Film
STAR
R57
470k 1/4W Metal Film
STAR

FB4

On 24AWG Wire 1uH Ferrite

STAR

ABUS
10pF 50V NP0 Ceramic
C82

R53
1

560R

2

1/4W Metal Film 3

CN11
/&K *1' 5&K

ABUS

3 Way Straight Header ABUS Audio Out

R55
1k8 1/4W Metal Film

R52
560R 1/4W Metal Film

5

U9:B

7

6

NE5532P

Audio Op Amp

R54

C79 10pF 50V
NP0 Ceramic

1k8 1/4W Metal Film

R58

+15V C81 1k8
1/4W Metal Film

STAR

U9:A
STAR

4

47nF 63V

Met. Polyester 3

1

2
R59
1k8

8

NE5532P Audio Op Amp
C80

1/4W Metal Film

LCh In RCh In

STAR

-15V

STAR

47nF 63V Met. Polyester

To enhance viewing, please print tAo AP319799/6 Preamp PCB Circuit Diagram (Buffers & Switches)

20

Cambridge Audio Azur 740A Amplifier

LarryR

To enhance viewing, please print to A3 AP19799/4 Preamp PCB Board Layout (Top Side)

21

Cambridge Audio Azur 740A Amplifier

To enhance viewing, please print to A3 AP19799/4 Preamp PCB Board Layout (Bottom Side)

22

Cambridge Audio Azur 740A Preamp PCB Assembly BOM

AP Part No.

Value

Description/Type Qty Component Ident

RESISTORS

1R

1/4W Metal Film

4

R1, R3, R6, R8

4.7R

1/8W Metal Film

1

R73

10R

2W Carbon

2

R17, R18

10R

1/4W Metal Film

2

R37, R38

47R

2W Carbon

1

R30

47R

1/4W Metal Film

4

R60-R63

100R

1/4W Metal Film

4

R27, R32, R133,

R134

100R

1/8W Metal Film

2

R71, R75

120R

1/8W Metal Film

2

R15, R142

180R

1/4W Metal Film

2

R4, R9

R16, R33-R36, R87-

220R

1/8W Metal Film

12 R90, R122, R123,

R130

220R

2W Carbon

1

R70

330R

1/4W Metal Film

4

R44-R47

360R

1/4W Metal Film

2

R5, R10

560R

1/4W Metal Film

6

R24, R25, R42, R43, R52, R53

620R

1/8W Metal Film

2

R13, R141

910R

1/8W Metal Film

1

R65

Wire Link

24AWG

2

R76, R77

No Fit

2

R78, R79

No Fit

1

R124

1k

1/4W Metal Film

1

R19

R50, R51, R83-R85,

1k

1206 Thick Film

12 R91, R93, R95, R97,

R99, R101, R103

1k

1/8W Metal Film

2

R80, R82

1k

1206 Thick Film

1

R105

1k5

1/4W Metal Film

4 R20, R26, R28, R31

1k8

1/8W Metal Film

1

R12

1k8

1/4W Metal Film

4 R54, R55, R58, R59

2k7

1/4W Metal Film

2

R23, R41

3k

1/8W Metal Film

1

R11

3k3

1/4W Metal Film

2

R22, R40

4k7

1/8W Metal Film

6

R29, R64, R66-R68, R72

4k7

1/4W Metal Film

1

R127

5k6

1/4W Metal Film

4

R2, R7, R21, R39

6k2

1/8W Metal Film

1

R48

7k5

1/4W Metal Film

1

R128

10k

1/8W Metal Film

10

R14, R74, R81, R129, R132, R136-R140

10k

1206 Thick Film

1

R49

10k

1/8W Metal Film

1

R131

10k

1/4W Metal Film

1

R144

R86, R92, R94, R96,

47k

1/8W Metal Film

12

R98, R100, R102, R104, R106, R108,

R109, R121

Type

Tolerance Factory P/N

AP19802/5
Notes

1% 1% 10% 1% 10% 1%
1%
1% 1% 1%
1%
10% 1% 1%
1%
1% 1%

1%

1%

1% 1%

R76 and R77 has

1%

been replaced

with wire link

1% 1% 1% 1% 1%

1%

1% 1% 1% 1%

1%

1% 1% 1%

1%

Note: resistors, capacitors and other 'generic' electronic componets are

not usually stocked by the manufacturer. Please obtain these locally.

23

Cambridge Audio Azur 740A Preamp PCB Assembly BOM

AP Part No.

Value

Description/Type Qty Component Ident

100k

1/8W Metal Film

2

R69, R126

470k

1/4W Metal Film

2

R56, R57

CAPACITORS

No fit

4 C27, C28, C30, C57

No Fit

1

C116

10pF 50V

NP0 Ceramic

2

C79, C82

100pF 50V
220pF 50V 680pF 50V

NP0 Ceramic
NP0 Ceramic NP0 Ceramic

C69, C70, C73, C74, C85, C86, C90, C91, 14
C94, C95, C98, C105, C117, C118

6

C99-C102, C114,

C115

2

C4, C5

1nF 50V

Ceramic

1

C64

10nF 63V

Polyester

2

C1, C2

10nF 50V 39nF 250V

Ceramic Met. Polyester

47nF 63V

Met. Polyester

100nF 100V 100nF 100V 100nF 50V

Mono Ceramic Polypropylene 1206 Ceramic

1

C63

1

C29

C3, C11, C14, C17, C23-C25, C33, C37, C40, C41, C44, C45, 32 C55, C59-C62, C67, C68, C75, C76, C80,
C81, C83, C84, C106-C111

7

C6, C9, C10, C20, C36, C58, C120

2

C48, C50

2

C52, C53

100nF 50V 330nF 100V
47uF 35V
47uF 16V

Mono Ceramic Mono Ceramic
Electrolytic
NP Electrolytic

1

C112

1

C31

6

C8, C12, C13, C22, C34, C35

C71, C72, C87-C89, 12 C92, C93, C96, C97,
C103, C104, C113

100uF 16V

Electrolytic

4 C7, C21, C51, C54

100uF 25V

Electrolytic

4 C15, C16, C77, C78

100uF 25V

Electrolytic 105

2

C18, C19

100uF 25V 470uF 10V 470uF 25V

NP Electrolytic Electrolytic Electrolytic

2

C47, C49

5

C38, C39, C42, C56, C119

2

C43, C46

Type

Tolerance Factory P/N
1% 1%

AP19802/5
Notes

5%

1181-100042000

1181-1010425%
000

5% 5% 10% 10% 10% 10%

1181-221042000
1181-681042000
1100-102043000 1117-
103053E000 1100-103043-
000

10%

1117-473053000

10% 10% 10%
10% 10% 20%

1106-104064001
1189-104042400
1100-104043000

20%
20% 20% 20% 20% 20% 20%

1105-470014000
1102-101014000
1102-101024000 1102-
101024E002 1105-101024-
000

Note: resistors, capacitors and other 'generic' electronic componets are

not usually stocked by the manufacturer. Please obtain these locally.

24

Cambridge Audio Azur 740A Preamp PCB Assembly BOM

AP Part No.

Value

Description/Type Qty Component Ident

Type

2200uF 35V

Electrolytic

2

C26, C32

6 Way

Straight Header

Stereo 6.35mm 10 Way 9 Way

Headphone Jack Straight Header Straight Header

6 Way

Straight Header

3 Way

Straight Header

5 Way

Straight Header

3 Way

Straight Header

7 Way
10 Way 9 Way
4 Way

Straight Header
FFC Connector Straight Header
Straight Header

4 Way

Gold Plated Phono

2 Way

Gold Plated Phono

400V 1A 100V 1A 75V 150mA
400V 1A

Rectifier Diode Schottky Rectifier
Signal Diode
Rectifier Diode

1uH Ferrite

On 24AWG Wire

Dual 2 Channel
+15V -15V +5V Negative Positive 16 Way

Audio Op Amp Volume IC Regulator Regulator Regulator
Adj Regulator Adj Regulator Input Switch

CONNECTORS

1

CN1

1

CN2

1

CN3

1

CN4

1

CN5

1

CN6

1

CN7

2

CN8, CN11

1

CN9

1

CN10

1

CN12

1

CN13

4

CN14-CN17

1

CN18

DIODES

7

D1-D3, D9-D12

4

D4-D7

3

D8, D14, D15

1

D13

INDUCTORS

3

FB3-FB5

INTEGRATED CIRCUITS

10 U1, U9, U11, U12, NE5532P U15-U20

1

U2

YAC526

1

U3

L7815

1

U4

L7915

1

U5

L7805

2

U6, U7

LM337T

1

U8

LM317T

1

U10

TC9163AF

Tolerance Factory P/N

AP19802/5
Notes

20%

1102-222034000

With Cambridge Sleeving as per
640C V2

2300-006000000
2330-005901300
2300-009000000
2300-006100004
2300-003400001
2300-005100004
2300-003100004 2300-
007100E002

2300-004100004 2330-
006900E001 2330-
003911E034
1401-140040000
1401-141480000
1401-140040000
1503-000000100
4155-320052900
4178150302E600
4179150302E600
4178050334E700 4133-700301-
800 4131-700301-
800 4191630103E001

Note: resistors, capacitors and other 'generic' electronic componets are

not usually stocked by the manufacturer. Please obtain these locally.

25

Cambridge Audio Azur 740A Preamp PCB Assembly BOM

AP Part No.

Value

Description/Type Qty Component Ident

Low Offset

Dual Comparator

2

U13, U14

RELAY

PY504

5V 2A

2P2T Relay

2

RL1, RL2

TRANSISTORS

PY1235 -80V 1.5A

PNP Power

2

Q1, Q5

PY1230

80V 1.5A

NPN Power

4

Q2-Q4, Q6

PY214 45V 300mA

NPN Signal

3

Q7, Q8, Q10

PY219 -45V 500mA

PNP Signal

4 Q9, Q11, Q12, Q14

PY1211 30V 500mA

NPN Darlington

1

Q13

Type LM393AP
ME2-5S
BD140 BD139 BC337-25 BC327-25 MPSA14

Tolerance Factory P/N
4139300052E900
4050-000005002
1301140000E800
1300139000E800 1300-337000-
100 1301-327000-
100 1300-140000-
100

AP19802/5
Notes

Note: resistors, capacitors and other 'generic' electronic componets are

not usually stocked by the manufacturer. Please obtain these locally.

26

Cambridge Audio Azur 740A Amplifier

Left

L SPEAKER TEST
7 RL1:C
6 8

ME11-012-2Z4

J5

4 RL2:B

2P2T Relay SPKRB

R80

3

5

15R

ME11-012-2Z4

1/2W Carbon

2P2T Relay

With xxxxxxxx Wurth

SPKRA

ferrite beads added

7

L1

C6

24.5T 0.9mm

J7

Output Inductor

330pF 50V Ceramic
5

Right

R SPEAKER TEST

4 RL1:B
3 5

ME11-012-2Z4

7 RL2:C 2P2T Relay

J11

R104

6 Spkr B

8

15R

ME11-012-2Z4

1/2W Carbon

2P2T Relay

With xxxxxxxx Wurth

Spkr A

8

ferrite beads added

1

L2

C75

C51

330pF 50V

Ceramic

J9

6

24.5T 0.9mm Output Inductor

330pF 50V Ceramic
3

2
C76
330pF 50V Ceramic
4

W19

W21

W23 W25

WIRE7
Black 18 AWG Insulated Wire

WIRE8
Black18 AWG Insulated Wire

W20 W22

WIRE9
Black 18 AWG Insulated Wire

WIRE10
Black 18 AWG Insulated Wire

W24

W26

CN5

1

2

3 SPKR A

4 Gnd

5 SPKR B

6

Relay Unreg

7 Relay Gnd

7 Way Straight Header

Relay Unreg

L Speaker Test R Speaker Test

D27
1N4004 Rectifier

R107
10K 1/8W Metal Film
R106
10K 1/8W Metal Film

1RL2:A
2 ME11-012-2Z4 Speaker A Relay
Q34
MPSA14 NPN Darlington

D28
1N4004 Rectifier

D11
1N4004 Rectifier

Relay Unreg

RL1:A
1

D26
1N4004 Rectifier
R103
10K 1/8W Metal Film
R105
10K 1/8W Metal Film

2 ME11-012-2Z4 Speaker B Relay
Q35
MPSA14 NPN Darlington

CT1
Black Cable Tie

CT2
Black Cable Tie

CN7:A

CN7:C

1

1

2

2

5

5

6

6

Loudspeaker

Loudspeaker

CN7:B

CN7:D

3

3

4

4

7

7

8

8

Loudspeaker

Loudspeaker

To enhance viewing, please print to A3 AP19794/4 Amplifier Circuit Diagram (Speaker PCB)

27

Cambridge Audio Azur 740A Amplifier

CN4
1 2
Straight Header 2 Way

Q32

2SC2240GR

+50V R

R76

NPN Low Noise

+50V. R

C38
Polyester 47nF 63V
R AMP
C33

C40
Electrolytic
Q29
MPSA92 PNP Signal

R51
1/8W Metal Film
150R R50
1K 1/8W Metal Film

Q28
MPSA92 PNP Signal
R48
1/4W Metal Film 47K

R46
1/8W Metal Film 150R
R47
1/8W Metal Film 100K
Q27
2SA970GR PNP Low Noise

R53
1/4W Metal Film 100R

R55
100R 1/4W Metal Film R AMP

22.73
C31 R68

1/8W Metal Film 10R
C39
Electrolytic
Q26 R AMP
2SC2240GR NPN Low Noise

Polypropylene 100nF 100V
C34 R54

1/8W Metal Film NP Electrolytic 47R 100uF 25V

R69

R52

10K 100K
1/8W Metal Film 1/8W Metal Film

Q22

Q21

2SA970GR 2SA970GR PNP Low Noise PNP Low Noise

C32
100pF 50V NP0 Ceramic

R57
1/8W Metal Film 22K

C36
220pF 63V Polypropylene film R AMP

24AWG 10pF 50V Wire Link NP0 Ceramic
R58
1/4W Metal Film
R56 10K
1/8W Metal Film 470R

C50
NP Electrolytic 47uF 16V
R AMP R AMP

C37
NP Electrolytic 100uF 25V

R43
1/4W Metal Film 22K

R41
1/8W Metal Film 47K

Q19
MPSA42 NPN Signal

R AMP
C29
Polyester 47nF 63V

C28
Electrolytic

R AMP

R49

1/8W Metal Film
Q20 18R

MPSA42 NPN Signal

C49
Polypropylene

1nF 63V

R AMP
Q23
2SC2240GR NPN Low Noise

R110

1/8W Metal Film

470R

R111

1/8W Metal Film

470R

Q25
MPSA92
PNP Signal R59
1/8W Metal Film 2K2
R44
13k
1/8W Metal Film C14
Polypropylene 1nF 63V

D30
Rectifier 1N4004
Q24
2SC2240GR NPN Low Noise
R122
2K7 1/8W Metal Film
R45
1/8W Metal Film 470R

Q17
MPSA42 NPN Signal
Q18
MPSA42 NPN Signal
R40
1/8W Metal Film 1K
R39
1/8W Metal Film 130R

R73
1/8W Metal Film
2K2

R70
1/8W Metal Film 100R

R138

B

1

1/8W Metal Film 100R

B 1 C

S D
4

3 3

C Q54
SAP15NY NPN Power
S 4
E RE1

RO 5

2

C35
Polypropylene film 10nF 63V

2

D
Q57
SAP15NY NPN Power

5

E
R134

CW

CCW

1

PR2

R78

Multiturn Preset

B200R 0.22R

3W Wirewound 2

1

0.22R

3

CCW

PR4

Multiturn Preset

B200R

2

3W Wirewound
R135

R65
0.22R 3W Wirewound

CW

0.22R

3

3W Wirewound
Q58

SAP15PY

RE2

4

PNP Power E
D

1 4 1

R AMP 3
3

S

D

2

R139 5

1/8W Metal Film

B

100R

C

R60 5

1/8W Metal Film

B

100R

C30

R61

Electrolytic
R38
1/8W Metal Film 100K

1/8W Metal Film 2K2

R37

E
S 2
Q53
SAP15PY PNP Power C

C61
220uF 63V Polarised Electrolytic
R AMP
D19
Rectifier 1N4004

J12 WIRE17

C59
Mono Ceramic 100nF 100V

Red 18 AWG Insulated Wire

Output Wires to Speaker PCB:

R66
4.7R
3W WireWound J16

WIRE18

Black 18 AWG Insulated Wire

R AMP

D20
Rectifier 1N4004

R AMP

C53
220uF 63V Polarised Electrolytic

1/8W Metal Film Q16

10R

2SA970GR

PNP Low Noise

-50V R

-50V. R

To enhance viewing, please print to A3 AP19794/4 Amplifier Circuit Diagram (Right Channel)

28

Cambridge Audio Azur 740A Amplifier

C21
Polyester 47nF 63V
L AMP

C19

Polypropylene 100nF 100V
C18 R9

CN1
1 2
Straight Header 2 Way Left Input

1/8W Metal Film NP Electrolytic 47R 100uF 25V

R31

R7

1/8W Metal Film 1/8W Metal Film

100K

10K

L AMP
C9
Polyester 47nF 63V

C23
Electrolytic

R6
1/8W Metal Film
150R R5

Q4
MPSA92 PNP Signal

1/8W Metal Film 1K

R8
100R 1/4W Metal Film

R10
100R 1/4W Metal Film

Q5

Q11

2SA970GR 2SA970GR PNP Low Noise PNP Low Noise

R12

C7
100pF 50V NP0 Ceramic

1/8W Metal Film 22K

C16
220pF 63V Polypropylene film L AMP

Q15

2SC2240GR

+50V L

R36

NPN Low Noise

+50V. L

Q3
MPSA92 PNP Signal

R3
1/8W Metal Film 150R
R2
1/8W Metal Film 100K

R114
1/4W Metal Film 47K

Q2
2SA970GR PNP Low Noise

22.73
L AMP

C8

R30

1/8W Metal Film 10R
C22
Electrolytic
L AMP
Q1
2SC2240GR NPN Low Noise

24AWG 10pF 50V Wire Link NP0 Ceramic
R13
1/4W Metal Film
R11 10K
1/8W Metal Film 470R

C5
NP Electrolytic 47uF 16V
L AMP L AMP

C20
NP Electrolytic 100uF 25V

R18
1/4W Metal Film 22K

R20
1/8W Metal Film 47K

R35 1/8W Metal Film R32

2K2

1/8W Metal Film

100R

B

1

C

R136

B

1

1/8W Metal Film 100R

3 3

C
Q52
SAP15NY NPN Power
S 4

C56
Polarised Electrolytic 220uF 63V
D21 L AMP
Rectifier 1N4004

S D
4

E LE1

LO 5

2

C17
Polypropylene film 10nF 63V

2

1

D
Q55
SAP15NY NPN Power

5

E
2
R133
0.22R 3W Wirewound

3

CW

CCW

1

R113
0.22R
PR1 3W Wirewound
Multiturn Preset B200R

CCW

PR3
Multiturn Preset B200R

3

CW

4

2
Q56
SAP15PY PNP Power D

R132
0.22R 3W Wirewound
E

R27
0.22R 3W Wirewound
LE2

J6

WIRE15

Red 18 AWG Insulated Wire
C15
Mono Ceramic 100nF 100V
Output Wires to Speaker PCB:

R28
4.7R
3W WireWound J17

WIRE16

Black 18 AWG Insulated Wire

1 4 1

Q9
MPSA42 NPN Signal

MPSA42 NPN Signal

L AMP
R4 Q10 1/8W Metal Film
18R
C4
Polypropylene 1nF 63V

L AMP
Q6
2SC2240GR NPN Low Noise

C11
100uF 63V Electrolytic

R17

1/8W Metal Film

470R

R16

1/8W Metal Film

470R

Q8
MPSA92
PNP Signal R29
1/8W Metal Film 2K2
R14
1/8W Metal Film 13k
C13
Polypropylene 1nF 63V

D29
Rectifier 1N4004
Q7
2SC2240GR NPN Low Noise

Q12
MPSA42 NPN Signal
Q13
MPSA42 NPN Signal

R67
1/8W Metal Film 2K7
R115
1/8W Metal Film 470R

R19
1/8W Metal Film 1K
R21
1/8W Metal Film 130R

S

D

2

R137 5

1/8W Metal Film

B

100R

C

R15 5

1/8W Metal Film

B

100R

C10

R24

Electrolytic
R22
1/8W Metal Film 100K

1/8W Metal Film 2K2

R23

1/8W Metal Film Q14

10R

2SA970GR

-50V L

PNP Low Noise

L AMP 3
3

E

L AMP

D22

S

Rectifier

2

1N4004

L AMP

C
Q51
SAP15PY
PNP Power

C12
Polarised Electrolytic 220uF 63V

-50V. L

To enhance viewing, please print to A3 AP19794/4 Amplifier Circuit Diagram (Left Channel)

29

Cambridge Audio Azur 740A Amplifier

DC Detection

+50V P

D5

Right Protection PCB (Clipping)
+50V. R

Left Protection PCB (Clipping)

R112
LO 100K 1/8W Metal Film
C55

1N4148 Signal Diode
D8

NP Electrolytic

DGND

10uF 25V

1N4148
Signal Diode D6

D7
1N4148

Signal Diode

R42
100K 1/8W Metal Film
R77

10k 1/8W Metal Film
Q31

R140
4K7

PIC DC Detect
Q49
MPSA42 NPN Signal

+50V. R

H16A H16B
R100
1/8W Metal Film 15K
H15B H15A

Q42
MPSA92 PNP Signal

R117
1/8W Metal Film 120K

+50V P

H8A H8B

+50V P

R89
1/8W Metal Film 15K H7B H7A

Q39
MPSA92 PNP Signal

R120
120K 1/8W Metal Film

L AMP
R63

1N4148 Signal Diode

RO

100K

D9

1/8W Metal Film

C54

NP Electrolytic 10uF 25V

1N4148
Signal Diode D10

R AMP

1N4148 Signal Diode

DGND

MPSA42 NPN Signal

1/8W Metal Film

Q30
MPSA92 PNP Signal

DGND

R109
100K 1/8W Metal Film

D25
H14B RO

R99
1/8W Metal Film 100K

1N4148 Signal Diode
R96
1/8W Metal Film 100K

R97
1/8W Metal Film 120K

Q43

R98

1/8W Metal Film

120K

D31

LO

1N4148 Signal Diode
Q44
MPSA42 NPN Signal

D24
H6B

R88
1/8W Metal Film 100K

1N4148 Signal Diode
R86
1/8W Metal Film 100K

R87
1/8W Metal Film 120K

Q38

R90
1/8W Metal Film 120K
Q45
MPSA42 NPN Signal

D32

1N4148 Signal Diode

PIC Clip Detect

R75
1/8W Metal Film 4K7

D17
Zener 5V1 1/2W

-50V P
Left Protection PCB Connector (A)
CN2 CN8

-50V. R

R95
1/8W Metal Film 15K H13A H13B

MPSA42 NPN Signal

R116
1/8W Metal Film 2K2
-50V. R

R118
1/8W Metal Film 100R
-50V P

H5A H5B

R85
1/8W Metal Film 15K

MPSA42 NPN Signal
-50V P

R119

R121

1/8W Metal Film 1/8W Metal Film DGND

2K2

100R

DGND

H1A

1

H2A

2

H3A

3

H4A

4

H5A

5

6

H7A

7

H8A

8

1

H1B VI Output (R)

2

H2B VI Bottom Input (R)

3

H3B Amp Output (R)

4

H4B VI Top Input (R)

5

H5B -45V (R)

6

H6B Amp Output (R)

7

H7B Clip Output (R)

8

H8B +45V (R)

H8B

R79
1/8W Metal Film 18K

C62
Ceramic 4.7nF 50V
Q33
MPSA92

R124
1/8W Metal Film 18K

C3
Ceramic 4.7nF 50V

Q46
MPSA92

H16B

R126
1/8W Metal Film 18K

C45
Ceramic 4.7nF 50V

Q47
MPSA92

R127
1/8W Metal Film 18K

C72
Ceramic 4.7nF 50V
Q48
MPSA92

Right Angle Pin Header Right Angle Pin Header

PNP Signal

PNP Signal

PNP Signal

PNP Signal

8 Way

8 Way

H9B H9A

Right Protection PCB Connector (B)

CN3 CN9

H9A

1

H10A

2

H11A

3

H12A

4

H13A

5

6

H15A

7

H16A

8

1

H9B VI Output (R)

2

H10B VI Bottom Input (R)

3

H11B Amp Output (R)

4

H12B VI Top Input (R)

5

H13B -45V (R)

6

H14B Amp Output (R)

7

H15B Clip Output (R)

8

H16B +45V (R)

Right Angle Pin Header Right Angle Pin Header

8 Way

8 Way

TH1

Left Protection PCB (VI)

+50V. L LE1

R33

H4A H4B

51K 1/4W Metal Film
R34
1/8W Metal Film 2K2
H3A H3B LO

C64 R83 Ceramic
220pF 50V 2K2 1/8W Metal Film

R84
2K2 1/8W Metal Film
C65
Electrolytic 10uF 63V

Temp Sense

PTC Thermistor 100 Degree 500R Mounted on Heatsink

DGND
PIC VI/Short PIC DC Detect PIC Clip Detect

CN6
1 2 3 4 5
5 Way Straight Header To input PCB/To PIC

LE2 -50V. L

R26
1/8W Metal Film 2K2
R25
H2A H2B 51K 1/4W Metal Film

C63

R81

220pF 50V

Ceramic

2K2

1/8W Metal Film

R82
2K2 1/8W Metal Film
C66
10uF 63V Electrolytic

R102
1/8W Metal Film 47K

R123
1/8W Metal Film 47K

Right Protection PCB (VI)
H1B H1A

R101
1/8W Metal Film 47K

R125
1/8W Metal Film 47K

Q37
MPSA42 NPN Signal
R130
1/8W Metal Film 47K
Q36
MPSA42 NPN Signal

+50V. R RE1

R131
1/8W Metal Film 47K

RE2 -50V. R

R71

H12A H12B

51K
1/4W Metal Film
R72

1/8W Metal Film 2K2

H11A H11B RO

R64
1/8W Metal Film 2K2
R62
H10A H10B 51K 1/4W Metal Film

C69
220pF 50V
R93 Ceramic
2K2 1/8W Metal Film

R94
2K2 1/8W Metal Film
C68
10uF 63V Electrolytic

C70
Ceramic
R91 220pF 50V
2K2 1/8W Metal Film

R92
2K2 1/8W Metal Film
C67
10uF 63V Electrolytic

Q40
MPSA42 NPN Signal

R128
1/8W Metal Film 47K

Q41
MPSA42 NPN Signal

R129
1/8W Metal Film 47K

R74
47K 1/8W Metal Film

D18
1N4148 Signal Diode
D16
Zener 5V1 1/2W

PIC VI/Short

DGND

To enhance viewing, please print to A3

AP19794/4 Amplifier Circuit Diagram (Protection)

30

Cambridge Audio Azur 740A Amplifier

+50V L

+50V R

Bus Bar (see page 6) Bus Bar (see page 6)

W7

W9

W8

+50V P
C24
105deg Electrolytic 6800uF 63V

C27
105deg Electrolytic 6800uF 63V

C42
105deg Electrolytic 6800uF 63V

W10
C41
105deg Electrolytic 6800uF 63V

C25
105deg Electrolytic 6800uF 63V

C26
105deg Electrolytic 6800uF 63V

C43
105deg Electrolytic 6800uF 63V

C44
105deg Electrolytic 6800uF 63V

-50V P
W11

W15

W12

W16

W17

W13

W14 W18

-50V L

L AMP

-50V R R AMP

C1

C2

39nF 250V Metallised Polyester
D13

Metallised Polyester 39nF 250V
D14

Rectifier 6A20
D12

Rectifier 6A20
D15

Rectifier 6A20
C46

Rectifier 6A20
C47

Metallised Polyester 39nF 250V

Metallised Polyester 39nF 250V

C52

C57

Metallised Polyester 39nF 250V
D3

Metallised Polyester 39nF 250V
D2

Rectifier 6A20
D4

Rectifier 6A20
D1

Rectifier 6A20
C58

Rectifier 6A20
C60

Metallised Polyester 39nF 250V

Metallised Polyester 39nF 250V

F4
Fast Blow Fuse F8A LBC

W1
Red-2

WIRE1
Red 18 AWG Insulated Wire

C48
Met Polypropylene X2 470nF 275V
F3
Fast Blow Fuse F8A LBC

W3 WIRE2
Yellow 18 AWG Insulated Wire
Yellow-2

C73

W2 WIRE3
Orange 18 AWG Insulated Wire
Orange-2

Ceramic

1nF 50V
R108

J19

1/4W Metal Film 100R

F1
Fast Blow Fuse F8A LBC

W4 WIRE4
Yellow 18 AWG Insulated Wire
Red

C71
Met Polypropylene X2 470nF 275V
F2
Fast Blow Fuse F8A LBC

W6 WIRE5
Red 18 AWG Insulated Wire
Yellow

C74
Ceramic 1nF 50V
R1
1/4W Metal Film 100R

W5 WIRE6
Orange 18 AWG Insulated Wire Orange
J4

Bus Bar (see page 6) Bus Bar (see page 6) Bus Bar (see page 6) Bus Bar (see page 6)

To enhance viewing, please print to A3 AP19794/4 Amplifier Circuit Diagram (Power Supply)

To Mains PCB Connection 2
To Mains PCB Connection 1
31

Cambridge Audio Azur 740A Amplifier

LarryR

To enhance viewing, please print to A3

AP19794/3 Amp PCB Board Layout (Top Side)

32

Cambridge Audio Azur 740A Amplifier

To enhance viewing, please print to A3 AP19794/3 Amp PCB Board Layout (Bottom Side)

33

Cambridge Azur 740A Amp PCB Assembly BOM

AP Part No.

Value

Description/Type

Qty Component Ident

Type

0.22R 24AWG
4.7R 10R 15R 18R 47R 100R
100R
130R 150R
470R
1K

3W Wirewound Wire Link
3W WireWound 1/8W Metal Film
1/2W Carbon 1/8W Metal Film 1/8W Metal Film 1/4W Metal Film
1/8W Metal Film
1/8W Metal Film 1/8W Metal Film
1/8W Metal Film
1/8W Metal Film

RESISTORS

8

R27, R65, R78, R113, R132-R135

2

R30, R68

2

R28, R66

4

R23, R36, R37, R76

2

R80, R104

2

R4, R49

2

R9, R54

6

R1, R8, R10, R53, R55, R108

R15, R32, R60, R70,

10

R118, R121, R136-

R139

2

R21, R39

4

R3, R6, R46, R51

R11, R16, R17, R45,

8

R56, R110, R111,

R115

4

R5, R19, R40, R50

R24, R26, R29, R34,

2K2

1/8W Metal Film

16

R35, R59, R61, R64, R72, R73, R81-R84,

R116, R119

2K2

1/8W Metal Film

2

R91, R93

2K2

1/8W Metal Film

2

R92, R94

2K7

1/8W Metal Film

2

R67, R122

4K7

1/8W Metal Film

2

R75, R140

10K

1/8W Metal Film

7

R7, R52, R77, R103, R105-R107

10K

1/4W Metal Film

2

R13, R58

13k

1/8W Metal Film

2

R14, R44

15K

1/8W Metal Film

4 R85, R89, R95, R100

18K

1/8W Metal Film

4

R79, R124, R126, R127

22K

1/8W Metal Film

2

R12, R57

22K

1/4W Metal Film

2

R18, R43

R20, R41, R74, R101,

47K

1/8W Metal Film

11

R102, R123, R125,

R128-R131

47K

1/4W Metal Film

2

R48, R114

51K

1/4W Metal Film

4

R25, R33, R62, R71

100K

1/8W Metal Film

R2, R22, R31, R38,

14

R42, R47, R63, R69, R86, R88, R96, R99,

R109, R112

120K
B200R
10pF 50V 100pF 50V 220pF 63V

1/8W Metal Film
Multiturn Preset
NP0 Ceramic NP0 Ceramic Polypropylene film

6

R87, R90, R97, R98, R117, R120

RESISTORS VARIABLE

4

PR1-PR4

CAPACITORS

2

C8, C31

2

C7, C32

2

C16, C36

220pF 50V

Ceramic

4 C63, C64, C69, C70

330pF 50V 1nF 63V 1nF 63V 1nF 50V 4.7nF 50V 10nF 63V

Ceramic Polypropylene Polypropylene
Ceramic Ceramic Polypropylene film

4

C6, C51, C75, C76

2

C4, C49

2

C13, C14

2

C73, C74

4

C3, C45, C62, C72

2

C17, C35

Tolerance

Factory P/N

5%

1072-208330E000

1%

5%

1074-707330E000

1%

10%

1%

1%

1%

1% 1% 1% 1% 1%

1%

1% 1% 1% 1% 1% 1% 1% 1%
1% 1% 1%
1%
1% 1%

1%

1%

10%

1062-001412E000

5%

1181-100042-000

5%

1181-101042-000

10%

5%

1100-221042-000

5%

1100-331042-000

5%

1114-102052E000

5%

1114-102052E000

10%

1100-102043-000

10%

1100-472043-000

10%

AP19797/6
Notes

Note: resistors, capacitors and other 'generic' electronic components are

not usually stocked by the manufacturer. Please obtain these locally.

34

Cambridge Azur 740A Amp PCB Assembly BOM

AP Part No.

Value

Description/Type

Qty

Component Ident

Type

Tolerance

Factory P/N

AP19797/6
Notes

39nF 250V
47nF 63V 100nF 100V 100nF 100V 470nF 275V
10uF 25V 10uF 63V 47uF 16V
100uF 63V

Metallised Polyester
Polyester Mono Ceramic Polypropylene Met Polypropylene X2 NP Electrolytic
Electrolytic NP Electrolytic
Electrolytic

8

C1, C2, C46, C47, C52, C57, C58, C60

4

C9, C21, C29, C38

2

C15, C59

2

C19, C33

2

C48, C71

2

C54, C55

4

C65-C68

2

C5, C50

8

C10, C11, C22, C23, C28, C30, C39, C40

10%

10%

1117-473053-000

10%

1106-104064-001

10%

20%

20%

1105-100024-000

20%

1102-100054-000

20%

1105-470014-000

20%

1102-101054-000

100uF 25V

NP Electrolytic

4 C18, C20, C34, C37

20%

1105-101024-000

220uF 63V 6800uF 63V
2 Way 8 Way 7 Way 5 Way 8 Way
200V 2A
75V 150mA
400V 1A 5V1 1/2W F8A LBC

Polarised Electrolytic 105deg Electrolytic
Straight Header Right Angle Pin Header
Straight Header Straight Header
Loudspeaker
Rectifier
Signal Diode
Rectifier Zener Fast Blow Fuse Fuse Holder Base

4 C12, C53, C56, C61

8

C24-C27, C41-C44

CONNECTORS

2

CN1, CN4

4

CN2, CN3, CN8, CN9

1

CN5

1

CN6

1

CN7

DIODES

8

D1-D4, D12-D15

11

D5-D10, D18, D24, D25, D31, D32

10

D11, D19-D22, D26D30

2

D16, D17

FUSES

4

F1-F4

4

F1-F4

20% 20%

2300-002100-003
2370-008110E000
2300-007100E002 2300-005100-004

6/2.54/1.5/3
Fully gold plated brass with AP design knobs

Stand Off PCB by 10mm

1401-141480-000

1401-140040-000 1402-511201E200

20mm Pitch

(alt. Camden YN:4031140000E000)

Fuse Holder Cover

PY594

24.5T 0.9mm 12V 8A

Output Inductor 2P2T Relay

PY910

120V 100mA

NPN Low Noise

PF075

-120V -100mA

PNP Low Noise

4

F1-F4

20mm Pitch

(alt. Camden YN:4034140000E000)

INDUCTORS

2

L1, L2

RELAY

2

RL1, RL2

ME11-012-2Z4

TRANSISTORS

Q1, Q6, Q7, Q15,

8

Q23, Q24, Q26, 2SC2240GR

Q32

3203-874801-000 4050-110122-001

AP13772/1

1300-224000E100

2

Q2, Q27

2SA970GR

1301-970000-100

Fit with flat side of TO92 away from
main heatsink

PY220

-300V -500mA

PF075 PY537

-120V -100mA 300V 500mA

PNP Signal
PNP Low Noise NPN Signal

Q3, Q4, Q8, Q25,

13

Q28-Q30, Q33,

MPSA92

Q39, Q42, Q46-Q48

2

Q5, Q11

2SA970GR

2

Q9, Q10

MPSA42

1301-920000-100

1301-970000-100 1300-420000-100

Q5/Q11 Matched to 2%
Q9/Q10 Matched to 2%

Note: resistors, capacitors and other 'generic' electronic components are

not usually stocked by the manufacturer. Please obtain these locally.

35

Cambridge Azur 740A Amp PCB Assembly BOM

AP Part No.

Value

Description/Type

Qty

PY537

300V 500mA

NPN Signal

14

PF075

-120V -100mA

PNP Low Noise

2

PY537

300V 500mA

NPN Signal

2

-120V -100mA

PNP Low Noise

2

PF075

30V 500mA

NPN Darlington

2

PY016

-160V 15A

PNP Power

4

PY010

160V 15A

NPN Power

4

Component Ident
Q12, Q13, Q17, Q18, Q31, Q36Q38, Q40, Q41, Q43-Q45, Q49
Q14, Q16
Q19, Q20
Q21, Q22
Q34, Q35 Q51, Q53, Q56,
Q58 Q52, Q54, Q55,
Q57

Type
MPSA42
2SA970GR MPSA42 2SA970GR MPSA14 SAP15PY SAP15NY

Tolerance

Factory P/N

AP19797/6
Notes

1300-420000-100

1301-970000-100 1300-420000-100
1301-970000-100 1300-140000-100 1301-150000-700

Q19/Q20 Matched to 2%
Q21/Q22 Matched to 2%

1300-150000-700

Note: resistors, capacitors and other 'generic' electronic components are

not usually stocked by the manufacturer. Please obtain these locally.

36

Cambridge Audio Azur 740A Amplifier

+12V

R47
10K 0805 Thick Film

+5V

CN1

&RQWURO%XV,5

10

$%863&%'*QG

9

$%86,5

8

$%866WDWXV

7

$%863&%9

6

5

4

3

2

1

FFC Connector ABUS Control Signals

C1
10uF 16V Electrolytic

ABUS STATUS CB PASS THRU
RC5 EN RC5 TX
FP IR On/Off

SW1

2

1

4

3

6

5

8

7

DPL-04K Black Piano DIP Switch

RC5 EN

C2
100nF 25V 0805 Ceramic

LOGIC GND

R50
10K 0805 Thick Film

Q1
BC846 NPN Small Signal

LOGIC GND EMITTER IN (MODULATED IR)
3.5mm JACK

LOGIC GND

Cambridge Control Bus

+5V

CN6

R49
220R 0805 Thick Film

D9
MV50640 Red LED

CKX-3.5-12

M2
AP17339/3 IR Demodulator
U7 IR receiver

IR Diode

+5V 3
GND 2
OPT 1

TSOP34836 36KHz

R46
47R 0805 Thick Film

C33
100nF 25V 0805 Ceramic
LOGIC GND

C32
10uF 16V Electrolytic

D1
MV50640 Red LED

CN2
3 2 1
3 Way Straight Header

RIGHT C36

C11
1nF 50V
R24 0805 NP0 Ceramic
1K 0805 Thick Film

47uF 25V Polarised Electrolytic
C9
47uF 25V Polarised Electrolytic
ABUS GND

ABUS GND

C30
100uF 16V Polarised Electolytic

+12V

LEFT C10
47uF 25V Polarised Electrolytic

R8
10K 0805 Thick Film
R7
4K7 0805 Thick Film

ABUS STATUS

R6
27K 0805 Thick Film

Q3
BC846 NPN Small Signal

Abus Powered Circuitry

Q2
BC856B PNP Small Signal
R10
100R 0805 Thick Film
R9
100R 0805 Thick Film

R15
10K 0805 Thick Film

R16
10K 0805 Thick Film

M1
AP17339/3 IR Demodulator
U3 IR receiver

IR Diode

+5V 3
GND 2
OPT 1

TSOP34837 37KHz

LOGIC GND +5V

ABUS GND

R51
47R 0805 Thick Film

C7
10uF 16V Electrolytic

C8
100nF 25V 0805 Ceramic

LOGIC GND

D3 BAS16

D4

Signal Diode

BZX84C2V7
D5 Zener Diode

U6 L7812 Regulator 3
VO

1 VI

+24V

100R

1/4W Fusible

FR1

D7

2 CN5
+24V IN
+24V 1

2 GND

R48

10K 0805 Thick Film

C28

33uF 25V

C31

Low ESR Electrolytic

100uF 16V

Polarised Electolytic
R41

ABUS GND

150K 0805 Thick Film

R40 5

120K

0805 Thick Film

6

R42

120K 0805 Thick Film

R39
150K 0805 Thick Film

C29
100nF 50V 1206 Ceramic
ABUS GND
U5:B
7
NJM5532M Op Amp
R43
150K 0805 Thick Film
C25
10pF 50V 0805 NP0 Ceramic

C27
100nF 50V 1206 Ceramic
R44
47R 0805 Thick Film
ABUS GND

+24V
C23

C26

1N4004 Rectifier Diode

Low ESR Electrolytic

220uF 35V

C34
100nF 50V Monolythic Ceramic

C35
Ceramic 1nF 50V

3 RDC-020-14A

ABUS GND

C22
10uF 35V Non Polarised Electrolytic
C24
47pF 50V 0805 NP0 Ceramic
F1

A-BUS A
KEYPAD A

8

LEFT AUDIO

7

6

IR

5

STATUS

4

RIGHT AUDIO

3

2

POWER

1

CN4

R38
120K 0805 Thick Film
R35
120K 0805 Thick Film

U5:A
3 2

4

8

100nF 25V 0805 Ceramic
1
NJM5532M Op Amp

ABUS GND

R37
150K 0805 Thick Film
C19

ABUS GND

R36

C21

47R 0805 Thick Film

10uF 35V Non Polarised Electrolytic
C20
47pF 50V 0805 NP0 Ceramic

ABUS GND

30VDC 1.1A Polyfuse

RJ45 ABUS GND

R30
120K 0805 Thick Film
R32
120K 0805 Thick Film

R31
150K 0805 Thick Film

R25
120K 0805 Thick Film

R26
150K 0805 Thick Film

R28
120K 0805 Thick Film

10pF 50V 0805 NP0 Ceramic

U4:B
5 7
6 NJM5532M Op Amp
C18

R33

10pF 50V 0805 NP0 Ceramic

150K

0805 Thick Film

+24V

C16

R34

C15

47R 0805 Thick Film

10uF 35V Non Polarised Electrolytic

C17

47pF 50V 0805 NP0 Ceramic

ABUS GND

U4:A
3 2

4

8

100nF 25V 0805 Ceramic
1
NJM5532M Op Amp
ABUS GND

ABUS GND
R29
47R 0805 Thick Film

C14
10uF 35V Non Polarised Electrolytic
C13
47pF 50V 0805 NP0 Ceramic

R27

ABUS GND

F2
30VDC 1.1A Polyfuse

A-BUS B
KEYPAD B

RIGHT AUDIO LEFT AUDIO IR STATUS
POWER

CN3
8 7 6 5 4 3 2 1
RJ45

ABUS GND

150K 0805 Thick Film
C12

10pF 50V 0805 NP0 Ceramic

U1:C
8 10
9
HEF4011BT VSS=LOGIC GND VDD=+5V
CONTROL BUS IN

U1:D
13 11
12
HEF4011BT VSS=LOGIC GND VDD=+5V

CN9:A

R5

U2

1

1

6

3 AV2-8.4-10

220R 0805 Thick Film

5

2

3

4

NC

4N25 Opto Isolator

+5V CB PASS THRU

C6
100nF 25V 0805 Ceramic

R2
10K 0805 Thick Film

U1:B
5 4
6
HEF4011BT VSS=LOGIC GND VDD=+5V
RC5 TX

LOGIC GND

LOGIC GND

R1
10K 0805 Thick Film

D6 BAS16
Signal Diode

U1:A
1
2
HEF4011BT VSS=LOGIC GND VDD=+5V

CONTROL BUS OUT

R3
3
100R 0805 Thick Film

CN9:B
2 4
AV2-8.4-10
C5
1nF 50V 0805 NP0 Ceramic

R17
470R 0805 Thick Film

R18
10K 0805 Thick Film

+5V
C3
100nF 25V 0805 Ceramic

LOGIC GND

R4 C4 2R2

100nF 25V

1/4W Metal Film

0805 Ceramic

ABUS GND

LOGIC GND

BZX84C2V7 Zener Diode

+12V
Q4
BC846 NPN Small Signal
R19
4K7 0805 Thick Film
ABUS GND

R23
100R 0805 Thick Film
R20
100R 0805 Thick Film
R14
100R 0805 Thick Film
R11
100R 0805 Thick Film

R21
27K 0805 Thick Film

R22
27K 0805 Thick Film

ABUS GND

R12
27K 0805 Thick Film

R13
27K 0805 Thick Film

ABUS GND

CN7
1 2
CKX-3.5-10 Green 3.5mm Jack Vertical
CN8
3 4
CKX-3.5-10 Green 3.5mm Jack Vertical

LOGIC GND

LOGIC GND

To enhance viewing, please print to A3

AP19925/1 Abus PCB Circuit Diagram

37

D1 R46 SW1

Cambridge Audio Azur 740A Amplifier

CN9

CN5

C5

C4

R5

R3

R4
U2 C3

R2

R1 U1

R51 C2

C6 R13 R14

CN8 R12 R22
R11 R23

CN7 R21
R20

Q3 Q2

R15

Q4

R19

R10

R6 R7 R8

R9 U3

R16 D6 D5
M1 R17 R18 D3 D4 C11

C7 C10
R24

C8 Q1

CN1 C1

R50

C9

CN3
C13 R29 R28 C12 R27 R25 R26 CN2
C36

F1 F2

C14 C15

D7 CN4 C21 C22 FR1

C16
U4 R30

C20 C17 R36 R34R35 C18C19 R33 R37 R32 R38
R39 R31

C23
U5 R40

C24 R44 C25
R43 R42
R41

C35 C34
U6

C27 C29

C26 C28

R47

C30

R48 C31

CN6 R49
D9 M2
U7
C33 C32

To enhance viewing, please print to A3

AP19925/1 Abus PCB Board Layout (Top Side)

38

Cambridge Audio Azur 740A Amplifier

To enhance viewing, please print to A3 AP19925/1 Abus PCB Board Layout (Bottom Side)

39

Cambridge Audio Azur 740A ABUS Hub PCB Assembly BOM

AP Part No Value

Description/Type Qty Component Ident

2R2 47R
100R
100R 220R 470R 1K 4K7
10K
27K
120K

1/4W Metal Film 0805 Thick Film
1/4W Fusible
0805 Thick Film 0805 Thick Film 0805 Thick Film 0805 Thick Film 0805 Thick Film
0805 Thick Film
0805 Thick Film
0805 Thick Film

RESISTORS

1

R4

6

R29, R34, R36, R44, R46, R51

1

FR1

7

R3, R9-R11, R14,

R20, R23

2

R5, R49

1

R17

1

R24

2

R7, R19

R1, R2, R8, R15, R16, 9
R18, R47, R48, R50

5 R6, R12, R13, R21, R22

8

R25, R28, R30, R32, R35, R38, R40, R42

150K

0805 Thick Film

R26, R27, R31, R33, 8 R37, R39, R41, R43
CAPACITORS

10pF 50V 0805 NP0 Ceramic 4 C12, C18, C19, C25

47pF 50V 1nF 50V 1nF 50V 100nF 25V 100nF 50V

0805 NP0 Ceramic 0805 NP0 Ceramic
Ceramic 0805 Ceramic 1206 Ceramic

4 C13, C17, C20, C24

2

C5, C11

1

C35

8 C2-C4, C6, C8, C16, C23, C33

2

C27, C29

100nF 50V Monolythic Ceramic 1

C34

10uF 16V
10uF 35V 33uF 25V 47uF 25V

Electrolytic
Non Polarised Electrolytic
Low ESR Electrolytic
Polarised Electrolytic

3

C1, C7, C32

4 C14, C15, C21, C22

1

C28

3

C9, C10, C36

100uF 16V Polarised Electolytic 2 220uF 35V Low ESR Electrolytic 1

10 Way 3 Way

FFC Connector

1

Straight Header

1

C30, C31 C26
CONNECTORS CN1 CN2

RJ45

2

CN3, CN4

DC Jack

1

CN5

Type

Tolerance Factory P/N

AP19929/1
NOTES

1%

1%

5%

Stand off PCB by 5mm

1%

1% 1% 1% 1%

1%

1%

1%

1%

5%

5% 5% 10%

1100-102043-000

10%

10% 1189-104042-400

10% 1100-104043-000

20% 1102-100014-000

20% 20% 20%

1102-470024-000

20% 20%

1102-101014-000

2300-003100-004 2399-008919E000 2303-003911E300

Note: resistors, capacitors and other 'generic' electronic components are

not usually stocked by the manufacturer. Please obtain these locally.

40

Cambridge Audio Azur 740A ABUS Hub PCB Assembly BOM

AP Part No Value

Description/Type Qty Component Ident

Type

Tolerance Factory P/N

AP19929/1
NOTES

Headphone Jack 3.5mm 1

Green 3.5mm Jack Vertical

2

2 Way Horizontal

Phono

1

Red LED

2

CN6 CN7, CN8
CN9 DIODES D1, D9

2320-003911E007 2320-004911E002
Must Have 2330-004900E002 Orange Inserts
3100-506400-000

75V 300mA

Signal Diode

2

D3, D6

1400-160001-400

2.7v

Zener Diode

2

D4, D5

1402-842701-400

400V 1A

Rectifier Diode

30VDC 1.1A

Polyfuse

Quad 2 Input

NAND Gate

PY1144 PY1007

37KHz

Opto Isolator IR Receiver

1

D7

FUSES

2

F1, F2

INTEGRATED CIRCUITS

1

U1

HEF4011BT

1

U2

4N25

1

U3

TSOP34837

1401-140040-000

4030-301100-001

4140-110102E100 4142-500050-001

CD4011BCM Fairchild /
MC14011BD ON
Add X to PN for VDE app.

3001-348370-000

Op Amp

2

U4, U5

NJM5532M

4155-320101-600

12V 1A

Regulator

1

U6

L7812

4178-120302-600

PY755

36KHz

IR Receiver

1

U7

TSOP34836

MODULES

IR Demodulator

2

M1, M2

TRANSISTORS

65V 100mA NPN Small Signal

3

Q1, Q3, Q4

BC846

3001-348360-000 6074-150001-000 1300-846000-500

-65V 100mA PNP Small Signal

1

Q2

BC856B

1301-856000-500

Note: resistors, capacitors and other 'generic' electronic components are

not usually stocked by the manufacturer. Please obtain these locally.

41

Cambridge Audio Azur 740A Amplifier

To Mains Switch

W22

W24

W23

W25

WIRE1
110mm Long +5mm Strip and Tin Black 18 AWG Insulated Wire

WIRE2
110mm Long +5mm Strip and Tin Black 18 AWG Insulated Wire

CN3
L E N SS-7B-1 IEC Socket

earth

W11
Switch

W12
Switch

C2
X1/Y1 Mains Rated 1nF 400V
S1
Chassis Connection
C1
X1/Y1 Mains Rated 1nF 400V

FU5
T8AL Slow Blow Fuse
C3
X1 Mains Rated 47nF 275V

W9
Transformer ES Screen connection

Mains Toroid TRANSFORMER

W1 8 RL1:C
6 7

W15 W2
BROWN/BLACK

2P2T Relay 12V 8A
5 RL1:B
3 4

2P2T Relay 12V 8A

W13

W18

BLUE/WHITE
W19

High Power Secondaries Power Amp supplies

8 RL2:C
6 7
2P2T Relay 12V 8A
5 RL2:B
3 4
2P2T Relay 12V 8A

W3
Secondary 1
W4

W21

W20

Secondary 2

Mains Toroid TRANSFORMER

W5

F1

30VDC 1.1A Polyfuse
W6

W7
Low Power secondary

F2
30VDC 1.1A Polyfuse

CN1
1 2 3
3 Way Straight Header

CN4
3 2 1
3 Way Straight Header

R3
220R 2W Carbon
D1
Rectifier Diode 1N4004

RL1:A
2
1 2P2T Relay 12V 8A

D11
Rectifier Diode 1N4004

RL2:A
2
1 12V 8A 2P2T Relay

R24

R2
1k 1/8W Metal Film

1k

Q3

1/8W Metal Film

MPSA14 NPN Darlington

R1
10k 1/8W Metal Film

Q4
MPSA14 NPN Darlington
R25
10k 1/8W Metal Film

To enhance viewing, please print to A3 AP19789/2 Mains PCB Circuit Diagram (Mains)

42

Cambridge Audio Azur 740A Amplifier

To enhance viewing, please print to A3 AP19789/5 Mains PCB Board Layout (Top Side)

43

Cambridge Audio Azur 740A Amplifier

To enhance viewing, please print to A3 AP19789/5 Mains PCB Board Layout (Bottom Side)

44

Cambridge Azur 740A Mains PCB Assembly BOM

AP Part No.

Value

Description/Type

Qty

220R 1k 10k

2W Carbon

1

1/8W Metal Film

2

1/8W Metal Film

2

1nF 400V

X1/Y1 Mains Rated

2

47nF 275V

X1 Mains Rated

1

3 Way 3 Pin 3 Way

Straight Header

1

IEC Socket

1

Straight Header

1

400V 1A

Rectifier Diode

2

30VDC 1.1A

Polyfuse

2

T8AL

Slow Blow Fuse

1

Fuse Holder Base

1

Fuse Holder Cover

1

PY594

12V 8A

2P2T Relay

2

PY1211

30V 500mA

NPN Darlington

2

Component Ident
RESISTORS R3
R2, R24 R1, R25 CAPACITORS C1, C2
C3 CONNECTORS
CN1 CN3 CN4 DIODES D1, D11 FUSES F1, F2 FU5
FU5

Type

Tolerance

Factory P/N

10% 1% 1%

20%

1119-102104-000

20%

1110-473094E000

2300-003400-001 2336-003910-002 2300-003100-004

1401-140040-000

4030-301100-001

20mm Pitch

FU5 RELAY RL1, RL2 TRANSISTORS Q3, Q4

20mm Pitch

ME11-0122Z4
MPSA14

4050-110122-001 1300-140000-100

AP19792/5
Notes

Note: resistors, capacitors and other 'generic' electronic components are

not usually stocked by the manufacturer. Please obtain these locally.

45

Cambridge Audio Azur 740A Amplifer IC Pin Layout Details
BD140 Input PCB - (Q1 & Q4) Preamp PCB ­ (Q1 & Q5)
BD139 Input PCB - (Q2, Q3, Q5 & Q6) Preamp PCB ­ (Q2, Q3, Q4 & Q6)
BC327-25 Input PCB - (Q7) Preamp PCB ­ (Q9, Q11, Q12 & Q14) BC337-25 Input PCB - (Q8) Front Panel PCB ­ (Q1, Q2 & Q3) Preamp PCB ­ (Q7, Q8 & Q10) MPSA14 Input PCB - (Q9) Main PCB ­ (Q3 & Q4) Amp PCB ­ (Q34 & Q35) Preamp PCB ­ (Q13) NE5532 Input PCB - (U1, U5, U6, U7, U9, U10, U12, U13, U14, U15, U16, U17 & U18)
L7915CV Input PCB - (U2)
46

L7805 Input PCB - (U3) L7815CV Input PCB - (U4) LM393A Input PCB - (U8)
TC9163AF Input PCB - (U11) Preamp PCB ­ (U10)
PIC16F877A-I/P Front Panel PCB - (U1)
M74HC4094B Front Panel PCB - (U2)
47

TSOP34836 Front Panel PCB - (U3)
M74HC02 Front Panel PCB - (U4)
NE5532P Front Panel PCB - (U100 & U200) Preamp PCB ­ (U1, U9, U11, U12, U15, U16, U17, U18, U19 & U20) 2SC2240GR Amp PCB - (Q1, Q6, Q7, Q15, Q23, Q24, Q26 & Q32)
2SA970GR Amp PCB - (Q2, Q5, Q11, Q14, Q16, Q21, Q22 & Q27)
48

MPSA92 Amp PCB - (Q3, Q4, Q8, Q25, Q28, Q29, Q30, Q33, Q39, Q42, Q46, Q47 & Q48)
MPSA42 Amp PCB - (Q9, Q10, Q12, Q13, Q17, Q18, Q19, Q20, Q31, Q36, Q37, Q38, Q40, Q41, Q43, Q44, Q45 & Q49)
SAP15PY Amp PCB - (Q51, Q53, Q56 & Q58)
SAP15NY Amp PCB - (Q52, Q54, Q55 & Q57)
YAC526 Preamp PCB - (U2)
L7815 Preamp PCB - (U3)
49

L7915 Preamp PCB - (U4)
L7805 Preamp PCB - (U5) LM337T Preamp PCB - (U6 & U7) LM317T Preamp PCB - (U8) LM393AP Preamp PCB - (U13 & U14)
HEF4011BT Abus Hub PCB - (U1)
OP4N25 Abus Hub PCB - (U2) TSOP34837 Abus Hub PCB - (U3)
50

NJM5532M Abus Hub PCB - (U4 & U5)
L7812 Abus Hub PCB - (U6) TSOP34836 Abus Hub PCB - (U7) BC846 Abus Hub PCB - (Q1, Q3 & Q4) BC856B Abus Hub PCB - (Q2)
51

Cambridge Azur 740A Amplifier Service Mode Instructions

Press and hold the mode button while turning the rear panel mains power on.

Please note: The `counters' menu is particularly useful to examine the history of use/misuse of the amplifier.

The LCD display will show SERVICE with these menu options:

DC DT:

Enable/disable the built-in DC error detection circuit (use with caution!).

LCD TEST: Press repeatedly (7 steps) to check LCD segments until all segments are lit.

TEMP DT: Enable/disable the built-in temperature detection and protection circuit (use with caution!).

COUNTERS: .This option accesses the following event counters:

CL Clipping events DC DC detection events OV Overload events

TM Over-temperature events SH Short circuit output events ON Number of hours used

RESET: Pressing this will reset all counters to zero.

V1.1 etc The current software version (related to the hex file installed)

52

Cambridge Azur 740A Amplifier Software Update Instructions Should it become necessary to update the front panel control software in this model, you will need to obtain a suitable `PIC' programmer, and the updated `hex' file from the service department at Cambridge Audio. One such programmer is the Kanda PIC-HH0010, and instructions follow on using this device. To perform the update, simply connect the lead from the programmer to the socket provided on the reverse of the front panel PCB. Do not power on the unit, as all power for re-programming is taken from the programmer itself. Once the appropriate hex file is loaded to the programmer, pressing the red download button should be followed shortly by a green light on the programmer to indicate successful download. To confirm the software revision number contained in the 740A, access the service mode.
Connector on rear of front panel:
53

KandaPICHandHeldProgrammerModificationInstructions
 ToProgrammeCambridgeAudioProducts: ProgrammerUsed SourcedFrom:http://www.kanda.com TherearetwoproductcodeswhichwillgetyouthesameprogrammerthatisusedatAP:
1. PICHH0010.ThiscomeswiththePCPICUploadSoftwareonCD. 2. PICHH0020.ThiscomeswithoutthePCUploadSoftwareandisslightlycheaper. Note:Someprogrammersaresuppliedwithflatbatteries.PleasereplacewithagoodqualityPP3battery whenrequired. Youalsoneedtopurchaseaflat06way250mmcableassembly(forexamplefromFarnell,ProductCode:303 2243). Procedure 1. InstallthePCSoftwareontoyourPCwiththesuppliedCDfollowingtheonscreeninstructions.Ifyou
alreadyhavethesoftwareinstalled,thereisnoneedtoreinstallthesoftwareagain.  2. Unpackthefollowingfromtheprogrammerkitbox(seepicturebelow): a. Yellowprogrammer. b. 10pinIDCtoparallelconverter. c. 10pinIDCsockettowireassembly. d. 10pinIDCto10pinIDCcable.
 3. Takethesockettowireassemblyandcuttheblackheaderendsoffeachwire(seepicturebelow).
 54

 4. Cuttheorangewire,thenstripandtin5mmoffeachotherwire(seepicturebelow).


5. TaketheFlat06Way250mmcableassemblyandcutoffoneoftheplugs.Stripandtin5mmoffeach wire(seepicturebelow).

 6. Usingthetablebelow,soldereachwiretogetherasfollows(seenextpage):







10pinIDCsockettowireassembly

Flat06way250mmcableassembly

Redwire

towire1(wirewiththeredstripeonit)

Bluewire

towire2

Yellowwire

towire3

Greenwire

towire4

 55

Brownwire 
7. Wrapinsulationtapearoundeachsolderjoint(seepicturebelow).

towire5

 8. Heatshrinktheassemblyjointsforaddedprotectionandtofinish.
 9. Loadupthe"PICkeyfobProgrammer"softwareonyourPC.
 10. SavethesuppliedPICHEXfiletoasuitablelocationonyourPC.
 11. Selectthecorrect"PICFamily"and"Device"forthePICyouwanttoprogramme.
 12. Makesurethe"ProgramUserID"boxisticked.
 13. Makesurethe"MatchDeviceID"and"VerifyConfigurationBytes"areunticked.
 14. SelectthecorrectfilelocationofthesoftwareyouwanttouploadtothePIC,bypressingthe"Browse"
button,locatingthecorrectHEXfileandselecting"Open".Thepicturebelowshowsthesetupforthe PCsoftwareusingthe340TTunersoftwareasanexample.
 56

 15. Connectthe"yellowprogrammer"tothePC'sparallelportusingthe10pinIDCtoparallelconverter
and10pinIDCto10pinIDCcable. 16. Pressthe"Upload"buttoninthe"PICkeyfobProgrammer"windowtostarttheuploadprocessintothe
PICprogrammer.  17. Thefollowingwindowwillappearwhenthesoftwareisbeinguploaded:
 18. Whenthesoftwarehasuploaded,theabovewindowwillclose.Nowpressonthe"Finish"buttonon
theotherwindowtocompletetheprocess.ThePCsoftwarewillthenclose.  57

 19. Ifyougetanyerrormessages,repeattheprocess.Note:Thebatterymaybelowandneedsreplacing.
 20. Disconnecttheprogrammer(withthe10pinIDCto10pinIDCcable)fromthe10pinIDCtoparallel
converter.  21. Connectthemodifiedcableassemblytothe10pinIDCto10pinIDCcablesocket.  22. ProgrammetheCambridgeAudiounitaccordingtotheseparateinstructionssupplied,where appropriate. Theprocessisnowcomplete.
 58

CN6 6 Way
Right Angle Header

3 2 1

6 5 4

RBB RC

RA RTB

R

RA

RC

RTB

RIGHT LK38

-15V
CN5
8 7 6 5 4 3 2 1

+15V SHIELD_SUPPLY

24 AWG R

8 Way Right Angle Header

L

RA LA

RBB

C101
1.5nF 63V Met. Polyester
R103
4K7 1/4W Metal Film
RC
LC

LTB

LEFT

C201
1.5nF 63V Met. Polyester

R203
4K7 1/4W Metal Film

LBB

LA

LC

LBB LC

LA LTB

2 1

3

6 5 4

L
CN7
6 Way Right Angle Header

-15V

C104

CA2
1 2 3 4 5 6

47nF 63V Met. Polyester
R
C103
10pF 50V NP0 Ceramic

See AP20043/1 6 Way to 4 Way Screened Audio cable

U100:B

NE5532P

6

Audio Op Amp

7

5

U100:A

4

NE5532P

3

Audio Op Amp

R106

1

2

2K2

R R107
2K2 1/4W Metal Film

1/4W Metal Film

C107

8

R

C106

10pF 50V NP0 Ceramic

47nF 63V Met. Polyester +15V
R
-15V
C204

LK39

24 AWG

R

LK40

R

47nF 63V Met. Polyester
L
C203
10pF 50V NP0 Ceramic

L
6 5

24 AWG
U200:BL
NE5532P Audio Op Amp
7

U200:A

4

NE5532P

L R207

3

Audio Op Amp

R206

1

2

2k2

1/4W Metal Film

2K2 1/4W Metal Film
C207

8

L

C206

10pF 50V NP0 Ceramic

L

+15V

47nF 63V Met. Polyester

CA1
1 2 3 4 5 6
See AP20044/1 6 Way to 5 Way Screened Audio cable

4 Way
CN10Straight Header
1 2 3 4

1

2

3

4

SHIELD_R2

CN4
4 3 2 1
4 Way Right Angle Header

SHIELD_L2

LK37
24 AWG

R18
1K1 1/8W Metal Film

R20
1K1 1/8W Metal Film

R24

R23
2K2

2K2 1/8W Metal Film

1/8W Metal Film

VR1:A
5k Push Action Linear Pot

VR2:B
5k Push Action Linear Pot
C10
680nF 63V Met. Polyester

VR1:B
5k Push Action Linear Pot

C18
680nF 63V Met. Polyester
5k VR2:A
Push Action Linear Pot

R21
1K1 1/8W Metal Film

R22
1K1 1/8W Metal Film

R25
2K2 1/8W Metal Film
LK1

24 AWG

R26
2K2 1/8W Metal Film

1

2

3

4

5

1 2 3 4 5

GUARD CN8 5 Way

59

Straight Header

+5V

+5V

LK7

L24KA1W4G

24 AWG
LK25
24LAKW3G6

24LAKW1G2

LK424 AWG

24 AWG

+5V

+5V

LK11

24LAKW3G2

24 AWG

+5V

+5V

LK3

2L4KA3W1G

24 AWG

CN11
1 2 3 4 5 6 6 Way

+5V PGC PGD MCLR
+5V

COL 1 SW1

COL 2 SW2

KPT-1105A
INPUT 1
SW4

KPT-1105A
INPUT 2

1.

SW5

ROW 2

KPT-1105A
INPUT 4
SW7 LK15

KPT-1105A
INPUT 5
SW8

LCD STR.

LK24LK13

LCD STR

24 AWG 24 AWG

R27
47K 1/4W Metal Film

R29
47K 1/4W Metal Film

ROW 3 R30
47K 1/4W Metal Film
ROW 4

KPT-1105A
ON/STBY
SW10

2. 24 AWGKPT-1105A
SPEAKER
LK9

+5V

+5V

LCD DECOUPLE

R19
100R 1/4W Metal Film

C9
100nF 50V Mono Ceramic

C4
100nF 50V Mono Ceramic

C7 C22
10uF 16V 47nF 50V Electrolytic Ceramic

LK35

124 AWG CN1

2

1a

1

2a

2

U2

3a 4a 5a 6a 7a 8a

3 4 5 6 7 8

4

LK33 5

LK34

6

24LAWKG30 7

24 AWG

14

24 AWG13

Q0 Q1 Q2 Q3 Q4 Q5

15 2x8 Way

16

DIL Bottom Entry HLeKad2er6

12 Q6 11 Q7

LK29 LK27 24 AWG
24 AWGLK28

9 QS 10 QS

D2 CLK 3 STB 1 OE 15 VCC 16
GND 8

24 AWG

M74HC4094B1R

24 AWG

LCD DISPLAY CONN

RS E
LCD STR.
+5V

KPT-1105A
DIRECT

L2K4 1AW7 G

24 AWG

1

2

3

4

LCD STR

5 6

LK23 C5
24 AWG

LK20
24 AWG

BRIGHT ON/OFF

7 8 9

10

11

12

22pF 50V NP0 Ceramic
C6

X1
Strip Cut Crystal

13 14 15 16

4MHz

17

C11

22pF 50V NP0 Ceramic

LK16

18 19 20

10nF 50V Ceramic

24 AWG +5V

1

R7

P5

10K

1/4W Metal Film

R12
220R 1/4W Metal Film

ON/OFF

R3
1K2 1/4W Metal Film

Q1
BC337-25 NPN Signal

D1
Blue Azur LED

1

Vss 1 Vdd 2
Vo 3 RS 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

CW CCW

PR1

Multiturn

2

500R

R1

56R

1/4W Metal Film

3

R6
300R 1/4W Metal Film

2

16

1

15

LCD CONN ORIENTATION FROM FRONT

Q2
BC337-25 NPN Signal

R2
56R 1/4W Metal Film

POWER AMP RELAY
LK18
24 AWG

R11
10K 1/4W Metal Film

R5
10K 1/4W Metal Film

BRIGHT
R10
10K 1/4W Metal Film

Q3
BC337-25 NPN Signal

R15
220R 1/4W Metal Film

+5V TO POWER AMP PCB

COL 3 SW3

KPT-1105A
INPUT 3
SW6

R31
47K 1/4W Metal Film

+5V

SPEAKER B RELAY SPEAKER A RELAY
PREAMP RELAY VI/SHORT
CLIP DETECT MAINS FAIL DC OFFSET OVER TEMP

CN9
1 2 3 4 5 6 7 8 9 10

RC5 BLOCK RC5 TX
PHONES DETECT DIRECT RELAY
PIC IR ON/OFF

1 2 3 4 5 6
L24KA2WG

CN2
6 Way Right Angle Header

TO PRE AMP PCB

KPT-1105A
TAPE MON
SW9

KPT-1105A

+5V

MODE

+5V

10K

10 Way

R32 Right Angle Header

100K

CONTROL BUS IR

1/4W Metal Film VOLUME STROBE

POWER AMP RELAY

ABUS IR

INPUT STROBE

SERIAL DATA SERIAL CLOCK

CN3
1 2 3 4 5 6 7 8 9

1/4W Metal Film

9 Way

R4
MCLR

LK6

U1 24 AWG

MCLR/VPP

RB7/PGD

RA0/AN0

RB6/PGC

RA1/AN1

RB5

RA2/AN2/Vref-/CVref RB4

RA3/AN3/VREF+ RB3/PGM

RA4/T0CKI/C1OUT

RB2

RA5/AN4/SS/C2OUT RB1

RE0/RD/AN5

RB0/INT

RE1/WR/AN6

VDD

RE2/CS/AN7

VSS

VDD

RD7/PSP7

VSS

RD6/PSP6

OSC1/CLKIN

RD5/PSP5

OSC2/CLKOUT RD4/PSP4

RCO/T1OSO/T1CKRI C7/RX/DT

RC1/T1OSI/CCP2 RC6/TX/CK

RC2/CCP1

RC5/SDO

RC3/SCK/SCL RC4/SDI/SDA

RD0/PSP0

RD3/PSP3

RD1/PSP1

RD2/PSP2

PGD 40 PGC 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21

PIC16F877A-I/P
PROGRAMMED_WITH=AP20357/x
R28

R13
47K 1/8W Metal Film
R39
1K 1/8W Metal Film

D4
1N4148 Signal Diode
DIRECT RELAY
PHONES DETECT
RC5 TX RC5 BLOCK OVER TEMP DC OFFSET MAINS FAIL CLIP DETECT

Right Angle Header

CONTROL BUS IR

LK10

CONTROL BUS IR

24 AWG
R811K/4W Metal Film

ROT1

R9

1 A SW

2 B SW

1K

3 C GND

1/4W Metal Film 4 FIX1

+5V

C1

C2

5 FIX2

100nF 50V Mono Ceramic

100nF 50V Mono Ceramic

Noble Rotary Encoder

1K 1/8W Metal Film
R16
R17

VI/SHORT PREAMP RELAY SPEAKER A RELAY SPEAKER B RELAY
SERIAL CLOCK
SERIAL DATA

C3
47nF 50V Ceramic
+5V

C8
10uF 16V Electrolytic

PIC IR ON/OFF

1K

1/8W Metal Film INPUT STROBE

R33

ABUS IR

R36

47K

POWER AMP RELAY 47K

1/4W Metal Film

VOLUME STROBE 1/4W Metal Film

R34

+5V
R14
47R 1/4W Metal Film
U3

47K 1/4W Metal Film
U4:D LK8 13

10K 1/4W Metal Film

U4:B

6

12

LK5 4

5

1 OPT 2 GND 3 +5V
TSOP34836 36KHz

C16

C17

100nF 50V 10uF 16V

Mono Ceramic Electrolytic

11

24 AWG

24 AWG

VCC=+5V

+5V

VCC=+5V

M74HC02

M74HC02

GND=GND

GND=GND

P2

P3

P4

P1

LK22

U4:C

+5V

9

10

8

VCC=+5V M74HC02 GND=GND

U4:A
3 1
2
VCC=+5V M74HC02 GND=GND

R35
47K 1/8W Metal Film

C12
10nF 50V Ceramic

C13
10nF 50V Ceramic

C14
10nF 50V
6C0eramic

C15
10nF 50V Ceramic

CONTROL BUS IR 1 1 1 1

L24KA2W1G

24 AWG


Acrobat Distiller 6.0.1 (Windows)