AP195971 Cambridge Azur 840A Service Manual 2

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AP195971 Cambridge Azur 840A Service Manual 2

Four parallel word clock outputs allow the 2192 to be used as a m

SERVICE MANUAL SPECIFICATIONS: Power Output 120W RMS into 8 Ohms 200W RMS into 4 Ohms THD (unweighted) < 0.0015% 1 kHz at 80% of rated power < 0.015% 20Hz – 20kHz at 80% of rated power Frequency Response 10Hz – 50kHz /- 1dB

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cambridge azur 840a
840A
Issue Date: 16th June 2006
________________________________________________________________________________
SERVICE MANUAL

________________________________________________________________________________

SPECIFICATIONS:

Power Output

120W RMS into 8 Ohms 200W RMS into 4 Ohms

THD (unweighted)

< 0.0015% 1 kHz at 80% of rated power

< 0.015% 20Hz ­ 20kHz at 80% of rated power

Frequency Response

10Hz ­ 50kHz +/- 1dB

S/N ratio (ref 1W/8 Ohm)

>83dB

Input Impedances

Input 1 (balanced) 10 kOhm Inputs 2-7 68 kOhm Tape Input 68 kOhm

Power Amp damping factor

> 110 at 1kHz

Max power consumption

800W

Minimum power consumption

Active (no signal) 70W Standby 7W

Bass & Treble controls

Shelving type Max bass boost/cut +/- 10dB at 10Hz Max treble boost/cut +/- 7.5dB at 20Hz

Dimensions (H x W x D)

115 x 430 x 385mm (4.5 x 16.9 x 15.2")

Weight

15.0kg (33Lbs)

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

AP19597/1 1

840A SERVICE MANUAL

TABLE OF CONTENTS
Safety Precautions & Important Notes Block Diagram Exploded Diagram Exploded Diagram Parts List Front Panel PCB Schematic (Microcontroller & LCD) Front Panel PCB Schematic (Shift Registers) Front Panel PCB Layout (Top Side) Front Panel PCB Layout (Bottom Side) Front Panel PCB BOM Input PCB Schematic (Input Select) Input PCB Schematic (Input Control) Input PCB Schematic (Input Amplifier) Input PCB Board Layout (Top Side) Input PCB Board Layout (Bottom Side) Input PCB BOM Preamp PCB Schematic (Relay Logic) Preamp PCB Schematic (Tone Control) Preamp PCB Schematic (Post Amp) Preamp PCB Board Layout (Top Side) Preamp PCB Board Layout (Bottom Side) Preamp PCB BOM Power Amplifier Schematic (Right Power Supplies & PSU) Power Amplifier Schematic (Right Channel) Power Amp Right & PSU PCB Board Layout (Top Side) Power Amp Right & PSU PCB Board Layout (Bottom Side) Power Amp Right PCB BOM Power Amp PSU PCB BOM Power Amp Schematic (Left Channel) Power Amp Schematic (Left Power Supplies) Power Amp PCB Board Layout (Top Side) Power Amp PCB Board Layout (Bottom Side) Power Amp Left PCB BOM Hub PCB Schematic

4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24-25 26 27 28 29 30-31 32 33 34 35 36 37-38 39

2

Hub PCB Board Layout (Top Side) Hub PCB Board Layout (Bottom Side) Hub PCB BOM Rectifier PCB Schematic Rectifier PCB Board Layout (Top Side) Rectifier PCB Board Layout (Bottom Side) Rectifier PCB BOM IC Pin Layout Details Technical Description Procedure to upgrade the Control (Pic) Software Notes

40 41 42-43 44 45 46 47 48-49 51-60 61-62 63

3

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 840A Amplifier

To enhance viewing, please print to A3

840A Block Diagram

5

Cambridge Audio Azur 840A Amplifier

6

15

12

16

17

2

9 10 1

3 15 11

6

8

5

7

4

18

5 14 13

To enhance viewing, please print to A3

840A Exploded Diagram

6

Cambridge Audio Azur 840A Amplifier

Drawing Ref:
1 2 2 3 3 4 4 5 5
6 6 7 7 8 8
9 10 11 12 13 14 15 16 17 18

AP Part Number
PY1118 PY1019 PY1020 PY1119 PY1120 PY1121 PY1123 PY1122 PY1124 PY1125 PY1126 PY1127 PY1128 PY1129 PY1130 PY1131 PY1132 PY1133
PY1135 PY1136 PY1138 PY1139 PY1159 PY1153 PY1146 PY1163 PY1155 PY1145 PY1137 PY1134 PY1165

Factory Ref:
2331-004909E301 3200-053044E000 3200-053045E000 3200-074051E001 3200-077811E000 6074-150003E000-01 6074-150003E001A01 6074-150004E000 6074-150004E000A01 6574-150009E000-01 6574-150009E000-02 6574-150013E000-01 6574-150013E000A01 8584-015010E301
6574-150012E000-01
6074-150005E000 6574-150015E000
3110-840000E000 6600-990112E000 2409-010200E001 9484-015000E041 9484-015000E341 9484-015000E141 9484-015000E091 9484-015001E091 9484-015000E331 9484-015000E071 9484-015000E111 9484-015000E061 9805-084000E001

Description
Speaker Binding Post BP331 (Black) Red & Black Toroid 230V/50Hz 36.5VACx4 5.5A TI-053044C Toroid 115V/50Hz 36.5VAC 5.5A TI-0853045C for 840A Toroid 230V/50Hz 7.5VAC750MA 17VAC*2 TO7405B STB Toroid 115V/50Hz 7.5VAC750MA 17VAC*2 STB 840A Bass / Treble Knob (Black) Painted Black 840A Bass / Treble Knob (Silver) Painted Silver Azur 840A Plastic Foot (Black) AP16837* Azur 840A Plasitc Foot (Silver) AP16837* Azur 840A Top Panel Black Painted Azur 840A Top Panel Silver Azur 840A Side Panel, Black Painted Azur 840A Side Panel,Silver Azur 840A Black Front Panel Assy Azur-840A Silver Front Panel Assy Azur 840-A B Front Panel Artwork AP186371/186381 (Metalwork Only) Azur 840-A Silver Front Panel Artwork AP186371/186381 (Metalwork Only) Azur 840A Volume Knob Plastic Insert (AP1743*) Azur 840A Volume Knob Skin, Black Azur 840A Volume Knob Skin, Silver LCD Display Highly Transflective DC00003E02 840A Azur 840A Display Backlight (AP16841*) Rotary Encoder Switch REBG161(9*7)PVB20FHINB1-2-24E Azur-840A AMP-Hub Control PCB Assy Rev A Azur-840A Amp Input PCB Assy Rev A Azur-840A EU/UK PSU Power Control PCB Assy Rev A Azur-840A Main-Amp Left PCB Assy Rev A Azur-840A Main-Amp Right PCB Assy Rev A Azur-840A Pre-Amp Board Rev A Azur-840A Amp-Rectifier PCB Rev A Azur-840A Amp Front Control PCB Assy Rev A Azur-840A LCD Display Board Assy Rev A Azur-840A Remote Control Assy Rev A

All spare parts should be ordered from AP Hong Kong office

Exploded Diagram Parts List

7

Cambridge Audio Azur 840A Amplifier

RS232 RX
R9
22K RS232 RX

+15V +5V

R11
10K
SERIAL RX 232
Q3
BC337
D3
1N4002
LOGIC GND

R12
2K2

RS232 TX
Q4 R13
22K

SERIAL TX 232

BC337

LOGIC GND

RS232 TX

COL 1 SW1
SW-TACT
INPUT 1
SW5
SW-TACT
INPUT 5 SW9
SW-TACT
MODE

COL 2 SW2
SW-TACT
INPUT 2
SW6
SW-TACT
INPUT 6 SW10
SW-TACT
ON/STBY

COL 3 SW3
SW-TACT
INPUT 3
SW7
SW-TACT
INPUT 7 SW11
SW-TACT SPEAKER SELECT

COL 4 SW4
SW-TACT
INPUT 4
SW8
SW-TACT
TAPE MON
POSITION FOR EXTRA SWITCH
spare

ROW 1

SPEAKER TEST

ROW 2

PHONES DETECT OVERLOAD
CLIP DETECT DC OFFSET OVER TEMP MAINS FAIL

ROW 3

+5V +15V

C19
100n

A

ON/STBY LED
D2
BLUE LED

K

C18 C21 C15

100n

100n

100pF

LOGIC GND
C16 C17
100pF 100n

CN1
1 2 3 4 5 6 7 8 9 10 11 12

C22

FFC 12WAY

CONNECTOR TO PREAMP PCB

100n

+5V

1 CN2

2

1a

1

2a

2

3a

3

4a

4

5a

5

6a

6

7a

7

8a

8

15

16

CONN-8 DUAL BOT

LCD DISPLAY CONN

LED BACKLIGHT POWER

R5

C20

100R

100nF

+5V

C2
100nF

LOGIC GND
C4
10U 16V LCD DECOUPLE
LOGIC GND

C7
100nF
LOGIC GND SHIFT REG DECOUPLE
RS

+5V
R14
10K
SPEAKER TEST SHIFT REG ENABLE

LCD DATA SHIFT REGISTER

E

C5

4 Q0
5 Q1
6 Q2 7
Q3 14
Q4 13
Q5 12
Q6 11 Q7
9 QS
10 QS
74HC4094 VDD=+5V VSS=LOGIC GND

2 D
3 CLK STB 1
15 OE
U2
BC327-25
Q8

SERIAL DATA SERIAL CLOCK
SHIFT REG ENABLE

22pF

C6

X1

R15
10K

CRYSTAL LOGIC GND 22pF FREQ=20MHz

LOGIC GND +5V

IR CONTROL BLOCK PIC TX
SERIAL IN FROM A-BUS HUB BOARD HUB DATA HUB CLOCK

R7
2K2

R2

R3

43R

1

2K2

CCW

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

2

16

1

15

LCD CONN ORIENTATION FROM FRONT

LOGIC GND

PRESET 20K 3296W 2

R1
22R

Q1

CW

BC327-25

3

CW

PR1
10U 16V
R6 1K1 D8 C24
BZX79C2V7 500MW 1K1
R8

D4
1N4148
R4
4K7
D5 D6

Q2 1N4148
BC337

1N4148

PIC INPUT EMC CAPS

LOGIC GND

U1

1

MCLR/VPP 2

RB7/PGD 40

RA0/AN0 3

RB6/PGC 39

RA1/AN1

RB5

4

38

RA2/AN2

RB4

5

37

RA3/AN3/VREF 6

RB3/PGM 36

RA4/T0CKI

7

RA5/AN4/SS

RB2 35 RB1

8

34

RE0/RD/AN5

RB0/INT

9

33

RE1/WR/AN6 10

VDD 32

RE2/CS/AN7 11 VDD

VSS 31 RD7/PSP7

12

30

VSS

RD6/PSP6

13

29

OSC1/CLKIN 14

RD5/PSP5 28

15

OSC2/CLKOUT

RD4/PSP4

RCO/T1OSO/T1CKI RC7/RX/DT

27

16

RC1/T1OSI/CCP2 RC6/TX/CK

26

17

25

RC2/CCP1

RC5/SDO

18

24

RC3/SCK/SCL 19

RC4/SDI/SDA 23

RD0/PSP0 20 RD1/PSP1

RD3/PSP3 22 RD2/PSP2

21

PIC16F877A

PORT B HAS WEAK PULLUPS RB4-RB7 HAS INTRPT ON CHANGE

CLIP DETECT OVERLOAD
OVER TEMP DC OFFSET MAINS FAIL PHONES DETECT
SERIAL RX 232 SERIAL TX 232 SERIAL DATA SERIAL CLOCK SERIAL STROBE
SERIAL CONTROL OUT

IR IN (FROM RECEIVER ON PREAMP BOARD)

+5V

C10

R23 10R R24 10R

ROT1
1 A SW
2 B SW
3 C GND
4 FIX1
5 FIX2

100n CER

NOBLE16ENCODER

C1

C3
10U 16V

100n

C11 100n CER
LOGIC GND

FRONT PANEL GND

LOGIC GND

IR IN (FROM JACK & PHONO ON HUB PCB)

PROGRAM_CLOCK

PROGRAM_DATA MCLR HUB

Programming Signals To ABUS Hub PIC

PGM

Q6

R19

BC337

10K

LOGIC GND

D7
1N4148
BC337
Q5

R17
10K
0 = BRIGHT TRISTATE= OFF 1= DIM
R18
2K2
TRISTATE LED CONTROL

100N CERAMIC

C23

P2

PAD
P3

47R R16

PAD

LOGIC GND

FRONT PANEL GND

FRONT PANEL GROUNDING

100N CERAMIC

C9

RS232 TX

RS232 RX

10R LOGIC GND

PGM

R10

MCLR HUB PROGRAM_DATA

PROGRAM_CLOCK

BLOCK

PIC TX

LOGIC GND HUB DATA

HUB CLOCK

1

TX

2

RX

3

RS232 GND

4

IR IN

5

IR GND

6

7

8

CN3

9

10

11

12

13

FFC 13WAY RS232 & IR CABLE TO HUB PCB SERIAL IN FROM A-BUS HUB BOARD

To enhance viewing, please printAtoPA136369/3 Front Panel PCB Schematic (Microcontroller & LCD)

8

Cambridge Audio Azur 840A Amplifier

FROM SHEET 1

SERIAL DATA SERIAL CLOCK SERIAL STROBE SHIFT REG ENABLE

+5V

C8
100nF

C12
100nF

C13
100nF

LOGIC GND

SHIFT REG DECOUPLE

C14
100nF

U3
2D 3
CLK 1
STB 15
OE

Q0 4 5
Q1 6
Q2 7
Q3 14
Q4 13
Q5 12
Q6 11
Q7

9 QS
10 QS

74HC4094 VDD=+5V VSS=LOGIC GND

U4
2 D
3 CLK
1 STB 15 OE

4 Q0
5 Q1 Q2 6 Q3 7
14 Q4
13 Q5 Q6 12 Q7 11

9 QS QS 10

74HC4094 VDD=+5V VSS=LOGIC GND

U5
2D 3
CLK 1
STB 15 OE

Q0 4 5
Q1 6
Q2 Q3 7 Q4 14
13 Q5
12 Q6
11 Q7

9 QS
10 QS

74HC4094 VDD=+5V VSS=LOGIC GND

CN4
1 2 3 4 5 6 7 8
FFC 08WAY

TO PREAMP BOARD

CN5
1 2 3 4 5 6 7 8
FFC 08WAY

TO PREAMP BOARD

CN6
1 2 3 4 5 6 7 8
FFC 08WAY

TO PREAMP BOARD

U6
2 D
3 CLK
1 STB
15 OE

4 Q0
5 Q1
6 Q2 Q3 7
14 Q4
13 Q5 Q6 12 Q7 11

9 QS QS 10

74HC4094 VDD=+5V VSS=LOGIC GND

CN7
1 2 3 4 5 6 7 8
FFC 08WAY

TO INPUT BOARD

To enhance viewing, please print to A3AP16369/3 Front Panel PCB Schematic (Shift Registers)

9

Cambridge Audio Azur 840A Amplifier

R13 C16 C17

R9

Q3 C9

Q4

C22

C21
Q6 R19

R12

C15

R15 D2
R14
SW10

U1

C18

C19

C14

C13

U2

U6 C3

U5 C12 U4 C8 U3

SW1

C1 X1 SW11

C7 C5
C6 SW9

SW2 SW3
SW4

C20

C4 CN2

R5 C2

SW5 SW6 SW7 SW8

(c) COPYRIGHT Audio Partnership PLC 2005 AP16370/3 AP16370/3

Q1 R1

R6 C24 R8 D4 Q5

R2 Q8
R3 R7 D8 R4 D7 R17

Q2 C10 C11

D5

D6

R18

P3
ROT1 P2
R24 R23

D3 R11 R10

C23 R16

To enhance viewing, please print to A3

AP16369/3 Front Panel PCB Layout (Top Side)

10

Cambridge Audio Azur 840A Amplifier

To enhance viewing, please print to A3 AP16369/3 Front Panel PCB Layout (Bottom Side)

11

Cambridge Audio Azur 840A Amplifier Front Panel PCB BOM

AP16372/5

AP No

Value

Description/Type

Qty

Component Ident

Notes

PY1100 PY219 PY214
PY1141 PY1142 PY1140 PY1138 PY043

RESISTORS 10R 22R 43R 47R 100R 1K1 2K2 4K7 10K 22K CAPACITORS 22pF 100pF
100nF
10uF
SEMICONDUCTORS
PIC16F877A - I/P
74HC4094 TRANSISTORS BC327-25

0.25 W 1% Metal Film 0.25 W 1% Metal Film 0.25 W 1% Metal Film 0.25 W 1% Metal Film 0.25 W 1% Metal Film 0.25 W 1% Metal Film 0.25 W 1% Metal Film 0.25 W 1% Metal Film 0.25 W 1% Metal Film 0.25 W 1% Metal Film

3 R10, R23, R24 1 R1 1 R2 1 R16 1 R5 2 R6, R8, 4 R3, R7, R12, R18, 1 R4 5 R11, R14, R15, R17, R19 2 R9, R13

Ceramic 50V 10% Pitch=5mm Ceramic 50V 10% Pitch=5mm
Ceramic 50V 10% Pitch=5mm
16V Electrolytic Radial (Height =5.2mm) Pitch=2.5mm

2 C5, C6 2 C15, C16
C1, C2, C7, C8, C9, C10, C11, 17
C12-C14, C17 - C21, C22, C23

3 C3, C4, C24

Note: Low profile electrolytic

PIC Flash Microcontroller 40 pin DIL Shift register 16 pin DIL

1 U1 5 U2 - U6

Contact Audio Partnership Service Department

PNP Small Signal TO92

2 Q1, Q8

BC337-25

NPN Small Signal TO92

4 Q2, Q3, Q4, Q5

DIODES

BLUE LED

Blue LED 3mm UNI flat top

1 D2

1N4148

General purpose diode

4 D4,D5, D6,D7

BZX 79C -2V7

Zener diode 2V7 400mW

1 D8

400mW DO 35 C ase.

1N4002

General Purpose Rectifier

1 D3

MISCELLANEOUS

D100-SSV-12

12-WAY FFC reverse-needle type, single-row contacts

1 CN1

D100-SSV-13

13-WAY FFC reverse-needle type, single-row contacts

1 CN3

8-WAY FFC FRONT-PREAMP

D100-SSV-08

CONNS, reverse-needle type single- 4 CN4, CN5, CN6, CN7

row contacts

REB161(9x7)PVB20FHIN Noble ROTARY ENCODER
B 1-2-24E

1 ROT1

2400-020200-000

T act switch

11 SW1-SW11

20MHz C RYST AL

HC 49/4H

1 X1

MULTITURN PRESET 20K

Side adjust. Foot print 9.5 x 4.5 mm

1 PR1

Note: resistors, capacitors and other 'generic' electronic components are not usually stocked by the manufacturer. Please obtain these locally.
12

Cambridge Audio Azur 840A Amplifier

C6
22pF
R60 10K

U14:B

INPUT 1 L-

R57 20K

NE5532

6

R3

7

INPUT 1 L+

5

47R

INPUT 1 CN1:B
3

R58 20K

R22

R59

100R

10K

QUAD PHONO

C5 22pF

LEFT

C77
10U 16V NP

RL1:B
4 3
5 RELAY

HUB 1L

INPUT 2
CN1:D
6 QUAD PHONO

C39

R4

10U NP 35V
R1
220K

1K
C24
47pF

6 5
R45
100K

U3:B C40
7

NE5532

10U 16V NP
R44
47K

RL2:B
4 3
5 RELAY
HUB 2L

INPUT 3 CN2:B
3
QUAD PHONO

C41

R5

10U NP 35V
R2
220K

1K
C23
47pF

6 5
R47
100K

U5:B C42
7

NE5532

10U 16V NP
R46
47K

RL3:B
4 3
5 RELAY
HUB 3L

INPUT 1 R+ INPUT 1 R-
INPUT 1 L+ INPUT 1 L-

CN10

1

INPUT ONE RIGHT +

2

INPUT ONE RIGHT -

3

GND

4

GND

5

INPUT ONE LEFT +

6

INPUT ONE LEFT -

JST 2,5MM B6B-XH-A

INPUT 1 R-
INPUT 1 R+ INPUT 1
CN1:A
2 1
QUAD PHONO
INPUT 2 CN1:C
5 4
QUAD PHONO

C7

22pF

R63

10K

RIGHT -15V

R61 20K 2

R62 20K R34
100R

3
22pF
R64
10K
C8

8

4

U14:A
NE5532
1

R14
47R
C4
100nF

+15V

C71
10U 16V NP

RL1:C
7 6
8 RELAY
HUB 1R

-15V

C38

R15

1K 10U NP 35V

R12

C32

220K

47pF

2 3
R42
100k

8

4

U3:A
NE5532
1

C37

10U 16V NP
C43
47N PE 63V

R43
47K

RL2:C
7 6
8 RELAY
HUB 2R

+15V

INPUT 3 CN2:A
2 1
QUAD PHONO

C36

R16

1K 10U NP 35V

R13

C27

220K

47pF

2 3
R40
100K

8

4

U5:A
NE5532
1

-15V
C35

10U 16V NP
C44
47N PE 63V

R41
47K

+15V

RL3:C
7 6
8 RELAY
HUB 3R

GROUND TERMINAL
J1
TERMINAL
P1
PAD

C3
100nF 100V
R23
100R
C72
100nF 100V
R85
100R

INPUT 4 CN2:D
6
QUAD PHONO

C45

R8

10U NP 35V
R6
220K

1K
C22
47pF

6 5
R66
100K

U6:B C48
7

NE5532

10U 16V NP
R55
47K

RL4:B
4 3
5 RELAY
HUB 4L

INPUT 5 CN3:B
3
QUAD PHONO

C46

R10

10U NP 35V
R7
220K

1K
C15
47pF

6 5
R67
100K

U7:B C49
7

NE5532

10U 16V NP
R56
47K

RL5:B
4 3
5 RELAY
HUB 5L

INPUT 6 CN3:D
6
QUAD PHONO

C47

R31

10U NP 35V
R30
220K

1K
C14
47pF

6 5
R68
100K

U8:B C50
7

NE5532

10U 16V NP
R65
47K

RL6:B
4 3
5 RELAY
HUB 6L

INPUT 7 CN4:B
3
QUAD PHONO

C60

R33

10U NP 35V
R32
220K

1K
C13
47pF

6 5
R76
100K

U18:B C61
7

NE5532

10U 16V NP
R77
47K

RL7:B
4 3
5 RELAY
HUB 7L

TAPE RETURN LEFT

CN4:D

C69 R36

6

QUAD PHONO

1K 10U NP 35V

R24

C31

220K

47pF

TAPE OUT L CN5:B 3
QUAD PHONO

U9:B
NE5532 6
7 5
R81
100K

C68
10U 16V NP
R82
47K

R9
100R

TAPE RETN L
-15V
C34

RL8:B
4 3
5 RELAY

47N PE 63V
U2:A
NE5532 1
C33

8

4

C11
10U 16V NP

2 3
+15V

R35
100K

47N PE 63V

INPUT L

INPUT 4 CN2:C
5 4
QUAD PHONO

C51

R17

1K 10U NP 35V

R20

C25

220K

47pF

INPUT 5 CN3:A
2 1
QUAD PHONO

C52

R18

1K 10U NP 35V

R21

C26

220K

47pF

INPUT 6 CN3:C
5 4
QUAD PHONO

C53

R26

1K 10U NP 35V

R28

C28

220K

47pF

INPUT 7 CN4:A
2 1
QUAD PHONO

C62

R27

1K 10U NP 35V

R29

C29

220K

47pF

TAPE RETURN R CN4:C 5
4
QUAD PHONO

C70

R37

10U NP 35V
R25
220K

1K
C30
47pF

TAPE OUT R CN5:A 2
1 QUAD PHONO

2 3
R69
100K

8

4

U6:A
NE5532
1

-15V
C57

10U 16V NP
C54
47N PE 63V

+15V

R72
47K

RL4:C
7 6
8 RELAY
HUB 4R

2 3
R70
100K

8

4

U7:A
NE5532
1

-15V
C58

10U 16V NP
C55
47N PE 63V

R73
47K

+15V

RL5:C
7 6
8 RELAY
HUB 5R

2 3
R71
100K

8

4

U8:A
NE5532
1

-15V
C59

10U 16V NP
C56
47N PE 63V

R74
47K

+15V

RL6:C
7 6
8 RELAY
HUB 6R

2 3
R78
100K

8

4

U18:A
NE5532
1

-15V
C63

10U 16V NP

C64
47N PE 63V

R79
47K

+15V

RL7:C
7 6
8 RELAY
HUB 7R

2 3
R75
100K

8

4

U9:A
NE5532
1

-15V
C66
10U 16V NP
C67
47N PE 63V

R80
47K

TAPE RETN R
-15V 47N PE 63V
C16

+15V

U4:A

4

R19
100R

NE5532 2
1 3
C17

8

+15V

RL8:C
7 6
8 RELAY
C12
10U 16V NP
R38
100K

47N PE 63V

HUB 1L HUB 2L HUB 3L
HUB 4L HUB 5L HUB 6L
HUB 7L TAPE RETN L
HUB IN L

-15V
C1

+15V
C2

100n CER

U1

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

TC9163

100n CER

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

HUB INPUT SWITCHER

HUB 1R HUB 2R HUB 3R
HUB 4R HUB 5R HUB 6R
HUB 7R TAPE RETN R

HUB IN R LOGIC GND

HUB IN L +5V

CN6

1 2

HUB IN L HUB IN R GND

3

GND

4

5

+5V POWER TO HUB

6

7

8 9 10

SWITCHER DATA SWITCHER CLOCK SWITCHER STROBE

FFC 10WAY

INPUT PCB - HUB PCB

INPUT R

PREAMP OUT CN5:D
6
QUAD PHONO
PREAMP OUT CN5:C
5 4
QUAD PHONO

PREAMP OUT L PREAMP OUT R

To enhance viewing, please print to A3 AP16361/3 Input PCB Schematic (Input Select)

13

Cambridge Audio Azur 840A Amplifier

INPUT PCB - PREAMP PCB

CN9
1 2 3 4 5 6

TO PREAMP LEFT TO PREAMP RIGHT
PREAMP OUT L PREAMP OUT R

JST 2,5MM B6B-XH-A

CN7
1 2 3 4 5 6 7 8
FFC 08WAY

+5V +9V
+15V -15V

LOGIC GND

+9V

+5V
C65
100nF 100V LOGIC GND

RL1:A
1
2 RELAY
INPUT 1

CN8
1 2 3 4 5 6 7 8
FFC 08WAY FROM FRONT PANEL PCB

U16

1 IN1
2 IN2
3 IN3
4 IN4
5 IN5
6 IN6
7 IN7
8 GND

OUT1 16 OUT2 15 OUT3
14 OUT4
13 OUT5
12 OUT6 11 OUT7
10 COM
9

ULN2003A

LOGIC GND

+9V

RL2:A
1
2 RELAY
INPUT 2

RL3:A
1
2 RELAY
INPUT 3

RL4:A
1
2 RELAY
INPUT 4

RL5:A
1
2 RELAY
INPUT 5

RL6:A
1
2 RELAY
INPUT 6

RL7:A
1
2 RELAY
INPUT 7

R11
10K

D1
1N4001

TAPE MONITOR RL8:A
1
2 RELAY

Q1
BC337

LOGIC GND

To enhance viewing, please print to A3 AP16361/3 Input PCB Schematic (Input Control)

14

Cambridge Audio Azur 840A Amplifier

+15V

C21
INPUT L 5

10U 16V NP

6

R39

R54

100K

100K

U2:B
7
NE5532

-15V

C9

R83

R48
1k

47R 1000uF 10V EL
C18
22p

R49
1k

TO PREAMP LEFT

INPUT AMPLIFIER + 6 dB

+15V

INPUT R

C20
5

10U 16V NP

6

R53

R52

100K

100K

U4:B
7
NE5532

-15V

C10

R84

47R 1000uF 10V EL

R50

1k

C19

22p

R51
1k

TO PREAMP RIGHT

D2
1N4001

To enhance viewing, please print to A3 AP16361/3 Input PCB Schematic (Input Amplifier)

15

R64

Cambridge Audio Azur 840A Amplifier

C21 C71

AP16362/3 AP16362/3

C3 J1
R23

To enhance viewing, please print to A3 AP16361/3 Input Board PCB Board Layout (Top Side)

TO HUB PCB
CN6

TO PREAMP PCB CN11

CN7

R57

R58

CN10

C65

Q1

CN8

FROM FRONT PANEL PCB

RL1

R11

D1

R43

R42

U16

R14 R61
R62

R59 L

C7 R63
U14 C4
R60 C6
C5

C77

R3

C32 R12

R15 C38

U3

C8

R

R22

R

R34

INPUT 1

C37 C40

RL2

C43

RELAY DRIVER LOGIC

U1 HUB SWITCHER

C1

C2

RL4

RL3

R45 R44 R41 R40
R47 R46 R72 R69
R66
R70

CN1 CN2
R L

R4 C39 C27C24

R1 R13

INPUT 2 INPUT 3

R16 C36

C35 C42

U5

C44

L

C23 R5 C41 C25 R20 R2

R

R17 C51

C57 C48

U6

C54

R8 C45

L R

R55 R73

CC2226R21

R6

R18

C52

INPUT 4 INPUT 5

C58 C49

RL5

RL6

R67 R56 R74 R71
R68 R65 R79 R78
R76 R77

U7

C55

C46

R L

R10

C15

R7

C28

R28

R26 C53

C59 C50

U8

C56

CN3 CN4
L R

R31 C47 C14 C29

R30 R29

INPUT 6 INPUT 7

R27 C62

C63 C61

U18

C64

L

R33 C60

C13

R32 R25

C30

R37

R

RL7

C70 C69

RL8

R36 C31 R24 R75

L

TAPE RETURN

C66

C72

R TAPE OUT

C67

C17

R80
U9
R82

R85 C12

L CN5

C68 C16

R PREAMP L OUT

R38 R81 C33

U4

R19 R50

C19 R52

C20

R51

R53
R35 R84
R9 R48 U2

P1 C11

C10

C9

C34 C18 R54 R49 R39
CN9 TO PREAMP PCB

R83

CN9

16

Cambridge Audio Azur 840A Amplifier

To enhance viewing, please print to AA3 P16361/3 Input Board PCB Board Layout (Bottom Side)

17

Cambridge Audio Azur 840A Amplifier Input PCB BOM

AP No

V alue

RESISTORS 47R 100R

1K

10K 20K

47K

D escr iption/T ype
0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film

100K

0.125 W Metal Film

220K CAPACITORS 22pF 47pF 47nF 100nF
10uF

10uF

1000uF

PY476 PY1162 PY1158
PY214

SEMICONDUCTORS T C 9163AF NE5532 ULN 2003A TRANSISTORS BC 337-25 DIODES 1N 4001 MISCELLANEOUS Q UAD PHO N O SO C KET

JST 2.5MM B6B-X H-A

0.125 W Metal Film
C eramic 50V 10% Pitch= 3mm C eramic 50V 10% Pitch= 3mm 63V 10% Polyester Pitch= 5mm C eramic 50V 10% Pitch= 5mm 16V Non Polarised Electrolytic Radial (5.2mm) Pitch= 2.5mm 35V Non Polarised Electrolytic Radial (5.2mm) Pitch= 2.5mm 10V Electrolytic Radial (10mm) Pitch= 5mm
Analogue Switch Array Low Noise Dual Audio Op-Amp (SMT) 7 Darlington Drivers
N PN Small Signal
D iode
PHO N O Vertical header

PY1140 FFC 8-WAY

D 100-SSV-08

PY1143 FFC 10-WAY RELAY ME-2-9 9V DC

D 100-SSV-10

Qty

C omponent Ident

AP16364/3
N otes

4 R3, R14, R83, R84 6 R9, R19, R22, R23, R34, R85
R4, R5, R8, R10, R15-R18, R26, R27, 18
R31, R33, R36, R37, R48-R51 5 R11, R59, R60, R63, R64 4 R57, R58, R61, R62
R41, R43, R44, R46, R55, R56, R65, 13
R72-R74, R77, R79, R80, R82 R35, R38-R40, R42, R45, R47, R5220 R54, R66-R71, R75, R76, R78, R81 R1, R2, R6, R7, R12, R13, R20, R21, 14 R24, R25, R28-R30, R32
6 C 5-C 8, C 18, C 19 14 C 13-C 15, C 22-C 32
C16, C17, C33, C34, C43, C44, C54 11
C56, C64, C67 6 C 1, C 2, C 4, C 3, C 65, C 72
C11, C12, C20, C21, C35, C37 C40, 20 C42, C48-C50, C57-C59, C61, C63,
C66, C68, C71, C77 C36, C38, C39, C41, C45-C47, C5114 C53, C60, C62, C69, C70
2 C9, C10

1 U1 10 U3, U5-U9, U18, U2, U4, U14
1 U16
1 Q1
1 D1
5 C N 1-C N 5 2 C N 9, C N 10
2 C N 7, C N 8
1 CN6 8 RL1-RL8

SO P28 Package SO8 Package
DIL16 Package
T O 92 Package
DO 41
Input 1 audio conn, i/o conn Vertical FFC conn, reverse-needle type Vertical FFC conn, reverse-needle type

Note: resistors and other 'generic' electronic components are not usually stocked by the manufacturer. Please obtain these locally.
18

Cambridge Audio Azur 840A Amplifier

A CABLE

C CABLE

INPUT PCB - PREAMP PCB

FRONT PCB - PREAMP PCB

+15V

CN11

CN2

1 2 3 4 5 6 7 8
CONN FFC-8

+5V +9V

+15V -15V

LOGIC GND

1 2 3 4 5 6 7 8 9 10 11 12 CONN FFC-12

+5V
SPEAKER TEST ON/STBY LED
PHONES DETECT OVERLOAD CLIP DETECT DC OFFSET OVERTEMP MAINS FAIL IR RX

LOGIC GND

IR RX

+9V

+5V
R104
47R
U10
OPT 1
GND 2 3 +5V
TSOP18 IR RX
IR RECEIVER TSOP1836/37
LOGIC GND

C19
100n ceramic

C20
10U 16V

SHIFT REGISTER CONNECTOR FROM FRONT PANEL PCB

CN6
1 2 3 4 5 6 7 8
CONN-H8

SHIFT REGISTER CONNECTOR FROM FRONT PANEL PCB

CN8
1 2 3 4 5 6 7 8
CONN-H8

U4

1 IN1
2 IN2
3 IN3
4 IN4 5
IN5 6
IN6 7
IN7 8 GND

OUT1 16
OUT2 15 OUT3 14 OUT4
13 OUT5
12 OUT6 11 OUT7 10 COM
9

ULN2003A

LOGIC GND

U5

1 IN1 2 IN2 3
IN3 4
IN4 5 IN5 6
IN6 7
IN7 8 GND

OUT1 16
OUT2 15
OUT3 14 OUT4 13 OUT5
12 OUT6 11 OUT7 10 COM
9

ULN2003A

LOGIC GND

RL1:A
1

RL2:A
1

2 RELAY
VOL 1 LOW VOLUME

2 RELAY
VOL 2

+9V +9V
RL12:A
1
2 RELAY
VOL 12
+9V

RL3:A
1 2 RELAY
VOL 3
RL13:A
1 2 RELAY
VOL 13

RL4:A
1
2 RELAY
VOL 4

RL5:A
1
2 RELAY
VOL 5

RL14:A
1

RL15:A
1

2
RELAY
VOL 14 HIGH VOLUME

2
RELAY
BAL L

RL6:A
1 2 RELAY
VOL 6
RL16:A
1 2 RELAY
BAL R

RL7:A
1 2 RELAY
VOL 7
RL17:A
1 2 RELAY
BAL1

RL8:A
1 2 RELAY
VOL 8
RL18:A
1 2 RELAY
BAL 2

SHIFT REGISTER CONNECTOR FROM FRONT PANEL PCB

CN9
1 2 3 4 5 6 7 8
CONN-H8

U7

1 IN1
2 IN2
3 IN3 4 IN4 5
IN5 6
IN6 7 IN7 8
GND

OUT1 16 OUT2 15 OUT3
14 OUT4
13 OUT5 12 OUT6 11 OUT7
10 COM 9

ULN2003A

LOGIC GND

+9V

+5V
C27

LO = MAINS ON INRUSH RELAY

C28

C29

XD ON/OFF OUTPUT RELAY A OUTPUT RELAY B
LOGIC GND

100n ceramic

100n ceramic

ULN2003 DECOUPLERS

100n ceramic

R111
4K7

R100
22K

MAINS ON/OFF RELAY

R110
10K

+5V
R83
22K
Q1
BC337

ON/STBY LED

R21 R20

430R

430R

Q2

ON/STBY LED CONTROL

BC337

LOGIC GND

RL9:A
1
2 RELAY
VOL 9

RL10:A
1
2 RELAY
VOL 10

RL11:A
1
2 RELAY
VOL 11

RL19:A
1 2 RELAY
BAL 3
+5V
PHONES R PHONES L
PHONES GND

CN1
8 7
3

RSW1 RSW2
R

2

L

4

LSW2

5

LSW1

1

GND

HEADPHONE JACK

PHONES DETECT

HI = PHONE JACK OUT
R19
100K
TIP = LEFT

RING = RIGHT

LOGIC GND

To enhance viewing, please print to A3 AP16365/4 Preamp PCB Schematic (Relay Logic)

19

Cambridge Audio Azur 840A Amplifier

C38

1N PE 63V

TREBLE

ALPHA RD902PF

6

4

VR1:B

5

R3

C1

R2

1K1

1N5 PE 63V

1K1

C3

R5

R1

R4

2K2

4K7

2K2

10pF

R15

5

2K2

6

4

BASS

VR2:B
ALPHA RD902PF

5

U1:B

7

6

CN3
1 2 3 4 5 6

C2
680n poly
P1
GROUND REINFORCE PAD
PREAMP OUT L PREAMP OUT R

NE5532
TONE CONTROL

JST 2,5MM B6B-XH-A

C39

TREBLE

1N PE 63V

ALPHA RD902PF

3

1

VR1:A
R8
1K1

2

R7
1K1
C4
1N5 PE 63V

C6

R10

R6

R9

2K2

4K7

2K2

+15V 10p

C13

R17

ALPHA RD902PF

3

1

BASS VR2:A

C5
680n poly

2

2K2

47N PE 63V

8

U2:A
3

1

2

NE5532

4

C14

47N PE 63V -15V

+15V

C9

470U 10V EL

R11
47k

C8

SW1:A
SW-DPDT DEFEAT

47N PE 63V
C36

100pF
2K2 R16

8

4

3 1
2
NE5532
U1:A

C10
470U 10V EL
R13
47k

R97
150R
R22
150R

RL17:B
4 3
5 RELAY
R85
390R

R105

R87

2K2

2K2

RL18:B
4 3
5 RELAY
R88
1K
R86
390R

RL15:C

7

6

8 RELAY

RL15:B

C18

4

3

5 RELAY

10U NP 16V

5

RL19:B

6

4

3

5 RELAY

R99

47K

LEFT

U9:B
NE5532 7

C21 TO VOLUME LEFT

1000U 10V EL

R103
47K

R89
2K2

2.5 dB

3.75 dB

5.5 dB

-15V

BALANCE CONTROL

BALANCE BUFFER

C37

C11

470U 10V EL

R12
47k

SW1:B
SW-DPDT DEFEAT

100pF
R18
2K2

5

U2:B

7

6

NE5532

C12
470U 10V EL
R14
47k

R98
150R
RL17:C
7 6
8 RELAY

R90

R96

150R

390R

+15V

RL18:C
7 6
8 RELAY
R94
1K
R92
390R

RL19:C
7
8 RELAY

RL16:C
7 6
8 RELAY
RL16:B
4 3
5 RELAY
6
RIGHT

C24
10U NP 16V

3 2
R101
47K
-15V

4

8

C15
47N PE 63V

U9:A
1

C25 TO VOLUME RIGHT

NE5532 1000U 10V EL

R102
47K

C22
47N PE 63V

R91

R93

R95

2K2

2K2

2K2

To enhance viewing, please print to A3 AP16365/4 Preamp PCB Schematic (Tone Control)

20

Cambridge Audio Azur 840A Amplifier

C35
47N PE 63V

+15V
C23
100nF ceramic

C31
47U NP 25V

R106
470R
R107
47K

8

C16
VOL OUT LEFT 10U NP 16V

-15V 3
2
R77
47K

4

U12:A
1
NE5532

P2
PAD GROUND REINFORCE
P3
PAD

R76
390R

POST AMPLIFIER

390R
R75
-15V
C33
18 pF
C34

15 pF

R81
220R
100nF ceramic
C26
HI = NORMAL OVERTEMP HI = NORMAL DC OFFSET HI = NORMAL OVERLOAD HI = NORMAL CLIP DETECT
D3
5V1

VOL OUT RIGHT

C17

10U NP 16V

R80
47K

U12:B
5 7
6
NE5532
R78
390R
R79
390R

LO = ON XD ON/OFF

R82
220R

C32
47U NP 25V

R108
470R
R109
47K

PREAMP OUT L

R84 47K

D1
1N4148

D2
1N4148

LOGIC GND

PREAMP OUT R

CN10

1

AUDIO TO L POWER AMP

2

JST 2.5MM B2B-XH-A

PREAMP PCB - POWER AMP LEFT PCB CONNS
+9V

+5V LOGIC GND
SPEAKER TEST
MAINS FAIL OUTPUT RELAY A OUTPUT RELAY B
PHONES R PHONES L PHONES GND

CN4

1

2 3

4

SPEAKER TEST

5

CLIP

6

OVERLOAD

7

DC OFFSET

8

OVERTEMP

9

XD ON/OFF

10

11

12

13 14

15 16

FFC 16WAY

C30
10u 25V

+15V
C7
10u 25V
-15V

OPAMP DECOUPLING

+9V +5V
LOGIC GND

MAINS FAIL IN

MAINS FAIL IN MAINS ON/OFF RELAY
INRUSH RELAY

CN5
1 2 3 4 5 6 7 8 9 10 11 12
FFC 12WAY

CN12

1 2

AUDIO TO R POWER AMP

JST 2.5MM B2B-XH-A

PREAMP PCB - PSU PCB CONN

PREAMP PCB - POWER AMP RIGHT PCB CONN

To enhance viewing, please print to A3 AP16365/4 Preamp PCB Schematic (Post Amp)

21

Cambridge Audio Azur 840A Amplifier

R82 R81 R100 R110
Q1 Q2 R83 R20 R21 R111 R19

C23 R104

R108

CN4

P1

R106 R107

R109

D1

CN3

C32

C31

D2

R84

D3

CN11

CN12 CN10

CN2

C26 CN1 PHONES

C16

C33

R77

C35

R76

R75

R23

RL1

RL2

RL3

RL4

RL5

RL6

RL7

R51

R49

R27

R25

R56 R55 R31 R32 R58 R57

R24 R50 C34 R26 R52 U12

R78 R79 R80

C17

R28

R54

R53

C19

R29

R30

C20 U10

R33 R59 R34 R35 R61 R60

C28

U4

RL8

RL9

RL10

RL11

RL12

RL13

RL14

U5

C2

CN6

CN8

R36 R37 R63 R62 R38 R39 R65 R64 R40 R66 R41 R42 R67 R68 R43 R44 R70

C27 C7 C30

C11

C9

R102

R71 R46

R72

P2

U1

R69R45 R48 R74 R47 R73

C10 C8
C36

R13

C25

R103

C21

R15 R16

C3

R9

R4

C5 VR2

R5

R10

R1

R7 C4

R2

CN5

RL17

RL18

RL19

RL16

RL15

U7

C1 VR1
R3

C38

R11

P3 SW1

R12 R91 R90 R98 R85 R87
R18 R17 C13 R101 R92 R94 C24 C18 C22 R99 C29 CN9

R8

U9

R97R22R105

C14

R93 R96 R88 R86 R89 R95

C6

C12

R6

C39

C15
U2 R14 C37

To enhance viewing, please print to A3

AP16365/3 Preamp PCB Layout (Top Side)

22

Cambridge Audio Azur 840A Amplifier

To enhance viewing, please print to A3 AP16365/3 Pre-amp PCB Layout (Bottom Side)

23

Cambridge Audio Azur 840A Amplifier Preamp PCB BOM

AP16368/4

AP No

Value

Description/Type

Qty

Component Ident

Notes

PY259 PY1158 PY214

RESISTORS 5R1 51R 150R 300R
390R
620R 1K 1K1 1K2
2K2
4K7 5K1 10K 20K 39K
47K
75K 82K 160K 200K 300K 620K 820K 1M2 5M1 47R 430R 470R 10K 22K 47K 100K CAPACITORS 10pF 15pF 18pF 100pF
1nF
1n5
47nF 100nF 680nF
10uF
10uF
10uF
47uF
470uF
1000uF
SEMICONDUCTORS NE5532 T SO P18 IR RX ULN 2003A TRANSISTORS BC 337-25 DIODES 1N 4148

0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film
0.125 W Metal Film
0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film
0.125 W Metal Film
0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film
0.125 W Metal Film
0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film

2 R47, R73 2 R48, R74 4 R22, R90, R97, R98 2 R44, R70
R85, R86, R92, R96, R75, R78, R76, 8
R79 2 R46, R72 4 R37, R63, R88, R94 4 R2, R3, R7, R8 2 R45, R71
R4, R5, R9, R10, R15-R18, R43, R69, 10
R87, R89, R91, R93, R95, R105 3 R1, R6, R111 2 R35, R61 11 R38-R42, R64-R68 4 R30, R32, R56, R58 2 R36, R62
R11-R14, R77, R80, R99, R101, R102, 9
R103, 2 R34, R60 2 R28, R54 2 R33, R59 2 R24, R50 2 R31, R57 2 R29, R55 2 R26, R52 4 R25, R27, R51, R53 2 R23, R49 3 R81, R82, R104 2 R20, R21 2 R106, R108 1 R110 2 R83, R100 3 R84, R107, R109 1 R19

C eramic 50V 10% Pitch= 3mm

2 C 3, C 6

C eramic 50V 10% Pitch= 3mm

1 C 34

C eramic 50V 10% Pitch= 3mm

1 C 33

Ceramic 50V 10% Pitch=3mm

2 C36, C37

Polyester 63V 10% Pitch=5mm

2 C38, C39

Polyester 63V 10% Pitch=5mm

2 C1, C4

63V 10% Polyester Pitch= 5mm

6 C 8, C 13, C 14, C 15, C 22, C 35

Ceramic 50V 10% Pitch= 5mm

6 C19, C23, C26-C29

Polyester 100V 5% Pitch= 15mm

2 C2, C5

25V Electrolytic Radial (5mm) Pitch= 2.5mm

2 C7, C30

16V Electrolytic Radial (5.2mm) Pitch= 1 C20
2.5mm

16V Electrolytic NP Radial (5.2mm) Pitch= 2.5mm

4 C16, C17, C18,C24,

25V Electrolytic NP Radial (8.4mm) Pitch= 3.5mm

2 C31, C32

10V Electrolytic Radial (8.4mm) Pitch= 4 C9-C12
3.5mm

10V Electrolytic Radial (10.4mm) Pitch= 5mm

2 C21, C25

Low Noise Dual Audio Op-Amp IR Receiver Module 7 Darlington Drivers

4 U1, U2, U9, U12 1 U10 3 U4, U5, U7

DIL08 Package Replaces T SO P18 DIL16 Package

2 Q 1, Q 2

T O 92

Small Signal Diode

2 D1, D2

Note: resistors, capacitors and other 'generic' electronic components are not usually stocked by the manufacturer. Please obtain these locally.
24

Cambridge Audio Azur 840A Amplifier Preamp PCB BOM

AP No

Value

Description/Type

Qty

Component Ident

BZX 79-C 5V1 MISCELLANEOUS

Zener diode 5V1 400mW

1 D3

PY1156 RD902PF-20B6-30F-B5K-0C ALPHA B5K LINEAR POT

2 VR1, VR2

PY1141

CK-6.35-04 7P JST 2,5MM B2B-XH-A JST 2,5MM B6B-XH-A
D100-SSV-12

PY1140 D100-SSV-08

PY1157 PY645

D100-SSV-16
ME-2-9 9V DC Push switch -DPDT

HEADPHONE JACK SKT 2-way vertical header 6-way vertical header Flat-film connector 12-way, reverseneedle type Single row contacts Flat-film connector 8-way, reverseneedle type Single row contacts Flat-film connector 16-way, reverseneedle type Single row contacts 9V DC Relay 2402-020200-010

1 CN1 2 CN10, CN12 1 CN3 2 CN2, CN5
4 CN6, CN8, CN9, CN11
1 CN4 19 RL1-RL19 1 SW1

AP16368/4
Notes 400mW DO 35 C ase. Retractable 9mm pot. With centre detent.
As used in 340A

Note: resistors, capacitors and other 'generic' electronic components are not usually stocked by the manufacturer. Please obtain these locally.
25

Cambridge Audio Azur 840A Amplifier

MAINS IN
J24
BROWN
LIVE

10A for 115V 6A3 for 230V
F1
T6A3 AL LVD!

MAINS ON/OFF RELAY C30 X1 10n

RL3:B

4/5

3/6

ME14FW009HS

INRUSH CONTROL RELAY C29 X1 10n

RL4:B

4/5

3/6

ME14FW009HS

R78
10R 10W WW

TO MAIN TRANSFORMER
J2
1
BROWN/BLACK
LIVE

C13

C23

X2 470N SUPPRESSION X2 470N SUPPRESSION

ALTERNATIVE POSITIONS FOR X-CAPS WITH DIFFERENT LEAD PITCHES

CN2

+15V

1

2

-15V

3

4

0V

5

6

+9V

7

8

MAINS FAIL IN

9 10

MAINS ON/OFF

11

INRUSH

12

FFC 12WAY

+15V -15V

+9V PSU

D25

MAINS ON/OFFD9 2

INRUSH CONTROL 2

PSU GND

+5V PSU

1N4001

PSU GND

1
ME14FW009HS 1N4001
RL3:A

1 ME14FW009HS
RL4:A

R87

D24

AC

47K 1N4002

MAINS FAIL RECTIFIER

C28
4U7 50V

R79

4K7

PSU PCB

PSU GND

J27
BROWN NEUTRAL
J26
BROWN
NEUTRAL

J1
2
BLUE/WHITE
NEUTRAL
J8
1
TERMINAL
J9
2
TERMINAL
NEUTRAL

MAIN TRANSFORMER
BROWN 230 V
Primary BLUE 0 V 117 DEG C
STANDBY TRANSFORMER
BROWN 230 V
Primary BLUE
0 V 113 DEG C

MAINS IN
CN3
N E L IEC-SOC

CHASSIS GND

C11
X1 10n
GROUND
C12
X1 10n

J25
BROWN

LIVE

MAINS SWITCH ON REAR PANEL

RED 5.5A

1 36 V

ORANGE
Secondary YELLOW
5.5A

2 0V

TO POWER AMP SUPPLY LEFT (SEPARATE PCB)

3 36 V

GREEN
100 mA RED 5.5A

4 38 V 1 36 V

ORANGE

2 0V

Secondary

YELLOW 5.5A

3 36 V

GREEN 100 mA

4 38 V

J13
TERMINAL
GREEN

J10
+48V IN TERMINAL RED

FROM RECTIFIER BOARD

J11
0V IN TERMINAL BLACK

F7
T1A AL LVD!

J12 -48V IN
TERMINAL
ORANGE D23
1N4002

+48V R

C25
15000uF-63V
C26
15000uF-63V

POWER AMP SUPPLY RIGHT

C27
1000uF-50V

-48V R
R88
33R 1W

C17
220uF 100V -51V R

RED 500mA Secondary 1
ORANGE

1 7.5 V 2 0V

J6
TERMINAL

F4
20MM T1AL

J7
TERMINAL

C34
X1 10n

D19
1N4002
D21
1N4002

D20
1N4002
D22
1N4002

AC 4700u 16V
C24

RELAY SUPPLY

7805

MICROCONTROLLER SUPPLY

1

VI

VO 3

+5V PSU

2 GND

C20

100nF ceramic

U2

C16
47u 16V

R95
2R2 0.5W

+9V PSU
C33

C31
100nF ceramic

PSU GND

4700u 16V

YELLOW 100mA

3 17 V

GREEN
Secondary 2 VIOLET 100mA

4 0V 5 17 V

J3
TERMINAL BLACK
J5

F2
20MM T1AL

TERMINAL GREY

J4
TERMINAL GREEN

F3
20MM T1AL

C37
C35
X1 10n

X1 10n

D15
1N4002

C36
X1 10n

D17
1N4002

D16
1N4002
D18
1N4002

U3

7815

1

VI

C14
1000U 35V EL

GND

C32 OPAMP SUPPLY

100nF ceramic

VO

3

+15V

C18
100u 25V

2

C15
470u 35V
2 VI
U4
7915

1 GND

3 VO
C22
100nF ceramic

C19
100u 25V

PSU GND -15V

PSU PCB

+5V IN

MAINS FAIL IN

R96

R81

100K

33K

+310 mV +600 mV

R80
2K2

R77
10K

5 7
6
U1:B
LM393

LOW = NORMAL MAINS FAIL
TO SHEET 1

MAINS FAIL DETECT

To enhance viewing, pleaAsePp1rin6t3to7A33/4 Power Amplifier (Right) Power Supplies & PSU PCB Schematic

26

Cambridge Audio Azur 840A Amplifier

+48V R

R2
100R
Q3
MPSA93

C8
47uF 16V
R56
2K2

C7
47uF 35V

D10
1N4148
D11
1N4148

R57
22K

R3
68R
Q4
MPSA93
R10
1K8

AMP IN RIGHT

JST 2.5MM B2B-XH-A

CN4

C1

1

2

47U 16V

R4
100R
Q5
MPSA93

R5
100R
Q6
MPSA93

R67
22K

R27
2K2

NFB-R

R11
1K2

3

R13
+48V R 2K2

C41

R14
100R

VR1

2

1K

1

R97
100K

4n7 COG

C6
1000U 10V EL

D30
1N4148
D31
1N4148

1

3

VR2 R99
2
1K 10K
C38
10U NP 16V

-48V R

R98
100K

DC OFFSET NULL

R100
22K

Q7
MPSA43
R6
68R

CHASSIS GND

C39
100pF

Q8
MPSA43
R7
68R

Q11
BC337

D34
1N4148
C10

Q9
MPSA43

100pF

R15
22K

R8

R89

2K2

10K

R91

R18

75K

100R

R12
18R
Q12
MJE340

R17
100R
D2
1N4148
Q19
MPSA43
C9
47uF 16V

Q1
MJE340

R54

R1

16K

10R

2K7

R93

R33

3K3

R52
1K

D28
12V
NFB-R

R21
0R1

Q20
MPSA93
D1
1N4148

R53
1K
R94
2K7 16K
R55

D29
12V
R34
3K6
R32
10R

D32
1N4148

R23
100R

D33
1N4148

Q2
MJE350
R92
56K
R24
100R

R22
0R1
Q15
2SC3264

Q10
MPSA43
R49
16K
R9
56R

Q25
MPSA43

R51

R90

10K

47K

R19
0R1
Q13
2SA1295

R20
0R1
Q14
2SA1295

R64
10K

Q16
2SC3264

R25 R26

0R1

0R1

R63
1K
Q26
MPSA43
R84
10K

R66
47K

R62
150R
Q27
MPSA93

D12
1N4148
D13
1N4148

R65
47K

R60

R61

1K1

1K1

Q29
MPSA93

Q28
MPSA93

R30

470R

Q17

Q18
MJE340

2SA1295

R31
0R68

R58

R59

470R

470R

-51V R

C21
100nF ceramic

+5V IN

R68

R69

4K7

10K

+850mV 3
2

TH1
ZPP22 100DEG POSITIVE THERMISTOR
850R at 100degC

R70
1K8

4

8

R71
1M

U1:A
1

LM393

HI = NORMAL

R74
4K7

OVERTEMP DETECT 100deg C cutout

BC337

MPSA43/93

OVERTEMP

+5V IN

CN1

+5V

1

LOGIC GND

2

SPEAKER TEST SENSE

3

+9V

4

OVERLOAD

5

CLIP

6

OVERTEMP

7

DC OFFSET

8

MAINS FAIL

9

XD ON/OFF

10

OUTPUT RELAY B

11

OUTPUT RELAY A

12

MAINS FAIL IN

13

spare PHONES GND

14 15

PHONES R

16

LOGIC GND
SPEAKER TEST SENSE
CLIP DC OFFSET
MAINS FAIL OUTPUT RELAY B OUTPUT RELAY A MAINS FAIL IN
PHONES OUT RIGHT

FFC 16WAY

PREAMP PCB - POWER AMP PCB CONN

XD ON/OFF

+9V IN

R86
47K

R16
10K

OUTPUT RELAY A

LOW = NORMAL

Q35
BC337

BC337
Q32

D14
1N4002
R72
4K7
Q31
BC337

RL1:A
2
1 RELAY

OUTPUT RELAY B

1N4002
D7
R82
4K7

R85
10K
10K R75

BC337
Q34

Q33
BC337

LOGIC GND

OUTPUT RELAY CONTROL

C4
220uF 80V

R40
220R 3W C
R41
470R 1W C

D26
1N5404

LEFT IN
J22
+5V IN
R101
1K

R29
10R 3W

L1
1,7U 10A
R28
2R2 3W

SPEAKER TEST SENSE

C2
0u1 POLYESTER

D27
1N5404

C5
220uF 80V

PHONES OUT RIGHT

RL1:C

J18

8

6

LEFT OUT A

7 RELAY

RL2:C

J20

8

6

LEFT OUT B

7 RELAY

RL1:B

J14

5

3

RIGHT OUT A

4 RELAY

R46
4K7

Q24
MPSA93

HI = NORMAL
R48

22K

CLIP

R47
47K

R45
47K

-48V R

RL2:B
5 3
4 RELAY

J16 RIGHT OUT B
J15 GND RIGHT
J17 GND RIGHT D8

1N4148
R43
47K

R44
47K
Q23
MPSA43

R42
4K7

+48V R

-48V R

RL2:A
2
1 RELAY
R50
10K
R83
10K

R39
10K

R35
47K

D4
1N4148

C3
22U 50V NP

D3
1N4148

1N4148
D5

R37
100K
Q21
MPSA43 10U 63V EL
C40
Q22
MPSA93

D6
1N4148

R36
4K7

LOW = NORMAL
Q36
10K BC337

R73

-48V R
DC OFFSET DETECT

HI = NORMAL DC OFFSET
R38
47K
R76
10K

RIGHT

E BC

C BE

To enhance viewing, please print to A3

AP16373/4 Power Amplifier Right Channel

27

Cambridge Audio Azur 840A Amplifier

To enhance viewing, please print toAAP316373/3 Power Amp (Right) & PSU PCB Layout (Top Side)

28

Cambridge Audio Azur 840A Amplifier

To enhance viewing, please printAtoPA136373/3 Power Amp Right & PSU PCB Layout (Bottom Side)

29

Cambridge Audio Azur 840A Amplifier Power Amp Right PCB BOM

AP No

V alue

D escr iption/T ype

Qty

C omponent Ident

N otes

RESISTORS 910R 2K2 4K7 10K 22K 33K 47K 100K 1M 10R 18R 56R 68R 100R 150R 470R 1K 1K1 1K2 1K8 2K2 2K7 3K3 3K6 4K7
10K
16K 22K
47K
56K 75K 100K 33R 470R 0R1 1R5
2R2
10R 220R CAPACITORS
100pF
10nF X1 CAP
100nF
100nF
10uF
10uF
22uF

0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film
0.25 W Metal Film
0.25 W Metal Film 0.25 W Metal Film
0.25 W Metal Film
0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 1 W Metal Film 1 W C arbon 3 W Wire Wound 3 W Wire Wound
3 W Wire Wound
3 W Wire Wound 3 W Carbon

1 R70

1 R80

5 R36 , R66, R68, R72, R74,

6 R16, R69, R75, R76, R77, R85,

1 R48

1 R81

2 R43, R90,

1 R96

1 R71

2 R1, R32

1 R12

1 R9

3 R3, R6, R7

9 R2, R4-R5, R14, R17, R18, R23, R24,

1 R62

3 R30, R58, R59

6 R52-R53, R63, R80, R99, R101

2 R60, R61

1 R11,

1 R10,

4 R8, R13, R27, R56,

2 R93, R94

1 R34

1 R33

3 R42, R46, R82

R39, R50, R51, R64, R73, R83, R84, , 8
R89,

3 R49, R54, R55

5 R15, R57, R67, R81, R100

R35, R38, R44, R45, R47, R65, R66, 8
R86

1 R92

1 R91

4 R37, , R97, R98

1 R88

Space off PCB

1 R41

Space off PCB

6 R19-R22, R25, R26

S pace off PCB

1 R31

Space off PCB

1 R28

Inductor damping res. No need to stand off PCB

1 R29

1 R40

Ceramic 100V 10% Pitch= 3mm MEX103K300A02 Pitch =10mm Ceramic 100V 10% Pitch= 5mm Polyester Pitch= 10mm 16V Electrolytic Radial Non Polarised (6.4mm) Pitch= 5mm 63V Electrolytic Radial (5mm diam) Pitch= 3.5mm 50V Non Polarised Electrolytic Radial (5.2mm) Pitch= 2.5mm

1 C10, C39 3 C11, C12, C20 2 C18, C21 1 C2 2 C20, C38
1 C40
1 C3

AP16376/7

Note: resistors, capacitors and other 'generic' electronic components are not usually stocked by the manufacturer. Please obtain these locally.
30

Cambridge Audio Azur 840A Amplifier Power Amp Right PCB BOM

AP16376/7

AP No

V alue

D escr iption/T ype

Qty

C omponent Ident

N otes

47uF

47uF

220uF

220uF

1000uF

1000uF

15000uF SEMICONDUCTORS

PY1152 LM393AP

PY1148 PY1150 PY021 PY013 PY214 PY1149 PY1147

TRANSISTORS MJE340 MJE350 MPSA93 MPSA43 BC337-25 2SA1295 2SC 3264 DIODES

1N4148

1N4002 1N5404 BZX 79-C 12 MISCELLANEOUS Z P221A501E

08-1950100-150

MULTITURN PRESET 1K MULTITURN PRESET 10K SS-7B-1

PY1151 D100-SSV-16

4031-050100-001 T1A AL

16V Electrolytic Radial (5mm) Pitch= 2.5mm 35V Electrolytic Radial (10mm) Pitch= 2.5mm 100V Electrolytic Radial (12.5mm) Pitch= 5mm 80V Electrolytic Radial (10.4mm) Pitch= 5mm 10V Electrolytic Radial (10.4mm) Pitch= 5mm 50V Electrolytic Radial (13.4mm) Pitch= 5mm 63V Electrolytic Radial (35.4mm) Pitch= 10mm

3 C1, C8, C9 1 C7 1 C17 2 C4 1 C6 1 C27 2 C25, C26

Low-offset dual Comparator, A-version for low offset voltage

1 U1

DIL08 Package

N PN Driver T ransistor PN P Driver T ransistor PNP Small Signal NPN Small Si gnal NPN Small Si gnal PNP Power Audio N PN Power Audio

3 Q 1, Q 12, Q 18

T O 126

1 Q2

T O 126

10 Q3-Q6, Q20, Q22, Q24, Q27-Q29 TO92WIDE

8 Q7-Q10, Q19, Q21, Q23, Q26, Q25, TO92WIDE

9 Q11, Q31-Q36

TO92

3 Q13, Q14, Q17

MT200

2 Q 15, Q 16

MT 200

MPSA92 ma MPSA42 ma

y be used y be used

Small Signal Diode
General Purpose Rectifier General Purpose Rectifier 12V Zener diode 400mW

D1-D6, D8, D10-D13, D17, D18, D30 18
D34 3 D7, D14, D23, 2 D26, D27 2 D28, D29

DIODE-IN4148
DO 41 Package DO 27 Package Clamp diodes 400mW DO 35 C ase.

PO SIT IVE T HERMIST O R

1 TH1

1.7uH 10A INDUCTOR

1 L1

Top adjust. Footprint 9.5 x 4.5 mm Top adjust. Footprint 9.5 x 4.5 mm W ong Feng IEC-SOCKET FFC CONNECTOR 16WAY, Vertical "Reverse needle" type, Single row of contacts Fuseholder 20mm FUSE-20MM 1A anti sur ge,

1 VR1 1 VR2 1 CN3
1 CN1
1 F7 1 F7

N ominal operatingtemp 100 degC 10 turns of 1.5mm copper wire, diameter 20mm, length approx 20mm Set quiescent current. Insert so adj screw next to R17 DC trim Insert so adj screw next to Q11
WMZ12A( )-100S80FLS

Note: resistors, capacitors and other 'generic' electronic components are not usually stocked by the manufacturer. Please obtain these locally.
31

Cambridge Audio Azur 840A Amplifier PSU PCB BOM

AP No

V alue

D escr iption/T ype

RESISTORS 2R2 10R 10W 8.5X53MM WireWound 4K7 47K CAPACITORS 10nF X1 Capacitor 100nF
470nF
4u7
47uF
100uF
470uF
1000uF
4700uF

0.5 W Metal Film
KN 10W J 10O hm B
0.25 W Metal Film 0.25 W Metal Film
MEX103K300A02 Pitch =10mm
Ceramic 100V Pitch= 5mm X2 Suppression CAP BOX 27.5X13 Pitch= 27.5mm or BOX 22.5X10 Pitch= 22.5mm 50V Electrolytic Radial (5.2mm) Pitch= 2.5mm 16V Electrolytic Radial (5mm) Pitch= 2.5mm 25V Electrolytic Radial (6mm) Pitch= 2.5mm 35V Electrolytic Radial (10.4mm) Pitch= 5mm 35V Electrolytic Radial (10.4mm) Pitch= 5mm 16V Electrolytic Radial (16.4mm) Pitch= 5mm

SEMICONDUCTORS

7805 7815 7915
DIODES 1N4002 1N 4001

5 Volt 1A Linear Regulator 15 Volt 1A Linear Regulator -15 Volt 1A Linear Regulator
General Purpose Rectifier General Purpose Rectifier

MISCELLANEOUS

PY1154

T1AL
T6.3 AL or T10A 4031-050100001 4034-000030000
D100-SSV-12
RELAY ME14F

1A antisurge fuse 20mm (low breaking capacity) 6.3A or 10A antisurge fuse 20mm (low breaking capacity)
Fuseholder 20mm
Fuseholder cover
FFC CONNECTOR 12-WAY, Vertical "Reverse needle" type, Single row of contacts RELAY ME14F-9H16S SPST 16A 250 Vac 9V coil

Qty

C omponent Ident

N otes

1 R95
1 R78
1 R79 1 R87

Space off PC B Inrush resistor. Space off PC B

6 C29, C30, C34-C37 4 C20, C22, C31, C32 1 C13 or C23 dependant on pitch

1 C28 1 C16 2 C18,C19 1 C15 1 C14 2 C 24, C 33

MAX IMUM HEIGHT 25 mm

1 U2 1 U3 1 U4
9 D15-D22, D24 2 D9, D25

T O 220 Package T O 220 Package T O 220 Package
DO41 Package DO 41 Package

3 F2 - F4 1 F1 4 F1, 2, 3, 4, 1 F1 1 CN2 2 RL3, RL4

T6A3 for 230V T10A for 115V Place on mains fuse holder F1
Mains & inrush control relays.

AP16376/7

Note: resistors, capacitors and other 'generic' electronic components are not usually stocked by the manufacturer. Please obtain these locally.
32

Cambridge Audio Azur 840A Amplifier

+48V

R2
100R
Q3
MPSA93

C8
47uF 16V
R56
2K2

C7
47uF 35V

D10
1N4148
D11
1N4148

R57
22K

R3
68R
Q4
MPSA93
R10
1K8

AMP IN LEFT
JST 2.5MM B2B-XH-A
CN3
1 2

C1
47U 16V

R4
100R
Q5
MPSA93

R5
100R
Q6
MPSA93

R67
22K

R27
2K2

NFB-L

R11
1K2

3

+48V

R13
2K2

C15

R14

VR1

100R

2

1K

1

1N4148

R78
100K

4n7 50V COG

C6
1000U 10V EL

D17
D18
1N4148

1

3

VR2 R80
2
1K
10K C20
10U NP 16V

R79
100K
-48V

DC OFFSET NULL

Q7
MPSA43
R6
68R

R81
22K
P1
PAD CHASSIS GND
C14
100pF

Q8
MPSA43
R7
68R

Q11
BC337

Q9
MPSA43

D23
1N4148
C10
100pF

R15
22K

R8

R16

2K2

10K

R72

R18

75K

100R

R12
18R
Q12
MJE340

R17
100R
D2
1N4148 MPSA43
C9
47uF 16V

Q1
MJE340

R54 R74 R1

16K

2K7

10R

Q19

R33

3K6

R52

D14

R21

1K

12V

0R1

NFB-L

R53

D16

R22

1K

12V

0R1

Q20

R34

MPSA93 3K3

R55
16K
D1
1N4148

R76

2K7

R32

10R

D24
1N4148

R23
100R

D25
1N4148

R73
56K

Q2
MJE350
Q15
2SC3264
R24
100R

Q10
MPSA43

R50
47K

Q25

R49

MPSA43

16K

R9

R51

56R

10K

-51V

+5V

R68
4K7
TH1
POSITIVE THERMISTOR ZPP22 100DEG 850R at 100degC
MJE340,350

R69
10K

R71

R75

1M

4K7

U1:B
5 7
6 HI = NORMAL
LM393

R70
1K8

C18
100n ceramic

OVERTEMP DETECT 100deg C cutout
BC337

MPSA43/93

R90
100R
D22
1N4002
R86
100R

R85
10K
R91 100R
3
2

D21
1N4002

R87
10R

4

8

R89
4K7

1
U1:A
LM393
100K
R88

LO = NO SHORT

SPEAKER SHORT CIRCUIT TEST SYSTEM

R19
0R1
Q13
2SA1295

R20
0R1
Q14
2SA1295

R62
150R
Q27
MPSA93

D12
1N4148
D13
1N4148

R65
47K

Q16
2SC3264
R25
0R1

R64
10K
R63
1K

R60

R61

1K1

1K1

Q29
MPSA93

Q28
MPSA93

R30

470R

Q17

Q18
MJE340

2SA1295

R26
0R1

Q26

MPSA43

R58

470R
R66

10K

R59
470R

R31
0R68

R82
47K

+5V

Q31 R83

10K MPSA93
XD ON/OFF
SPEAKER TEST

LOGIC GND

CN2

LOGIC GND

1

+5V

2

+9V

3

SPEAKER TEST

4

CLIP

5

OVERLOAD

6

DC OFFSET

7

OVERTEMP

8

XD ON/OFF

9

MAINS FAIL

10

OUTPUT RELAY A

11

OUTPUT RELAY B

12

PHONES GND

13

MAINS FAIL IN

14

15

PHONES R

16

PHONES L

FFC 16WAY

PHONES L

PREAMP PCB - LEFT POWER AMP PCB CONN

D20
1N4148
D19 1N4148

C4
220uF 80V
D7
1N5404

R29
10R 3W

L1
1,7U 10A
R28
2R2 3W

C2
0u1 POLYESTER

D9
1N5404

R40
220R 3W C

PHONES L

R41
470R 1W C

R46
4K7

Q24
MPSA93

NORMAL = HI
R48
CLIP 22K
R47
47K 210mW

J5
LEFT OUT
TERMINAL
J6
TERMINAL
J7 OUTPUT GROUND
TERMINAL
D8

-48V
R45
47K 50mW

C5
220uF 80V

1N4148
R43
47K 50mW

R44
47K 50mW
Q23
MPSA43

R42
4K7

+48V

R35
47K

CLIP

DC OFFSET

CN1

1

+5V

2

LOGIC GND

3

SPEAKER TEST SENSE

4

+9V

5

OVERLOAD

6

CLIP

7

OVERTEMP

8

DC OFFSET

9

MAINS FAIL

10

XD ON/OFF

11

OUTPUT RELAY B

12

OUTPUT RELAY A

13

MAINS FAIL IN

14

15

PHONES GND

16

PHONES R

FFC 16WAY

LEFT POWER AMP TO RIGHT POWER AMP CONNECTOR

LOGIC GND
D4
1N4148

1N4148
D5

R37
100K
Q21
MPSA43

D3

C3
22U 50V NP

1N4148

Q22
MPSA93
D6
1N4148

LOGIC GND

R36

4K7

DC OFFSET DETECT

-48V

-48V DC OFFSET HI = NORMAL
LEFT

E CB

E BC 321

Looking at pins C BE

To enhance viewing, please print to A3

AP16693/5 Power Amplifier Left Channel

33

Cambridge Audio Azur 840A Amplifier

230 V 1

MAIN TRANSFORMER
BROWN

Primary

0V 2

BLUE 115 DEG C

RED 5.5A

1 36 V

ORANGE
Secondary YELLOW
5.5A

2 0V 3 36 V

GREEN
100 mA RED 5.5A

4 38 V 1 36 V

FROM RECTIFIER BOARD

+48V IN

J1
TERMINAL
RED

J2

0V IN

TERMINAL

ORANGE

J3

-48V IN
TERMINAL
YELLOW

J4
+48V IN
TERMINAL
GREEN

F1
T1A AL LVD!

D15
1N4002

ORANGE

2 0V

Secondary

YELLOW 5.5A

3 36 V

TO POWER AMP SUPPLY RIGHT

GREEN 100 mA

4 38 V

-

+

-

+

C12
15000U 63V
C13
15000U 63V
C11
1000uF 50V
R38
33R 1W

+48V
POWER AMP SUPPLY LEFT
-48V
C17
220uF 100V -51V

To enhance viewing, please print to A3 AP16693/5 Power Amplifier Left Power Supplies

34

Cambridge Audio Azur 840A Amplifier

J4

J3

RED ORANGE

V-

J1

V+

0V BLACK
J2

GREEN

F1

38V AC

TH1 Q13

D15

RED OUTPUT
J5

BLK BLK

GND GND

J6

J7

R38

C12

C11

R28 D7

FIX2 C4 C13

L1 C2 R29 Q12

Q14 R19 R20 R18
Q1
R3 D10
C17 D9

AP16694/4 AP16694/4
Q3

C9 Q19 VR2
Q20 C6
C14 P1

D17

Q15

Q16

Q17

R26

R31

R25

R30

Q18

R17

R21

D2

R1

R12

Q4 C7 VR1 BIAS

R10 R11
R57
D11 R67 R56

R33 R52
R54 R81 R27

R5

R14

R2 Q6

R4

Q5

C1

D14 R74
R72

R40

Q29

Q27 Q26

R22

R32

R24

R62

R58

Q2

R53
Q8 R8 Q7

R23 D1 R73 R76 D16 R34 C10
R55 Q9
R7
R6
R13 Q25

D23 D25 D24

Q11

Q10

R60 R61

R64 D12 D13
R65 R9
R35

R15

D4

D5

DC OFFSET

R49

FIX3

R16

R51

R44 D8

Q21

Q28

R59 R63

R66

C3 D3

D6

Q22

R36 R37
R42

R68
R69 R70 R50 R71 R75

C18

C20

CN3

R43

CLIP DETECT Q24

U1

Q23

R79

R80

R78

C8

R45

D18

R46

R47

R85 R91
R89

SPKR TEST

R83
R82 Q31

OVERTEMP

CN2

R86 R90 R88

R87

R41 CN1

D19 D20

FIX1 R48

D22

D21

To enhance viewing, please print to A3 AP16693/5 Power Amp PCB Board Layout (Top Side)

35

Cambridge Audio Azur 840A Amplifier

To enhance viewing, please print to A3AP16693/5 Power Amp PCB Board Layout (Bottom Side)

36

Cambridge Audio Azur 840A Amplifier Power Amp Left PCB BOM

AP16696/9

AP N o

Value
RESISTORS 10R 100R 910R 4K7 10K 22K 47K 100K 1M 10R 18R 56R 68R
100R
150R 470R 1K 1K1 1K2 1K8 2K2 2K7 3K3 3K6 10K 16K 22K 47K 56K 75K 100K 33R 470R 0R1 1R5
2R2
10R
220R
CAPACITORS
100pF
100nF
100nF
10uF
22uF

Description/T ype
0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film
0.25 W Metal Film
0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 1W Metal Film 1 W C arbon Pitch = 18mm 3 W Wire Wound 3 W Wire Wound
3 W Wire Wound
3 W Wire Wound
3 W C arbon Pitch = 22.5mm
Ceramic 100V 10% Pitch= 3mm Ceramic 100V 10% Pitch= 5mm
Polyester 10% Pitch= 10mm
16V Non Polarised Electrolytic Radial (5.2mm) Pitch= 2.5mm 50V Non Polarised Electrolytic Radial (5.2mm) Pitch= 2.5mm

Q ty

C omponent Ident

N otes

1 R87

3 R86, R90, R91

1 R70

6 R36, R42, R46, R68, R75, R89

3 R69, R83, R85

1 R48,

4 R43, R44, R45, R50

2 R37, R88

1 R71

2 R1, R32,

1 R12

1 R9

3 R3, R6, R7

R2, R4, R5, R14, R17, R18, R23, 10
R24,

1 R62

3 R30, R58, R59

4 R52, R53, R63, R80,

2 R60, R61

1 R11,

1 R10

4 R8, R13, R27, R56

2 R74, R76

1 R34

1 R33

4 R16, R51, R64, R66,

3 R49, R54, R55

4 R15, R57, R67, R81

5 R35, R47, R65, R73, R82

1 R73

1 R72

2 R78, R79,

1 R38

Space off PC B

1 R41

Space off PC B

6 R19-R22, R25, R26

Space off PCB

1 R31

Space off PC B

1 R28

Inductor damping res. No need to stand off PCB

1 R29

ZO BEL RES. Space off PC B

1 R40

Space off PC B

2 C10, C14 1 C18 1 C2 1 C20

1 C3

Note: resistors, capacitors and other 'generic' electronic components are not usually stocked by the manufacturer. Please obtain these locally.

37

Cambridge Audio Azur 840A Amplifier Power Amp Left PCB BOM

AP16696/9

AP N o

Value

Description/T ype

Q ty

C omponent Ident

N otes

47uF 47uF 220uF 220uF 1000uF 1000uF 15000uF

35V Electrolytic Radial (10mm) Pitch= 2.5mm 16V Electrolytic Radial (5mm) Pitch= 2.5mm 80V Electrolytic Radial (10.4mm) Pitch= 5mm 100V Electrolytic Radial (12.5mm) Pitch= 5mm 10V Electrolytic Radial (10.4mm) Pitch=5 mm 50V Electrolytic Radial (13.4mm) Pitch= 5mm 63V Electrolytic Radial (35.4mm) Pitch= 10mm

SEMICONDUCTORS

1 C7 3 C1, C8, C9 2 C4, C5 1 C17 1 C6 1 C11 2 C12, C13

PY1152 LM393AP

Dual differential comparator, A-version for low offset voltage

1 U1

D IL08

TRANSISTORS

PY1148 PY1150
PY021

MJE340 MJE350
MPSA93

NPN Power Transistor PN P Power T ransistor
PNP High Voltage

PY013
PY214 PY1149 PY1147

MPSA43

NPN High Voltage

BC 337-25 2SA1295 2SC3264
DIODES

N PN Small Signal PNP Power Audio NPN Power Audio

1N4148

Small Signal Diode

1N 5404 1N4002 ZENER 12V 400mW

General Pupose Rectifier General Pupose Rectifier
Zener BZX79-C12

MISCELLANEOUS

4 Q1, Q12, Q18, Q30

TO126

1 Q2

T O 126

Q3-Q6, Q20, Q22, Q24, Q27-

11

TO92WIDE MPSA92 may be used

Q29, Q31

Q7-Q10, Q19, Q21, Q23, Q25,

9

TO92WIDE MPSA42 may be used

Q26

1 Q 11

T O 92

3 Q13, Q14, Q17

MT200

2 Q15, Q16

MT200

D1-D6, D8, D10-D13, D1718
D20, D23-D25 2 D7, D9 3 D15, D21, D22
2 D14, D16

DO 27 DO41
400mW DO35 Case.

ZP221A501E PO SIT IVE T HERMIST O R

1 TH1

MULTITURN PRESET 1K

Top adjust. Footprint 9.5 x 4.5 mm

1 VR1

MULTITURN PRESET 10K

Top adjust. Footprint 9.5 x 4.5 mm

1 VR2

FFC CONNECTOR 16-WAY,

PY1151 D100-SSV-16 Vertical "Reverse needle" type, 2 CN2

Single row of contacts

T1A AL

1 Amp 20mm antisurge fuse

1 F1

N ominal operating temp 100 deg C Set quiescent current. Insert so adj screw next to R12 DC trim Insert so adj screw next to R78

4031-050100-001 Fuseholder 20mm

1 F1

08-1950100-150 1.7uH 10A INDUCTOR

AP16831/3

To drawing Main heatsink

1 L1 1 Q13, 14, 15, 16, 17

10 turns of 1.5mm copper wire, diameter 20mm, length approx 20mm

Note: resistors, capacitors and other 'generic' electronic components are not usually stocked by the manufacturer. Please obtain these locally.
38

Cambridge Audio Azur 840A Amplifier

INPUT 1: BALANCED INPUTS

INPUT 1 RIGHT + INPUT 1 RIGHT -
XLR GND XLR GND INPUT 1 LEFT + INPUT 1 LEFT -

CN5
1 2 3 4 5 6

JST 2,5MM B6B-XH-A
CONN TO INPUT PCB

XLR FEMALE

CN8

1+G GND + 2
-

RIGHT

3

XLR GND

XLR FEMALE
CN7
1+G GND + 2
-

LEFT

3

36K

RIGHT

SIG GND

LOOKING AT LEADS

IN

OUT

78L12

R55

R28

10K

10K

C37
220U 25V EL

C19
220U 25V EL

ABUS GND

C27
47U 25V
C20

47U 25V

ABUS GND
R26
4K7
R14
4K7

HUB - INPUT PCB CONN

CN3

HUB IN L HUB IN R

1 2

SIG GND SIG GND
+5V

3 4 5 6

LOGIC GND

7

SWITCHER DATA OUT SWITCHER CLOCK OUT

8 9

10

SWITCHER STROBE OUT

LEFT

+5V

36K

R59 R60

47K

47K

FFC 10WAY

LOGIC GND +5V
C6

C26
47U 25V

R27
4K7

C21

R4

4K7 47U 25V

14

C10
10uF 16V

C23
100nF

LOGIC GND

MCLR HUB

VDD

RA7/OSC1/CLKIN

RA0/ANO

16

17

RA6/OSC2/CLKOUT

RA1/AN1

15

18

RA2/AN2/VRef

1

RA5/MCLR/THV RA3/AN3/COMP1

4

2

RA4/T0CKI/CMP2

3

RB0/INT

6

RB1/RX/DT

7

RB2/TX/CK

8

RB3/CCP1

9

RB4/PGM

10

RB5

11

RB6/T1OSO/T1CKI

12

RB7/T1OSI

13

5 VSS

U5

PIC16F627-04/P

HUB CLOCK OUT HUB DATA OUT

STATUS

PROGRAM_DATA PROGRAM_CLK

+5V

+5V

1

2

3

+5V
R34
47R

CA IR DEMODULATOR

U6 36 kHz

D1

TSOP1836 IR RECEIVER A

+5V

GND

OPT

IR receiver K

R44
220R

LOGIC GND

R58
10K
PGM

IR IN
3.5mm JACK
JACK-CKX-3.5-12
CN9

R19
47R

C17

C18

100nF

10uF 16V

100nF
R12 100R
SIG GND

ABUS GND

+24V IN
R56
390K +24V DETECT
R57
100K
LOGIC GND

R11
22K

+12V

R10
10K
R9
4K7
Q2
BC337

Q1
BC327
R7
100R
R8
100R
R42
10K

CA IR DEMODULATOR

ABUS GND

STATUS LINE DRIVER

R43
10K

C25
47U 25V
C22
47U 25V

R40
4K7
R32
4K7

C28
47uF 25V
C24
47U 25V

R41
4K7
R33
4K7

C29
100nF

C31
10uF 16V

LOGIC GND

U7:A

1

IR IN

3

2

4011 VDD=+5V

5

IR IN

CN10:A

AV2-8,4-14/EC R45
1

2

220R

U8
1

LOGIC GND 6

5

2

3

4

NC

OP4N25

R46

220K

+5V

R51
10K
R47
10K

CN15

TX

1

RX

2

GND

3

4

GND

5

6

7

8

9

BLOCK

10

PIC TX

11 12

13

LOGIC GND IR IN

RS232 CONN CN16

1 2

TX R48
RX

3

GND 10K

4

CHAS

Q4
BC337

PGM

CONN-2.5PH-SIL4

MCLR HUB

FEMALE

PROGRAM_DATA

PROGRAM_CLK

LOGIC GND

HUB DATA OUT HUB CLOCK OUT

C30
100nF CERAMIC

FFC 13WAY RS232 & IR CABLE FROM FRONT PANEL PCB

LOGIC GND

Q6
BC337

R53
100K
R54
10K

R52
10K
Q5
BC337

LOGIC GND

3

2

IR

1

U4

+5V GND OPT
IR receiver

TSOP1837 IR RECEIVER
37 kHz

U7:D
12
13
4011 VDD=+5V
U7:C
8
9
4011 VDD=+5V

5 4
6

4011

U7:B

VDD=+5V

VSS=LOGIC GND

11
R50
100R

IR OUT CN10:B
AV2-8,4-14/EC 3
4

5

10
C39
1N 50V NP0 CHASSIS GND
C11
100nF

LOGIC GND

R49
2R2

A
K
D2

D5
1N4148
D6
1N4148

R20

R21

470R

10K

ABUS GND

D7
BZX79C2V7
D8
BZX79C2V7

+12V
Q3
BC337
R39
4K7
ABUS GND

+12V
C8
10uF 25V
R6
12K

U2
7812 3 VO
C7
100nF

+24V

VI

1

2 GND

+24V

ABUS GND
C1

+24V IN

R13

D3

F3

C910R 2W 1N4004
220U 35V EL

POLYFUSE 1-1A

2 CN2
1
C32
100n3F RICCO PCB JACK
+24V IN

8

R29
12K
R30
12K
R31
12K

100nF

3

U1:A

1

2

NE5532

4

ABUS GND
R5
12K
C3
10pF
U1:B
5 7
6 NE5532
R3
12K
C2

ABUS GND
R1
47R
RIGHT
ABUS GND
R2
47R
LEFT
ABUS GND

C4
10uF 25V
C33
47pF
C5
10uF 25V
C34
47pF

10pF +24V
C12

8

100nF

3

U3:A

1

2

NE5532

4

ABUS GND
C14
10pF
R18
12K
U3:B
5 7
6

R17

NE5532

12K
C13

ABUS GND
R15
47R
RIGHT

C15
10uF 25V
C35
47pF

ABUS GND

R16
47R
LEFT

C16
10uF 25V
C36
47pF

ABUS GND

A-BUS A
TOP OF CONN

POLYFUSE 1-1A
F1

CN1:B

9

GND

10

L

11

GND

12

IR

13

STATUS

14

R

15

0V

16

+24V

VERT2RJ45

CN1:C

17 GND

18

GND2

19

GND3

20

GND4

21

GND5

22

GND6

VERT2RJ45

CHASSIS GND

POLYFUSE 1-1A
F2

CN1:A

8

GND

7

L

6

GND

5

IR

4

STATUS

3

R

2

0V

1

+24V

VERT2RJ45

A-BUS B
BOTTOM OF CONN

10pF

R22
100R
R23
100R
R35
100R
R36
100R

R24

R25

27K

27K

ABUS GND

R37

R38

27K

27K

ABUS GND

CN4
IR EMITTER OUTPUTS
1 2
CN6
IR EMITTER OUTPUTS
3 4

To enhance viewing, please print to A3

AP163771/3 Hub PCB Schematic

39

Cambridge Audio Azur 840A Amplifier

CHAS GND RX TX

AP16378/3

RS232
AP16378/3

To enhance viewing, please print to A3

AP16377/3 Hub PCB Layout (Top Panel)

40

Cambridge Audio Azur 840A Amplifier

To enhance viewing, please print to A3

AP16377/3 Hub PCB Layout (Bottom Panel)

41

Cambridge Audio Azur 840A Amplifier Hub Board BOM

AP16380/5

AP No

V alue

D escr iption/T ype

Qty

C omponent Ident

N otes

RESISTORS 47R
4K7

10K
12K 22K 27K 100K 390K 2R2 47R
100R
220R 470R 4K7 10K 47K 10R CAPACITORS 10pF 47pF
100nF

10uF

10uF

47uF

220uF

PY259 PY1144

220uF
SEMICONDUCTORS N E5532
CD4011BE
7812 O P4N 25

PIC16F627 -04/P

PY1007 PY755 PY219 PY214
PY962

T SO P34837 T SO P34836 TRANSISTORS BC 327-25 BC 337-25 DIODES 1N4004
MV50640
1N4148 BZX79C2V7 MISCELLANEOUS AJ-600-21-F-4-B RDC-020-05 C KX -3.5-10 JY-5033P*030 CKX-3.5-12

0.125 W Metal Film
0.125 W Metal Film
0.125 W Metal Film
0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.125 W Metal Film 0.25 W Metal Film 0.25 W Metal Film
0.25 W Metal Film
0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 0.25 W Metal Film 2 W Wire Wound

4 R1, R2, R15, R16

R4, R9, R14, R26, R27, R32, R33, 9
R40, R41

R10, R28, R42, R43, R47, R48, R51, 10
R52, R54, R55

8 R3, R5, R6, R17, R18, R29-R31

1 R11

4 R24, R25, R37, R38

2 R53, R56

1 R57

1 R49

2 R19, R34

R7, R8, R12, R22, R23, R35, R36, 8
R50

2 R44, R45

1 R20

1 R39

3 R21, R51, R58

2 R59, R60

1 R13

Space off PC B

C eramic 50V 10% Pitch = 3mm C eramic 50V 10% Pitch = 3mm
C eramic 50V 10% Pitch = 5mm
16V Electrolytic Radial (6.4mm) Pitch =2.5mm 25V Electrolytic Radial (6.4mm) Pitch =2.5mm 25V Electrolytic Radial (5.2mm) Pitch =2.5mm 25V Electrolytic Radial (5.2mm) Pitch =2.5mm 35V Electrolytic Radial (8.4mm) Pitch =3.5mm

4 C 2, C 3, C 13, C 14 4 C 33-C 36
C1, C6, C7, C11, C12, C17, C23, 10
C29, C30, C32 3 C10, C18, C31
5 C4, C5, C8, C15, C16
8 C20-C22, C24-C28
2 C19, C37
1 C9

Low noise dual O p Amp

2 U1, U3

Texas Instruments Quad NAND gate 1 U7
IC

12V, 1A regulator, T O 220

1 U2

O ptoisolator

1 U8

PIC Microcontroller

1 U5

37Khz IR Receiver Module 36Khz IR Receiver Module

1 U4 1 U6

D IL08
Alternative is N ational semi C D4011BC N
T O 220 D IL06 DIL18 Contact Audio Partnership Service Department T SO P18V (Replaces T SO P1837) T SO P18V (Replaces T SO P1836)

PN P Small Signal N PN Small Signal

1 Q1 5 Q 2-Q 6

T O 92 T O 92

General Purpose Rectifier diode Red LED Small Signal Diode Zener Diode 2.7 Volts

1 D3 2 D1, D2 2 D5, D6 2 D7, D8

NO ALTERNATIVE LED TO BE USED Fitted as part of assembly with AP17339/3

Allsun Dual vertical RJ45 DC power in connector Dual 3.5mm jack socket (green) Female XLR socket with gold pins Single 3.5mm jack socket (black)

1 CN1 1 CN2 2 C N 4, C N 6
2 CN7, CN8 1 CN9

IR EMIT T ER O UT PUT S

Note: resistors, capacitors and other 'generic' electronic components are not usually stocked by the manufacturer. Please obtain these locally.

42

Cambridge Audio Azur 840A Amplifier Hub Board BOM

AP No

V alue

D escr iption/T ype

AV2-8,4-14/EC
PY1143 D100-SSV-10
PY1142 D100-SSV-13 C O N N -2.5PH-SIL4 C O N N -2.5PH-SIL6 AP17339/3 PO LYFUSE 1-1A

Dual phono socket with EMC gnd Orange inserts Vertical FFC conn, reverse-needle type single-row contacts 10-way Vertical FFC conn, reverse-needle type single-row contacts 13-way JST vertical header type X H JST vertical header type X H IR Receiver Housing
RLD 30P110U

Qty

C omponent Ident

1 CN10

1 CN3

1 CN15
1 C N 16 1 CN5 2 Fit over D2/U4 and D1/U6 3 F1, F2, F3

AP16380/5
N otes
For RS232 conn cableform For balanced input POLYFUSE 1.1A 30Vdc 7.4*14.2*3MM 6.6Sec

Note: resistors, capacitors and other 'generic' electronic components are not usually stocked by the manufacturer. Please obtain these locally.
43

Cambridge Audio Azur 840A Amplifier

230 V 1

MAIN TRANSFORMER
BROWN

Primary

0V 2

BLUE 115 DEG C

RED 5.5A

J1

1

36 V TERMINAL

RED

F1
T6A3 AL LVD!

ORANGE
Secondary YELLOW
5.5A
GREEN 100 mA
RED 5.5A

2 0V

J2 ORANGE
TERMINAL

3 36 V J3
TERMINAL
YELLOW

F2
T6A3 AL LVD!

4 38 V

1 36 V

C3
10nF

4

C1

C2

10nF

10nF

ORANGE

2 0V

Secondary

YELLOW 5.5A

3 36 V

TO POWER AMP SUPPLY RIGHT

GREEN 100 mA

4 38 V

3

1

BR1
2 BRIDGE BR-254

J4
+48V OUT
TERMINAL VIOLET
J6
TERMINAL GREEN
J5
-48V OUT TERMINAL
BLUE

To enhance viewing, please print to A3

AP17575/2 Rectifier PCB Schematic

44

Cambridge Audio Azur 840A Amplifier

AUDIO PARTNERSHIP 2005

To enhance viewing, please print to A3AP17575/2 Rectifier Board PCB Board Layout (Top Side)

45

Cambridge Audio Azur 840A Amplifier

To enhance viewing, please print toAAP3 17575/2 Rectifier Board PCB Board Layout (Bottom Side)

46

Cambridge Audio Azur 840A Amplifier, Rectifier PCB BOM

AP No

Value

Description/Type

CAPACITORS 10nF X1 Capacitor DIODES

MEX103K300A02 Pitch =10mm

Qty

Component Ident

3 C14-C16

Bridge Rectifier BR254 400PIV 25A blk metal case

1 BR1

MISCELLANEOUS T6A3 AL 4031-050100-001

6.3 Amp 20mm anti surge Fuse, low breaking 2
capacity

Fuseholder 20mm

2

F1, F2 F1, F2

Notes

AP17578/2

Rectifier is not soldered to PCB until PCB is fixed to amplifier heatsink

Note: resistors, capacitors and other 'generic' electronic components are not usually stocked by the manufacturer. Please obtain these locally.
47

Cambridge Audio Azur 840A Amplifier IC Pin Layout Details
TC9163AF ­ Input PCB (U1)
NE5532 Input PCB - (U2, U3, U4, U5, U6, U7, U8, U9, U14 & U18) A-BUS PCB ­ (U1 & U3) Pre-Amp PCB ­ (U1, U2, U9 & U12) ULN2003A Input PCB - (U16) Pre-Amp PCB ­ (U4, U5 & U7)
BC337 Input PCB - (Q1) Pre-Amp PCB ­ (Q2, Q3, Q4 & Q5) Front Panel PCB ­ (Q2, Q3, Q4 & Q5) Right Hand Power Amp PCB ­ (Q11, Q31, Q32, Q33, Q34, Q35 & Q36) A-BUS PCB ­ (Q2, Q3, Q4, Q5 & Q6) Left Hand Power Amp ­ (Q11) TSOP18 Pre-Amp PCB - (U10)
PIC16F877A-I/SP Front Panel PCB
48

74HC4094 Front Panel PCB - (U2, U3, U4, U5 & U6)
BC327 Front Panel PCB - (Q1 & Q8) A-BUS PCB ­ (Q1)
LM393AP Right Hand Power Amp PCB - (U1) Left Hand Power Amp PCB ­ (U1)
MJE340 Right Hand Power Amp PCB - (Q1, Q12 & Q18) Left Hand Power Amp PCB ­ (Q1, Q12, Q18 & Q30)
MJE350 Right Hand Power Amp PCB - (Q2) Left Hand Power Amp PCB ­ (Q2)
MPSA93 Right Hand Power Amp PCB - (Q3, Q4, Q5 Q6, Q20, Q22, Q24, Q27, Q28 & Q29) Left Hand Power Amp PCB ­ (Q3, Q4, Q5, Q6, Q20, Q22, Q24, Q27, Q28, Q29, Q31)
MPSA43 Right Hand Power Amp PCB - (Q7, Q8, Q9, Q10, Q19, Q21, Q23, Q25 & Q26) Left Hand Power Amp PCB ­ (Q7, Q8, Q9, Q10, Q19, Q21, Q23, Q25, Q26)
49

2SA1295 Right Hand Power Amp PCB - (Q13, Q14 & Q17) Left Hand Power Amp PCB ­ (Q13, Q14 & Q17)
2SC3264 Right Hand Power Amp PCB - (Q15 & Q16) Left Hand Power Amp PCB ­ (Q15 & Q16)
CD4011BE A-BUS PCB - (U7)
7812 A-BUS PCB - (U2)
OP4N25 A-BUS PCB - (U8)
PIC16F627-04/P A-BUS PCB - (U5)
TSOP34837 A-BUS PCB - (U4)
TSOP34836 A-BUS PCB - (U6)
50

AP16396/2 Azur 840A Amplifier Technical Description

Start: Updated:

11 Aug 05 Version 2 29 Nov 05

Revision history V1->V2 More info added to operating instructions summary

This document gives a concise guide to the operation of the 840A XD amplifier.

CONTENTS

Azur 840A power supply PCB

AP16373/3_B

Azur 840A front panel PCB

AP16369/3

Azur840A input board PCB

AP16361/3

Azur 840A preamp PCB

AP16365/3

Azur 840A power amp Left PCB AP16693/4

Azur 840A power amp Right PCB AP16373/3_A

Azur 840A A-BUS Hub PCB

AP16377/3

Azur 840A Rectifier PCB

AP17575/2

Operating instructions summary

Service Menu

---==========================================---

NOTES Logic signals are in upper case, thus; MAINS FAIL References to "the PIC" or "the main PIC" are to the main housekeeping PIC on the front panel PCB unless otherwise stated.

51

The Power Supply PCB This carries:
Power supplies for everything except power amps Mains on/off and inrush control switching relays X2 capacitor The mains-fail detect circuit
There are four power supply rails:
+15V Opamp supply -15V Opamp supply +9V Relay supply +5V Microcontroller, logic and comparator supply

The power supply board also carries the mains switching relays that control the supplies to the power amplifiers. When the amplifier goes from standby to ON, the inrush control relay RL4 closes first with R78 limiting the inrush current. After 3 seconds (while speaker-short testing is going on- see below) the On/Off relay RL3 closes. 100 msec later (to ensure no break in the supply) RL4 opens. When the amplifier goes from ON to standby, RL3 simply opens.

The front panel PCB This carries:
The main PIC The volume rotary encoder and control switches. The LCD display Shift registers for driving the relays The RS232 interface for control and software updates

U1 is the main housekeeping microcontroller for the amplifier; it is a 16F977A PIC running at 20 MHz. It handles all the control functions of the amplifier except for those on the A-BUS hub PCB, which are dealt with by another PIC on that board.

PIC pins handling amplifier conditions:

Speaker short-circuit detect Phones detect Mains fail DC offset protection Overtemperature protection Overload protection Clip detection

Pin Normal 7 LOW
27 HIGH 28 LOW 29 HIGH 30 HIGH 33 HIGH 34 HIGH

Active HIGH Active= short found LOW Active= Phone jack in HIGH LOW LOW LOW LOW

The LCD display module interfaces to the front panel PCB through CN2. Display data from the PIC is clocked serially into shift register U2 and sent to the LCD module in byte-wide parallel format. The LCD module is powered from the +5V rail.

52

The relays on the other PCBs are controlled by a set of shift registers that convert serial data from the PIC into 32 latched outputs. Four shift registers (U3,U4,U5,U6) are connected so that the serial input enters the first register and is clocked through and out of its serial output into the serial input of the second register. Changing any output requires 32 bits to be clocked through the registers by the SERIAL CLOCK signal. When SERIAL STROBE goes high the data is latched in each register to give a static output. Data appears at the outputs only when the SHIFT REG ENABLE line is high. This line is kept low at start-up to prevent random data at the outputs, and only goes high when the PIC has initialised the shift registers.
The RS232 interface is used to control the amplifier and can also be used to reprogram the main PIC. The interface consists of Q3 and Q4. Q3 handles incoming RS232 data, providing a level-shift from RS232 levels (nominally +/-9V) to PIC levels (+5V/0V). Q4 handles outgoing RS232 data, level shifting it to give a +15V/0V output.
The main PIC is reprogrammed by holding the standby/ON button in when the mains power is turned on. The word DOWNLOAD appears on the LCD. A PC running a Windows program is used to download the program.
The Hub PIC can in turn be reprogrammed by the main PIC. This is done by the PGM, MCLR HUB, PROGRAM_DATA, and PROGRAM_CLOCK lines that go to the Hub PCB via CN3.
The Input PCB The input PCB carries:
Input buffers Input select relays Tape out buffer Input amplifier +6 dB Hub input switcher Relay drivers
The input PCB has one stereo input (Input 1) that accepts both balanced and unbalanced signals, and six more unbalanced stereo inputs. There is a further input for tape monitor use. There is a tape output, taken from before the tone and volume controls, and a preamp output taken from after the tone and volume controls.
All component numbers here refer to the Left channel.
The A-BUS hub also uses the amplifier inputs. The required input is selected separately from the main amplifier input by the CMOS switching IC U1. This is controlled by serial data from the microcontroller on the hub PCB, in response to switch presses or IR commands.
The relays are driven from an 8-bit serial-in parallel-out (SIPO) shift register on the front panel PCB. The eight logic signals come in on CN8 and control the 7-way open-collector relay driver U16. The eighth relay is controlled by Q1.
53

The Preamplifier PCB The preamplifier PCB carries:
The tone controls and DIRECT switch Relay balance control Balance control buffer Amplifier Relay volume control Volume control post amplifier Relay drivers ON/standby LED control The IR receiver Headphone socket

All component numbers here refer to the Left channel.

The balance control operates in discrete steps selected by relays. There are eight steps on each side of the central position. This is implemented by switching in combinations of three attenuator sections; the first is R97,R22,R105, the second R85,R87 and the third R88,R86,R89. These are switched in or out by relays RL17, RL18 and RL19. When none of these relays are energised the balance network gives the first step of attenuation due to R97. When RL15 is energised the balance attenuator network is inserted into the left channel and the stereo image is shifted to the right. When RL16 is energised the balance attenuator network is inserted into the right channel and the stereo image is shifted to the left.

The balance control attenuation steps are:

Step Nominal

dB

0

0

1

-1.3

2

-2.5

3

-3.4

4

-4.5

5

-5.5

6

-6.8

7

-7.7

8

-8.8

The volume control is a relay-driven stepped attenuator that gives 1 dB steps from 0 dB to -64 dB. There are 2 dB steps from -64 dB to -76 dB, and two final steps of -84 dB and -infinity. The final step also opens the power amplifier output relays to ensure that "off" is well and truly off, The volume control has an array of 14 resistances connected to an output rail. Each resistance is connected to either the input signal rail or ground by its associated relay. (RL1 to RL14) The resistances are typically made up two resistors to obtain the exact desired value. This represents a potential divider that allows very fine control of attenuation. The 1 db steps are accurate to within +/-0.2 dB. The volume network has a constant output impedance of 312 Ohms, independent of volume setting. The volume setting is stored in non-volatile memory when the unit is switched off at the mains. The volume control can be set to ramp up from zero to the stored setting at power-up, and to ramp down on going to standby; this is an option on the configuration menu.

54

The volume control and balance relays are driven from three 8-bit serial-in parallel-out (SIPO) shift registers on the front panel PCB. The logic signals come in on CN6, CN8 and CN9, and control the 7way open-collector relay drivers U4,U5,U7. Driver U7 also controls the mains on/off and inrush relays, (on the PSU PCB) the two amplifier output relays, (on the right amplifier PCB).
R111 is a pull-up resistor which allows MAINS ON/OFF RELAY to go high during testing if the PSU board is not being used to power front-panel and preamp PCBs, and thus permits the LED control to work properly in this condition.
Headphone socket The phones Left and Right signals come in from the two amplifier PCBs. When a jack is inserted in to the phones socket, the normally-closed contacts open, and the PHONES DETECT signal goes low, signalling the PIC to open the output relays and disconnect the loudspeakers.
Power Amplifier PCBs The power amplifier boards are very similar. The left channel is described in detail, and the right channel description deals only with the differences.
Power Amplifier Left PCB This description is subdivided as follows:
Input stage DC trim system. The Voltage Amplifier Stage Biasing system Output stage The XD Crossover Displacement system Power supplies Overload protection Clip detection DC offset protection Over-temperature protection Speaker short-circuit detection Headphone output attenuator
DC trim system. VR2 and its associated components make up the DC trimming network; this allows to output DC offset to be reduced to less than 1mV.
The XD Crossover Displacement system.
The essence of the Crossover Displacement principle is the injection of an extra current, varying with the signal, into the output point of a conventional Class-B output stage, with the result that the crossover point is displaced away from the no-signal voltage. The displacement current is made proportional to the output voltage. For example, if the displacement current is 1 Amp with the output at quiescent at 0V, it is set to increase to 2 Amps with the output fully negative, and to reduce to zero with the output fully positive.
55

The XD control circuit is a differential pair of transistors with one input grounded and the other driven by the main amplifier output voltage, scaled down appropriately by R63, R64. The drive to the displacer is taken from collector load R58, to give the required phase inversion. R59 is present simply to equalise the dissipation in the differential pair transistors to maintain their balance. The tail of the differential pair is fed by constant-current source Q27. Since half of the standing current through the differential pair flows through R58, the value of the tail current-source sets the quiescent displacement current. Q27 is a simple current-source biased by silicon diodes D12, D13. The displacement current itself is handled by the voltage-controlled current source Q18, Q17. The Q18, Q17 structure acts as a unity-gain voltage stage with 100% voltage feedback from Q17 collector to Q18 emitter, and it sets up the voltage across R58 as a voltage across the low-value resistor R31, minus the Vbe drop of Q18.
There is provision for turning off the XD system under PIC control, to make servicing easier. This is done by Q26. Normally the XD ON/OFF signal coming in on Pin 9 of CN2 is high, (+5V) so Q31 is held off and Q26 is off. When XD is disabled, XD ON/OFF goes low and Q31 is turned on via R83. Q26 is then turned on via R82. The equivalent to Q26 on theright power amp PCB is also turned on by the connection through Pin 10 of CN1.
Power supplies The power supply for the power amplifier consists of three rails. The voltages given here are nominal as they depend on the exact value of the mains supply voltage
The +48V rail supplies all the positive power to the amplifier.
The -48V rail powers only the amplifier output stage, including the XD Crossover Displacement system.
The -51V rail provides negative power for the small-signal circuitry. This permits greater output as without it the negative-going voltage-swing of the voltage-amplifier stage is limited, and negative clipping occurs before positive clipping.
Overload protection. The amplifier is protected against short-term overloads by dual slope VI limiting. The upper half of the output stage is protected by Q19 and associated components. When overload occurs Q19 conducts and shunts current away from the base of Q1, limiting the amplifier output. The current so shunted is limited in magnitude by the current-source Q4. D2 prevents Q19 conducting backwards on negative output excursions. The protection of the lower half of the output stage is very similar, Q20 being the VI limiter. However, in this case the current shunted away when Q20 conducts is not inherently limited; this is done by the extra current-limiting circuit Q11, R15, R16. When the voltage across R9 becomes excessive, Q11 turns on and shunts the base drive away from Q9.
The amplifier is protected against long-term overloads by the PIC opening the output relay. Operation of the VI limiter Q20 draws extra current through R9 and turns on Q25 via R49; this happens at a lower current than that at which Q11 limits the VAS current.
Q25 collector is wire-ORed with the equivalent transistor on the right-hand amplifier PCB, and the OVERLOAD SIGNAL goes to the preamp PCB via CN2, pin6.
56

Clip detection. When it is enabled, the clip-detect system turns down the volume when excess clipping of either amplifier output occurs. Very brief episodes of clipping are ignored. The volume stays reduced and does not ramp back up in the absence of clipping. The clip detect system is based on Q23, Q24 and associated components. Normally both transistors are on, and the CLIP signal at Q24 collector is high.

Since the circuit operates by monitoring how far the output is from the supply rails, variations in supply voltage are compensated for.

DC offset protection:

The output of the Left amplifier is filtered by R35 and C3 to remove audio content. If a DC voltage of

either polarity exists Q21,Q22 turn on and the voltage on Q21 collector falls. This point is wire-ORed

with the DC offset detector voltage on the right power amplifier PCB via CN1.

Detailed operation is as follows:

+ve DC offset:

D4, Q21, Q22, D6 conduct. Other diodes reverse-biased.

-ve DC offset:

D3, Q21, Q22, D5 conduct. Other diodes reverse-biased.

Overtemperature protection Positive thermistor TH1 is mounted on the main amplifier heat-sink. At approx 100degC, its resistance has risen to the point that the voltage on pin 6 of comparator U1:B exceeds the reference voltage of +850 mV set up by R69,R70, and the comparator output goes low to 0V. R71 provides a small amount of hysteresis to give clean switching. The comparator has an open-collector output and R75 is the external pull-up resistor. The output signal is passed to the main PIC.

Speaker short-circuit detection When the amplifier goes from standby to ON, the speaker outputs are checked for short-circuits before the output relays are closed. This system is centred on comparator U1:A but also involves circuitry on the Right Amplifier PCB. Short-circuits are checked for by passing a small current through the loudspeaker impedances and monitoring the resulting voltage. A DC current of 5mA is injected through R101 on the Right Amplifier PCB, via the normally-closed contacts of RL1 and RL2. This places all connected loudspeakers, left and right, A and B, in parallel so the resulting voltage is not large. It is sent to the left amplifier PCB, where comparator U1:A compares it with a reference voltage of 5mV set up by potential divider R85,R87. If the combined loudspeaker resistance is below 1 Ohm, the output of U1:A goes high, signalling a short condition to the main PIC.

Headphone output attenuator The headphone output attenuator comprises R40 and R41. The headphone socket is on the preamp PCB.

Power Amplifier Right PCB This description is subdivided as follows:

The right power amplifier The output relays Output relay control system Mains-fail detect system

57

The right power amplifier and its various protection systems operate identically to those on the left amplifier PCB, except for the following differences:
Mains-fail detect system The mains-fail detect system is based on comparator U1:B. It takes the MAINS FAIL IN signal from the PSU board (see above) and compares it with a reference voltage of +310 mV set up by potential divider R81,R80. When MAINS FAIL IN drops below this threshold, the output goes high. This signal, MAINS FAIL, is sent to the PIC via CN1, pin 9.
A-BUS Hub Board This board carries the following functions:
The XLR sockets for the balanced input mode of Input 1 Two A-bus outputs Hub IR input Hub microcontroller Hub Power supply IR in/out interface
The XLR sockets simply pass the Input 1 signals down to the input board via screened cables.
The A-bus outputs take an input selected by the hub input switcher, amplify it by 2.5 times, and send it to the remote keypads. R59,R60 are DC drain resistors that minimise clicks shortly after power-up. The output amplifiers U1,U2 work from a single +24V rail, and so are biased to sit at +12V. The bias supply is derived from the +12V supply rail.
The hub amplifiers have their own ground (ABUS GND) to prevent ground loops, and this use of the differential amplifier performs a change of reference so a clean signal reaches the hub amplifier seven if the two grounds have noise voltage between them.
The hub microcontroller U5 is a PIC16F72. This performs the following tasks: Control Hub input switcher from IR commands Send input select data to main PIC Control Hub input switcher to prevent thumps on 840A output Control A-bus status line
IR commands to the A-bus keypads are sent to the hub so that the required input can be selected and external equipment controlled. Thus, for example, a tuner station can be changed from the keypad; the IR comes to the hub, is sent out again via the IR emitter outputs, and activates emitters pointing at the tuner unit. Modulated IR signals coming in from the keypads are diode-ORed together by D5, D6. The Zener diodes D7, D8 reject low-level noise on the incoming IR lines. The combined IR signals are buffered by emitter-follower Q3, and sent out via CN4, CN6 to drive external IR emitters. Incoming modulated IR signals for input select are also sent to the Hub PIC U5; LED D2 is driven from Q3, and points at IR receiver U4, the pair being housed in a small light-tight enclosure. The demodulated IR is then applied to Pin 7 of Hub PIC U5, which sends appropriate commands to the hub input selector IC on the input PCB, over the strobe, clock and data lines.
58

Information on which Hub input is selected (or if no input is selected) is sent from the Hub PIC to the main PIC by the two lines HUB CLOCK OUT and HUB DATA OUT. This is then displayed on the LCD. The active 840A input is denoted by a round marker; the active Hub input is denoted by a circle around it.

The Hub PIC controls the A-bus status line so that it is high when the 840A is powered and low when it is not. It also implements the "all off" feature; when this command is received from one keypad the Hub PIC ensures that both are turned off.

The Hub PIC can be reprogrammed by the main PIC. This is done by the PGM, MCLR HUB, PROGRAM_DATA, and PROGRAM_CLOCK lines that come from the front panel PCB via CN15.

IR in/out interface The other IR system on the Hub PCB is wholly concerned with control of the 840A amplifier itself, and has no connection with the Hub IR system. Modulated IR data (as an electrical signal) enters via 3.5mm jack CN9, and drives LED D1, which illuminates IR receiver U6, the pair being housed in a small light-tight enclosure. This demodulates the IR and passes it on to U7:A, which ORs it with the data from the unmodulated IR input, and sends the IR IN signal to the main PIC via CN15. When it reaches the front panel PCB (see above) it is further ORed with the IR data from the receiver on the front of the 840A unit. The unmodulated IR signals enter via phono connector CN10:A, and drive optocoupler U8; this isolates the grounds and prevents ground loops. The optocoupler output drives Q4 through R47. Q4 collector, if Q6 is off, provides the IR signal to U7:A as mentioned above, and also drives Q5 via R53, to re-invert the signal and preserve its phase. It is then OR-ed with the PIC TX signal by U7:B, and buffered by U7:C and U7:D to provide enough drive for the IR output. R50 protects the output and C11,R49 isolate the IR output ground. IR commands can also be generated by the 840A itself. These come from the main PIC as the signal PIC TX on CN15, and are combined into the IR output as described above. When such commands are being sent, it is important to disable any external IR commands from being sent through as they will combine to give garbled data. This is done by the BLOCK signal from the main PIC, coming in via CN15. When this is high it turns on Q6 and prevents external IR commands from reaching Q5.

The Rectifier PCB This board mounts on the main heat-sink of each amplifier module. It consists of the rectifier itself, three suppression capacitors to reduce RF noise created by rectifier commutation, and two fuses in the incoming AC lines from the transformer.

---================

==================

============---

Operating Instructions Summary This is a very brief guide to enable all the controls and menus of the 840A to be accessed if the full manual is not available. (seewww.cambridge-audio.comfor a downloadable user manual).

To adjust the balance: Briefly press the Mode button. The balance display appears and can be changed using the volume knob. To return to volume mode, give the Mode button another quick press. The 840A will automatically return to volume mode after 5 seconds.

59

To rename inputs: Press and hold the relevant input select button. Letters in the name are selected by turning the volume knob.

To access the configuration menu: Press and hold the Mode button. These are the menu options:
Clip detector on/off LCD brightness (off/dim/bright) Input gain trim menu access Volume ramp on/off Volume display: -84 to 0 dB or 0 to 72 units Fixed input gain menu access

To adjust the gain of an input: Press the button next to INP TRIM Select the input required Use volume knob to set gain between 0 and -12 dB (the available range is restricted if the volume is set very low) Press Mode button to return to volume display

To set up fixed input gain Press the button next to FIXED INP Select the input required Set the fixed gain using the volume control. (the OFF setting does not disable the input- it leaves the input gain subject to the volume control) Press Mode button to return to volume display

To access the service menu: Hold in the Mode button when mains power is switched on. These are the menu options:
Speaker short detection on/off DC offset detect on/off XD system on/off Counter access Press Mode button to return to volume display

The counter page keeps a total of the number of times these events have occurred:

Clipping detected

CL

DC offset detected

DC

Overload protection

OV

Overtemperature shutdown

TM

Speaker short detected

SH

Time on in hours

ON

Press Mode button to return to service menu

To reprogram the PICs: Hold in the ON/standby button when mains power is switched on. The word DOWNLOAD appears on the LCD.

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840A Software Loading Instructions
1) Push and hold the "Standby / On" on the front of the840A whilst turning on the power switch at the rear. After about 4 seconds the following should be displayed on the LCD:
2) Connect a Null Modem RS232 cable from the 840A to the PC's comm port. 3) Run the Loader program from the Azur 840A program group in the start menu. The following window will be displayed: 4) Choose the comm port the RS232 cable is attached to and click OK. The following window will be displayed:
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5) Click the Load File button, the following window will be displayed:
Locate the file "840A.hex" and click open. The following window should be displayed:
6) Click the Download Code button, "Loading..." will be displayed on the LCD. The ABUS processor will be programmed followed bythe Main processor. Once the programming has finished, "Programming Completed!" will be displayed and the 840A will reset.
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840A
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Notes.
Gallery Court Hankey Place London SE1 4BB UK Tel: +44 (0)20 7940 2200 Fax: +44 (0)20 7940 2233
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Acrobat Distiller 6.0.1 (Windows)