Cambridge Audio Azur 640A User manual

Gallery Court Hankey Place London SE1 4BB UK
Tel: [phone] Fax: [phone]
640A Integrated Amplifier
Issue Date: 16th December 2003 (Revised May 2008)
SERVICE MANUAL – AP14676/1
SPECIFICATIONS:
Power Output: 65 watts into 8 Ohms
100 watts into 4 Ohms
Input Impedance: 47k Ohms
Loudspeaker Impedance: 4 to 8 Ohms
Line: 380mV
Phono (using optional phono stage): 1.75mV
Total Harmonic Distortion (into 8 Ohms 80% rated power): 0.005% THD (No weighting) @ 1kHz
0.003% THD (A weighted) @ 1kHz
0.01% THD (No weighting) @ 20Hz - 20kHz
Frequency Response: 5Hz to 50kHz +/- 1dB
Bass: +/- 10dB @100Hz
Treble: +/- 10dB @10kHz
Signal to Noise Ratio (No weighting): 92dB
Slew rate (into 8 ohms): 40V/uS
Max. Power Consumption: 615 watts
Dimensions (mm): 430 x 320 x 100
Weight: 7 kg/15.4 lbs

640A SERVICE MANUAL
TABLE OF CONTENTS
Safety Precautions & Important Notes 3
Amplifier Bias Set-up 4
Main Assembly BOM (Silver Unit) 5 – 7
Input & Tone PCB Schematic (Tone Control) 8
Revised: Input & Tone PCB Schematic (Input Select) 9
Input & Tone PCB Layout (Top Side) 10
Input & Tone PCB Layout (Bottom Side) 11
Input & Tone PCB BOM 12
Front Panel Schematics 13
Front Panel PCB Layout (Top Side) 14
Front Panel PCB Layout (Bottom Side) 15
Front Panel PCB BOM 16
Power Amp Schematic (Power Supply) 17
Power Amp Schematic (Protection) 18
Power Amp Schematic (Left Channel) 19
Power Amp Schematic (Right Channel) 20
Power Amp PCB Layout (Top Side) 21
Power Amp PCB Layout (Bottom Side) 22
Power Amp PCB BOM 23 – 25
Speaker Output Schematic 26
Speaker Output PCB Layout (Top Side) 27
Speaker Output PCB Layout (Bottom Side) 28
Speaker Output PCB BOM 29
Mains Input Schematic 30
Mains Input PCB Layout (Top Side) 31
Mains Input PCB Layout (Bottom Side) 32
Mains Input PCB BOM 33
IC Pin Layout Details 34 – 38
Silver / Black Difference BOM 39
Amended Input Circuit Schematic (Jan 2004) 40
Amended Input Circuit Schematic (March 2005) 41

SAFETY PRECAUTIONS & IMPORTANT NOTES
1.Check that the rear of the product indicates the correct supply voltage
for you 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.
© 2005 Audio Partnership PLC. All rights reserved.
Cambridge Audio and Azur are registered trademarks of 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.

Cambridge Audio Azur 640A Amplifier Bias Setup
To set the bias on the 640A Amplifier:
Measure the voltage across R22 and R100 (Left channel) individually; they
should be adjusted using Preset R116 so that the voltage measured on each
resistor is greater than 13mV. This procedure should then be repeated for the
Right channel by measuring the voltage across R52 and R69 whilst adjusting
Preset R68 so that the voltage measured on each resistor is greater than 13mV.
4

AP13133/6
AP PART No. DRAWING NO DESCRIPTION QTY COMMENTS
NEW CAMBRIDGE AMP PACKED UK VERSION 1
AP13074/1 POLY ENDCAP PACKAGING 2
AP13075/1 CARTON PACKAGING W/HANDLE 1 PRINTED TO ARTWORK AP…………
AP136131/1 CAMBRIDGE AUDIO NON-WOVEN BLUE BAG FOR
REMOTE
1 PACK REMOTE CONTROL INSIDE,
CAMBRIDGE NEW STYLE REMOTE COMPLETE 1 MOUNTED INTO POLY ENDCAP PACKING IN
REBATE PROVIDED
AAA ALKALINE BATTERIES 3 FOR REMOTE. PLACE IN INSTRUCTION MANUAL
POLYBAG
PY540 AP13969/1 AMPLIFICATION INSTRUCTION MANUAL 1
AP13933/2 CARTON LABEL (MODEL NO.) UK Silver 1 FOR BOX
SERIAL NUMBER LABEL, BLANK (6.5X35.5mm) 3 1 X REAR PANEL, 1 X BOX, 1 X SHIPPING CARTON
ISO 9002 LABEL 1 AFFIXED TO REAR PANEL ABOVE IEC SOCKET
AP10087/2 "MADE UNDER LICENCE IN PRC" STICKER 1 AFFIXED TO REAR PANEL BELOW IEC SOCKET
POLYBAG 173X260X4C mm 1 FOR INSTRUCTION MANUALOWNERS
CERTIFICATE AND REMOTE BATTERIES
AP13611/1 CAMBRIDGE AUDIO NON-WOVEN BLUE BAG 120mm
HEIGHT
1 PACK AMP UNIT INSIDE
1830mm AC IEC POWER CORD SET BS STANDARD
FUSED 3 AMP
1 MUST BE BS APPROVED
RED TAPE SEAL FOR CAMBRIDGE CARTON 1
NEW CAMBRIDGE AMP UK VERSION ASSEMBLED &
TESTED
1
FRONT PANEL ASSEMBLY
PY592 AP10209/3 CAMBRIDGE SELECTOR KNOB MK3 3
AP10224/1 CAMBRIDGE KNOB INSERT MK2 3 INSERT INTO SELECTOR KNOBS
PY590 CAMBRIDGE NEW RANGE AMP VOLUME KNOB 1
PY581 AP12740/2 CAMBRIDGE NEW RANGE AMP FRONT PANEL
(PUNCHED AND PRINTED)
1 SCREENED WITH ARTWORK AP13679/2
AP12935/1 CAMBRIDGE NEW RANGE AMP IR LENS 1 GLUED IN PLACE ON THE FRONT PANEL
AP12746/2 CAMBRIDGE NEW RANGE AMP SUB PLATE 1 FASTENEND IN PLACE INBETWEEN THE LEDGES
ON THE FRONT PANEL
AP12931/1 CAMBRIDGE NEW RANGE AMP LIGHTGUIDE 5 FASTEN TO SUBPLATE
M3 X 6 POZI PAN STP SCREW 5 AFFIXES LIGHTGUIDES TO SUBLATE
M3 X 6 C/S POZI MACHINE SCREW 8 FASTEN THE SUB PLATE TO THE FRONT PANEL
AP11782/1 OPUS CONTROL BOX BUTTON 1 POSITION IN PLACE ON THE FRONT PANEL
AP13585/1 CAMBRIDGE NEW RANGE AMP 9mm TAC SWITCH
CUSHION
1 POSITION ON THE SUBPLATE OVER THE POWER
BUTTON CUT AND AFFIX USING ADHESIVE
PROVIDED ON THE CUSHION.
AP12925/1 CAMBRIDGE NEW RANGE AMP 7mm TAC SWITCH
BUTTON
6 POSITION IN PLACE ON THE FRONT PANEL
AP12934/1 CAMBRIDGE NEW RANGE AMP 7mm TAC SWITCH
CUSHION
6 POSITION ON THE SUBPLATE OVER THE POWER
BUTTON CUT AND AFFIX USING ADHESIVE
PROVIDED ON THE CUSHION.
AP12926/2 CAMBRIDGE NEW RANGE AMP 7mm PUSH SWITCH
BUTTON
2 POSITION IN PLACE ON THE FRONT PANEL
CONTROL PCB ASSEMBLY (FRONT PANEL SWITCH
PCB)
M3 X 6 POZI PAN MACHINE SCREW 10 USED FOR FIXING THE CONTROL PCB'S TO THE
SUBPLATE STANDOFF'S
AP13388/3 A600 FRONT PANEL PCB CABLE 1 CONNECTS TO FRONT PANEL SWITCH PCB AND
RUNS ALONG FRONT PANEL CONNECTING THE
SWITCH PCB TO THE POWER SWITCH AND THE
IR PCBS
Cambridge Azur 640A Amplifier (Main Assembly BOM Silver Unit)
5

AP PART No. DRAWING NO DESCRIPTION QTY COMMENTS
AP13453/2 A600 INPUT PCB TO FRONT PANEL SWITCH PCB 1 ATTACH FRONT PANEL PCB TO INPUT PCB AS
PER DRAWING
CABLE TIE 2.5mm X 100mm 2 ATTACH CABLE LOOM TO SUB PANEL
AP13391/2 A600 VOLUME MOTOR CABLE 1 ATTACH VOLUME POT MOTOR TO FRONT
PANEL SWITCH PCB
AP13394/2 A600 AMP PCB TO FRONT PANEL CONTROL PCB
CABLE
1 ATTACH FRONT PANEL PCB TO AMP PCB AS PER
DRAWING
BOTTOM PANEL ASSEMBLY
AP12734/1 CAMBRIDGE NEW RANGE AMP BOTTOM PANEL 1
PY541 AP12652/2 CAMBRIDGE NEW RANGE FOOT MOULDING 4 POSITION IN PLACE ON BOTTOM PANEL
PY544 AP12883/3 CAMBRIDGE NEW RANGE FOOT PAD 4 AFFIX ON FOOT USING ADHESIVE SURFACE
M3 X 6 PLASTITE POZI PAN 4 AFFIX FEET TO BOTTOM PANEL
12.7mm PLASTIC PCB STANDOFF 9 PUSH SNAP FIT ON BOTTOM PANEL
M3 X 6 POZI PAN TAPTITE SCREW 12 TO AFFIX SUPPORT BRACKETS (POWER AMP
ASSEMBLY) TO BOTTOM PANEL
M4 X 12 POZI PAN MACHINE BOLT 2 FIX THROUGH EARTHING POINT HOLES ON
BOTTOM PANEL
M4 NUT STANDARD 2 USED TO FIX ABOVE BOLTS
M4 LOCK WASHER 2 FOR EARTH BOLTS
M6 X 60 POZI PAN MACHINE BOLT 1 USED TO FIX MAIN TRANSFORMER IN PLACE
THROUGH THE BOTTOM PANEL
AP12629/5 230V 194VA TOROID TRANSFORMER 1
NEOPRENE TRANSFORMER INSULATION WASHERS 2 TO FIT EITHER SIDE OF TRANSFORMER
TRANSFORMER METAL BOTTOM PLATE 1 TO FIT UNDER BOTTOM PLATE ON M6 BOLT
M6 LOCK WASHER 1 PLACE ABOVE TRANSFORMER ON M6 BOLT
TRANSFORMER METAL TOP PLATE 1 PLACE ON TOP OF TRANSFORMER
M6 NUT STANDARD 1 USED TO FIX ABOVE BOLT
INPUT PCB ASSEMBLY 1 FIXES IN THE CORRECT POSITION ONTO THE
PLASTIC PCB STANDOFFS
AP12715/4 BARE INPUT PCB 1
M2.6 X 6 POZI PAN MACHINE SCREW 10 TO AFFIX BOTTOM PANEL TO SIDE, FRONT AND
REAR PANELS
M2.6 X 10 POZI PAN PLASTITE 4 FIX CORNERS OF BOTTOM PANEL TO PLASTIC
INSERTS
SIDE PANEL ASSEMBLY 2
AP12726/1 CAMBRIDGE AUDIO NEW RANGE PRESSED SIDE PANEL
(3 RIDGE)
2 POSITION IN PLACE ON PLASTIC FRONT INSERTS
AP12729/1 CAMBRIDGE AUDIO NEW RANGE FRONT PLASTIC
SUPPORT (3 RIDGE)
2 POSITION AT FRONT WITHIN SIDE PANELS
AP12730/1 CAMBRIDGE AUDIO NEW RANGE REAR PLASTIC
SUPPORT (3 RIDGE)
2 POSITON AT REAR WITHIN SIDE PANELS
M2.6 X 10 C/S POZI PLASTITE 8 TO AFFIX SIDE PANELS TO PLASTIC INSERTS
A600 REAR PANEL ASSEMBLY 1
AP12919/2 CAMBRIDGE AUDIO NEW RANGE AMP REAR PANEL
PRINTED
1 SCREENED WITH ARTWORK AP13665/2 THEN
POSITION ON REAR PLASTIC SUPPORTS
M3 X 10 POZI PAN PLASTITE 4 TO AFFIX REAR PANEL TO REAR PLASTIC INSERTS
M3 X 8 POZI PAN PLASTITE 9 TO FIX SPEAKER TERMINAL PCB AND ALSO FIX
PHONO SOCKETS ON THE INPUT BOARD TO
THE REAR PANEL
M4 X 8 POZI PAN TAPTITE 2 FIXES THE IEC SOCKET MOUNTED ON THE
POWER BOARD TO THE REAR PANEL
M3X12 MACHINE SCREW WITH PLASTIC KNOB AND
EXTERNAL TOOTH ZINC WASHER
1 PHONO GND SCREW ON REAR PANEL
6

AP PART No. DRAWING NO DESCRIPTION QTY COMMENTS
AP13389/2 A600 AMP PCB TO INPUT PCB POWER CABLE 1 FIT AS PER DRAWING - JST CONNECTORS
AP13393/2 A600 AMP PCB TO MAINS PCB CABLE 1 FIT AS PER DRAWING - JST CONNECTORS
AP13396/2 A600 INPUT PCB TO AMP PCB SIGNAL CABLE 1 FIT AS PER DRAWING - JST CONNECTORS
AP13392/2 A600 AMP PCB TO SPEAKER PCB CABLE 1 FIT AS PER DRAWING - JST CONNECTORS
SELF ADHESIVE CABLE TIE FIXING PAD 19mm X 19mm 3 2X SIDE PANEL, 1X REAR PANEL TO ATTACH
AP13395/1 LOOM TO SIDE OF CHASSIS
CABLE TIE 2.5mm X 100mm 10 (PLEASE FOLLOW EXAMPLE ON
MANUFACTURING SAMPLE UNIT OR USE AS
NECESSARY)
AP13340/1 A600 LIDDING TAPE FOR FRONT AND REAR PANELS 2 FIX TO THE CORRECT SURFACES FOR LID
AP13342/1 A600 LIDDING TAPE FOR SIDE PANELS 2 FIX TO THE CORRECT SURFACES FOR LID
PY542 AP12733/2 CAMBRIDGE AUDIO NEW RANGE TOP PANEL WITH
VENTS
1 POSITIONON TOP OF THE PRODUCT
PY516 M2.6 x 8 M/C Torx Recessed Plated 8 TOP PANEL SCREWS
7

Cambridge Audio Azur 640A Integrated Amplifier
AP12714/5 Input & Tone PCB Schematic (Tone Control)
C1
330p poly
R1
22k
R2
4k7
R3
4k7
R4
8k2
R11
8k2
C6
150n poly
C9
5p
SW1:A
SW-DPDT
DEFEAT
-15V
+15V
R12
10k R13
10k
C10
330p poly
R20
22k
R42
4k7
R43
4k7
R44
8k2
R45
8k2
C11
150n poly
C15
5p
SW1:B
SW-DPDT
DEFEAT
-15V
+15V
R46
10k
R47
10k
-15V
+15V
C16
47n poly
C17
47n poly
C19
47n poly
C20
47n poly
C24
47n poly
C27
47n poly
C32
100u 25V
C33
100u 25V
+15V
-15V
3
2
1
8
4
U2:A
NE5532
5
6
7
U2:B
NE5532
3
2
1
8
4
U4:A
NE5532
5
6
7
U4:B
NE5532
3
2
1
8
4
U5:A
NE5532
5
6
7
U5:B
NE5532
R CH IN
L CH IN
R CH OUT
L CH OUT
HEADPHONE
SW2:A
SW-DPDT
TAPE
SW2:B
SW-DPDT
TAPE
J1
TERMINAL
J2
TERMINAL
J3
TERMINAL
J4
TERMINAL
SPEAKER SWITCHING
RSW1
RSW2
R
L
GND
LSW1
LSW2
2
4
3
1
7
8
5
CN2
HEADPHONE JACK
J5 TERMINAL
J6 TERMINAL
J7
TERMINAL
C18
22p
C21
22p
C28
10u 16V NP
C29
10u 16V NP
C30
10u 16V NP
C31
10u 16V NP
R52
150k
R54
150k
R59
150k
R60
150k
13
2
VR1:A
20K MOTORISED DUAL POT
46
5
VR1:B
20K MOTORISED DUAL POT
46
5
VR4:B
MN20K BALANCE
1
3
2
VR4:A
MN20K BALANCE
13
2
VR2:A
B20K LINEAR
46
5
VR2:B
B20K LINEAR
13
2
VR3:A
B20K LINEAR
46
5
VR3:B
B20K LINEAR
R61
220R 3W C
R62
470R 1W C
R63
220R 3W C
R64
470R 1W C
1
2
3
4
5
6
CN3
H6 2.54mm
TO POWER AMP
To enhance viewing, please print to A3 8

Cambridge Audio Azur 640A Integrated Amplifier
AP12714/6 Input & Tone PCB Schematic (Input Select)
(Production change in 2003 - if R48/R56 fail, please refer to
Service Bulletin: TNBC-0006)
CD IN L
TUNER IN L
DVD IN L AV IN L CD IN R
TUNER IN R
DVD IN R AV IN R
PHONO/AUX IN L PHONO/AUX IN R TAPE OUT2 R TAPE OUT1 R TAPE OUT2 L TAPE OUT1 L TAPE MON L
TAPE MONR PREOUT R PREOUT L
st
dat
clk
© COPYRIGHT
The Audio Partnership
Gallery Court
Hankey Place
LONDON SE1 4BB
Tel : [phone]
Fax : [phone]
6CN10:D
QUAD PHONO
3CN11:B
QUAD PHONO
6CN11:D
QUAD PHONO
3CN12:B
QUAD PHONO
5
4CN10:C
QUAD PHONO
2
1CN11:A
QUAD PHONO
5
4CN11:C
QUAD PHONO
2
1CN12:A
QUAD PHONO
5
4CN13:C
QUAD PHONO
1
2
3
4
5
6
CN8
HEADER6
PHONO I/O
LK1
6CN13:D
QUAD PHONO
1
2
3
4
5
6
CN7
HEADER6
PHONO PSU
3CN10:B
QUAD PHONO
2
1CN10:A
QUAD PHONO
3
2
1
84
U6:A
NE5532
R9
56R
R8
56R
5
6
7
U6:B
NE5532
3CN13:B
QUAD PHONO
6CN12:D
QUAD PHONO
2
1CN13:A
QUAD PHONO
5
4CN12:C
QUAD PHONO
3
2
1
84
U3:A
NE5532
5
6
7
U3:B
NE5532
-15V
+15V
+12V -12V
LK2
R21
220K
R23
220K
R24
100R
R25
100R
R26
100R
R27
220K
R28
220K
R29
100R
R30
100R
R31
100R
R17
220K
R32
220K
R33
220K
R34
100R
R35
100R
R36
100R
R37
100R
R38
100R
R39
100R
R40
220K
R41
220K
+15V
-15V
+30V
C2
47n poly
C3
47n poly
C4
47n poly
C5
47n poly
C7
47n poly
C8
47n poly
C12
22p
C13
22p
R6
220K
R5
10k
R7
10k
R10
10k
R14
10k
R15
100K
R16
100K
C25
10u 16V NP
R18
100K
R19
100K
C14
10u 16V NP
R49
100R
R51
100R
R53
100R Pre Only
C26
100n Pre Only
-15V
+15V
+45V
+30V
R55
680R
LCHIN
RCHIN
LCHOUT
RCHOUT
HEADPHONE
VEE 1
L1 2
L2 3
L4 5
L3 4
L-COM1 6
L-COM2 9
L5 7
L6 8
L-COM3 12
L7 10
L8 11
ST 13
VSS 14 CK
15
DATA
16
R8
18
R7
19
R-COM3
17
R6
21
R5
22
R-COM2
20
R-COM1
23
R3
25 R4
24
R2
26
R1
27
VDD
28
U1
NJU7313
R22
220K
R50
220K
2
1
CN4:A
DUAL PHONO
3
CN4:B
DUAL PHONO
L R
J8
CHASSIS
4
3
2
1
CN1
H4 2.54mm
4
3
2
1
CN22
H4 2.54mm
R48
100R
R56
100R
D1
12V Zener 400mW
D2
12V Zener 400mW
+12V
-12V
C22
10u 25V
C23
10u 25V
To enhance viewing, please print to A3 9

Cambridge Audio Azur 640A Integrated Amplifier
AP12714/5 Input & Tone PCB Layout (Top Side)
To enhance viewing, please print to A3 10

Cambridge Audio Azur 640A Integrated Amplifier
AP12714/5 Input & Tone PCB Layout (Bottom Side)
To enhance viewing, please print to A3 11

Cambridge Azur Input and Tone PCB BOM AP131336
AP PART No. DRAWING
NO
DESCRIPTION QTY DESIGNATOR COMMENTS
AP12715/5 BARE INPUT PCB 1
220R 3W CARBON FILM RESISTOR 2 R61, R63
470R 1W CARBON FILM RESISTOR 2 R62, R64
680R 1W CARBON FILM RESISTOR 1 R55
56R 0.25W METAL FILM RESISTOR 2 R8, R9
100R 0.25W METAL FILM RESISTOR 14 R24, R25, R26, R29, R30, R31,
R34, R35, R36, R37, R38, R39,
R49, R51
4k7 0.25W METAL FILM RESISTOR 4 R2, R3, R42, R43
8k2 0.25W METAL FILM RESISTOR 4 R4, R11, R44, R45
10k 0.25W METAL FILM RESISTOR 8 R5, R7, R10, R12, R13, R14,
R46, R47
22k 0.25W METAL FILM RESISTOR 2 R1, R20
100k 0.25W METAL FILM RESISTOR 4 R15, R16, R18, R19
150k 0.25W METAL FILM RESISTOR 4 R52, R54, R59, R60
220k 0.25W METAL FILM RESISTOR 12 R6, R17, R21, R22, R23, R27,
R28, R32, R33, R40, R41, R50
5p CERAMIC 50/100V 5mm PITCH CAPACITOR 4 C9, C15
22p CERAMIC 50/100V 5mm PITCH CAPACITOR 4 C12, C13, C18, C21
330p POLY 50/100V 5mm PITCH CAPACITOR 2 C1, C10
47n POLY 50/100V 5mm PITCH CAPACITOR 12 C2, C3, C4, C5, C7, C8, C16,
C17, C19, C20, C24, C27
150n POLY 50/100V 5mm PITCH CAPACITOR 2 C6, C11
10u 35V NON POLAR ELECTROLYTIC CAPACITOR 6 C14, C25, C28, C29, C30, C31
100u 25V ELECTROLYTIC CAPACITOR 2 C32, C33
PY487 NJU 7313 AUDIO SWITCH IC 1 U1
PY108 NE5532 OP AMP 5 U2, U3, U4, U5, U6
4 WAY JST CONNECTOR 2.54mm PITCH 3 CN1, CN22
6 WAY JST CONNECTOR 2.54mm PITCH 1 CN3
ZUANBAO CK-6.35-08A (SILVER BEZEL)
HEADPHONE JACK
1 CN2
ZUANBAO AV2-8.4-9 GOLD DUAL PHONO SOCKET 1 CN4
ZUANBAO AV4-8.4-9 GOLD QUAD PHONO
SOCKET
4 CN10, CN11, CN12, CN13
6 WAY PIN HEADER 2.54mm PITCH 13mm LONG 2 CN7, CN8 AS PER EXISTING A500 INPUT PCB
DPDT WEALTH PBS-22HO1-T18-SL SWITCH 2 SW1, SW2
PY004 20k MOTORISED DUAL LOG POT RM16 WITH 22mm
LEGS
1 VR1
PY535 B20k LINEAR POT 2 VR2, VR3
PY005 MN20k BALANCE POT 1 VR4
LINK WIRE 24SWG 20mm LONG 30 LK1, LK2, ALL BLANK LINK
POSITIONS
M3 X 14 POZI PAN MACHINE SCREW BLACK 1 USED TO FIT OPTIONAL PHONO
STAGE
M3 LOCKWASHER 1 USED TO FIT OPTIONAL PHONO
STAGE
M3 NUT BLACK 2 USED TO FIT OPTIONAL PHONO
STAGE
AP13395/2 640A INPUT PCB TO SPEAKER PCB LOOM 1 CONNECT AS PER DRAWING TO
INPUT PCB BEFORE FITTING
INPUT PCB TO CHASSIS
AP10001/2 CAMBRIDGE AUDIO SCREENING CAN 1 EMBOSSED WITH ARTWORK
AP10018/1
12

Cambridge Azur 640A Integrated Amplifier
AP12711/9 Front Panel Schematics
temp
dc
clip
speaker relay
overcurrent/short
standby relay
REMOTE IN
RB7
17
RB6
16
RB5
15
RB4
14
RB3
13
RB2
12
RB1
11
RB0
10
VDD
2
VSS
4
RTCC
1
N/C
3
N/C
5
RC4
22
MCLR/VPP
28
RA0
6
RA1
7
RA2
8
RA3
9
RC5
23
RC6
24
CKIN
27
RC7
25
CKOUT
26
RC1
19
RC0
18
RC2
20
RC3
21
U5
PIC16C57
CRS1
FREQ=4MHz
1
2
CN7
H2 2.54mm 90
MOTOR
D1
1N4148
C21
100n
FIN
1
GND1
2
RIN
3
NC
4
GND2
5
VCC
6
OUT2
7
COM
8
OUT1
9
U6
BA6218
C22
100n
+5V
DGND
DGND1
R27
10k
R28
10k
R29
10k
+5V
DGND1
+5V
DGND1
+5V
DGND1
C23
100n
R30
33k
D
2
CLK
3
STB
1
OE
15
Q0
4
Q1
5
Q2
6
Q3
7
Q4
14
Q5
13
Q6
12
Q7
11
QS
9
QS
10
VDD
16
VSS
8
U7
74HC4094
R33
820R
+5V
C24
100n
D2
CHANNEL LED
D3
CHANNEL LED
D4
CHANNEL LED
D5
CHANNEL LED
D6
CHANNEL LED
D7
CHANNEL LED
SW3
STANDBY
SW4
CD
SW5
TUNER
SW6
AV
SW7
PHONO/AUX
SW9
TAPE MON
SW10
DVD
D8
Red LED
protection
lead mounted
+5V
3
OPT
1
GND
2
U9
TSOP18 IR RECEI
R35
10k
+5V
HEADPHONE
HEADPHONE
C1
100n
+5V
DGND
R1
220R
strobe
data
clock
clock
data
strobe
vol up
vol down
vol up
vol down
R2
10k
C3
47u 16V
LK1
LINK
DGND1
R3
820R
LK5
LINK
LK3
LINK
C4
100n
1
2
3
4
5
6
7
8
CN2
H8 2.54mm 90
DGND
+5V
1
2
3
4
CN1
H4 2.54mm 90
LK8
LINK
LK9
LINK
R4
10k
D9
Blue flat top LED
Standby
DGND1
1
2
3
4
5
6
7
8
9
CN6
H9 2.54mm 90
1
2
3
4
5
6
7
8
9
CN5
CONN-H9
DGND1
Q2
BC337
R5
10k
R6
820R
DGND1
R7
820R
SNAP OFF SECTION (c)
SNAP OFF SECTION (d)
To enhance viewing, please print to A3 13

Cambridge Azur 640A Integrated Amplifier
AP12711/9 Front Panel PCB Layout (Top Side)
To enhance viewing, please print to A3 14

Cambridge Azur 640A Integrated Amplifier
AP12711/9 Front Panel PCB Layout (Bottom Side)
To enhance viewing, please print to A3 15

Cambridge Azur Front Panel PCB BOM
AP PART
No.
DRAWING NO DESCRIPTION QTY DESIGNATOR COMMENTS
CONTROL PCB ASSEMBLY (FRONT PANEL)
AP12712/8b CONTROL PCB SNAP OFF (FRONT PANEL) 1
220R 0.25W 1% METAL FILM RESISTOR 2 R1
820R 0.25W 1% METAL FILM RESISTOR 2 R3,R6,R7 R33
10k 0.25W 1% METAL FILM RESISTOR 6 R2, R4,R5, R27, R28, R29,
R35
33k 0.25W 1% METAL FILM RESISTOR 1 R30
100n CERAMIC 50/100V 5mm PITCH CAPACITOR 5 C4, C21, C22, C23, C24
47u 16V ELECTROLYTIC CAPACITOR 1 C3
4MHz CRYSTAL RESONATOR WITH BUILT IN CAPS
(3 TERMINAL)
1 CRS1
PY597 PIC16C57C -04P MICROPROCESSOR IC 1 U5 TO BE PROGRAMMED WITH
AP13424/1 HEX CODE
28 PIN 0.6" TURNED PIN SOCKET FOR ABOVE PIC 1 (U5)
PY260 BA6218 MOTOR DRIVE IC 1 U6
PY524 74HC4094 SHIFT REGISTER IC 1 U7
PY214 BC337 NPN TRANSISTOR 1 Q2
1N4148 SIGNAL DIODE 1 D1
PY064 FLAT TOP BLUE LEDS (AS PER CURRENT
CAMBRIDGE)
6 D2, D3, D4, D5, D6, D7
3mm STANDARD DIFFUSED RED LED 1 D8 TO BE FITTED TO CABLE AS PER
DRAWING AP13388/3 AND THEN
GLUED INTO THE 'PROTECTION'
LIGHT GUIDE FITTED TO THE SUB
PANEL
2 WAY JST CONNECTOR 2.54mm PITCH 90 DEGREE
MOUNTED
1 CN7
4 WAY JST CONNECTOR 2.54mm PITCH 90 DEGREE
MOUNTED
1 CN1
8 WAY JST CONNECTOR 2.54mm PITCH 90 DEGREE
MOUNTED
1 CN2
9 WAY JST CONNECTOR 2.54mm PITCH 90 DEGREE
MOUNTED
1 CN6
TACTILE SWITCH 1 SW3
LINK WIRE 24SWG 20mm LONG 7 LK1, LK3, LK5, LK8, LK9,
X, X,
CONTROL PCB ASSEMBLY (POWER SWITCH)
AP12712/8c CONTROL PCB SNAPOFF (POWER SWITCH) 1 FASTENEND IN PLACE TO
STANDOFFS SUPPLIED ON SUB
PLATE.
TACTILE SWITCH 6 SW4, SW5, SW6, SW7,
SW9, SW10
AS PER CAMBRIDGE D500SE
PY064 FLAT TOP BLUE LEDS (AS PER CURRENT
CAMBRIDGE)
1D9
CONTROL PCB ASSEMBLY (I/R RECEIVER)
AP12712/8d CONTROL PCB SNAPOFF (IR RECEIVER) 1 FIXED INTO PEENED HOLE ON
SUBPLATE
PD092 TSOP18 IR RECEIVER MODULE (VISHAY) 1 U9
100n CERAMIC 50/100V 5mm PITCH CAPACITOR 1 C1 TO BE MOUNTED ON BACK OF PCB
M3 X 6 POZI PAN TAPTITE SCREW 1 FOR FIXING IR SNAP OFF PCB TO SUB
PANEL
1mm NYLON WASHER 1 USED AS A SPACER FOR AP12711/5d
16

Cambridge Azur 640A Integrated Amplifier
AP12707/6 Power Amp Schematic (Power Supply)
+15V
-15V
D17
1N5402
D18
1N5402
D20
1N5402
D19
1N5402
C32
47n poly
C20
47n poly
C25
2200uF
C62
2200uF
C26
2200uF
C21
2200uF
C23
2200uF
C63
2200uF
C30
2200uF
C29
2200uF
+45V
-45V
C31
100n
R97
47R
J1
RED
J2
YELLOW
J3
ORANGE
J4
CHASSIS
D13
1N4002
D14
1N4002
D16
1N4002
D15
1N4002
J13
TERMINAL
green
J14
TERMINAL
purple
J15
TERMINAL
blue
C53
470u 35V
C54
100u 35V
C57
47n poly
C58
47n poly
VI
1
VO
3
GND
2
U8
7805
C59
47u 16V
C56
47n poly
VI
1
VO
3
GND
2
U9
7815
VI
2
VO
3
GND
1
U10
7915
C60
100u 16V
C61
100u 16V
+5V
J17
TERMINAL
J18
TERMINAL
J16
J20
1
2
CN4
H2 2.54mm
PHONO PSU
J19
YELLOW
J21
YELLOW
WIRE LINK
C55
47n poly
LK18
LINK
1
2
3
CN6
H3 2.54mm
digital
C67
47n poly
C68
47n poly
To enhance viewing, please print to A3 17

Cambridge Azur 640A Integrated Amplifier
AP12707/6 Power Amp Schematic (Protection)
570mV +-1%
Q20
MJE340
To be mounted
on heatsink
R87
4k7 8th
R88
11k 8th
5
6
7
U7:B
LM393
PIC TEMP
C52
100n
R86
1k
1k / (1k + 11k) with 570mV transistor
voltage gives 92deg C cutout
R92
1k 8th
For 1mA
R93
10k 8th
R89
100R 8th
R90
10R 8th
digital
3
2
1
8
4
U7:A
LM393
D12
1N4148
+5V
Speaker short circuit tester
R91
4k7 8th
OpenC
Senses a DC resistance of 2 ohms or less
3
2
7
4
6
1 85
U1
NE5534
R104
220k 8th
R105
220k 8th
R13
1M 8th
R12
1M 8th
C6
5p
C5
5p
C4
100n
C3
100n
-15V
RICLIP
RFCLIP
R63
220k 8th
R62
220k 8th
R60
1M 8th
R61
1M 8th
C35
5p
C34
5p
LICLIP
LFCLIP
Q6
BC337
Q1
BC327
digital
ROCLIP
LOCLIP
D25
1N4148
D26
1N4148
LOCLIP
ROCLIP
digital
PIC CLIP
D30
10V Zener 400mW
R6
4k7
D29
10V Zener 400mW
Q4
BC337
digital
R7
4k7 8th
Q3
BC337
D21
1N4148
D22
1N4148
ROCLIP
LOCLIP
Q2
BC327
R9
10k 8th
R10
10k 8th
PIC DC
RE1
RE2
R24
2k2
R23
2k2
R25
470R 8th
R45
47k
R47
18k
D7
4V7 Zener 400mW
g1
PIC OVERCURRENT/SHORT
+45V
R46
4k7 8th
R48
18k
C27
4.7n
D6
1N4148
Q5
BC337
R5
4k7
R4
4k7 8th
R2
10k 8th
R3
10k 8th
digital
+5V-1
C1
1u 16V
PIC OVERCURRENT/SHORT
PIC DC
PIC CLIP
PIC TEMP
PIC SPEAKER
digital
+5V-1
PIC SPEAKER
+15V
C15
220p
D23
1N4148
D24
1N4148
ROCLIP
LOCLIP
D27
1N4148
D28
1N4148
ROCLIP
LOCLIP
R49
47k
3
2
7
4
6
1 85
U6
NE5534
C36
100n
C37
100n
+15V
-15V
digital
digital
LK13
LINK
LK11
LINK
LK12
LINK
g1
LK10
LINK
PIC STANDBY 1
2
3
4
CN5
H4 2.54mm
1
2
3
CN8
H3 2.54mm
PIC STANDBY
+15V
digital
LK20
LINK
LK17
LINK
+5V-1
+5V-1
+5V-1
+5V
LK16
LINK
R94
4k7 OpenC
R95
100R
R11
100R
R1
10k 8th
R8
10k 8th
LK4
LINK
LK3
LINK
LK14
LINK
LK15
LINK
LK19
LINK
LK2
LINK
1
2
3
4
5
6
7
8
CN7
H8 2.54mm
+5V
LK26
LINK
R106
100k
R107
100k
R108
470R 8th
C69
220p
C70
220u 16V
C71
220u 16V
+45V2
-45V2
R109
820R 8th
R110
820R 8th
LE1
LE2
R111
2k2
R112
2k2
R113
470R 8th
C72
220p
R114
100k
R115
100k
R66
470R 8th
C73
220p
C74
220u 16V
C75
220u 16V
+45V3
-45V3
R117
820R 8th
R118
820R 8th
LORO
Q19
MPSA42/43
Q35
MPSA42/43
Q22
MPSA42/43
Q36
MPSA42/43
Q21
MPSA92/93
D31
1N4002
To enhance viewing, please print to A3 18

Cambridge Azur 640A Integrated Amplifier
AP12707/6 Power Amp Schematic (Left Channel)
1
2
CN2
H2 2.54mm
SIGNAL IN
D4
IN4004
D2
IN4004
+45V
-45V
R44
4R7 3W
WW
R99
100R
R21
100R
Q14
MJE350
R27
150R
R43
150R
C66
220u 50V
C65
220u 50V
R28
150R
R30
100R 8th
R31
100R 8th
R102
33k
R103
150R
C8
470p
R34
1k 8th
C17
100u NP 16V
Q11
MJE340
D1
ZEN 3V3
R41
150R
C11
220u 50V
C7
220u 50V
R16
8k2 0.66W
GND
R15
47R 8th
R14
47R 8th
R36
33k 8th
C2
100p poly
R35
4k7 8th
C18
10u NP 16V
R37
330k 8th
C24
100n
C13
10u NP 16V
C9
33p
WIRE3
R18
1k
LK6
LINK
R19
18k
R100
0.22R 3W
R22
0.22R 3W
WIRE4
RE1
RE2
RICLIP RFCLIP
J6
TERMINAL
J8
TERMINAL
LK8
LINK
WIRE LINK
WIRE LINK
E
S
C
B
D
5
4
3
1
2
U3
SAP15N
E
S
C
B
D
5
1
3
2
4
U2
SAP15P
R40
10R 8th
C19
47n poly
R29
1k
R42
10k 8th
R39
10k 8th
C22
47u 50V
R17
100R
signal1
signal1
Q12
MJE340
+45V2
-45V2
RO
Q13
MPSA13
Q15
MPSA92/93
Q18
MPSA42/43
Q16
MPSA92/93
Q7
MPSA92/93
Q8
MPSA92/93
Q10
MPSA42/43
Q9
MPSA42/43
C49
2.2n PPE Bypass (640A only)
C77
22p
R53
150R 8th
13
2
R116
47R
C14
15n poly
R119
47R 8th
-45V2
+45V2
C46
100n 160V Poly
To Loudspeaker PCB
To enhance viewing, please print to A3 19

Cambridge Azur 640A Integrated Amplifier
AP12707/6 Power Amp Schematic (Right Channel)
1
2
CN11
H2 2.54mm
SIGNAL IN
D10
IN4004
D8
IN4004
+45V
-45V
R50
4R7 3W
WW
R70
100R
R51
100R
Q31
MJE350
R71
150R
R98
150R
C43
220u 50V
C45
220u 50V
R72
150R
R81
100R 8th
R80
100R 8th
R65
33k
R64
150R
C51
470p
R79
1k 8th
C41
100u NP 16V
signal2
Q24
MJE340
D9
ZEN 3V3
R96
150R
C64
220u 50V
C33
220u 50V
R57
8k2 0.66W
R58
47R 8th
R59
47R 8th
R82
33k 8th
C38
100p poly
R83
4k7 8th
C39
10u NP 16V
R78
330k 8th
C28
100n
C50
33p
C47
10u NP 16V
R55
1k
R69
0.22R 3W
R52
0.22R 3W
LE1
LE2
R54
18k
LK22
LINK
LICLIP
LFCLIP
WIRE2
J10
TERMINAL
J12
TERMINAL
LK9
LINK
WIRE LINK
WIRE LINK
WIRE1
E
S
C
B
D
5
1
3
2
4
U4
SAP15P
E
S
C
B
D
5
4
3
1
2
U5
SAP15N
R74
1k
C44
5p
R75
10k 8th
R77
10k 8th
C42
47u 50V
R84
10R 8th
C40
47n poly
R56
100R
signal2
Q25
MJE340
+45V3
-45V3
LO
Q23
MPSA13
Q30
MPSA92/93
Q32
MPSA42/43
Q33
MPSA92/93
Q27
MPSA42/43
Q26
MPSA42/43
Q28
MPSA92/93
Q29
MPSA92/93
C76
2.2n PPE Bypass (640A only)
C78
22p
R67
150R
13
2
R68
47R
C12
15n poly
R101
47R 8th
-45V3
+45V3
C48
100n 160V Poly
To Loudspeaker PCB
To enhance viewing, please print to A3 20