Service Manual
A32
Issue 1.0
FMJ A32, P35 & P35/3
Amplifiers
ARCAM
Contents List
!
Phono board L870
o Circuit description
o Component overlay
o Parts list
o Circuit diagrams
!
Amplifier & PSU board L882
o Circuit description
o Component overlay
o Parts list
o Circuit diagrams
!
Display board L928
o Component overlay
o Parts list
o Circuit diagrams
!
Preamplifier board L937
o Circuit description
o Component overlay
o Parts list
o Circuit diagrams
!
3rd Channel Amplifier board L911
o Component overlay
o Parts list
o Circuit diagrams
!
Transformer specifications
o L914TX
o L915TX
!
General assembly
o A32 - Mechanical parts list
o P35 - Mechanical parts list
o P35/3 - Mechanical parts list
Phono
Board
L870
Contents
!
Circuit description
!
Component overlay
!
Parts list
!
Circuit diagrams
AV8 Phono Board
Circuit Description
Refer to circuit diagram L870 sheet 1
The phono board is a simple single stage RIAA amplifier
and consists of two channels of high gain amplification,
and the ability to switch between moving magnet (MM)
and moving coil (MC) settings.
PSU
The unit derives its + 15V regulated rails from the unit it is
fitted into with only local decoupling capacitors on board.
Interface
The unit connects to the host unit via a 8 way connector.
Amplification
The left channel has designators beginning with 100, and
the right with 200. For the purposes of this description the
left channel will be described, as the right channel is the
same in all respects.
The amplifier is a small signal class A voltage feedback
amplifier with switch able gain. The input consists of an
actively loaded differential pair of very low noise PNP
transistors (TR106, TR107). These transistors are very
specific and should only be replaced with identical parts
with the E grade high gain. TR100 and TR101 form a
current source for the pair, which sets the quiescent current
for the entire amplifier. The active load consists of TR110
and TR111, which forms part of the differential current
mirror with TR112, TR113 & TR114. This differential
stage also has an active load (TR102 & TR103) to keep
gain to a maximum.
Both of these differential stages are designed to have as
much gain as possible to enable the single stage design.
The RIAA response is achieved in the feedback network:
C101, C110, C111, C112, C119, C120 and R115, R112.
C115 is used to correct between MM and MC gains as the
amplifier is non-inverting.
SW100 switches between MM and MC. Two poles of the
switch change between the different loading required for
each type of the cartridge: R108 & C109 for MM and
added in parallel for MC R104 & C108. The other two
poles change the feedback resister value to alter the gain:
R105 for MM and added in parallel for MC R123.
The DC offset is controlled by a non-inverting servo built
around IC100. The amount of servo current is different for
each gain setting via R111 (MM) and R124 (MC) so that
the low frequency high pass point remains the same for
both settings. However the high pass point for the circuit
is set by C113. This gives a warp filter, stops DC start-up
thumps from upsetting DC coupled circuitry and an
approximation of the RIAA/IEC curve (-2dB @ 20Hz)
The output is class A buffered by a dual mirror follower
(TR104, TR105, TR108, TR109). The quiescent current is
set by D100 and R118 and R119.
Closed loop stability is achieved with C16, C117, giving
symmetrical slewing capability.
L870 Phono Board Parts List Issue 2.0
Designator Part
Description
C1
C100
C101
C102
C103
C104
C105
C106
C107
C108
C109
C110
C111
C112
C113
C115
C116
C117
C118
C119
C120
C200
C201
C202
C203
C204
C205
C206
C207
C208
C209
C210
C211
C212
C213
C215
C216
C217
C218
C219
C220
D100
D101
D102
D200
D201
D202
IC100
IC200
PCB1
R100
R101
R102
R104
R105
R106
R108
R109
R110
R111
R112
R113
R114
R115
R116
CERD 100N 63V -20% +80% RA
ELST 22U 63V
PPRO 1N0 5% 63V RA
ELEC 100U 25V SILMIC
ELEC 100U 25V SILMIC
PEST 100N 63V 10%
PEST 100N 63V 10%
PEST 100N 63V 10%
PEST 100N 63V 10%
PPRO W 470P 63V 5% RA
PPRO W 100P 63V 5% RA
PPRO 4N7 63V 5% RA
PPRO 10N 63V 1% AXIAL
PPRO 10N 63V 1% AXIAL
CAP MKS2 1U0 16V 10%
PPRO 1N3 63V 5% RA
PPRO W 470P 63V 5% RA
PPRO W 470P 63V 5% RA
ELST NON POLAR 10UF 35V
PPRO 100P 63V 5% RA
PPRO 1N0 5% 63V RA
ELST 22U 63V
PPRO 1N0 5% 63V RA
ELEC 100U 25V SILMIC
ELEC 100U 25V SILMIC
PEST 100N 63V 10%
PEST 100N 63V 10%
PEST 100N 63V 10%
PEST 100N 63V 10%
PPRO W 470P 63V 5% RA
PPRO W 100P 63V 5% RA
PPRO 4N7 63V 5% RA
PPRO 10N 63V 1% AXIAL
PPRO 10N 63V 1% AXIAL
CAP MKS2 1U0 16V 10%
PPRO 1N3 63V 5% RA
PPRO W 470P 63V 5% RA
PPRO W 470P 63V 5% RA
ELST NON POLAR 10UF 35V
PPRO 100P 63V 5% RA
PPRO 1N0 5% 63V RA
SSDIODE 1N4148 75V
SSDIODE 1N4148 75V
SSDIODE 1N4148 75V
SSDIODE 1N4148 75V
SSDIODE 1N4148 75V
SSDIODE 1N4148 75V
IC FET OPAMP TL071
IC FET OPAMP TL071
PRINTED CIRCUIT BOARD
RES MF W4 1% 330R
RES MF W4 1% 100R
RES MF W4 1% 100R
RES MF W4 1% 100R
RES MF W4 1% 100R
RES MF W4 1% 100R
RES MF W4 1% 47K
RES MF W4 1% 12K
RES MF W4 1% 12K
RES MF W4 1% 56K
RES MF W4 1% 100K
RES MF W4 1% 100K
RES MF W4 1% 100K
RES MF W4 1% 15K
RES MF W4 1% 2M2
2A410
2N622
2D210
2P710AS
2P710AS
2K410
2K410
2K410
2K410
2D147W
2D110W
2D247N
2D310
2D310
2K510
2D213N
2D147W
2D147W
2U610
2D110N
2D210
2N622
2D210
2P710AS
2P710AS
2K410
2K410
2K410
2K410
2D147W
2D110W
2D247N
2D310
2D310
2K510
2D213N
2D147W
2D147W
2U610
2D110N
2D210
3A4148
3A4148
3A4148
3A4148
3A4148
3A4148
5B071
5B071
L870PB_2
1H133
1H110
1H110
1H110
1H110
1H110
1H347
1H312
1H312
1H356
1H410
1H410
1H410
1H315
1H522
L870 Phono Board Parts List Issue 2.0
Designator Part
Description
R117
R118
R119
R120
R121
R122
R123
R124
R200
R201
R202
R204
R205
R206
R208
R209
R210
R211
R212
R213
R214
R215
R216
R217
R218
R219
R220
R221
R222
R223
R224
SK1
SK2
SW100
TR100
TR101
TR102
TR103
TR104
TR105
TR106
TR107
TR108
TR109
TR110
TR111
TR112
TR113
TR114
TR200
TR201
TR202
TR203
TR204
TR205
TR206
TR207
TR208
TR209
TR210
TR211
TR212
TR213
TR214
RES MF W4 1% 2M2
RES MF W4 1% 22R
RES MF W4 1% 22R
RES MF W4 1% 22R
RES MF W4 1% 22R
RES MF W4 1% 39K
RES MF W4 1% 10R
RES MF W4 1% 5K6
RES MF W4 1% 330R
RES MF W4 1% 100R
RES MF W4 1% 100R
RES MF W4 1% 100R
RES MF W4 1% 100R
RES MF W4 1% 100R
RES MF W4 1% 47K
RES MF W4 1% 12K
RES MF W4 1% 12K
RES MF W4 1% 56K
RES MF W4 1% 100K
RES MF W4 1% 100K
RES MF W4 1% 100K
RES MF W4 1% 15K
RES MF W4 1% 2M2
RES MF W4 1% 2M2
RES MF W4 1% 22R
RES MF W4 1% 22R
RES MF W4 1% 22R
RES MF W4 1% 22R
RES MF W4 1% 39K
RES MF W4 1% 10R
RES MF W4 1% 5K6
PHONO SKT 2-WAY HOR EMC GOLD
8-WAY AMP CT CONN
SW PUSH 4PCO
TRANS LF SS P BC556B
TRANS LF SS P BC556B
TRANS LF SS P BC556B
TRANS LF SS P BC556B
TRANS LF SS P BC556B
TRANS LF SS P BC556B
TRANS LF SS P 2SA1085
TRANS LF SS P 2SA1085
TRANS LF SS N BC546B
TRANS LF SS N BC546B
TRANS LF SS N BC546B
TRANS LF SS N BC546B
TRANS LF SS N BC546B
TRANS LF SS N BC546B
TRANS LF SS N BC546B
TRANS LF SS P BC556B
TRANS LF SS P BC556B
TRANS LF SS P BC556B
TRANS LF SS P BC556B
TRANS LF SS P BC556B
TRANS LF SS P BC556B
TRANS LF SS P 2SA1085
TRANS LF SS P 2SA1085
TRANS LF SS N BC546B
TRANS LF SS N BC546B
TRANS LF SS N BC546B
TRANS LF SS N BC546B
TRANS LF SS N BC546B
TRANS LF SS N BC546B
TRANS LF SS N BC546B
1H522
1H022
1H022
1H022
1H022
1H339
1H010
1H256
1H133
1H110
1H110
1H110
1H110
1H110
1H347
1H312
1H312
1H356
1H410
1H410
1H410
1H315
1H522
1H522
1H022
1H022
1H022
1H022
1H339
1H010
1H256
8D230
8K2408
A1013
4A556
4A556
4A556
4A556
4A556
4A556
4A1085
4A1085
4A546
4A546
4A546
4A546
4A546
4A546
4A546
4A556
4A556
4A556
4A556
4A556
4A556
4A1085
4A1085
4A546
4A546
4A546
4A546
4A546
4A546
4A546
1
2
3
4
5
6
8
7
D
D
C
C
Q_1
SK1
PHONO2HG
LEFT CHANNEL
L870C2_2.0.SCH
LEFT IN
+15V
Q_3
LEFT OUT
EMC
C1
100N CD
SK2
Q_5
1
0V_SIG
Q_2
RIGHT CHANNEL
L870C3_2.0.SCH
RIGHT IN
Q_4
Q_6
RIGHT OUT
0V_SIG
1
2
3
4
5
6
7
8
AMPCT8
Q_7
-15V
0V_SIG
Q_8
0V_HF
B
A
B
PCB1
DRAWING TITLE
EL1
PCB
L870PB_2
A
A85 PHONO STAGE - TOP LEVEL
Update Box
23425
UPDATE_BOX
Circuit Diagram
Notes:
01_1070
JAG
17/4/01
A & R Cambridge Ltd.
Pembroke Avenue
00_1051
JAG
22/3/01
Denny Industrial Centre
ECO No. INITIALS
DATE
Waterbeach
Date Printed
Filename
Cambridge CB5 9PB
G:\DATA\ECO\ECO AGENDA\01_1070 l870 A85 PHONO ISSUE2\L870_2.0.ddb - L870c1_2.0.PRJ 23-Apr-2001
1
2
3
4
5
6
updated pcb and scm
2
PRODUCTION ISSUE
1
DESCRIPTION OF CHANGE
Drawn by:
Sheet 1 of 3
JBR
7
ISSUE
DRAWING NO. L870C1
8
1
2
3
4
5
6
8
+15V
Q_102
+
7
C102
100U SILMIC
C104
100N PE
C119
D
R100
330R MF
0V_HF
R101
100R MF
100P PP
D
0V_SIG
R102
100R MF
C101
TR100
BC556B
TR102
BC556B
1N0 PP
TR103
BC556B
C110
TR101
BC556B
+ C100
22U EL
4N7 PP
C120
1N0 PP
C112
R109
12K MF
TR108
BC546B
10N PP AX
C111
R115
R110
12K MF
15K MF
10N PP AX
LEFT IN
C105
100N PE
7
TR107
2SA1085
R111
Q_101
1U0 PE
R108
47K MF
10
C109
100P PPW
11
SW100D
4PCO
R105
100R MF
0V_SIG
R119
22R MF
R117
C118
6
R122
39K MF
2M2 MF
10U NP
4
TL071CD
R113
100K MF
TR104
BC556B
0V_SIG
TR105
BC556B
12
R124
5K6 MF
IC100
3
2
56K MF
C
C113
LEFT OUT
2M2 MF
TR106
2SA1085
C108
470P PPW
C106
100N PE
R116
4
5
6
D100
1N4148
100K MF
C115
1N3 PP
R104
100R MF
R118
22R MF
R112
SW100B
4PCO
C
TR109
BC546B
R114
R123
10R MF 100K MF
C117
470P PPW
C116
0V_SIG
470P PPW
TR112
BC546B
TR113
BC546B
B
B
TR110
BC546B
TR111
BC546B
TR114
BC546B
D101
1N4148
D102
1N4148
R106
100R MF
R120
22R MF
+
R121
22R MF
0V_HF
C103
100U SILMIC
0V_SIG
C107
100N PE
Q_103
-15V
DRAWING TITLE
A
A
A85 PHONO STAGE - LEFT CHANNEL
23425
1
2
3
4
Circuit Diagram
Notes:
01_1070
JAG
17/4/01
A & R Cambridge Ltd.
Pembroke Avenue
00_1051
JAG
22/3/01
Denny Industrial Centre
ECO No. INITIALS
DATE
Waterbeach
Date Printed
Filename
Cambridge CB5 9PB
23-Apr-2001
G:\DATA\ECO\ECO
AGENDA\01_1070
l870
A85
PHONO
ISSUE2\L870_2.0.ddb
L870C2_2.0.SCH
5
6
updated pcb and scm
2
PRODUCTION ISSUE
1
DESCRIPTION OF CHANGE
Drawn by:
JBR
7
Sheet 2 of 3
DRAWING NO. 8L870C2
ISSUE
1
2
3
4
5
6
8
+15V
Q_202
+
7
C202
100U SILMIC
C204
100N PE
C219
D
R200
330R MF
0V_HF
R201
100R MF
100P PP
D
0V_SIG
R202
100R MF
C201
TR200
BC556B
TR202
BC556B
1N0 PP
C210
TR203
BC556B
TR201
BC556B
4N7 PP
C220
+ C200
22U EL
1N0 PP
C212
R209
12K MF
TR208
BC546B
10N PP AX
C211
R215
R210
12K MF
15K MF
10N PP AX
RIGHT IN
C205
100N PE
2
3
1
7
Q_201
56K MF
1U0 PE
IC200
3
C218
10U NP
R213
100K MF
TR204
BC556B
100P PPW
R205
100R MF
0V_SIG
0V_SIG
TR205
BC556B
9
8
7
C209
470P PPW
R222
39K MF
2M2 MF
2
TL071CD
R219
22R MF
R217
6
4
SW100CR224
4PCO 5K6 MF
C
C213
RIGHT OUT
2M2 MF
TR207
2SA1085
R211
R208
47K MF
C206
100N PE
R216
1N3 PP
TR206
2SA1085
R204
100R MF
D200
1N4148
100K MF
C215
C208
R218
22R MF
R212
SW100A
4PCO
C
TR209
BC546B
R214
R223
10R MF 100K MF
C216
470P PPW
0V_SIG
C217
470P PPW
TR212
BC546B
TR213
BC546B
B
B
TR210
BC546B
TR211
BC546B
TR214
BC546B
D201
1N4148
D202
1N4148
R206
100R MF
R220
22R MF
+
R221
22R MF
0V_HF
C203
100U SILMIC
0V_SIG
C207
100N PE
Q_203
-15V
DRAWING TITLE
A
A
A85 PHONO STAGE - RIGHT CHANNEL
23425
1
2
3
4
Circuit Diagram
Notes:
01_1070
JAG
17/4/01
A & R Cambridge Ltd.
Pembroke Avenue
00_1051
JAG
22/3/01
Denny Industrial Centre
ECO No. INITIALS
DATE
Waterbeach
Date Printed
Filename
Cambridge CB5 9PB
23-Apr-2001
G:\DATA\ECO\ECO
AGENDA\01_1070
l870
A85
PHONO
ISSUE2\L870_2.0.ddb
L870C3_2.0.SCH
5
6
updated pcb and scm
2
PRODUCTION ISSUE
1
DESCRIPTION OF CHANGE
Drawn by:
JBR
7
Sheet 3 of 3
DRAWING NO. 8L870C3
ISSUE
Amplifier + PSU
Board
L882
Contents
!
Circuit description
!
Component overlay
!
Parts list
!
Circuit diagrams
Amplifier & PSU Circuit Description
Refer to L882 circuit diagrams
This is the printed circuit board that provides the power
supply and output stage amplifiers for the A32 integrated and
P35 power amplifiers.
Its function is to:
! Drive the loudspeakers
! Provide an (always on) auxiliary 5VDC supply for the
micro controller and display interface
! Receive logic signals from the micro controller to turn
on the main amplifier supply relay (mains) and connect
either pair of speaker output sockets
! Send logic signals to the micro controller pertaining to
the state of the amplifiers (short circuit protection, DC
offset protection, thermal protection)
! Receive and demodulate RC5 remote style control
codes via the rear panel jack and transmit them to the
micro controller
! Send a 12V trigger output via the rear panel jack for
control of an auxiliary power amp when the unit is on
! Receive a 12V trigger input from the rear jack (for use
in the power amp only version)
! Drive a pair of headphones via attenuating resistor
networks The power amplifier is a symmetrical, class B,
bipolar junction transistor output, current-feedback
design (of which more later) with DC-coupled signal
and feedback paths, featuring an active integrating
voltage servo to control DC offsets.
It features ‘instantaneous’ safe operating area protection in
addition to sending a signal to the micro to turn off the output
relays in the event of user or thermal overload. Since it is a
DC-coupled design, the unit senses DC at the output and
triggers the micro to turn off the loudspeaker relays in the
event of excessive levels (possibly due to a faulty source
component or short circuit output transistor).
The output stage uses Sanken specialised ‘audio amplifier’
power bipolar Darlington transistors which are optimised for
use with this type of topology. Consequently the unit has
excellent measured performance in terms of noise, slew rate,
output impedance and distortion (harmonic and
intermodulated) and is essentially load invariant (to a first
order the measured performance is independent of the load
impedance).
L882 Circuit Sheet 1
The audio input to the amplifier is connected to SK102
(which connects to the output of the preamp PCB). This
signal is passed on via SK104A which forms the preamp out
connection to the outside world.
SK104B provides the power amp input connection, with
switchSW100 selecting between pre / power and integrated
modes. The unit is wired as a preamp / power amp
combination with the switch depressed, allowing the user to
insert a processor or other function (e.g. graphic EQ) between
the output of the preamp and the input of the power amp.
With the switch in the ‘out’ position the power amp input
socket is ignored and the input to the power amp is connected
internally to the output of the preamp. PL100 and PL101 are
‘handbag’ links fitted to the power amp only version to
connect both pairs of phono sockets in parallel for daisy
chaining (as there is no preamp output on a power amp).
Relays RLY100 and RLY101 switch the two pairs of
loudspeaker output sockets and are controlled by the micro
lines describes above. Transistors TR100 and TR101 operate
in ‘constant current sink’ mode which allow relay current to
be approximately constant although the main power supply
rails will vary with mains input and load conditions. The
current is around 20mA per relay.
Star point SP100 is the ground ‘mecca’ for the entire
amplifier (comprising all three PCBs within the unit). All
of the separately named grounds are joined explicitly at
this point. Different named grounds are used to ensure that
no two ‘different’ grounds share copper, which could
compromise the noise, distortion or crosstalk performance
of the amplifier.
The loudspeaker output signals are passed to socket
SK106 which connects to SK107 and onto the headphone
output via the attenuation resistors R103 thru R106.
The hierarchy containing the other sheets is self
explanatory. Each of the port names shown on the top
sheet connects to the port of the same name on the lower
sheets.
L882 Circuit Sheet 2
This sheet contains the power supplies, the rear panel jack
socket trigger circuits, the standby relay control and the
‘interface’circuits between the output signals of the power
amplifiers and the inputs expected by the micro processor.
The mains input enters the unit at SK203, with capacitors
C205 and C206 acting as conducted RF suppression. The
earth connection is passed on to the chassis (for safety
reasons the chassis metalwork remains connected to mains
power earth at all times). Switch SW200 is the voltage
selector switch, allowing the unit to be operated in 230V
or 115V mains countries by switching the dual-primary
mains transformers between series and parallel winding.
Varistors VR200 and VR201 act to prevent over-voltage
surges from damaging the unit. If the user selects 115V
operation and then connects the unit to a 230V supply, the
varistors will go to a low impedance and blow the primary
fuses. Any very high voltage line transients will also be
suppressed, helping to eliminate transformer isolation
breakdown.
Relay RLY200 switches the primary side of the mains
transformer, allowing the micro to control the on / off
status of the amplifier. Its contacts are snubbed by
capacitors C207 and C208 (to eliminate switching spark
transients and prolong relay lifespan). The primary
windings of the toroidal mains transformer connect to
SK204.
PCB mounted transformer TX200 is powered all the time
that mains is present on SK203, irrespective of the on / off
status of the amplifier. This is to ensure that the micro
processor is always operational and can thus control the
mains switching for the main amplifier. Secondary fuse
F202 limits the current in the event of a failure mode, as
the short circuit primary current of TX200 would be
insufficient to blow the mains fuses.
Diodes D200 thru D203, C227 and IC201 provide the
5VDC supply which powers the micro and display PCB
and the relay coils. C224 is to reduce diode noise being
transmitted back through the leakage capacitance of
TX200.
The mains transformer secondary winding is connected to
SK200. This is a centre tapped winding, and is used with
full bridge rectifier BR200 to produce the main positive
and negative supplies for the power amp. C209 and C210
are the large reservoir capacitors, with C211 and C212
acting as high frequency decouplers. The main power
supply rails and ground are accessible on SK205 for future
module expansion.
The circuitry around SK201A and IC200 is to receive and
demodulate remote control commands sent in via the rear
panel jack socket. This is for multi-room applications. L200
and C200 form a parallel resonant circuit at approximately
37kHz. The output from this bandpass filter is passed into
IC200A where it is ‘chopped’ and fed to IC200B to provide
the output signal.
SK201B is a 13VDC signal trigger output which is active
whenever the amplifier is powered up. R218 and DZ207 /
C223 provide a reference voltage which is buffered by
TR200. TR201 and R217 act as a current limit and prevent
damage due to a short circuit on the output of SK201B. The
maximum current is approximately 65mA.
TR203 and TR202 are a complementary Darlington pair
which turn on mains relay RLY200 when activated by a
signal from the microprocessor.
TR204 and its associated components are to detect whenever
AC mains is present at the IEC socket. This is to notify the
microprocessor if the user has unplugged the mains cord, so
that it can take the necessary action (muting all the outputs
and switching off the mains relay). The reservoir capacitors
should last at least 4 mains cycles which gives the
microprocessor plenty of time for a controlled shutdown.
TR204 forms a monostable circuit. Each cycle of AC turns on
TR204 via R211. TR204 then ‘shunts’ C229 ensuring that it
is kept at a low potential. If more than one mains cycle is
missing, then R219 charges up C229 sufficiently to trigger
Schmitt inverter IC202E thus passing on a logic signal to the
microprocessor. The use of a Schmitt inverter for IC202 is to
ensure that the micro receives ‘clean’ logic levels - the
hysteresis voltage (about 0.5V) is sufficient to prevent circuit
noise from producing a string of ‘ghost’ signals when
analogue levels are near the threshold point.
TH200 is a positive tempco thermistor placed adjacent to the
heatsink on which the output transistors are mounted. When
the temperature of the thermistor exceeds 90 degrees Celsius
the thermistor goes to a high impedance and so the input to
IC202F goes low. This triggers a HIGH output to the micro
indicating thermal overload.
The VI protection signals from the left and right channels
pass into IC202A and IC202B respectively, to be ‘cleaned
up’ via the Schmitt trigger. They are then NOR’d using
TR205 which sends a HIGH signal to the micro in the event
of either channel suffering a short circuit or current overload.
Exactly the same approach is used for the DC fault lines
using IC202C and IC202D.
L882 Circuit Sheet 3
This is the main audio power amplifier circuit. The amplifier
is a class B design, which uses SAP ‘audio’ transistors in a
symmetrical current feedback configuration. Input and
feedback paths are DC coupled and there is an active
integrating servo to remove DC offsets from the output.
The basic principle of operation is follows:
The input signal is amplified by a factor of 2 in IC300A. This
drives a 44˜ impedance to ground causing the supply pin
currents to change with the signal level. These changing
supply pin currents are then ‘reflected’ by a pair of
complementary Wilson mirrors and passed on to a series of
buffer transistors before being connected to the load. The
‘feedback current’ flows back from the output terminal via
R331 and R332 and attempts to provide the current necessary
to allow IC300A to swing its output without drawing
excessive current from its supply pins, thus making the
change in supply current very small indeed. This is why the
term ‘current feedback’ is used - it is the current flowing in
the feedback resistors that sets the overall gain of the
amplifier.
IC300B acts as an inverting integrator and its purpose is to
remove DC from the loudspeaker output. Any positive DC
offset will cause the output of IC300B to go negative, thus
increasing the current in its negative supply pin and
pulling the output voltage back towards zero. R330 and
C317 set the time constant of this integrator (0.47 seconds)
so that audio frequency components are ignored and only
DC and subsonic frequencies are removed.
The input to the amplifier is limited to ±5.4V via back-toback zener diodes DZ302 and DZ303. This is to prevent
the user from grossly overdriving the input to the amplifier
and possibly causing damage. The diodes appear before
series resistor R324 so that their variable capacitance does
not introduce high frequency harmonic distortion.
R324, R327 and C316 act as an input filter - this is a first
order low pass filter with a corner frequency of around
340kHz to prevent RF signals from being injected into the
front end of the amplifier. The corner frequency was
chosen such that the phase shift introduced is less than 5˜
at 20kHz (considered by the AES to be the minimum
perceptible relative amount by the human ear). The input
impedance of the amplifier is 23kW at DC, falling to
around 14kW at 20kHz.
Operational amplifier IC300A is acting as a non-inverting
gain of 2, driving the input signal into a 44W impedance to
ground via R322 and R337. Its output voltage will be an
accurate amplification of its input voltage (i.e. the signal
on pin 1 should look identical to that on pin 3 but at twice
the amplitude). The op-amp is used in a slightly unusual
configuration here, in that its power supply pins are used
as a (current) output, and its output pin is used as a
(current) feedback.
Transistors TR311 and TR303 supply the ±15V rails to the
op-amp, and act as cascades to pass its supply pin currents
through to the current mirrors, which sit at a potential too
high for the op-amp to be connected directly.
TR300, TR301 and TR321 form a PNP Wilson current
mirror, which reflects the current sunk by the positive
supply pin of IC300. Likewise TR314, TR315 and TR320
form an NPN Wilson current mirror, which reflects the
current sourced by the negative supply pin of IC300.
R315 thru R318 provide emitter degeneration of
approximately 300mV for the current mirrors (as they pass
about 3mA DC in quiescent conditions), to ensure accurate
operation independent of the small variations between the
transistors in the current mirrors. They also ensure that the
current passing down the next stage is reasonably constant
as the internal temperature of the amplifier changes,
swamping out small thermal variations in the VBE of the
mirror transistors.
R319 and R320 slightly decouple the rails to the current
mirrors from the main power rails of the amplifier, to
allow the bootstrap circuit to operate. The bootstrap
consists of C302 and C306 with metal film power resistors
R352 and R353. The bootstrap is provided to allow the
power supply rails of the current mirrors to go up and
down slightly with the output signal into the loudspeaker.
This enables the driver stage to fully saturate the output
transistors and thus give the greatest power output and best
thermal efficiency for any given power rail voltage. The
voltage on the ‘inside’ end of R319 and R320 will vary by
about 12 volts peak to peak at full output power, rising
above the main power rails during signal peaks.
C307 and C308 with R333 and R335 provide the
compensation necessary to ensure stability when the loop is
closed. They are Miller capacitors which dramatically reduce
the transimpedance (i.e. current to voltage gain) of the current
mirrors at high frequencies. The present value of 47pF
provides for a unity gain open loop bandwidth of around
75MHz, whilst ensuring a closed loop gain margin of around
6dB (note that gain margin in a current feedback design is not
dependent on system bandwidth to a first order
approximation). R333 and R335 provide a ‘zero’ in the open
loop frequency response which is tailored to give the best
time domain performance (i.e. to make high frequency square
waves look square with minimal ringing or overshoot).
DZ304 and C311 provide a fixed 4.7V bias voltage to allow
the following stages to operate correctly. C311 is there to
ensure that both halves of the following stage receive an
equal AC signal component at high frequency.
TR310 and TR307 are the ‘pre-driver’ transistors, which act
to buffer the outputs from the preceding stage and drive the
Darlington output power transistors. TR309 and R321 act as a
current limit, to ensure that the emitter current of TR310 does
not exceed 30mA in a fault condition. TR306 and R323
provide the same function for TR307.
R338 and R339 are to loosely couple the outputs of the predriver stage to the inputs of the Darlington power output
devices. This is so that the inbuilt temperature sensing diodes
of the output transistors can accurately control the quiescent
current of the output stage as the junction temperature of the
power devices varies. C312 and C318 ensure that both halves
of the output stage receive an equal AC signal component.
The output transistors are TR318 and TR319. These are
Sanken SAP15N and SAP15P devices respectively. They are
specially designed for audio power amplifier use. In addition
to high current gain (Darlington with a typical hFE of 20,000)
they provide an inbuilt emitter resistor (thick film power
resistor of 0W22) and temperature sensing diodes which
closely and rapidly track the VBE versus temperature
characteristic of the power transistors, allowing for easy, fastresponding and reasonably accurate control of quiescent
current.
RV300 is for fine trimming of the quiescent current. PL300
provides a convenient measuring point for this, which is
short-circuit protected in the event of a slip with the
multimeter probe! All of the remaining circuitry to the right
of TR318 and TR319 is essentially for output stage
protection...
Transistors TR312 and TR304, along with the network of
resistors and capacitors to which they are connected, provide
instantaneous overload protection of the output stage. This is
a conventional single slope VI protection scheme, which
allows much greater current to be delivered into a rated load
than into a short circuit. The values allow for 18A peak
delivery (at clip) into a purely resistive load, 7A peak (at clip)
into a purely capacitive load and around 4A peak into a short
circuit. R345, C303, R346 and C304 allow these values to be
doubled for short transient bursts (approximately 2.7
milliseconds) so that impulsive musical transients can be
delivered cleanly with minimal risk of damaging the output
transistors.
TR313, TR302 and their associated components send a signal
to the microprocessor when the instantaneous protection
circuits are having to work ‘hard’ to prevent amplifier
overload. This instructs the micro that the user is severely
abusing the amplifier and will switch off the loudspeaker
relays to prevent possible permanent damage. In reality, if
you short circuit the outputs at any appreciable volume level,
this circuit will trigger and the microprocessor will turn off
the loudspeaker relays and send a signal to the user.
R308, R314 and C320 form a low pass filter from which
the DC detection circuits can sense excessive DC at the
loudspeaker outputs. If there is any positive DC present,
then TR316 will turn on, which turns on TR305 and thus
activates the DC protection line to the micro, turning off
the loudspeaker relays.
If there is any negative DC present, then TR308 will turn
on, which turns on TR317 which then turns on TR305 in
turn, causing the same effect.
R350 and C319 are the Zobel network which is provided
to ensure the amplifier ‘sees’ a constant and resistive load
at very high frequencies, to aid stability, although the
amplifier will be stable without the Zobel fitted.
C313 locally couples the ‘high frequency’ and loudspeaker
ground returns together at the output to overcome the
effects of track inductance back to the star point. C309
couples the ‘high frequency’ and signal grounds together
at the input for the same reason.
D303 and D304 are ‘flyback’ diodes to protect the output
transistors from reverse bias when the amplifier is heavily
clipped into an inductive load (such as a loudspeaker voice
coil!)
Sheet 4 is an identical copy of sheet 3 so I will not
describe it separately.
L882 Amplifier and PSU Board Parts List Issue 3.0
Designator Part
Description
BR200
C100
C200
C201
C202
C203
C204
C205
C206
C207
C208
C209
C210
C211
C212
C213
C214
C215
C216
C217
C218
C219
C220
C221
C222
C223
C224
C225
C226
C227
C228
C229
C230
C231
C232
C233
C234
C235
C300
C301
C302
C303
C304
C305
C306
C307
C308
C309
C310
C311
C312
C313
C314
C315
C316
C317
C318
C319
C320
C400
C401
C402
BRIDGE RECTIFIER 8A 200V
MLC 1N0 50V X7R 10% SM
PPRO 680P 5% 63V RA
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
SUPPR CAP 3N3 250V
SUPPR CAP 3N3 250V
SUPPR CAP 3N3 250V
SUPPR CAP 3N3 250V
ELST 10m 63V RA 35mm
ELST 10m 63V RA 35mm
PCRB 100N 100V 10% RA 5mm
PCRB 100N 100V 10% RA 5mm
MLC 10N 50V X7R 10% SM
MLC 10N 50V X7R 10% SM
MLC 10N 50V X7R 10% SM
MLC 10N 50V X7R 10% SM
MLC 10N 50V X7R 10% SM
MLC 10N 50V X7R 10% SM
MLC 10N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 10N 50V X7R 10% SM
ELST 10U 50V
ELST 10U 50V
CERD 100N 63V 20% RA
CERD 100N 63V 20% RA
CERD 100N 63V 20% RA
ELST 3M3 25V
ELST 1M0 10V
ELST 22U 63V
MLC 10N 50V X7R 10% SM
MLC 1N0 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
ELST 10U 50V
220NF CLASS X2 CAP 275VRMS
MLC 1N0 50V X7R 10% SM
ELST 100U 25V
ELST 100U 25V
ELST 100U 100V
ELST 100U 25V
ELST 100U 25V
ELST 10U 50V
ELST 100U 100V
MLC 100P 50V NPO 5% SM
MLC 100P 50V NPO 5% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
PCRB 100N 100V 10% RA 5mm
MLC 10N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
PPRO W 470P 63V 5% RA
PEST 470N 63V 10%
ELST 10U 50V
PEST 100N 63V 10%
ELST NON POLAR 100UF 16V
ELST 100U 25V
ELST 100U 25V
ELST 100U 100V
3BGBU8D
2C210
2D168
2C410
2C410
2C410
2C410
2K233
2K233
2K233
2K233
2N910A
2N910A
2H410
2H410
2C310
2C310
2C310
2C310
2C310
2C310
2C310
2C410
2C310
2N610
2N610
2A410
2A410
2A410
2N833
2N810A
2N622
2C310
2C210
2C410
2N610
2D422
2C210
2N710
2N710
2N710B
2N710
2N710
2N610
2N710B
2C110
2C110
2C410
2C410
2H410
2C310
2C410
2C410
2C410
2D147W
2K447
2N610
2K410
2V710
2N710
2N710
2N710B
L882 Amplifier and PSU Board Parts List Issue 3.0
Designator Part
Description
C403
C404
C405
C406
C407
C408
C409
C410
C411
C412
C413
C414
C415
C416
C417
C418
C419
C420
D100
D101
D200
D201
D202
D203
D205
D206
D300
D301
D302
D303
D304
D400
D401
D402
D403
D404
DZ204
DZ207
DZ300
DZ301
DZ302
DZ303
DZ305
DZ306
DZ400
DZ401
DZ402
DZ403
DZ405
DZ406
EL
F200
F200
F200
F201
F201
F201
F202
HS200
HS200
IC200
IC201
ELST 100U 25V
ELST 100U 25V
ELST 10U 50V
ELST 100U 100V
MLC 100P 50V NPO 5% SM
MLC 100P 50V NPO 5% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
PCRB 100N 100V 10% RA 5mm
MLC 10N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
PPRO W 470P 63V 5% RA
PEST 470N 63V 10%
ELST 10U 50V
PEST 100N 63V 10%
ELST NON POLAR 100UF 16V
RECTIFIER 1N4003F 1A 200V
RECTIFIER 1N4003F 1A 200V
RECTIFIER 1N4003F 1A 200V
RECTIFIER 1N4003F 1A 200V
RECTIFIER 1N4003F 1A 200V
RECTIFIER 1N4003F 1A 200V
DIODE SS SM BAS16W
DIODE SS SM BAS16W
DIODE SS SM BAS16W
DIODE SS SM BAS16W
DIODE SS SM BAS16W
RECTIFIER 1N4003F 1A 200V
RECTIFIER 1N4003F 1A 200V
DIODE SS SM BAS16W
DIODE SS SM BAS16W
DIODE SS SM BAS16W
RECTIFIER 1N4003F 1A 200V
RECTIFIER 1N4003F 1A 200V
ZENER 4V7 OW 35 SM SOT23
ZENER 15V OW35 SM SOT23
ZENER 15V OW35 SM SOT23
ZENER 15V OW35 SM SOT23
ZENER 4V7 OW 35 SM SOT23
ZENER 4V7 OW 35 SM SOT23
ZENER 4V7 OW 35 SM SOT23
ZENER 4V7 OW 35 SM SOT23
ZENER 15V OW35 SM SOT23
ZENER 15V OW35 SM SOT23
ZENER 4V7 OW 35 SM SOT23
ZENER 4V7 OW 35 SM SOT23
ZENER 4V7 OW 35 SM SOT23
ZENER 4V7 OW 35 SM SOT23
EARTH LEAD
FUSE 20mm 2A AS
INS COVER PCB FUSEHOLDER
FUSEHOLDER 20mm PCB
INS COVER PCB FUSEHOLDER
FUSEHOLDER 20mm PCB
FUSE 20mm 2A AS
FUSE R452 T500mA
HEATSINK TO220 8.6 DEGC/W
HEATSINK CLIP TO220 13/8.6 DC/W
IC COMPARATOR SM DUAL LM393A
IC VREG POS 7805
2N710
2N710
2N610
2N710B
2C110
2C110
2C410
2C410
2H410
2C310
2C410
2C410
2C410
2D147W
2K447
2N610
2K410
2V710
3B4003
3B4003
3B4003
3B4003
3B4003
3B4003
3AS16W
3AS16W
3AS16W
3AS16W
3AS16W
3B4003
3B4003
3AS16W
3AS16W
3AS16W
3B4003
3B4003
3CW34V7
3CW315V
3CW315V
3CW315V
3CW34V7
3CW34V7
3CW34V7
3CW34V7
3CW315V
3CW315V
3CW34V7
3CW34V7
3CW34V7
3CW34V7
8M101
C12207
F022
8S004
F022
8S004
C12207
C3501
F008
F006
5M393AD
5D7805
L882 Amplifier and PSU Board Parts List Issue 3.0
Designator Part
Description
IC202
IC300
IC400
L200
L300
L400
PCB
PL100
PL101
PL300
PL400
R100
R101
R102
R103
R104
R105
R106
R107
R108
R200
R201
R202
R203
R204
R205
R206
R207
R208
R209
R210
R211
R212
R213
R214
R215
R216
R217
R218
R219
R220
R221
R222
R223
R224
R225
R226
R227
R228
R229
R230
R231
R300
R301
R302
R303
R304
R305
R306
R307
R308
R309
SURFACE MOUNT HEX SCHMITT TRIGGER
IC AUDIO SM DUAL TL072
IC AUDIO SM DUAL TL072
27mH INDUCTOR
INDUCT 2U2 12x20mm
INDUCT 2U2 12x20mm
PRINTED CIRCUIT BOARD
2WAY MOLEX VERT MALE CONNECTOR
2WAY MOLEX VERT MALE CONNECTOR
2WAY MOLEX VERT MALE CONNECTOR
2WAY MOLEX VERT MALE CONNECTOR
RES MF W4 1% 10R
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES CF 1W 330R 5%
RES CF 1W 330R 5%
RES CF 1W 100R 5%
RES CF 1W 100R 5%
RES SM W4 1% 220R 1206
RES SM W4 1% 220R 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 4K7 1206
RES SM W4 1% 4K7 1206
RES SM W4 1% 4K7 1206
RES SM W4 1% 4K7 1206
RES SM W4 1% 4K7 1206
RES SM W4 1% 10R 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 1K8 1206
RES SM W4 1% 10R 1206
RES SM W4 1% 10R 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 1K8 1206
RES SM W4 1% 1K8 1206
RES SM W4 1% 470R 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 100K 1206
RES SM W4 1% 100K 1206
RES SM W4 1% 1K5 1206
RES W25 5% VR25 1M5
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
5J7414D
5B072D
5B072D
7D327
7D002C
7D002C
L882PB_3
8K6201
8K6201
8K6201
8K6201
1H010
1A110
1A110
1.00E+133
1.00E+133
1.00E+110
1.00E+110
1A122
1A122
1A210
1A210
1A210
1A210
1A210
1A210
1A210
1A210
1A310
1A310
1A310
1A310
1A247
1A247
1A247
1A247
1A247
1A010
1A310
1A218
1A010
1A010
1A310
1A310
1A218
1A218
1A147
1A210
1A410
1A410
1A215
1K515
1A310
1A310
1A310
1A310
1A310
1A310
1A310
1A310
1A310
1A310
L882 Amplifier and PSU Board Parts List Issue 3.0
Designator Part
Description
R310
R311
R312
R313
R314
R315
R316
R317
R318
R319
R320
R321
R322
R323
R324
R325
R326
R327
R328
R329
R330
R331
R332
R333
R334
R335
R336
R337
R338
R339
R340
R341
R342
R343
R344
R345
R346
R347
R348
R349
R350
R351
R352
R353
R354
R355
R400
R401
R402
R403
R404
R405
R406
R407
R408
R409
R410
R411
R412
R413
R414
R415
RES SM W4 1% 4K7 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 4K7 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 22R 1206
RES SM W4 1% 22R 1206
RES SM W4 1% 22R 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 4K7 1206
RES SM W4 1% 4K7 1206
RES SM W4 1% 1M0 1206
RES SM W4 1% 1K5 1206
RES SM W4 1% 1K8 1206
RES SM W4 1% 3K3 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 3K3 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22R 1206
RES SM W4 1% 150R 1206
RES SM W4 1% 150R 1206
RES SM W4 1% 100K 1206
RES SM W4 1% 330R 1206
RES SM W4 1% 330R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 0R0 1206
RES SM W4 1% 0R0 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES CF 2W 5R6 5%
RES MF W4 1% 10R
RES 2W MF 5% 470R
RES 2W MF 5% 470R
RES SM W4 1% 1K0 1206
RES SM W4 1% 6K8 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 4K7 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 4K7 1206
RES SM W4 1% 100R 1206
1A247
1A310
1A310
1A310
1A247
1A110
1A110
1A110
1A110
1A110
1A110
1A022
1A022
1A022
1A210
1A210
1A210
1A322
1A247
1A247
1A510
1A215
1A218
1A233
1A322
1A233
1A322
1A022
1A115
1A115
1A410
1A133
1A133
1A110
1A110
1A000
1A000
1A110
1A110
1A110
1C856
1H010
1J147
1J147
1A210
1A268
1A310
1A310
1A310
1A310
1A310
1A310
1A310
1A310
1A310
1A310
1A247
1A310
1A310
1A310
1A247
1A110
L882 Amplifier and PSU Board Parts List Issue 3.0
Designator Part
Description
R416
R417
R418
R419
R420
R421
R422
R423
R424
R425
R426
R427
R428
R429
R430
R431
R432
R433
R434
R435
R436
R437
R438
R439
R440
R441
R442
R443
R444
R445
R446
R447
R448
R449
R450
R451
R452
R453
R454
R455
RLY100
RLY101
RLY200
RV300
RV400
SH200
SK100
SK101
SK102
SK103
SK104
SK105
SK106
SK107
SK200
SK201
SK202
SK203
SK204
SK205
SW100
SW200
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 22R 1206
RES SM W4 1% 22R 1206
RES SM W4 1% 22R 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 4K7 1206
RES SM W4 1% 4K7 1206
RES SM W4 1% 1M0 1206
RES SM W4 1% 1K5 1206
RES SM W4 1% 1K8 1206
RES SM W4 1% 3K3 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 3K3 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22R 1206
RES SM W4 1% 150R 1206
RES SM W4 1% 150R 1206
RES SM W4 1% 100K 1206
RES SM W4 1% 330R 1206
RES SM W4 1% 330R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 0R0 1206
RES SM W4 1% 0R0 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES CF 2W 5R6 5%
RES MF W4 1% 10R
RES 2W MF 5% 470R
RES 2W MF 5% 470R
RES SM W4 1% 1K0 1206
RES SM W4 1% 6K8 1206
RELAY G5Z-2A-E 24V
RELAY G5Z-2A-E 24V
RELAY MAINS DPDT 5V 5A
PRES 100R LIN HORIZ
PRES 100R LIN HORIZ
MAINS EMC SHIELD
CAMCON BINDING POST 4WAY GOLD
CAMCON BINDING POST 4WAY GOLD
4-WAY AMP CT CONN
FFC 14W 2.54MM VER PTH
PHONO SKT 4-WAY EMC GOLD
STEREO JACK PCB
4-WAY AMP CT CONN
4-WAY AMP CT CONN
MOLEX MINI FIT HCS 6 WAY
MIN JACK DUAL 3.5mm HSJ1002-01-1020
CAGE CLAMP 16A 1 WAY ARC003-236
IEC MAINS CONN PCB INS PX
MOLEX MINI FIT HCS 8 WAY
6-WAY AMP CT CONN
SW PUSH 2PCO
VOLTAGE SELECTOR SLIDE SWITCH
1A110
1A110
1A110
1A110
1A110
1A022
1A022
1A022
1A210
1A210
1A210
1A322
1A247
1A247
1A510
1A215
1A218
1A233
1A322
1A233
1A322
1A022
1A115
1A115
1A410
1A133
1A133
1A110
1A110
1A000
1A000
1A110
1A110
1A110
1C856
1H010
1J147
1J147
1A210
1A268
A207
A207
A219
6F110
6F110
E5402
8D418G
8D418G
8K2404
8K7014
8D225
8D301
8K2404
8K2404
8K2306
8D302
8Q003
8A001
8K2308
8K2406
A1008
A1404
L882 Amplifier and PSU Board Parts List Issue 3.0
Designator Part
Description
TH200
TR100
TR101
TR200
TR201
TR202
TR203
TR204
TR205
TR206
TR300
TR301
TR302
TR303
TR304
TR305
TR306
TR307
TR308
TR309
TR310
TR311
TR312
TR313
TR314
TR315
TR316
TR317
TR318
TR319
TR320
TR321
TR322
TR400
TR401
TR402
TR403
TR404
TR405
TR406
TR407
TR408
TR409
TR410
TR411
TR412
TR413
TR414
TR415
TR416
TR417
TR418
TR419
TR420
TR421
TR422
TX200
THERMISTOR SIEMENS B59008
NPN TRANS MP BD179
NPN TRANS MP BD179
NPN TRANS MP BD179
TRANS LF SS N SM FMMT497
TRANS LF SS P SM FMMT597
TRANS LF SS N SM FMMT497
TRANS LF SS N SM BC849B
TRANS LF SS P SM BC856B
TRANS LF SS P SM BC856B
TRANS LF SS P SM FMMT597
TRANS LF SS P SM FMMT597
TRANS LF SS P SM FMMT597
TRANS LF SS P SM FMMT597
TRANS LF SS P SM FMMT597
TRANS LF SS P SM FMMT597
TRANS LF SS P SM FMMT597
TRANS LF SS P SM FMMT597
TRANS LF SS P SM FMMT597
TRANS LF SS N SM FMMT497
TRANS LF SS N SM FMMT497
TRANS LF SS N SM FMMT497
TRANS LF SS N SM FMMT497
TRANS LF SS N SM FMMT497
TRANS LF SS N SM FMMT497
TRANS LF SS N SM FMMT497
TRANS LF SS N SM FMMT497
TRANS LF SS N SM FMMT497
TRANS POWER NPN SAP15N
TRANS POWER PNP SAP15P
TRANS LF SS N SM FMMT497
TRANS LF SS P SM FMMT597
TRANS LF SS N SM FMMT497
TRANS LF SS P SM FMMT597
TRANS LF SS P SM FMMT597
TRANS LF SS P SM FMMT597
TRANS LF SS P SM FMMT597
TRANS LF SS P SM FMMT597
TRANS LF SS P SM FMMT597
TRANS LF SS P SM FMMT597
TRANS LF SS P SM FMMT597
TRANS LF SS P SM FMMT597
TRANS LF SS N SM FMMT497
TRANS LF SS N SM FMMT497
TRANS LF SS N SM FMMT497
TRANS LF SS N SM FMMT497
TRANS LF SS N SM FMMT497
TRANS LF SS N SM FMMT497
TRANS LF SS N SM FMMT497
TRANS LF SS N SM FMMT497
TRANS LF SS N SM FMMT497
TRANS POWER NPN SAP15N
TRANS POWER PNP SAP15P
TRANS LF SS N SM FMMT497
TRANS LF SS P SM FMMT597
TRANS LF SS N SM FMMT497
TRANSFORMER 3VA 9V+9V TYPE 9301
1T002
4B179
4B179
4B179
4AFMMT497
4AFMMT597
4AFMMT497
4A849B
4A856B
4A856B
4AFMMT597
4AFMMT597
4AFMMT597
4AFMMT597
4AFMMT597
4AFMMT597
4AFMMT597
4AFMMT597
4AFMMT597
4AFMMT497
4AFMMT497
4AFMMT497
4AFMMT497
4AFMMT497
4AFMMT497
4AFMMT497
4AFMMT497
4AFMMT497
4CSAP15N
4CSAP15P
4AFMMT497
4AFMMT597
4AFMMT497
4AFMMT597
4AFMMT597
4AFMMT597
4AFMMT597
4AFMMT597
4AFMMT597
4AFMMT597
4AFMMT597
4AFMMT597
4AFMMT497
4AFMMT497
4AFMMT497
4AFMMT497
4AFMMT497
4AFMMT497
4AFMMT497
4AFMMT497
4AFMMT497
4CSAP15N
4CSAP15P
4AFMMT497
4AFMMT597
4AFMMT497
7A9301
2
3
4
5
6
L882C3
L882C3_4.1.SCH
L SIG
0V_SIG
0V_LS_L
0V_HF_L
+49V
-49V
D
INPUT
0V_SIG
0V_LS
0V_HF
VPOS
VNEG
3
0V_SIG
VIPROT_L
DCPROT_L
LS L
VIPROT
DCPROT
OUTPUT
INPUT
0V_SIG
0V_LS
0V_HF
VPOS
VNEG
VIPROT_R
DCPROT_R
LS R
VIPROT
DCPROT
OUTPUT
STANDBY
VIPROT_L
VIPROT_R
0V_TRIG
DCPROT_L
DCPROT_R
L SIG
R SIG
2
1
SK104B
FROM PREAMP
0V_LS_L
TP102
SK104A
LS R
F
N
TP100
EMC
PL101
D100
1N4003F
4
5
SK105
PHONO4G
R103
330R 1W CF
TP119
6
7
R104
330R 1W CF
TP120
HPSKT
2
1
SK107
1
2
3
4
0V_LS_R
7
0V_LS_L
0V_PSU
RLY101C
RLY G5Z-2A-E
TR101
BD179
TR100
BD179
D101
1N4003F
R101
SPKR1 ON
100R SM
R102
SPKR2 ON
100R SM
AMPCT4
R105
R106
100R 1W CF 100R 1W CF
R107
220R SM
R108
220R SM
6
0V_SIG
5
D
2
C
TP118
2
3
1
0V_SIG
4
RLY100C
RLY G5Z-2A-E
AMPCT4
N
PHONO4G
SP100
STAR_8
F
C100 0V_SIG
1N0 SM
AMPCT4
+5V_D
+49V
-49V
THERMPROT
VIPROT
AC PRESENT
DCPROT
REMOTE
TRIGGER
SK106
1
2
3
4
PL100
1
8
0V_HF_L
0V_D
+5V(D)
0V_PSU
VPOS
PWRON
VNEG
VIPROT_L
THPROT_uC
VIPROT_R
VIPROT_uC
0V_TRIG
AC_PRES
DCPROT_L DCPROT_uC
DCPROT_R
RC5 IN
TRG IN
3
2
1
L882C2
L882C2_4.1.SCH
0V_HF_R
LS L
TP101
SK102
1
2
3
4
1
0V_D
6
TP121
+49V
SW100A
2PCO
C
5
0V_TRIG
0V_D
0V_PSU
L882C4
L882C4_4.1.SCH
R SIG
0V_SIG
0V_LS_R
0V_HF_R
+49V
-49V
8
7
4
1
SW100B
2PCO
0V_D
INTEGRATED / PRE-POWER
MODE SELECT SWITCH
SK100A
RLY100A
LS L
SK100B
RLY101A
Top+
TP111
+5V_D
TP113
RLY G5Z-2A-E
Bot+
TP115
RLY G5Z-2A-E
PCB
0V_LS_L
PCB
B
TopSK103
1
2
3
4
5
6
7
8
9
10
11
12
13
14
R100
+49V
B
Bot-
CAMCON_G
CAMCON_G
L882PB_4
10R MF
EL
STANDBY
SPKR1 ON
SPKR2 ON
THERMPROT
VIPROT
DCPROT
AC PRESENT
TRIGGER
REMOTE
0V_D
TP103
TP104
TP105
TP106
TP107
TP108
TP109
TP110
TP117
SK101A
RLY100B
LS R
Top+
TP112
TP114
RLY G5Z-2A-E
EARTH LEAD
8M101
EARTH LEAD
SK101B
RLY101B
Bot+
TP116
RLY G5Z-2A-E
0V_LS_R
Top-
Bot-
CAMCON_G
CAMCON_G
FFC 14W 2.54MM VER
8K7014
DRAWING TITLE
A
A
A85 amplifier and PSU - top sheet
23425
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
1
2
3
4
Circuit Diagram
Notes:
Filename
02_E062
JBR
20/3/02
LDO REG FITTED TO IC201
02_E035
JBR
4/2/2002
FUSE VALUES UPRATED TO T4A
ECO No.
INITIALS
20-Mar-2002
5
6
4.0
DESCRIPTION OF CHANGE
Drawn by:
Date Printed
L882C1_4.1.PRJ
DATE
4.1
J Reckless
7
Sheet 1 of 4
DRAWING NO.
ISSUE
L882C1
8
1
2
3
4
5
6
7
8
NEUTRAL
SK204
7
2
6
1
5
TP203
HS200
TO220HS08REG
TX200
1 0V
MOLEXPWR8
F202
T750mA SM
LIVE
C205
3N3 MAINS
EMC Shield
Green
1
TP200
NEUTRAL
SK202
CAGECLAMP1
NF
VR200
VDR 115V
C207
F200
TP202
3N3 MAINS
T4A
C206
3N3 MAINS
BC200
TOOLING4.1
SW200B
VOL SEL SLIDE
L
L
E
N
SH200
EMCMAINS
E
NEUTRAL
TP201
SW200A
VOL SEL SLIDE
F201
TP210
3N3 MAINS
EARTH
C234
Vout
O
+5V(D)
TP205
C225
100N CD
+
C226
100N CD
+ C228
1000u 10V
C227
3300u 25V
D201
1N4003F
C208
LIVE
Vin
D203
1N4003F
NF
VR201
VDR 115V
DPDT5V
TP207
I
D202
1N4003F
C224
100N CD
0V
6
7
9V
RLY200B
LIVE
TP206
2 115V
3
D200
1N4003F
+5V_D
G
DPDT5V
N
IC201
L4940V5
TP204
5
9V
RLY200A
D
9VRMS
HS
SK203
IEC3 NO RIVETS
8
3
GND
D
4
0V_D
0V
8
4 115V
TX 3VA 9301
0V_D
T4A
MAINS WIRING AND AUXILIARY SUPPLY
220N X2 CLASS
R231
1M5 VR25
+5V_D
R219
1K8 SM
9VRMS
IC202E
C
TR204
BC849B
+49V
1
+
SK200
6
2
5
74HC14D
~
2
~
0V_PSU
+ C210
10,000u 63V
4
D206
BAS16W SM
SK205
1
2
3
4
5
6
C211
100N PC
0V_PSU
+ C229
22U EL
MICROPROCESSOR SIGNALS INTERFACE
0V_D
AMPCT6
4
1
3
-
3
AC_PRES
10K SM
VPOS
+ C209
10,000u 63V
C
R220
10
10R SM
R211
TP208
BR200
BRGBU8D
11
C212
100N PC
MOLEXPWR6
+5V_D
TP209
VNEG
POWER AMP SUPPLY
14
TH200
PTH90DEG
C201
100N SM
IC202G
74HC14D
C202
100N SM
IC202F
13
12
7
-49V
CARRIER FILTER AND DEMODULATOR
THPROT_uC
74HC14D
+5V_D
R209
10K SM
TRG IN
R221
10R SM
R205
1K0 SM
R223
10K SM
0V_D
IC200A
2
B
TP211 470R SM
Near to PCB
JACK3.5X2
3
100K SM
L200
27mH
R224
1K8 SM
C200
680P PP
+5V_D
IC200C
LM393A SM
LM393A SM
DZ204
4V7 350MW SM
R227
1K0 SM
8
1
R228
R229
100K SM
C232
100N SM
+ C233
10U EL
B
IC202A
4
R226
SK201A
R201
VIPROT_L
MODULATED RC5
REMOTE CONTROL INPUT
R230
1K5 SM
R208
10K SM
VIPROT_R
5
R202
1K0 SM
R222
6
10K SM
LM393A SM
R225
1K8 SM
1
2
TR205
BC856B
R213
C203
100N SM
4K7 SM
C214
10N SM
74HC14D
IC202B
C230
10N SM
IC200B
7
RC5 IN
1K0 SM
3
VIPROT_uC
4
C215
10N SM 74HC14D
R214
4K7 SM
R206
1K0 SM
C219
10N SM
C218
10N SM
C231
1N0 SM
0V_D
0V_D
+5V_D
0V_TRIG
+49V
R218
10K SM
+5V_D
RLY200C
DPDT5V
TR200
BD179
D205
BAS16W SM
R200
1K0 SM
STANDBY RELAY CONTROL
TR202
FMMT597
1K0 SM
DZ207
15V 350MW SM
+ C223
10U EL
DCPROT_R
5
6
TR206
BC856B
R215
C204
100N SM
4K7 SM
C216
10N SM
R204
1K0 SM
R217
10R SM
74HC14D
9
DCPROT_uC
8
C217
10N SM 74HC14D
R216
4K7 SM
R207
1K0 SM
C221
10N SM
C220
100N SM
TP212
SK201B
R210
10K SM
Far from PCB
R203
IC202D
TR201
FMMT497
C213
10N SM
TRIGGER OUTPUT
APPROX 13.5VDC
60mA MAX CURRENT
A
IC202C
DCPROT_L
+ C222
10U EL
0V_D
A
0V_D
JACK3.5X2
PWRON
R212
DRAWING TITLE
0V_TRIG
TR203
FMMT497
A85 amplifier - power supply and microcontroller interface
0V_TRIG
4K7 SM
C235
CAMCON_G
SK101C
23425
CHASS
1N0 SM
0V_D
1
2
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
3
4
5
Circuit Diagram
Notes:
Filename
02_E062
JBR
20/3/02
LDO REG FITTED TO IC201
02_E035
JBR
4/2/2002
FUSE VALUES UPRATED TO T4A
ECO No.
INITIALS
L882C2_4.1.SCH
6
DATE
20-Mar-2002
7
4.0
DESCRIPTION OF CHANGE
Drawn by:
Date Printed
4.1
J Reckless
Sheet 2 of 4
ISSUE
DRAWING NO.
8
L882C2
1
2
3
4
5
6
7
8
VPOS
D
D
R319
100R SM
R315
100R SM
R300
10K SM
R316
100R SM
PRE DRIVER
PNP CURRENT MIRROR
TR300
FMMT597
TR310
FMMT497
TR301
FMMT597
R301
10K SM
+
C300
100U EL
DZ300
15V 350MW SM
TR309
FMMT497
R321
22R SM
TR302
FMMT597
TR321
FMMT597
OUTPUT STAGE
R338
150R SM
0V_HF
3K3 SM
TR311
FMMT497 C317
TR318
SAP15N
6
5
0V_SIG
INPUT
V TO I AMP
R324
3
1K0 SM
DZ302
4V7 350MW SM
2
0V_SIG
IC300A
1
TL072CD
R327
22K SM
DZ303
4V7 350MW SM
TP304
+
R343
100R SM
D303
1N4003F
TR312
FMMT497
TR313
FMMT497
R349
100R SM
R355
6K8 SM
R345
0R0 SM
R340
100K SM
PL300
1
2
+ C303
100U EL
R351
L300
2U2H LAC SMALL
DC OFFSET SIGNAL
TO MICRO
+ C304
100U EL
C312
10N SM
R326
1K0 SM
+ C306
100U EL 100V
TP306
BOOTSTRAP
R344
100R SM
TR305
FMMT597
R346
0R0 SM
R304
10K SM
R348
R342
TR304
FMMT597
D304
1N4003F
100R SM
C308
TR319
SAP15P
100P SM
TR320
FMMT497
0V_SIG
R339
150R SM
OUTPUT STAGE
TR306
FMMT597
ZOBEL NETWORK
DC OFFSET
DETECTION
D302
BAS16W SM
C313
R307
10K SM
TP308
R336
22K SM
C319
100N PE
0V_LS
R308
22K SM
R302
10K SM
100N SM
0V_HF
0V_LS
TR316
FMMT497
DZ306
4V7 350MW SM
V-I PROTECTION
R310
4K7 SM
R313
10K SM
C320
100U NP
R314
10K SM
C315
100N SM
0V_HF
C301
100U EL
R350
5R6 2W CF
R303
10K SM
330R SM
3K3 SM
C
10R MF
MEASURE
BIAS
(SET TO 16mV)
D300
BAS16W SM
DCPROT
+ C318
10U EL
R354
1K0 SM
R335
DZ305
4V7 350MW SM
+ C305
10U EL
100R SM
470R 2W MF 5%
R353
TR303
FMMT597
C314
100N SM
DZ301
15V 350MW SM
R352
470R 2W MF 5%
C311
100N PC
0V_SIG
0V_HF
VIPROT
R306
10K SM
OUTPUT
TP303
C309
100N SM
TP307
0V_HF
1K8 SM
0V_SIG
0V_SIG
R325
1K0 SM
RV300
100R PSET
R332
R337
22R SM
VI PROTECT
SIGNAL TO MICRO
R305
10K SM
ADJ BIAS
1M0 SM
TR322
FMMT497
C316
470P PPW
R347
330R SM
+ C302
100U EL 100V
R330
R331
1K5 SM
R322
22R SM
R341
BOOTSTRAP
TL072CD 0V_SIG
TP302
8
INPUT FILTER
R328
4K7 SM
4
C
R334
22K SM
TP305
DC SERVO
IC300B
7
R329
4K7 SM
D301
BAS16W SM
100P SM
470N PE
C310
100N SM
V-I PROTECTION
C307
R333
R323
22R SM
0V_HF
0V_HF
R309
10K SM
TR314
FMMT497
TR315
FMMT497
NPN CURRENT MIRROR
R317
100R SM
B
TR307
FMMT597
TR308
FMMT597
PRE DRIVER
R318
100R SM
R311
10K SM
B
TR317
FMMT497
R320
100R SM
R312
10K SM
VNEG
A
A
DRAWING TITLE
A85 amplifier - power output stage left
23425
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
1
2
3
4
5
Circuit Diagram
Notes:
Filename
02_E062
JBR
20/3/02
LDO REG FITTED TO IC201
02_E035
JBR
4/2/2002
FUSE VALUES UPRATED TO T4A
ECO No.
INITIALS
L882C3_4.1.SCH
6
DATE
20-Mar-2002
7
4.0
DESCRIPTION OF CHANGE
Drawn by:
Date Printed
4.1
J Reckless
Sheet 3 of 4
ISSUE
DRAWING NO.
8
L882C3
1
2
3
4
5
6
7
8
VPOS
D
D
R419
100R SM
R415
100R SM
R400
10K SM
R416
100R SM
PRE DRIVER
PNP CURRENT MIRROR
TR400
FMMT597
TR410
FMMT497
TR401
FMMT597
R401
10K SM
+
C400
100U EL
DZ400
15V 350MW SM
TR409
FMMT497
R421
22R SM
TR402
FMMT597
TR421
FMMT597
OUTPUT STAGE
R438
150R SM
0V_HF
3K3 SM
TR411
FMMT497 C417
TR418
SAP15N
6
5
0V_SIG
V TO I AMP
R424
INPUT
3
1K0 SM
DZ402
4V7 350MW SM
0V_SIG
IC400A
1
TL072CD
TP404
R427
22K SM
DZ403
4V7 350MW SM
R422
22R SM
R437
22R SM
+
DZ401
15V 350MW SM
R452
470R 2W MF 5%
R443
100R SM
D403
1N4003F
TR412
FMMT497
TR413
FMMT497
R449
100R SM
DZ405
4V7 350MW SM
+ C405
10U EL
100R SM
R445
0R0 SM
R440
100K SM
PL400
1
2
+ C403
100U EL
R451
L400
OUTPUT
R455
6K8 SM
+ C404
100U EL
C412
10N SM
C411
100N PC
R426
1K0 SM
+ C406
100U EL 100V
TP406
BOOTSTRAP
3K3 SM
TR419
SAP15P
100P SM
TR420
FMMT497
R444
100R SM
TR405
FMMT597
R446
0R0 SM
R404
10K SM
R448
R442
TR404
FMMT597
D404
1N4003F
100R SM
R439
150R SM
OUTPUT STAGE
R436
22K SM
TR406
FMMT597
ZOBEL NETWORK
DC OFFSET
DETECTION
TP408
D402
BAS16W SM
C413
R407
10K SM
0V_LS
100N SM
0V_HF
0V_LS
TR416
FMMT497
DZ406
4V7 350MW SM
V-I PROTECTION
C419
100N PE
R408
22K SM
R402
10K SM
R410
4K7 SM
R413
10K SM
C420
100U NP
R414
10K SM
C415
100N SM
0V_HF
C401
100U EL
R450
5R6 2W CF
R403
10K SM
330R SM
C408
0V_SIG
2U2H LAC SMALL
DC OFFSET SIGNAL
TO MICRO
DCPROT
+ C418
10U EL
R454
1K0 SM
R435
C
10R MF
MEASURE
BIAS
(SET TO 16 mV)
D400
BAS16W SM
470R 2W MF 5%
R453
TR403
FMMT597
C414
100N SM
VIPROT
R406
10K SM
0V_HF
1K8 SM
0V_SIG
0V_HF
R425
1K0 SM
RV400
100R PSET
TP403
C409
100N SM
TP407
R432
0V_SIG
0V_SIG
VI PROTECT
SIGNAL TO MICRO
R405
10K SM
ADJ BIAS
1M0 SM
TR422
FMMT497
C416
470P PPW
R447
330R SM
+ C402
100U EL 100V
R430
R431
1K5 SM
2
R441
BOOTSTRAP
TL072CD 0V_SIG
TP402
8
INPUT FILTER
R428
4K7 SM
4
C
R434
22K SM
TP405
DC SERVO
IC400B
7
R429
4K7 SM
D401
BAS16W SM
100P SM
470N PE
C410
100N SM
V-I PROTECTION
C407
R433
R423
22R SM
0V_HF
0V_HF
R409
10K SM
TR414
FMMT497
TR415
FMMT497
NPN CURRENT MIRROR
R417
100R SM
B
TR407
FMMT597
TR408
FMMT597
PRE DRIVER
R418
100R SM
R411
10K SM
B
TR417
FMMT497
R420
100R SM
R412
10K SM
VNEG
A
A
DRAWING TITLE
A85 amplifier - power output stage right
23425
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
1
2
3
4
5
Circuit Diagram
Notes:
Filename
02_E062
JBR
20/3/02
LDO REG FITTED TO IC201
02_E035
JBR
4/2/2002
FUSE VALUES UPRATED TO T4A
ECO No.
INITIALS
L882C4_4.1.SCH
6
DATE
20-Mar-2002
7
4.0
DESCRIPTION OF CHANGE
Drawn by:
Date Printed
4.1
J Reckless
Sheet 4 of 4
ISSUE
DRAWING NO.
8
L882C4
Display
Board
L928
Contents
!
Component overlay
!
Parts list
!
Circuit diagrams
CAM Products 2000(TM): L928PB_B.GTO
L928 Display Board Parts List Issue B.3
Designator Part
Description
C1
C2
C3
C4
C5
C6
C7
C8
C9
C10
C11
C12
C13
C14
C15
C16
C17
C25
C26
C28
C29
C31
C32
C33
C34
C37
C38
C39
C40
C41
C43
C44
C45
C46
C47
C48
C49
C50
C51
C52
C53
C54
C55
C60
C61
C62
C63
D1
D2
D3
DC1
DC2
DISP1
IC1
IC2
IC5
IC6
IC7
IC8
IC11
LED1
LED2
MLC 18P 50V X7R 10% SM
MLC 18P 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
ELST 10U 50V SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
ELST 10U 50V SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
ELST 10U 50V SM
ELST 10U 50V SM
ELST 100U 25V SM
MLC 10P 50V NPO 10% SM
MLC 10P 50V NPO 10% SM
ELST 220U 16V
ELST 220U 16V
MLC 1N0 50V X7R 10% SM
MLC 1N0 50V X7R 10% SM
MLC 1N0 50V X7R 10% SM
MLC 1N0 50V X7R 10% SM
MLC 1N0 50V X7R 10% SM
MLC 1N0 50V X7R 10% SM
MLC 1N0 50V X7R 10% SM
MLC 1N0 50V X7R 10% SM
MLC 1N0 50V X7R 10% SM
MLC 1N0 50V X7R 10% SM
MLC 1N0 50V X7R 10% SM
MLC 1N0 50V X7R 10% SM
CAP PACK NPO 0612 4X100P 50V 5%
CAP PACK NPO 0612 4X100P 50V 5%
CAP PACK NPO 0612 4X100P 50V 5%
CAP PACK NPO 0612 4X100P 50V 5%
CAP PACK NPO 0612 4X100P 50V 5%
CAP PACK NPO 0612 4X100P 50V 5%
CAP PACK NPO 0612 4X100P 50V 5%
CAP PACK NPO 0612 4X100P 50V 5%
CAP PACK NPO 0612 4X100P 50V 5%
CAP PACK NPO 0612 4X100P 50V 5%
ZENER 33V BZX55C33V
DIODE SS SM BAS16W
DIODE SS SM BAS16W
DISPLAY CRADLE E916PM
DISPLAY CRADLE E916PM
MN12818A VFD ITRON
H8/3048 128K FLASH MICROCONTROLLER
IC MICRO RESET DS1233 SM
IC CMOS EPROM 24C02 SM
IC COMPARATOR SM DUAL LM393A
IC COMPARATOR SM DUAL LM393A
IC COMPARATOR SM DUAL LM393A
DUAL OUTPUT SINGLE SUPPLY AMP AD8532
LED GREEN 5MM
LED GREEN 5MM
2C018
2C018
2C410
2C410
2C410
2C410
2C410
2C410
2C410
2C410
2M610
2C410
2C410
2M610
2C410
2C410
2C410
2C410
2M610
2M610
2M710
2C010A
2C010A
2N722
2N722
2C210
2C210
2C210
2C210
2C210
2C210
2C210
2C210
2C210
2C210
2C210
2C210
2W110X4
2W110X4
2W110X4
2W110X4
2W110X4
2W110X4
2W110X4
2W110X4
2W110X4
2W110X4
3C13304
3AS16W
3AS16W
E916PM
E916PM
B1013
5H3048
5H1233A
5G2402
5M393AD
5M393AD
5M393AD
5M8532
3D001
3D001
L928 Display Board Parts List Issue B.3
Designator Part
Description
LED3
LED4
LED5
LED6
LED7
LED8
LED9
LED10
LED11
Q1
Q2
Q3
Q4
Q5
R1
R2
R3
R4
R5
R6
R7
R8
R9
R10
R11
R12
R13
R14
R15
R16
R17
R18
R19
R20
R21
R22
R23
R24
R25
R26
R27
R28
R29
R30
R31
R32
R33
R34
R35
R36
R37
R38
R39
R40
R41
R42
R43
R44
R45
R46
R47
R48
LED GREEN 5MM
LED GREEN 5MM
LED GREEN 5MM
LED GREEN 5MM
LED GREEN 5MM
LED GREEN 5MM
LED GREEN 5MM
LED GREEN 5MM
LED RED/GREEN 3MM L-93WEGW
TRANS LF SS N SM BC847B
TRANS LF SS N SM BC847B
TRANS LF SS N SM BC847B
TRANS LF SS N SM BC847B
NPN TRANS MP BD179
RES SM W4 2% 10K
RES SM W4 2% 10K
RES SM W4 2% 10K
RES SM W4 2% 10K
RES SM W4 2% 10K
RES SM W4 2% 10K
RES SM W4 2% 10K
RES SM W4 2% 10K
RES SM W4 2% 10K
RES SM W4 2% 10K
RES SM W4 2% 10K
RES SM W4 2% 10K
RES SM W4 2% 10K
RES SM W4 2% 10K
RES SM W4 2% 10K
RES SM W4 2% 10K
RES SM W4 2% 330R
RES SM W4 2% 330R
RES SM W4 2% 330R
RES SM W4 2% 330R
RES SM W4 2% 330R
RES SM W4 2% 330R
RES SM W4 2% 330R
RES SM W4 2% 330R
RES SM W4 2% 330R
RES SM W4 2% 10K
RES SM W4 2% 10K
RES SM W4 2% 10K
RES SM W4 2% 10K
RES SM W4 2% 10K
RES SM W4 2% 330R
RES SM W4 2% 10K
RES SM W4 2% 330R
RES SM W4 2% 150R
RES SM W4 2% 10K
RES SM W4 2% 10K
RES SM W4 2% 10K
RES SM W4 2% 1K2
RES SM W4 2% 2K2
RES SM W4 2% 4K7
RES SM W4 2% 100K
RES SM W4 2% 100K
RES SM W4 2% 100K
RES SM W4 2% 100K
RES SM W4 2% 10K
RES SM W4 2% 1K2
RES SM W4 2% 4K7
RES SM W4 2% 0R0
3D001
3D001
3D001
3D001
3D001
3D001
3D001
3D001
3D006
4A847
4A847
4A847
4A847
4B179
1A310
1A310
1A310
1A310
1A310
1A310
1A310
1A310
1A310
1A310
1A310
1A310
1A310
1A310
1A310
1A310
1A133
1A133
1A133
1A133
1A133
1A133
1A133
1A133
1A133
1A310
1A310
1A310
1A310
1A310
1A133
1A310
1A133
1A115
1A310
1A310
1A310
1A212
1A222
1A247
1A410
1A410
1A410
1A410
1A310
1A212
1A247
1A000
L928 Display Board Parts List Issue B.3
Designator Part
Description
R49
R50
R51
R52
R53
R54
R55
R56
R57
R58
R59
R64
R65
R66
R67
R68
R69
R70
R71
R72
R73
R74
R75
R76
RX1
SK1
SK2
SK3
SK4
SP1
SP2
SP3
SP4
SP5
SP6
SP7
SP8
SP9
SP10
SP101
SP102
SP103
SP
SW1
SW2
SW3
SW4
SW5
SW6
SW7
SW8
SW9
SW10
SW11
SW12
SW13
SW14
SW15
SW16
SW17
SW18
X1
RES SM W4 2% 10K
RES SM W4 2% 10K
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES MF W4 1% 3K3
RES SM W4 2% 10K
RES SM W4 2% 10K
RES SM W4 2% 10K
RES SM W4 2% 0R0
RES SM W4 2% 0R0
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES SM W4 2% 10K
RES SM W4 1% 2R2 1206
RES SM W4 1% 2R2 1206
RES SM W4 1% 2R2 1206
RES SM W4 1% 2R2 1206
RES SM W4 2% 10K
RES SM W4 2% 10K
RES SM W4 2% 10K
RES SM W4 2% 10K
REMOTE RX PIC-26043TM2 38KHZ
FFC 14W 2.54MM HOR PTH
5-WAY AMP CT CONN
22-WAY FFC CONN HORIZ 1MM PTH
14 WAY DIL HEADER HORIZ
LED SPACER
LED SPACER
LED SPACER
LED SPACER
LED SPACER
LED SPACER
LED SPACER
LED SPACER
LED SPACER
LED SPACER
STICKY PAD S/A 10 X 15mm
STICKY PAD S/A 10 X 15mm
IR RX SUPPORT PAD
IR RX SUPPORT PAD
TACT SWITCH SM SDTM-610-NTR
TACT SWITCH SM SDTM-610-NTR
TACT SWITCH SM SDTM-610-NTR
TACT SWITCH SM SDTM-610-NTR
TACT SWITCH SM SDTM-610-NTR
TACT SWITCH SM SDTM-610-NTR
TACT SWITCH SM SDTM-610-NTR
TACT SWITCH SM SDTM-610-NTR
TACT SWITCH SM SDTM-610-NTR
TACT SWITCH SM SDTM-610-NTR
TACT SWITCH SM SDTM-610-NTR
TACT SWITCH SM SDTM-610-NTR
TACT SWITCH SM SDTM-610-NTR
TACT SWITCH SM SDTM-610-NTR
TACT SWITCH SM SDTM-610-NTR
TACT SWITCH SM SDTM-610-NTR
TACT SWITCH SM SDTM-610-NTR
EC16B2414
XTAL 16MHZ SM GSX49-4
1A310
1A310
1A110
1A110
1A110
1H233
1A310
1A310
1A310
1A000
1A000
1A110
1A110
1A110
1A110
1A310
1A822
1A822
1A822
1A822
1A310
1A310
1A310
1A310
B2107
8K7014A
8K2005
8K8022A
8K6315
F195
F195
F195
F195
F195
F195
F195
F195
F195
F195
F163
F163
E822AP
E822AP
A1505
A1505
A1505
A1505
A1505
A1505
A1505
A1505
A1505
A1505
A1505
A1505
A1505
A1505
A1505
A1505
A1505
A1211
7X040
1
2
3
4
5
6
8
7
A32 FMJ DISPLAY PCB
D
D
L928CT_B.1
L928CT_2_B.3.SCH
MICRO
FD_1
FD_2
FIDUCIAL
FIDUCIAL
FIX7
FIX2
FIX10
FIXING HOLE 3.5
FIXING HOLE 3.5
FIXING HOLE 3.5
FIX5
FIX6
FIX13
FIXING HOLE 3.5
FIXING HOLE 3.5
FIXING HOLE 3.5
C
C
CHASSIS 1
(BY SK3)
C39
1N0 SM
C40
1N0 SM
0V_D
0V_D
C41
1N0 SM
C43
1N0 SM
0V_D
0V_D
0V_D
FIX1
FIX8
FIX9
FIX3
FIXING HOLE 3.5
FIXING HOLE 3.5
FIXING HOLE 3.2
FIXING HOLE 3.5
C38
1N0 SM
C44
1N0 SM
0V_D
FIX11
FIX12
FIXING HOLE 3.5 FIXING HOLE 3.2
C45
1N0 SM
CHASSIS 2
(BY SK1)
C46
1N0 SM
0V_D
0V_D
C47
1N0 SM
0V_D
C48
1N0 SM
CHASSIS 3
(BY SK2)
0V_D
C37
1N0 SM
C49
1N0 SM
0V_D
0V_D
PCB1
PCB
B
B
L928PB_B
DRAWING TITLE
A
A
A32 FMJ AMP DISPLAY PCB
23425
WAF
Circuit Diagram
Notes:
26/9/01
2
3
4
5
6
B.3
JBR
10/9/01
PRE PRODUCTION RELEASE
B.2
WAF
9/08/01
UPDATED PROTOTYPE
B.0
INITIAL PROTOTYPE
A.0
A & R Cambridge Ltd.
Pembroke Avenue
CL
25/04/01
Denny Industrial Centre
ECO No. INITIALS
DATE
Waterbeach
Date Printed
Filename
Cambridge CB5 9PB
10-Oct-2001
J:\Released_Documents\Native_format_files\Protel_DDB\L928_B.3.Ddb - Documents\L928CT_1_B.3.PRJ
1
STICKY PADS RENUMBERED
DESCRIPTION OF CHANGE
Drawn by:
Sheet 1 of 2
CL
7
DRAWING NO.
ISSUE
L928CT1
8
7
MODE
D
DOWN
DVD
UP
ENTER
POWER
SELECT
CD
TUNER
VCR
SP2
TAPE
SP1
SP4
SP2
SP5
LED
SPACER
SP9
LED
SPACER
SP10
SP1
R1
R2
R3
R4
R5
R6
R7
R8
10K SM
10K SM
10K SM
10K SM
10K SM
10K SM
10K SM
10K SM
SW6
SW12
SW11
SW8
SW7
SW13
SW14
SW15
TACTSW A1505 TACTSW A1505 TACTSW A1505 TACTSW A1505 TACTSW A1505 TACTSW A1505 TACTSW A1505 TACTSW A1505
R68
R9
R10
R11
R12
R13
R14
R15
R16
10K SM
10K SM
10K SM
10K SM
10K SM
10K SM
10K SM
10K SM
10K SM
SW17
SW16
SW1
SW4
SW2
SW5
SW3
SW10
SW9
TACTSW A1505 TACTSW A1505TACTSW A1505 TACTSW A1505 TACTSW A1505 TACTSW A1505 TACTSW A1505 TACTSW A1505 TACTSW A1505
R17
330R SM
R18
330R SM
Q_65
LED7
Q_66
LED8
R19
330R SM
R20
330R SM
Q_67
LED6
R21
330R SM
Q_68
LED3
R22
330R SM
Q_69
LED10
R25
330R SM
Q_70
LED9
R24
330R SM
Q_71
LED1
R23
330R SM
Q_72
LED4
R31
330R SM
Q_73
LED2
D
Q_74
LED5
LED GREEN
LED GREEN
LED11
LED GREEN
LED GREEN
LED GREEN
LED GREEN
IND7
IND3
IND4
IND9
IND6
IND5
IND1
IND8
IND2
IND10
BUT16
BUT15
BUT5
BUT10
BUT1
BUT14
BUT12
BUT9
BUT8
BUT7
BUT6
BUT13
0V_D
BUT4
R34
150R SM
BUT3
R33
330R SM
BUT2
R30
10K SM
IND11
IND12
R29
10K SM
TONE
BUT17
Q2
BC847B
Q1
BC847B
RECORD
SP3
SPACER F195SPACER F195SPACER F195SPACER F195SPACER F195SPACER F195SPACER F195SPACER F195SPACER F195SPACER F195
+5V
BUT11
AV
PHONO/
AUX
SP6
LED
SPACER
SP8
LED
SPACER
SP7
8
LED
SPACER
6
LED
SPACER
5
LED
SPACER
4
LED
SPACER
3
LED
SPACER
2
LED
SPACER
1
LED GREEN
LED GREEN
LED GREEN
LED GREEN
IC7B
5
0V5
Q_59
7 SAMDATA
+5V
R47
4K7 SM
0V_D
1
SAMBUSY
2
Q4
BC847B
1
2
Q_53
R45
10K SM IC8B
0V5
2
RECEIVE
SAMRX2Q_115
1
3
0V5
7
5
0V_D
LM393A SM
LM393A SM
2
IR RX
SUPPORT PAD
O/P
O/P
C9
IR RX SUPPORT PAD
0V_D
Case
Case
Q_47
RX1
100N SM
+5V
VIPROT
DCPROT
ACPRESENT
SEL8
SEL9
MUTE
TONE
IRIN
PHASEB
PHASEA
PLACE ONE ON TOP OF
PR_VCC
PR_RXD
RECEIVE
Q_55
VPROG
PB0
2
4
6
8
10
12
14
PR_VPP
PR_PMODE
+5V
IR RX
SUPPORT PAD
THE OTHER UNDER RX1
0V_D
PR_GND
PR_TXD
1
3
5
7
9
11
13
TRANSMIT
RESPIN
0V_D
SW18
ALPS_ENCODER
A
B
IR RX SUPPORT PAD
1
2
+5V
VFD_VDD2
Q_82
DISPLAY CRADLE E916PM
Q_49
IC11A
AD8532 SM
+5V
1
SBX1610-52/PIC-26043TM2
SP103
Programming adaptor
SK4
R75
10K SM
0V_D
C6
100N SM
Graphics Display
DISPLAY CRADLE E916PM
DC2
DISPLAY CRADLE
E916PM
SP
R44
100K SM
+5V
10K SM
+5V
Q_54
Q3
BC847B
R76
IROUT
6
0V_D
DC1
DISPLAY CRADLE
E916PM
R46
1K2 SM
3
2
Q_50
Q_58
R57
10K SM
Q_57
PR_MD
PR_RESET
Q_48
R59
7
6
C
Q_80 0R0 SM
5
F2CLOCK R53
Q_78
100R SM
PHASEA
PHASEB
0V_D
R58
1
F1CLOCK R52
R56
Q_79
100R SM
10K SM
10K SM R27
0R0 SM R48
R49
10K SM
3
LM393A SM
R38
1K2 SM
10K SM R28
R37
10K SM IC6A
IC7A
LM393A SM
F1CLOCK
F2CLOCK
IRIN IRIN
Q_35
+5V
C
R73
10K SM
3
2V7
6
LM393A SM
R42
100K SM
IC8A
R74
10K SM
F2
F2
F2
SAMTX2
5
+5V
GND
GND
R41
100K SM
2K2 SM
15
16
17
+
R43
100K SM
10K SM
R40
4K7 SM
IC6B
TRANSMIT R50
SAMHOLD
2V7
10K SMQ_34
+5V
10K SM
DISPLAT
DISPBLK
DISPCLK
+5V
R39
3
10U EL SM
C11
R36
F1 to F2 = 4Vac 150mA
VDD2 = 40Vdc 20mA
Q_83
Q_84
Q_85
LEFTAUDIO
R35
DISP1
B1013
SIN
VDD1
SOUT
LAT
BLK
CLK
VSS
VSS
VDD2
+5V
0V_D
SP101
DOUBLE SIDED
STICKY PAD
10 X 15MM
STICKY PAD DS 10X15MM
SP102
DOUBLE SIDED
STICKY PAD
10 X 15MM
STICKY PAD DS 10X15MM
+5V
1
2
3
LM393A SM
0V_D
Q_22
+5V
+5V
G
R
Q_21
4
5
6
7
8
9
10
11
12
2V7
DISPDAT
+5V
6
F1
F1
F1
7
LED RED/GRN 3MM
Q_81 0R0 SM
IC11B
AD8532 SM
SAMHOLD
C
3
0V_D
100
99
98
97
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
80
79
78
77
76
+5V
SLOAD
SCLK
C32
10P SM
Q_42
0V_D
0V_D
Q_99
Q_100
Q_101
Q_102
Q_103
Q_104
Q_105
Q_106
Q_107
Q_108
Q_109
Q_110
Q_111
Q_112
Q_113
Q_114
Q_97
Q_96
Q_95
Q_94
Q_93
Q_92
IND7
BUT10
IND5
BUT15
IND6
BUT16
IND11
IND12
BUT4
IND2
BUT5
IND1
BUT1
BUT3
0V_D
WP
SDA
SCL
7
5
6
10K SM
IND10
BUT13
IND8
BUT11
IND4
BUT14
IND9
BUT12
C5
100N SM
R32
A2
A1
A0
VDD
4
BUT9
BUT8
BUT7
BUT6
BUT2
IND3
3
2
Q_39
C7
4
1
0V_D
(FIT CLOSE TO SK1)
Vcc
Res
Gnd
Gnd
C63B 100PX4 SM
8
C8
100N SM
3
2
1
A
0V_D
C63A 100PX4 SM
0V_D
To preamp board
SK3
22 Q_1
SEL1
21 Q_2
SEL2
20 Q_3
SEL3
19 Q_4
SEL4
18 Q_5
SEL5
17 Q_6
SEL6
16 Q_7
SEL7
15 Q_8
SEL8
14 Q_9
SEL9
13
12 Q_10 LEFTAUDIO
11
10 Q_11
MUTE
9
Q_12
TONE
8
Q_117
7
Q_14 TONEID
6
Q_118
5
Q_15
SDATA
4
Q_119
3
Q_16
SLOAD
2
Q_120
1
SCLK
Q_17
C50A 100PX4 SM
C50B 100PX4 SM
C50C 100PX4 SM
C50D 100PX4 SM
C51A 100PX4 SM
C51B 100PX4 SM
C51C 100PX4 SM
C51D 100PX4 SM
C52A 100PX4 SM
C52B 100PX4 SM
C52C 100PX4 SM
C52D 100PX4 SM
C53A 100PX4 SM
C53B 100PX4 SM
C53C 100PX4 SM
C53D 100PX4 SM
C54A 100PX4 SM
C54B 100PX4 SM
C54C 100PX4 SM
C54D 100PX4 SM
C55A 100PX4 SM
C55B 100PX4 SM
C55C 100PX4 SM
C55D 100PX4 SM
FFC 22W 1MM HOR
0V_D
+SUP
3
4
Q5
BD179 NPN TO-126 VFD_VDD2
Q_23
+5V
R54
3K3 MF
Q_64
+
D1
ZENER 400MW 33V
C28
10U EL SM
Q_75
+
IC6C
LM393A SM
C10
100N SM
IC7C
LM393A SM
C15
100N SM
IC8C
LM393A SM
C16
100N SM
IC11C
AD8532 SM
C25
100N SM
+ C29
100U EL SM
Q_116
C26
10U EL SM
0V_D
A
0V_D
DRAWING TITLE
A32 FMJ AMP DISPLAY PCB
23425
0V_D
2
FFC 14W 2.54MM HOR
0V_D
CHASSIS 1
1
Q_129
0V_D
DS1233 SM
100N SM
IRIN
CHASSIS 2
0V_D
Q_40
VSS
Q_86
Q_87
Q_88
Q_89
Q_90
Q_91
IC2
+5V
Q_98
Q_41
4
SAMTX2
SAMRX2
BUT17
B
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
+5V
R51
100R SM
IC5
24C02 SM
100N SM
C4
100N SM
+ C34
220U EL
H8/3048F
0V_D
+5V
+ C33
220U EL
8
C31
10P SM
TONEID
SDATA
Q_44
C12
RESPIN
4
100R SM
100R SM
C2
18P SM
Q_38
STANDBY
Q_122
SP1ON
Q_123
SP2ON
THERMPROTQ_124
Q_125
VIPROT
Q_126
DCPROT
ACPRESENT Q_127
Q_128
8
R67
Q_43
+5V
4
R66
0V_D
Q_121
8
Q_45
100R SM
X1
16MHZ SM
+SUP
4
DISPBLK
DISPLAT
R65
Q_37
8
DISPCLK
RECEIVE
To power amp / PSU
SK1
14
C60D 100PX4 SM
13
C60C 100PX4 SM
12
C60B 100PX4 SM
11
C60A 100PX4 SM
10
C61D 100PX4 SM
9
C61C 100PX4 SM
8
C61B 100PX4 SM
7
C61A 100PX4 SM
6
C62D 100PX4 SM
5
C62C 100PX4 SM
4
C62B 100PX4 SM
3
C62A 100PX4 SM
2
C63D 100PX4 SM
1
C63C 100PX4 SM
C1
18P SM
4
100R SM
H8/3048F
0V_D
STANDBY
SP1ON
SP2ON
THERMPROT
2R2 SM
TRANSMIT
+5V
AMPCT5
2R2 SM
R69
Q_46
10K SM
2R2 SM
R70
R64
Q_20
2R2 SM
R71
DISPDAT
MD2
MD1
MD0
P6.6/LWR
P6.5/HWR
P6.4/RD
P6.3/AS
Vcc
XTAL
EXTAL
Vss
NM1
RES
STBY
CLKOUT
P6.2/BACK
P6.1/BREQ
P6.0/WAIT
Vss
P5.3/A19
P5.2/A18
P5.1/A17
P5.0/A16
P2.7/A15
P2.6/A14
R26
Q_56
R72
Q_52
Vcc
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB7
Vpp/RESO
Vss
TxD0/P9.0
TxD1/P9.1
RxD0/P9.2
RxD1/P9.3
IRQ4/SCK0/P9.4
IRQ5/SCK1/P9.5
D0/P4.0
D1/P4.1
D2/P4.2
D3/P4.3
Vss
D4/P4.4
D5/P4.5
D6/P4.6
75
74
73
72
71
70
69
68
67
66
65
64
63
62
61
60
59
58
57
56
55
54
53
52
51
+5V
D2
BAS16W SM
1
2
3
4
5
DS1233
D3
BAS16W SM
PA7
PA6
PA5
PA4
PA3
PA2
PA1
PA0
Vss
P8.4/CS0
P8.3/IRQ3
P8.2/IRQ2
P8.1/IRQ1
P8.0/IRQ0
AVss
P7.7/AN7/DA1
P7.6/AN6/DA0
P7.5/AN5
P7.4/AN4
P7.3/AN3
P7.2/AN2
P7.1/AN1
P7.0/AN0
Vref
AVcc
PB0
SEL7
SEL6
SEL5
SEL4
SEL3
SEL2
SEL1
VPROG
Q_51
B
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
Q_19
SAMDATA
SAMBUSY
+5V
C13
100N SM 0V_D
SK2
0V_D
D7/P4.7
D8/P3.0
D9/P3.1
D10/P3.2
D11/P3.3
D12/P3.4
D13/P3.5
D14/P3.6
D15/P3.7
Vcc
A0/P1.0
A1/P1.1
A2/P1.2
A3/P1.3
A4/P1.4
A5/P1.5
A6/P1.6
A7/P1.7
Vss
A8/P2.0
A9/P2.1
A10/P2.2
A11/P2.3
A12/P2.4
A13/P2.5
0V_D
R55
10K SM
+5V
IC1
C17
100N SM
+5V
+ C14
10U EL SM
C3
100N SM
0V_D
5
HEADER 7X2HORIZ
5
WAF
Circuit Diagram
Notes:
26/9/01
B.3
JBR
10/9/01
PRE PRODUCTION RELEASE
B.2
WAF
9/08/01
UPDATED PROTOTYPE
B.0
INITIAL PROTOTYPE
A.0
A & R Cambridge Ltd.
Pembroke Avenue
CL
25/04/01
Denny Industrial Centre
ECO No. INITIALS
DATE
Waterbeach
Date Printed
Filename
Cambridge CB5 9PB
10-Oct-2001
J:\Released_Documents\Native_format_files\Protel_DDB\L928_B.3.Ddb - Documents\L928CT_2_B.3.SCH
6
STICKY PADS RENUMBERED
7
DESCRIPTION OF CHANGE
Drawn by:
CL
Sheet 2 of 2
ISSUE
DRAWING NO. L928CT2
8
Preamplifier
Board
L937
Contents
!
Circuit description
!
Component overlay
!
Parts list
!
Circuit diagrams
Pre-amplifier circuit description
Refer to L937 circuit diagrams
The A32 preamplifier is a high-performance, DC coupled
design with microprocessor control of input select, two
independent tape loops, electronic volume control, tone
bypass and electronic tone control.
It features a discrete power supply and low-noise linear
circuitry to obtain very good distortion and noise
performance, suitable for high quality source material such
as CD or DVD-A.
Input switching
Each of the inputs has a pair of diodes to the ±15V rails to
prevent static spikes from causing damage to the CMOS
multiplexers. In addition, there is a simple resistorcapacitor filter with a corner frequency of approximately
340kHz to remove any unwanted high frequency
interference from the signal. This uses high-quality
polypropylene capacitors for best performance.
Z104 and Z105 are the main input select multiplexers,
which are configured in a ‘virtual earth’ unity gain
arrangement with Z115 and Z116. This arrangement is
slightly lower distortion than the ‘normal’ one, at the cost
of a slightly higher noise floor. It is an inverting
configuration, which is restored to correct polarity by the
inverting electronic volume control which follows.
Z115B and Z116B are integrating servos, which take out
any DC from the input signal before the following stages.
The servos are 2-pole, with a passive 2 nd pole being
formed by R180 and C147 (for the left channel) to remove
broadband noise from the output of the servo and improve
speed of response.
Z100 thru Z103 are the input selectors for the 2 tape loops.
These are normal non-inverting selectors which are
buffered before being passed on to the phono sockets.
Z109A output is decoupled by R108 which is included in
the feedback path. Local high frequency feedback occurs
around C108 to allow the tape loop output to be very low
impedance, whilst being stable into a capacitive load such
as may be presented by a screened interconnect cable. This
is the same for all tape outputs.
Z106 is configured as a double pole changeover switch,
used to select the tone controls. The tone controls are
bypassed when not required so that the noise and distortion
can be minimised.
Tone control circuit
The tone control circuit is a non-inverting one, using a
gyrated ‘bell’ filter for the bass and a simple shelving filter
for the treble.
Left channel description
The input is attenuated by 6dB and biased to a voltage of
+2.5V DC by C111, R113, R112, R110, R111 and C110.
This is so the signals fall within the 0 - 5VDC required by
the digital potentiometer Z108.
Z111B and its associated components form an active
equivalent of a series resonant LCR circuit. This has an
impedance minimum of 5.4k˜ at around 80Hz with Q=0.7
The reason the bass is done as a band-boost filter rather
than a shelving filter is so that you can boost the ‘real’
bass without causing lots of sub-audio loudspeaker cone
excursion which wastes power and may damage the drive
units.
The digital pots Z108D and Z108A control the bass and
treble respectively. This is done by moving the wiper
connected to the frequency-sensitive impedance between the
non-inverting and inverting terminals of Z112A, effectively
changing the ratio of feedback boost and feed-forward
attenuation of the circuit at the desired frequencies, thus
providing a EQ gain control that is symmetrical on a
logarithmic scale, with the use of a linear pot.
Z112B provides the 6dB of gain necessary to bring the
nominal signal level back to unity. C116 and C117 remove
the 2.5VDC offset from the output, to prevent clunks when
the tone controls are activated.
Z108 is controlled by a simple 3-wire serial interface from
the microprocessor. Each of the digital lines has its own
ground return to minimise electromagnetic interference.
They are connected together only at the GND pin of the IC.
Volume control
Z107 is a VSDVC electronic volume control IC. It works, in
conjunction with an external op-amp, by varying the feedforward and feedback resistors in an inverting gain
configuration. In this way, it can allow output signal swings
of up to 22Vpp whilst operating from a single +5VDC power
supply. Also, it allows the user the choice of external
circuitry to fine-tune the performance. The gain is controlled
from the microprocessor via a 3-wire serial interface. The
analogue supply rail is derived from the local +5V via R185
and C156 // C157.
Z117 is the output op-amp. Its outputs are decoupled via
R186, R187, C158 and C159 so that it has a low output
impedance but can drive cable capacitance without
oscillation. R186 and R187 are included in the audio
frequency feedback loop to reduce output impedance when
driving ‘difficult’ cables.
RLY100 is a mute relay which shunts the preamp output to
ground. This is to prevent thumps and squeals when the units
is powered up or down.
Power supply
The transformer winding is connected to SK300. The voltage
is rectified and smoothed by D300, D301, D306, D307 and
C300, C310. The unregulated voltage should be around
±27VDC. F300 and F301 are secondary fuses, as the low
power preamp winding would not blow the primary fuses if
short circuited.
The voltage regulators are discrete compound emitter
followers. I will describe the +15V supply as the negative is
essentially an exact mirror image.
Q300 and R300 act as a constant current source, supplying
around 7mA into D310. C302 and C314 reduce ripple and
broadband noise on the zener diode. Q305 and Q306 form a
complementary Darlington NPN transistor which is
configured as an emitter follower, producing the +15VDC at
its output. C303 is to provide bulk charge storage and to
reduce the AC output impedance of the power supply. D302
prevents reverse bias of the supply during
power down.
Z301 is a conventional LM317 type circuit to drop the +15V
rail down to +5V for the tone and volume control circuits.
Star point SP300 explicitly connects the differently named
ground nets together at one point, to minimise hum.
L937 Preamplifier Board Parts List Issue 1.0
Designator Part
Description
C100
C101
C102
C103
C104
C105
C106
C107
C108
C109
C110
C111
C112
C113
C114
C115
C116
C117
C118
C119
C120
C121
C122
C123
C124
C125
C126
C127
C128
C129
C130
C131
C132
C133
C134
C135
C136
C137
C138
C139
C140
C141
C142
C143
C144
C145
C146
C147
C148
C149
C150
C151
C152
C153
C154
C155
C156
C157
C158
C159
C160
C161
MLC 1N0 50V X7R 10% SM
WIMA FKP2 470P 63V CAP
WIMA FKP2 470P 63V CAP
WIMA FKP2 470P 63V CAP
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100P 50V NPO 5% SM
MLC 100P 50V NPO 5% SM
ELST 100U 25V
ELEC 10U 50V CERAFINE
PEST 470N 63V 10%
PEST 470N 63V 10%
WIMA FKP2 2N2 63V CAP
MLC 22P 50V NPO 5% SM
ELEC 10U 50V CERAFINE
ELEC 10U 50V CERAFINE
MLC 100N 50V X7R 10% SM
MLC 10N 50V X7R 10% SM
ELST 10U 50V
MLC 1N0 50V X7R 10% SM
WIMA FKP2 470P 63V CAP
WIMA FKP2 470P 63V CAP
WIMA FKP2 470P 63V CAP
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100P 50V NPO 5% SM
MLC 100P 50V NPO 5% SM
ELST 100U 25V
ELEC 10U 50V CERAFINE
PEST 470N 63V 10%
PEST 470N 63V 10%
WIMA FKP2 2N2 63V CAP
MLC 22P 50V NPO 5% SM
ELEC 10U 50V CERAFINE
ELEC 10U 50V CERAFINE
MLC 1N0 50V X7R 10% SM
WIMA FKP2 470P 63V CAP
WIMA FKP2 470P 63V CAP
WIMA FKP2 470P 63V CAP
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
PEST 100N 63V 10%
MLC 22P 50V NPO 5% SM
MLC 22P 50V NPO 5% SM
PEST 470N 63V 10%
PEST 470N 63V 10%
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
ELST 10U 50V
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
ELST 100U 25V
MLC 22P 50V NPO 5% SM
MLC 22P 50V NPO 5% SM
MLC 1N0 50V X7R 10% SM
WIMA FKP2 470P 63V CAP
2C210
2D147W
2D147W
2D147W
2C410
2C410
2C410
2C410
2C110
2C110
2N710
2P610CC
2K447
2K447
2D222W
2C022
2P610CC
2P610CC
2C410
2C310
2N610
2C210
2D147W
2D147W
2D147W
2C410
2C410
2C410
2C410
2C110
2C110
2N710
2P610CC
2K447
2K447
2D222W
2C022
2P610CC
2P610CC
2C210
2D147W
2D147W
2D147W
2C410
2C410
2C410
2C410
2K410
2C022
2C022
2K447
2K447
2C410
2C410
2N610
2C410
2C410
2N710
2C022
2C022
2C210
2D147W
L937 Preamplifier Board Parts List Issue 1.0
Designator Part
Description
C162
C163
C164
C165
C166
C167
C168
C169
C170
C171
C172
C173
C174
C175
C176
C177
C178
C179
C180
C181
C182
C183
C184
C185
C186
C187
C188
C189
C190
C191
C192
C193
C300
C302
C303
C304
C305
C306
C307
C308
C309
C310
C312
C313
C314
C315
D100
D101
D102
D103
D104
D105
D106
D107
D108
D109
D110
D111
D112
D113
D114
D115
WIMA FKP2 470P 63V CAP
WIMA FKP2 470P 63V CAP
MLC 1N0 50V X7R 10% SM
WIMA FKP2 470P 63V CAP
WIMA FKP2 470P 63V CAP
PEST 100N 63V 10%
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
ELST 10U 50V
ELST 10U 50V
ELST 10U 50V
ELST 10U 50V
ELST 10U 50V
PEST 470N 63V 10%
PEST 470N 63V 10%
ELST 1M0 35V
ELST 220U 16V
ELST 3M3 25V
MLC 100N 50V X7R 10% SM
ELST 10U 50V
ELST 470U 25V RA
PEST 470N 63V 10%
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
ELST 1M0 35V
ELST 220U 16V
ELST 3M3 25V
PPRO 1N0 5% 63V RA
PPRO 1N0 5% 63V RA
DIODE SS SM BAV99W
DIODE SS SM BAV99W
DIODE SS SM BAV99W
DIODE SS SM BAV99W
DIODE SS SM BAV99W
DIODE SS SM BAV99W
DIODE SS SM BAV99W
DIODE SS SM BAV99W
DIODE SS SM BAV99W
DIODE SS SM BAV99W
DIODE SS SM BAV99W
DIODE SS SM BAV99W
DIODE SS SM BAV99W
DIODE SS SM BAV99W
DIODE SS SM BAV99W
DIODE SS SM BAV99W
2D147W
2D147W
2C210
2D147W
2D147W
2K410
2C410
2C410
2C410
2C410
2C410
2C410
2C410
2C410
2C410
2C410
2C410
2C410
2C410
2C410
2C410
2C410
2C410
2C410
2C410
2N610
2N610
2N610
2N610
2N610
2K447
2K447
2N810C
2N722
2N833
2C410
2N610
2N747
2K447
2C410
2C410
2N810C
2N722
2N833
2D210
2D210
3AV99W
3AV99W
3AV99W
3AV99W
3AV99W
3AV99W
3AV99W
3AV99W
3AV99W
3AV99W
3AV99W
3AV99W
3AV99W
3AV99W
3AV99W
3AV99W
L937 Preamplifier Board Parts List Issue 1.0
Designator Part
Description
D116
D117
D118
D119
D120
D121
D122
D300
D301
D302
D304
D305
D306
D307
D308
D310
D311
F300
F301
PCB1
Q100
Q300
Q301
Q303
Q305
Q306
Q307
R100
R101
R102
R103
R104
R105
R106
R107
R108
R109
R110
R111
R112
R113
R114
R115
R116
R117
R118
R119
R120
R121
R122
R123
R124
R125
R126
R127
R128
R129
R130
R131
R132
R133
R134
DIODE SS SM BAV99W
DIODE SS SM BAV99W
DIODE SS SM BAV99W
DIODE SS SM BAV99W
DIODE SS SM BAS16W
DIODE SS SM BAV99W
DIODE SS SM BAV99W
RECT S1D 1A 200V SM
RECT S1D 1A 200V SM
DIODE SS SM BAS16W
DIODE SS SM BAS16W
DIODE SS SM BAS16W
RECT S1D 1A 200V SM
RECT S1D 1A 200V SM
DIODE SS SM BAS16W
ZENER 15V OW35 SM SOT23
ZENER 15V OW35 SM SOT23
FUSE R452 T750mA
FUSE R452 T750mA
PRINTED CIRCUIT BOARD
TRANS LF SS N SM BC849B
TRANS JFET N J112
TRANS AUDIO DRIVER N 2SC5248
TRANS JFET N J112
TRANS AUDIO DRIVER P 2SA1964
TRANS LF SS N SM BC846B
TRANS LF SS P SM BC856B
RES SM W4 1% 1K0 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 100K 1206
RES SM W4 1% 100K 1206
RES SM W4 1% 100K 1206
RES SM W4 1% 1M0 1206
RES SM W4 1% 1M0 1206
RES SM W4 1% 47R 1206
RES SM W4 1% 47R 1206
RES SM W4 1% 2K2 1206
RES SM W4 1% 2K2 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 2K7 1206
RES SM W4 1% 2K7 1206
RES SM W4 1% 5K6 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 2R2 1206
RES SM W4 1% 2R2 1206
RES SM W4 1% 2R2 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 100K 1206
RES SM W4 1% 100K 1206
RES SM W4 1% 100K 1206
RES SM W4 1% 1M0 1206
RES SM W4 1% 1M0 1206
RES SM W4 1% 47R 1206
RES SM W4 1% 47R 1206
3AV99W
3AV99W
3AV99W
3AV99W
3AS16W
3AV99W
3AV99W
3BS1D
3BS1D
3AS16W
3AS16W
3AS16W
3BS1D
3BS1D
3AS16W
3CW315V
3CW315V
C3751
C3751
L937PB_1
4A849B
4J112
4B5248
4J112
4B1964
4A846B
4A856B
1A210
1A210
1A210
1A410
1A410
1A410
1A510
1A510
1A047
1A047
1A222
1A222
1A322
1A322
1A322
1A227
1A227
1A256
1A322
1A322
1A322
1A322
1A822
1A822
1A822
1A210
1A210
1A210
1A410
1A410
1A410
1A510
1A510
1A047
1A047
L937 Preamplifier Board Parts List Issue 1.0
Designator Part
Description
R135
R136
R137
R138
R139
R140
R141
R142
R143
R144
R145
R146
R147
R148
R149
R150
R151
R152
R153
R154
R155
R156
R157
R158
R159
R160
R161
R162
R163
R164
R165
R166
R167
R168
R169
R170
R171
R172
R173
R174
R175
R176
R177
R178
R179
R180
R182
R183
R184
R185
R186
R187
R188
R189
R190
R191
R192
R193
R194
R195
R196
R197
RES SM W4 1% 2K2 1206
RES SM W4 1% 2K2 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 2K7 1206
RES SM W4 1% 2K7 1206
RES SM W4 1% 5K6 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 100K 1206
RES SM W4 1% 100K 1206
RES SM W4 1% 100K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 100K 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 1M0 1206
RES SM W4 1% 1M0 1206
RES SM W4 1% 22R 1206
RES SM W4 1% 47R 1206
RES SM W4 1% 47R 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 100K 1206
RES SM W4 1% 100K 1206
RES SM W4 1% 100K 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 100K 1206
1A222
1A222
1A322
1A322
1A322
1A227
1A227
1A256
1A322
1A322
1A322
1A322
1A322
1A322
1A322
1A322
1A322
1A322
1A322
1A322
1A322
1A210
1A210
1A210
1A410
1A410
1A410
1A322
1A322
1A322
1A322
1A322
1A322
1A322
1A322
1A322
1A322
1A322
1A322
1A322
1A322
1A322
1A322
1A322
1A322
1A410
1A110
1A510
1A510
1A022
1A047
1A047
1A310
1A210
1A210
1A210
1A410
1A410
1A410
1A210
1A210
1A410
L937 Preamplifier Board Parts List Issue 1.0
Designator Part
Description
R198
R199
R200
R201
R202
R203
R204
R300
R302
R303
R304
R307
RLY100
SK2
SK3
SK4
SK5
SK6
SK100
SK101
SK102
SK103
SK300
SK301
Z100
Z101
Z102
Z103
Z104
Z105
Z106
Z107
Z108
Z109
Z110
Z111
Z112
Z113
Z114
Z115
Z116
Z117
Z301
RES SM W4 1% 100K 1206
RES SM W4 1% 100K 1206
RES SM W4 1% 2R2 1206
RES SM W4 1% 2R2 1206
RES SM W4 1% 2R2 1206
RES SM W4 1% 4K7 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 330R 1206
RES SM W4 1% 1K2 1206
RES SM W4 1% 470R 1206
RES SM W4 1% 330R 1206
RES SM W4 1% 220R 1206
RELAY DPDT 5V SM NEC EB2-5NU
PHONO SKT 4-WAY EMC GOLD
PHONO SKT 4-WAY EMC GOLD
PHONO SKT 4-WAY EMC GOLD
PHONO SKT 4-WAY EMC GOLD
PHONO SKT 2-WAY EMC GOLD
Connector 1mm vertical 22way Molex 52806-2210
30-WAY FFC VERT CONN SM 1MM
4-WAY AMP CT CONN
8-WAY AMP CT CONN
MOLEX MINI FIT HCS 4 WAY
4-WAY FR LOCK CONN
IC 8 TO 1 MUX DG408DY SO16
IC 8 TO 1 MUX DG408DY SO16
IC 8 TO 1 MUX DG408DY SO16
IC 8 TO 1 MUX DG408DY SO16
IC 8 TO 1 MUX DG408DY SO16
IC 8 TO 1 MUX DG408DY SO16
IC QUAD SPST CMOS SW SO16
IC AUDIO DIGITAL VOL SM
IC DS1844S-010
IC AUDIO SM DUAL TL072
IC AUDIO SM DUAL TL072
IC AUDIO SM DUAL TL072
IC AUDIO SM DUAL TL072
IC AUDIO SM DUAL TL072
IC AUDIO SM DUAL TL072
IC OPAMP DUAL SM OPA2134PA
IC OPAMP DUAL SM OPA2134PA
IC OPAMP DUAL SM OPA2134PA
IC VREG POS LM317T
1A410
1A410
1A822
1A822
1A822
1A247
1A310
1A133
1A212
1A147
1A133
1A122
A216
8D225
8D225
8D225
8D225
8D226
8K8022B
8K8330
8K2404
8K2408
8K2304
8K6604
5S408DY
5S408DY
5S408DY
5S408DY
5S408DY
5S408DY
5S413DY
5AVSDVC
5A1844
5B072D
5B072D
5B072D
5B072D
5B072D
5B072D
5B2134
5B2134
5B2134
5D317T
1
2
3
4
D
D
C
C
Main signal path
L937C2_1.1.SCH
Power supply
L937C3_1.1.SCH
B
B
USE EXCLUDE NF WHEN USING RUNOUT SHEET PROGRAM
DRAWING TITLE
Integrated amplifier preamp
PCB1
A
PCB
L937PB_1
1
23425
Circuit Diagram
Notes:
A
01_E014
JBR
28/11/01
Fuses uprated to 2A
1.1
A & R Cambridge Ltd.
Pembroke Avenue
01_1142
JBR
14/8/01
First production release
1.0
Denny Industrial Centre
ECO No. INITIALS
DATE
DESCRIPTION OF CHANGE
ISSUE
Waterbeach
Drawn by:
Date Printed
Filename
Cambridge CB5 9PB
Sheet 1 of 3
DRAWING NO. L937C1
JBR
28-Nov-2001
J:\Change_Control\ECO_AGENDA\01_E014 Fuse changes on A32 preamp\L937_1.1.ddb - Documents\Schematic\L937C1_1.0.PRJ
2
3
4
-15V
TUNER R
0V_SIG
C122
470P FKP2
AVL1
EMC
1
AVL
R126
MODULE L
C126
100N SM
0V_SIG
+5V
0V_SIG
VCR01
VCR11
VCR21
AV L
1K0 SM
F
AVR1
C121
1N0 SM
VCR 0
VCR 1
VCR 2
0V_SIG
AVR
-15V
AV R
C124
470P FKP2
R130
100K SM
+15V
D108
BAV99W DUAL SM
D112
BAV99W DUAL SM
4
5
6
7
12
11
10
9
MODULE R
C127
100N SM 0V_SIG
-15V
C128
100N SM
0V_SIG
DVDL
R156
DVD INPUT
0V_SIG
DVD L
DVDR1
C140
470P FKP2
AUX L
CD L
TUNER L
AV L
DVD L
TAPE IN L
VCR IN L
MODULE L
0V_SIG
0V_SIG
PHONO4G
DVDR
R157
DVD R
1K0 SM
+15V
+15V
-15V
B
R160
100K SM
C141
470P FKP2
D113
BAV99W DUAL SM
+15V
D114
BAV99W DUAL SM
TAPE INPUT
1
EMC
TAPEIL
R158
X0
X1
X2
X3
X4
X5
X6
X7
V+
D
+15V
Z110B
TL072 SM
13
5
8
R161
100K SM
N
TAPEIR1
C142
470P FKP2
-15V
1K0 SM
+15V
C146
100N SM
0V_SIG
TAPEIR
TAPE IN R
R189
-15V
R192
100K SM
6
A
1K0 SM
F
R193
100K SM
N
C160
1N0 SM
VCRIR1
X0
X1
X2
X3
X4
X5
X6
X7
V+
D
13
C162
470P FKP2
3
R175
22K SM
R167
22K SM
R176
22K SM
R168
22K SM
R177
22K SM
R169
22K SM
AUXIR1
1
Z115A
C147
100N PE
C149
0V_SIG
VCR IN R
0V_SIG
1K0 SM
+15V
V+
D
R194
100K SM
C163
470P FKP2
+15V
AUXL
D117
BAV99W DUAL SM
1
-15V
1
2
3
4
C152
100N SM
5
6
Z116_1A
7
0V_SIG
TONE*
8
OPA2134PA SM
AUX L
0V_SIG
AUXR
R199
SEL2
D1
D2
S1
S2
V-
V+
GND
VL
S4
S3
D4
D3
SEL4
SEL3
16
TONE*
+
15
20
VCC
GND
DS1844
19
18
15
14
+15V
Z116B
C167
100N PE
+5V
5
C153
100N SM
12
11
0V_SIG
Z107_13
AUX R
+15V2
C168
100N SM
Z109C
AUXL1 TL072 SM
AUX L
-15V1
-15V2
-15V
C172
100N SM
9
TONE*
0V_SIG
+15V
C176
100N SM
Z110C
TL072 SM
0V_SIG
C169
100N SM
TAPE IN R
VCR IN L
VCR IN R
0V_SIG
LFO
3
C158
22P SM
2
2
LMO
14
RFO
LIN
LGND
Z117A
R186
1
SK102
1
2
3
4
SK102_1
47R SM
OPA2134PA SM
0V_SIG
R182
100R SM
RIN
RMO
15
5
R188
0V_SIG
10K SM
FFC30V SM
0V_MODULE
AMPCT4
TO POWER AMP I/P
Z117B
R187
7
RLY100A
RLY100B
47R SM
RLY DPDT 5V SM
OPA2134PA SM
0V_SIG
Z107
VSDVC
RLY DPDT 5V SM
0V_SIG
+5V
C180
100N SM
Z111C
TL072 SM
0V_SIG
C173
100N SM
0V_SLOAD
0V_SCLK
2R2 SM
R201
R181
10K SM
C177
100N SM
D120
BAS16W SM
+ RLY100C
RLY DPDT 5V SM
-
2R2 SM
R202
+5V
2R2 SM
C186
Q100
BC849B
100N SM
0V_SIG
Z112C
TL072 SM
0V_SIG
+ C187
10U EL
R203
MUTE*
4K7 SM
0V_SIG
C181
100N SM
0V_D
A
+15V
C165
0V_SIG
470P FKP2
AUX R
-15V
C170
100N SM
Z113C
TL072 SM
C166
470P FKP2
C174
100N SM
Z114C
TL072 SM
0V_SIG
C171
100N SM
0V_SIG
C175
100N SM
C178
100N SM
Z115C
0V_SIG
C179
100N SM
C182
100N SM
Z116C
0V_SIG
C184
100N SM
4
DRAWING TITLE
Integrated amplifier preamp - main signal path
Z117C
0V_SIG
C183
100N SM
C185
100N SM
-15V
3
B
SK102_3
6
RGND
MODULE L
MODULE R
SK101
1
2
3
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
R200
+15V
AUXR1
13
1M0 SM
5
TAPE IN L
-15V
0V_SIG
12
0V_SIG
+15V1
Z107_1
DVD R
-15V
D121
BAV99W DUAL SM
C159
22P SM
10
0V_SDATA
SK103
1
2
3
4
5
6
7
8
4
13
OPA2134PA SM
0V_SIG
C156
100N SM
3
Z107_4
R184
6
7
100K SM
0V_HF
R198
100K SM
SEL1
/TONE
DG413DY
470N PE
0V_SIG
2
1
-15V
+ C189
10U EL 0V_SIG
D119
BAV99W DUAL SM
0V_SIG
TONE*
C151
AMPCT8
-15V
5
0V_SIG
Z116A
22R SM
C155
100N SM
+15V
+ C191
10U EL 0V_SIG
+ C157
100U EL
D122
BAV99W DUAL SM
0V_SIG
Z106
1M0 SM
+ C188
10U EL
2
C154
10U EL
R185
R183
OPA2134PA SM
+15V
22K SM
8
Z115B
100K SM
R179
13
3
1K0 SM
-15V
AUX L
+ C190
10U EL
+5V
+
6
7
22P SM
X0
X1
X2
X3
X4
X5
X6
X7
C
FFC22V1MM
DVD L
Z115_1A
DG408DY
-15V
R196
SCLK
0V_SCLK
AV R
R180
0V_SIG
PHONO2G
R141
2K7 SM
AUX R
8
VCRIR
R191
SLOAD
0V_SLOAD
+15V
4
0V_SIG
PHONO4G
SDATA
0V_SDATA
0V_SIG
470N PE
+15V
R197
100K SM
C164
1N0 SM
TONEID
470N PE
OPA2134PA SM
2
EN
1
A0
16
A1
15
A2
LISTEN 0
LISTEN 1
LISTEN 2
R195
470N PE
C193
C150
Z105
4
5
6
7
12
11
10
9
1K0 SM
F
N
0V_SIG
AUXIL1
0V_D
TUNER R
2
8
DG408DY
R174
22K SM
R166
22K SM
-15V
D110
BAV99W DUAL SM
22K SM
2
EN
1
A0
16
A1
15
A2
TO PHONO PCB
1
AUX INPUT
0V_SIG
Z113B
TL072 SM
R178
Z104
4
5
6
7
12
11
10
9
LISTEN 0
LISTEN 1
LISTEN 2
D118
BAV99W DUAL SM
SK6
VCR IN L
MUTE*
+ C137
10U CERAFINE
R142
5K6 SM
AV L
-15V
VCRIL
R140
2K7 SM
22P SM
0V_SIG
R190
R146
22K SM
TONE*
6
47R SM
+15V
14
GND
3
V-
EMC
SK5A VCRIL1
1
EMC
VCR INPUT
R155
22K SM
TUNER L
14
GND
3
V-
+15V
R154
22K SM
R150
22K SM
C148
C161
470P FKP2
-15V
R153
22K SM
R149
22K SM
CD R
0V_SIG
+15V
R148
22K SM
CD L
R173
22K SM
R165
22K SM
D115
BAV99W DUAL SM
D116
BAV99W DUAL SM
R152
22K SM
0V_SIG
R172
22K SM
R164
22K SM
LISTEN0
LISTEN1
LISTEN2
R145
22K SM
C135
CFKP2 63V 2N2
SK100
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
R151
22K SM
R147
22K SM
C130
100P SM
+5V
0V_SIG
PHONO4G
C145
100N SM
0V_SIG
10U CERAFINE
R144
22K SM
7
R134
7
R132
1M0 SM
0V_SIG
+15V
6
C136
22P SM
R143
C134
470N PE
5
LISTEN 0
LISTEN 1
LISTEN 2
VCR 0
VCR 1
VCR 2
TAPE 0
TAPE 1
TAPE 2
Z106_11
0V_TONEID
C144
100N SM
TAPE IN L
Z108C
4
C138
Z114_7
0V_SIG
R171
22K SM
R163
22K SM
AUX R
CD R
TUNER R
AV R
DVD R
TAPE IN R
VCR IN R
MODULE R
Z108_3
7
C133
R170
22K SM
-15V
-15V
1K0 SM
C139
1N0 SM
0V_SIG
TAPEIL1
F
Z113_7
VCR02
-15V
SK4A
Z116_1B
PHONO4G
DG408DY
R162
22K SM
LIST0
LIST1
LIST2
Z108B
7
5
22K SM
N
+5V
C143
100N SM
0V_SIG
0V_SIG
0V_SIG
0V_SIG
-15V
R159
100K SM
F
0V_SIG
14
GND
3
V-
1K0 SM
F
47R SM
+ C132
10U CERAFINE
Z114_1
2
C129
100P SM
2
EN
1
A0
16
A1
15
A2
VCR 0
VCR 1
VCR 2
VCR0
VCR1
VCR2
-15V
DVDL1
2
+15V
+5V
0V_SIG
VCR OUTPUT
VCRO1 SK5B
R133
1
R131
1M0 SM
Z103
AUX R
CD R
TUNER R
AV R
DVD R
TAPE IN R
1K0 SM
+15V
3
8
3
1
22K SM
R138
22K SM
Z114B
TL072 SM
DG408DY
0V_SIG
N
D
Z110A
TL072 SM
13
-15V
R127
SK3B
V+
2
R136
C131
100U EL 2K2 SM
14
GND
3
V-
0V_SIG
PHONO4G
+15V
X0
X1
X2
X3
X4
X5
X6
X7
2
EN
1
A0
16
A1
15
A2
C123
470P FKP2
R129
100K SM
N
0V_SIG
-15V
-15V
SK3A
AV INPUT
C125
100N SM
4
5
6
7
12
11
10
9
+
7
C
AUX L
CD L
TUNER L
AV L
DVD L
TAPE IN L
1
22K SM
-15V
D109
BAV99W DUAL SM
DVCC
+15V
+15V
Z114A
TL072 SM
0V_SIG
Z114_3
Z113_1 R139
11
0V_SIG
+15V
Z102
+15V
D106
BAV99W DUAL SM
D107
BAV99W DUAL SM
DG408DY
2R2 SM
0V_SCLK
3
8
R128
100K SM
0V_SIG
R123
0V_SIG
D111
BAV99W DUAL SM
Z113A
TL072 SM
Z113_3
R137
-15V
-15V
+5V
AGND
1K0 SM
+15V
R135
2K2 SM
4
TUNR
R125
2R2 SM
0V_SDATA
470N PE
14
GND
3
V-
0V_SIG
PHONO4G
R116
2K7 SM
+5V
16
0V_SIG
C119
10N SM
0V_TONEID
R124
470N PE
C192
8
TUNR1
TAPE 0
TAPE 1
TAPE 2
R204
10K SM
2R2 SM
0V_SIG
0V_SIG
D
1
PS
8
R/W
11
DOUT
R122
C112
C109
100P SM
2
EN
1
A0
16
A1
15
A2
IC DS1844
+ C116
10U CERAFINE
R117
5K6 SM
47R SM
4
N
TAPE0
TAPE1
TAPE2
6
Z115_1B
XMUTE
C103
470P FKP2
R105
100K SM
R107
1M0 SM
R121
22K SM
SCLK 13
CLK
SDATA 12
DIN
TONEID 9
RST
+ C120
10U EL
TO MICRO / DISPLAY PCB
0V_SIG
7
R115
2K7 SM
Z111B
TL072 SM
R109
R120
22K SM
C114
CFKP2 63V 2N2
SCLK
SDATA
TONEID
C118
100N SM
Z108E
TO PLUG IN MODULE PCB
+5V
5
8
10U CERAFINE
R119
22K SM
+
VCR IN R
MODULE R
0V_SIG
-15V
TUNER L
1K0 SM
13
8
TUNL
R102
D
4
TUNL1
F
V+
6
OPA2134PA SM
SK2B
TUNER INPUT
X0
X1
X2
X3
X4
X5
X6
X7
+5V
Z106_14
7
8
C107
100N SM
4
5
6
7
12
11
10
9
C117
Z112_7
C115
5
AUX R
CD R
TUNER R
AV R
DVD R
C106
100N SM
-15V
D104
BAV99W DUAL SM
8
D102
BAV99W DUAL SM
Z109B
TL072 SM
7
6
22P SM
R118
C113
470N PE
5
Z111_7
-15V
4
+15V
Z101
2
Z108A
14
DS1844
0V_SIG
+15V
5
10
+15V
Z108_19
Z112B
TL072 SM
Z112_1
1
22K SM
DG408DY
-15V
Z108D
17
1
+15V
C111
10U CERAFINE
0V_SIG
TAPE02
14
GND
3
V0V_SIG
+
PHONO4G
OPA2134PA SM
D101
BAV99W DUAL SM
R113
22K SM
3
3
C102
470P FKP2
R104
100K SM
22K SM
0V_SIG
8
-15V
2
Z112A
TL072 SM
Z112_3
R114
AVCC
1K0 SM
+15V
0V_SIG
Z111_1
1
+ C110
R111
100U EL 2K2 SM
N
0V_SIG
3
22K SM
C108
100P SM
2
EN
1
A0
16
A1
15
A2
TAPE 0
TAPE 1
TAPE 2
TAP0
TAP1
TAP2
Z111A
TL072 SM
Z111_3
R112
F
4
D
-15V
CD R
TAPE OUTPUT
OPA2134PA SM
CDR
R101
TAPEO1
47R SM
DS1844
0V_SIG
PHONO4G
0V_SIG
2
2
+5V
R108
1
R106
1M0 SM
R110
2K2 SM
SK4B
3
8
DGND
C105
100N SM 0V_SIG
0V_SIG
CDR1
D
Z109A
TL072 SM
13
8
N
VCR IN L
MODULE L
V+
6
XCS
9
DATA
10
CCLK
C101
470P FKP2
R103
100K SM
C100
1N0 SM
C104
100N SM
X0
X1
X2
X3
X4
X5
X6
X7
8
D105
BAV99W DUAL SM
SLOAD
SDATA
SCLK
1K0 SM
F
EMC
CD L
4
R100
4
5
6
7
12
11
10
9
8
1
AUX L
CD L
TUNER L
AV L
DVD L
+15V
4
CD INPUT
CDL
7
-15V
D103
BAV99W DUAL SM
DS1844
+15V
Z100
CDL1
6
+5V
+15V
SK2A
5
8
D100
BAV99W DUAL SM
4
4
+15V
3
16
2
6
1
5
23425
Circuit Diagram
Notes:
01_E014
JBR
28/11/01
Fuses uprated to 2A
1.1
A & R Cambridge Ltd.
Pembroke Avenue
01_1142
JBR
14/8/01
First production release
1.0
Denny Industrial Centre
ECO No. INITIALS
DATE
DESCRIPTION OF CHANGE
ISSUE
Waterbeach
Drawn by:
Filename
Date Printed
Cambridge CB5 9PB
Sheet 2 of 3
DRAWING NO. L937C2
28-Nov-2001
JBR
J:\Change_Control\ECO_AGENDA\01_E014 Fuse changes on A32 preamp\L937_1.1.ddb - Documents\Schematic\L937C2_1.0.SCH
6
7
8
1
2
3
4
D302
D304
BAS16W SM
Q305
2SA1964
I
SK300
MOLEXPWR4
3
4
Q306
BC846B
UR+
D300
S1D
F300
D301
S1D
+ C300
1000u 35V
AC1
Q300
J112
R300
330R SM
+
D310+
1
2
C308
100N SM
C303
3300u 25V
D310
15V 350MW SM
C314
1N0 PP
C
F301
AC2
C309
100N SM
Vout
C315
1N0 PP
D
D305
BAS16W SM
+ C312
220U EL
R302
1K2 SM
D307
S1D
+ C310
1000u 35V
D311
15V 350MW SM
C305
10U EL
+15V SK301
1
2
3
-15V
4
0V_PSU
IDC4S
0V_PSU
0V_MODULE
SP300
STAR POINT 4
0V_PSU
Q307
BC856B
0V_SIG
-15V3
0V_HF
0V_MODULE
-15V
Q301
2SC5248
D308
B
C
D311-
R304
330R SM
UR-
+ C306
470U EL 25V
+
+ C313
3300u 25V
Q303
J112
R303
470R SM
R307
220R SM
+ C302
220U EL
T2A SM
D306
S1D
+5V
+3.75V
C304
100N SM
T2A SM
C307
470N PE
Vin
ADJ
+15V3
+5V
O
A
D
Z301 BAS16W SM
LM317T
+15V
0V_SIG
B
BAS16W SM
DRAWING TITLE
Integrated amplifier preamp - power supply
23425
A
Circuit Diagram
Notes:
A
01_E014
JBR
28/11/01
Fuses uprated to 2A
1.1
A & R Cambridge Ltd.
Pembroke Avenue
01_1142
JBR
14/8/01
First production release
1.0
Denny Industrial Centre
ECO No. INITIALS
DATE
DESCRIPTION OF CHANGE
ISSUE
Waterbeach
Drawn by:
Date Printed
Filename
Cambridge CB5 9PB
Sheet 3 of 3
DRAWING NO. L937C3
JBR
28-Nov-2001
J:\Change_Control\ECO_AGENDA\01_E014 Fuse changes on A32 preamp\L937_1.1.ddb - Documents\Schematic\L937C3_1.0.SCH
1
2
3
4
3rd Channel
Board
L911
Contents
!
Component overlay
!
Parts list
!
Circuit diagrams
L911 3rd Channel Amplifier Board Parts List Issue 1.1
Designator Part
Description
BR100
C100
C101
C102
C103
C104
C105
C106
C107
C108
C109
C300
C301
C302
C303
C304
C305
C306
C307
C308
C309
C310
C311
C312
C313
C314
C315
C316
C317
C318
C319
C320
D100
D101
D300
D301
D302
D303
D304
DZ300
DZ301
DZ302
DZ303
DZ305
DZ306
IC100
IC300
L300
PB
PL300
R100
R101
R102
R103
R104
R105
R106
R107
R300
R301
R302
R303
BRIDGE RECTIFIER 8A 200V
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
ELST 100U 25V
MLC 10N 50V X7R 10% SM
MLC 10N 50V X7R 10% SM
MLC 1N0 50V X7R 10% SM
ELST 10m 63V RA 35mm
ELST 10m 63V RA 35mm
PCRB 100N 100V 10% RA 5mm
PCRB 100N 100V 10% RA 5mm
ELST 100U 25V
ELST 100U 25V
ELST 100U 100V
ELST 100U 25V
ELST 100U 25V
ELST 10U 50V
ELST 100U 100V
MLC 100P 50V NPO 5% SM
MLC 100P 50V NPO 5% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
PCRB 100N 100V 10% RA 5mm
MLC 10N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
MLC 100N 50V X7R 10% SM
PPRO W 470P 63V 5% RA
PEST 470N 63V 10%
ELST 10U 50V
PEST 100N 63V 10%
ELST NON POLAR 100UF 16V
RECTIFIER 1N4003F 1A 200V
RECTIFIER 1N4003F 1A 200V
DIODE SS SM BAS16W
DIODE SS SM BAS16W
DIODE SS SM BAS16W
RECTIFIER 1N4003F 1A 200V
RECTIFIER 1N4003F 1A 200V
ZENER 15V OW35 SM SOT23
ZENER 15V OW35 SM SOT23
ZENER 4V7 OW 35 SM SOT23
ZENER 4V7 OW 35 SM SOT23
ZENER 4V7 OW 35 SM SOT23
ZENER 4V7 OW 35 SM SOT23
SURFACE MOUNT HEX SCHMITT TRIGGER
IC AUDIO SM DUAL TL072
INDUCT 2U2 12x20mm
PCB
2WAY MOLEX VERT MALE CONNECTOR
RES SM W4 1% 1K0 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 220R 1206
RES SM W4 1% 220R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 2R2 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
3BGBU8D
2C410
2C410
2N710
2C310
2C310
2C210
2N910A
2N910A
2H410
2H410
2N710
2N710
2N710B
2N710
2N710
2N610
2N710B
2C110
2C110
2C410
2C410
2H410
2C310
2C410
2C410
2C410
2D147W
2K447
2N610
2K410
2V710
3B4003
3B4003
3AS16W
3AS16W
3AS16W
3B4003
3B4003
3CW315V
3CW315V
3CW34V7
3CW34V7
3CW34V7
3CW34V7
5J7414D
5B072D
7D002C
L911PB_1
8K6201
1A210
1A210
1A210
1A122
1A122
1A110
1A110
1A822
1A310
1A310
1A310
1A310
L911 3rd Channel Amplifier Board Parts List Issue 1.1
Designator Part
Description
R304
R305
R306
R307
R308
R309
R310
R311
R312
R313
R314
R315
R316
R317
R318
R319
R320
R321
R322
R323
R324
R325
R326
R327
R328
R329
R330
R331
R332
R333
R334
R335
R336
R337
R338
R339
R340
R341
R342
R343
R344
R345
R346
R347
R348
R349
R350
R351
R352
R353
R354
R355
RLY100
RLY101
RV300
SK100
SK101
SK102
SK103
TH100
TR100
TR101
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 4K7 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 10K 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 22R 1206
RES SM W4 1% 22R 1206
RES SM W4 1% 22R 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 1K0 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 4K7 1206
RES SM W4 1% 4K7 1206
RES SM W4 1% 1M0 1206
RES SM W4 1% 1K5 1206
RES SM W4 1% 1K8 1206
RES SM W4 1% 3K3 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 3K3 1206
RES SM W4 1% 22K 1206
RES SM W4 1% 22R 1206
RES SM W4 1% 150R 1206
RES SM W4 1% 150R 1206
RES SM W4 1% 100K 1206
RES SM W4 1% 330R 1206
RES SM W4 1% 330R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 0R0 1206
RES SM W4 1% 0R0 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
RES CF 2W 5R6 5%
RES CF 2W 5R6 5%
RES 2W MF 5% 470R
RES 2W MF 5% 470R
RES SM W4 1% 1K0 1206
RES SM W4 1% 6K8 1206
RLY SPST 24V SPKR
RLY SPST 24V SPKR
PRES 100R LIN HORIZ
FFC 14W 2.54MM VER PTH
PHONO SKT 2-WAY EMC GOLD
CAMCON BINDING POST 4WAY GOLD
MOLEX MINI FIT 4 WAY
THERMISTOR SIEMENS B59008
NPN TRANS MP BD179
NPN TRANS MP BD179
1A310
1A310
1A310
1A310
1A322
1A310
1A247
1A310
1A310
1A310
1A310
1A110
1A110
1A110
1A110
1A110
1A110
1A022
1A022
1A022
1A210
1A210
1A210
1A322
1A247
1A247
1A510
1A215
1A218
1A233
1A322
1A233
1A322
1A022
1A115
1A115
1A410
1A133
1A133
1A110
1A110
1A000
1A000
1A110
1A110
1A110
1C856
1C856
1J147
1J147
1A210
1A268
A213
A213
6F110
8K7014
8D226
8D418G
8K2304
1T002
4B179
4B179
L911 3rd Channel Amplifier Board Parts List Issue 1.1
Designator Part
Description
TR300
TR301
TR302
TR303
TR304
TR305
TR306
TR307
TR308
TR309
TR310
TR311
TR312
TR313
TR314
TR315
TR316
TR317
TR318
TR319
TR320
TR321
TR322
TRANS LF SS P SM FMMT597
TRANS LF SS P SM FMMT597
TRANS LF SS P SM FMMT597
TRANS LF SS P SM FMMT597
TRANS LF SS P SM FMMT597
TRANS LF SS P SM FMMT597
TRANS LF SS P SM FMMT597
TRANS LF SS P SM FMMT597
TRANS LF SS P SM FMMT597
TRANS LF SS N SM FMMT497
TRANS LF SS N SM FMMT497
TRANS LF SS N SM FMMT497
TRANS LF SS N SM FMMT497
TRANS LF SS N SM FMMT497
TRANS LF SS N SM FMMT497
TRANS LF SS N SM FMMT497
TRANS LF SS N SM FMMT497
TRANS LF SS N SM FMMT497
TRANS POWER NPN SAP15N
TRANS POWER PNP SAP15P
TRANS LF SS N SM FMMT497
TRANS LF SS P SM FMMT597
TRANS LF SS N SM FMMT497
4AFMMT597
4AFMMT597
4AFMMT597
4AFMMT597
4AFMMT597
4AFMMT597
4AFMMT597
4AFMMT597
4AFMMT597
4AFMMT497
4AFMMT497
4AFMMT497
4AFMMT497
4AFMMT497
4AFMMT497
4AFMMT497
4AFMMT497
4AFMMT497
4CSAP15N
4CSAP15P
4AFMMT497
4AFMMT597
4AFMMT497
1
2
3
4
5
6
7
8
+5V_D
SK100
1
2
3
4
5
6
7
8
9
10
11
12
13
14
D
14
+5V_D
C100
100N SM
C101
100N SM
+ C102
100U EL
TP103
SPKR1 ON
SPKR2 ON
THERMPROT
VIPROT1
DCPROT1
0V_D
TP104
TP105
TP106
TP107
TP108
D
+5V_D
0V_D
FFC 14W 2.54MM VER
IC100E
PIN 1 TO THE LEFT AS YOU LOOK FROM THE FRONT
11
10
7
2R2 SM
0V_D
SP100
TP116
THERMPROT
0V_LS
R100
1K0 SM
R107
0V_SIG
TH100
PTH90DEG
IC100G
74HC14D
TP102
STAR POINT 8 0V_HF
74HC14D
IC100F
13
0V_PSU
12
74HC14D
0V_D
C
C
IC100A
R101
+49V
1
1K0 SM
RLY101B
RLY SPST SPKR
D100
1N4003F
RLY100B
RLY SPST SPKR
R102
1
R105
N
INPUT
0V_SIG
0V_LS
0V_HF
VPOS
VNEG
+49V
C105
1N0 SM
SPKR2 ON
100R SM
PHONO2G
VIPROT1
8
DCPROT1
74HC14D
IC100D
5
69
C104
10N SM 74HC14D
74HC14D
VIPROT
DCPROT
OUTPUT
TP111
0V_D
RLY101A
TP112
SK102A
RLY100A
TP113
Top+
RLY SPST SPKR
SK102B
Bot+
RLY SPST SPKR
-49V
0V_SIG TP110
R104
220R SM
4
L911C2_1
L911C2_1.1.SCH
F
SPKR1 ON
EMC
R103
220R SM
TP109
100R SM
R106
74HC14D
IC100C
D101
1N4003F
SK101
TR100
BD179
23
C103
10N SM
1K0 SM
TR101
BD179
IC100B
Top-
0V_HF
Bot-
0V_LS
B
B
0V_LS
0V_D
+49V
1
TP100
BR100
BRGBU8D
+ C106
10,000u 63V
2
3
~
~
+ C107
10,000u 63V
L911PB_1
TP101
DRAWING TITLE
TP115
A
PCB
0V_PSU
C109
100N PC
4
4
3
SK103
MOLEXPWR4
PB
C108
100N PC
2
-
1
+
TP114
POWER AMP SUPPLY
A
AP85 third channel - top level
23425
-49V
Circuit Diagram
Notes:
01_1101
JR
4/6/01
A & R Cambridge Ltd.
Pembroke Avenue
01_1018
JR
30/1/01
Denny Industrial Centre
ECO No. INITIALS
DATE
Waterbeach
Date Printed
Cambridge CB5 9PB Filename
4-Jun-2001
J:\ECO_wip\01_1101 A85 RANGE PCB FUSES AND DC OFFSET\L911_1.1.DDB - Documents\L911C1_1.1.PRJ
1
2
3
4
5
6
DC OFFSET CHANGES
1.1
PRODUCTION ISSUE
1.0
DESCRIPTION OF CHANGE
Drawn by:
J Reckless
7
Sheet 1 of 2
DRAWING NO.
ISSUE
L911C1
8
1
2
3
4
5
6
8
7
VPOS
D
D
R319
100R SM
R315
100R SM
R300
10K SM
R316
100R SM
PRE DRIVER
PNP CURRENT MIRROR
TR300
FMMT597
TR310
FMMT497
TR301
FMMT597
R301
10K SM
+
C300
100U EL
DZ300
15V 350MW SM
TR309
FMMT497
R321
22R SM
TR302
FMMT597
TR321
FMMT597
OUTPUT STAGE
R338
150R SM
0V_HF
TR318
SAP15N
3K3 SM
TR311
FMMT497 C317
R328
4K7 SM
C
INPUT
V TO I AMP
R324
3
1K0 SM
DZ302
4V7 350MW SM
2
8
INPUT FILTER
0V_SIG
IC300A
1
TL072CD
DZ303
4V7 350MW SM
R322
22R SM
4
R327
22K SM
R337
22R SM
+
DZ301
15V 350MW SM
R352
470R 2W
TR313
FMMT497
R349
100R SM
R345
0R0 SM
R340
100K SM
+ C303
100U EL
1
2
R351
L300
2U2H LAC SMALL
DC OFFSET SIGNAL
TO MICRO
R355
6K8 SM
DCPROT
+ C318
10U EL
+ C304
100U EL
C312
10N SM
C311
100N PC
R326
1K0 SM
+ C306
100U EL 100V
R354
1K0 SM
TP306
BOOTSTRAP
R344
100R SM
ZOBEL NETWORK
TR305
FMMT597
R346
0R0 SM
R304
10K SM
R348
R342
3K3 SM
C308
TR319
SAP15P
100P SM
0V_SIG
TR320
FMMT497
TR304
FMMT597
D304
1N4003F
100R SM
TR306
FMMT597
C319
100N PE
C313
0V_LS
R308
22K SM
R307
10K SM
TP308
R336
22K SM
D302
BAS16W SM
100N SM
0V_HF
0V_LS
TR316
FMMT497
DZ306
4V7 350MW SM
V-I PROTECTION
R310
4K7 SM
R313
C320
100U NP
10K SM
R314
10K SM
C315
100N SM
0V_HF
C301
100U EL
DC OFFSET
DETECTION
R302
10K SM
R339
150R SM
OUTPUT STAGE
R350
5R6 2W CF
R303
10K SM
330R SM
R335
C
5R6 2W CF
MEASURE
BIAS
D300
BAS16W SM
470R 2W
R353
TR303
FMMT597
C314
100N SM
R343
100R SM
D303
1N4003F
TR312
FMMT497
100R SM
DZ305
4V7 350MW SM
+ C305
10U EL
OUTPUT
0V_SIG
0V_HF
VIPROT
R306
10K SM
0V_HF
1K8 SM
TP303
C309
100N SM
TP307
R332
0V_SIG
0V_SIG
R325
1K0 SM
PL300
TR322
FMMT497
C316
470P PPW
VI PROTECT
SIGNAL TO MICRO
R305
10K SM
ADJ BIAS
RV300
100R PSET
R331
1K5 SM
TP304
R347
330R SM
+ C302
100U EL 100V
TL072CD 0V_SIG
TP302
R341
BOOTSTRAP
6R330
1M0 SM
5
IC300B
0V_SIG
R334
22K SM
TP305
DC SERVO
7
R329
4K7 SM
D301
BAS16W SM
100P SM
470N PE
C310
100N SM
V-I PROTECTION
C307
R333
R323
22R SM
0V_HF
0V_HF
R309
10K SM
TR314
FMMT497
TR315
FMMT497
TR307
FMMT597
TR308
FMMT597
NPN CURRENT MIRROR
R317
100R SM
B
PRE DRIVER
R318
100R SM
R311
10K SM
B
TR317
FMMT497
R320
100R SM
R312
10K SM
VNEG
A
A
DRAWING TITLE
AP85 third channel - output stage
23425
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
1
2
3
4
5
Circuit Diagram
Notes:
01_1101
JR
4/6/01
DC OFFSET CHANGES
01_1018
JR
30/1/01
PRODUCTION ISSUE
ECO No. INITIALS
Filename
L911C2_1.1.SCH
6
DATE
4-Jun-2001
7
1.0
DESCRIPTION OF CHANGE
Drawn by:
Date Printed
1.1
J Reckless
Sheet 2 of 2
ISSUE
DRAWING NO.
8
L911C2
Transformer
Specifications
Contents
!
L914TX
!
L915TX
Mechanical
Assembly
Contents
!
General assembly
parts list A32
!
General assembly
parts list P35
!
General assembly
parts list P35/3
A32 General Assembly Parts List E047rs_2
ITEM
A
B
1
7
39
35
230V
L813RC
115V
100V
SILVER
BLACK
L907TX
E045AY
E838CP
E839AY
HA4V06S
E045AYB
E838CPB
E839AYB
HA4V06B
DESCRIPTION
HANDY REMOTE 3 DIVA/DIVA SERIES CR389
TRANSF A85 100V
FRONT PANEL ASSEMBLY
COVER
LARGE VOLUME KNOB
M4 x 6mm Screw
54
2
3
4
N/A
E046AY
E804HK
E804MI
N/A
REAR PANEL ASSEMBLY
HEAT SINK
MAINS INSULATOR
5
6
8
9
10
51
38
40
12
13
14
16
17
18
19
20
21
41
49
22
48
37
24
23
25
47
46
36
42
43
44
52
45
E820CH
E822PM1
E850MC
E853MC
E860MC
E878MC
E879SL
E907MC
E912MC
E920MC
E938MC
F022
F037
F038
F062
F065
F082
F164
E83001
HA3V10A
HA3V06A
HA4A12B
HA5K70A
HA5L20B
HA6K60A
HE6V06B
HF4V09B
HJ4A00A
HJ4C00D
HL4SB
HL5EB
HP008
HP008
CHASSIS
FOOT
HEAT SHUNT
PRE AMP REG CLAMP
DIVA A85 MODULE SLOT BLANKING PANEL
PHONO BOARD BRACKET
CONFIGURATION LABEL
KOOL PAD
TRANSISTOR CLAMP
HEATSINK CLAMP
DAMPING PLATE
FUSE HOLDER COVER
TOROID CLAMP ø90
RUBBER WASHER ø90
FUSE CLIP
ADHESIVE CABLE CLIP
TO220 SIL PAD
FOAM TAPE
TRANSFORMER GASKET
M3 x 10mm SCREW
M3 x 6mm SCREW
M4 x 12mm SCREW
M5 x 70mm BOLT
M5 x 20mm HEX HEAD BOLT BLACK
M6 x 60mm BOLT
SFTP TORX SCREW NO.6x6mm BK
TORX SCREW NO.4x9mm + WASHER
M4 NUT
M4 WAISTED NUT
M4 SHAKE PROOF WASHER
M5 WASHER BLACK
PLASTIC SNAP RIVET
SNAP RIVET BLACK PLASTIC
WHERE USED
COVER TO CHASSIS
ON CHASSIS FLOOR UNDER POWER
SUPPLY PCB
ON CHASSIS FLOOR
E850MC
FIXES PHONO BOARD
CHASSIS
HEATSINK
ON E804HK
ON E804HK
ON CHASSIS FLOOR
TOP OF TRANSFORMER
ON TOP OF TRANSFORMER
SPARE FUSE
TRANSFORMER
UNDER VOLTAGE REG
FRONT PANEL TO COVER
UNDER TRANSFORMER
HEATSHUNT
POWER, PREAMP & DISPLAY PCB’S
EARTHING SCREWS
HEATSINK SCREWS
TRANSISTORS TO HEATSINK
TRANSFORMER
EARTHING NUT
EARTH
EARTH
HEATSINK SCREWS
E878MC TO L870AY
BLANKING PLATES
QTY
1
1
1
1
1
4
1
1
1
1
6
1
1
1
1
1
1
4
1
1
2
1
1
1
1
3
400mm
1
2
31
2
3
4
1
4
20
1
1
1
3
1
4
A32 General Assembly Parts List E047rs_2
ITEM
A
B
50
28
31
30
32
33
34
53
29
27
230V
L813RC
115V
100V
L907TX
L870AY
L882AY
L914CA
L914TX
L915CA
L916CA
L917CA
L918CA
L928AY
L937AY
WA8511A
L894AY
L915TX
SILVER
BLACK
DESCRIPTION
HANDY REMOTE 3 DIVA/DIVA SERIES CR389
TRANSF A85 100V
PHONO PCB
A85 POWERAMP PCB
DISPLAY TO PRE AMP CABLE ASSY
A32 TRANSFORMER
DISPLAY TO POWERAMP CABLE ASSY
POWERAMP TO HEADPHONE CABLE ASSY
PREAMP TO POWERAMP CABLE ASSY
PHONO TO PREAMP CABLE ASSY
A32 DISPLAY PCB
A32 PREAMP PCB
WHERE USED
THROUGH REAR PANEL
QTY
1
1
1
1
1
1
1
1
1
1
1
1
P35 General Assembly Parts List E078rs_2
ITEM
1
2
3
4
5
230V
115V
8K004
8K006
DESCRIPTION
FASCIA ASSEMBLY
COVER
M4 x 6mm Screw
2-WAY JUMPER SOCKET 0.1” M7571-05
CONNECTOR 14MM LINK BAR P2148
7
8
9
E060AY
E804HK
E804MI
REAR PANEL ASSEMBLY
HEAT SINK
MAINS INSULATOR
10
11
12
13
14
15
16
17
18
19
20
21
E820CH
E822PM1
E861MC
E879SL
E907MC
E912MC
E920MC
E938MC
F022
F037
F038
F164
CHASSIS
FOOT
RD
3 CHANNEL BLANKING PLATE
CONFIGURATION LABEL
KOOL PAD
TRANSISTOR CLAMP
HEATSINK CLAMP
DAMPING PLATE
FUSE HOLDER COVER
TOROID CLAMP ø90 (METAL)
RUBBER WASHER ø90
FOAM TAPE
22
23
24
25
26
27
28
29
30
F200
E83001
HA3V06A
HA4A12B
HA5K70A
HA5L20B
HA6K60A
HE6V06B
HF4V09B
9,5 I.D. HOLE BLANKING GROMMET
TRANSFORMER GASKET
M3 x 6mm SCREW
M4 x 12mm SCREW
M5 x 70mm BOLT
M5 x 20mm HEX HEAD BOLT BLACK
M6 x 60mm BOLT
SFTP TORX SCREW NO.6x6mm BK
TORX SCREW NO.4x9mm + WASHER
31
32
33
34
35
36
37
38
HJ4A00A
HJ4C00D
HL4SB
HL5EB
L882AY
L884TX
L915CA
L929AY
M4 NUT
M4 WAISTED NUT
M4 SHAKE PROOF WASHER
M5 WASHER BLACK
A85 POWERAMP PCB
TRANSFORMER
DISPLAY TO POWERAMP CABLE ASSY
P35 SWITCH PCB
WA8511A
L884TX
100V
L894AY
L880TX
SILVER
E058AY
E838CP
HA4V06S
BLACK
E058AYB
E838CPB
HA4V06B
WHERE USED
FRONT OF CHASSIS
COVER (SIDE) TO CHASSIS
ON L882AY (NEAR SWITCH)
FITTED TO REAR PANEL
CHASSIS REAR
CHASSIS FLOOR
ON CHASSIS FLOOR UNDER POWER
SUPPLY PCB
BASE OF CHASSIS
REAR PANEL
CHASSIS
HEATSINK
HEATSINK
HEATSINK
ON CHASSIS FLOOR
TOP OF TRANSFORMER
ON TOP OF TRANSFORMER
FRONT PANEL TO COVER
REAR PANEL (FOR LINK BAR)
UNDER TRANSFORMER
POWER & DISPLAY PCB’S
EARTHING SCREW
HEATSINK BOLTS
TRANSISTORS TO HEATSINK
TRANSFORMER
CHASSIS TO SUB PANEL
COMPONENTS TO REAR PANEL +
COVER TO REAR PANEL + REAR
PANEL TO CHASSIS
EARTHING NUT
EARTH
EARTH
HEATSINK BOLT (AT THE FRONT)
CHASSIS FLOOR
CHASSIS FLOOR
L882AY TO L929AY
SUB PANEL
QTY
1
1
4
2
1
1
1
1
1
6
1
1
1
4
1
1
2
1
1
400m
m
2
1
17
1
3
4
1
4
16
1
1
1
1
1
1
1
1
P35/3 Channel General Assembly Parts List E079rs_2
ITEM
1
2
3
4
5
7
8
9
230V
115V
8K004
8K006
E060AY
E804HK
E804MI
DESCRIPTION
FASCIA ASSEMBLY
COVER
M4 x 6mm Screw
2-WAY JUMPER SOCKET 0.1” M7571-05
CONNECTOR 14MM LINK BAR P2148
REAR PANEL ASSEMBLY
HEAT SINK
MAINS INSULATOR
10
11
12
13
14
15
16
17
18
19
20
21
22
23
E806HK
E820CH
E822PM1
E879SL
E907MC
E909MC
E912MC
E921MC
HEAT SINK
CHASSIS
FOOT
CONFIGURATION LABEL
KOOL PAD
RD
3 CHANNEL SIL PAD
TRANSISTOR CLAMP
HEATSINK CLAMP
E938MC
DAMPING PLATE
ON CHASSIS FLOOR
F037
F038
F164
TOROID CLAMP ø90 (METAL)
RUBBER WASHER ø90
FOAM TAPE
TOP OF TRANSFORMER
ON TOP OF TRANSFORMER
FRONT PANEL TO COVER
24
25
26
27
28
29
30
31
32
F200
E83001
HA3V06A
HA4A12B
HA5K70A
HA5L20B
HA6K60A
HE6V06B
HF4V09B
9,5 I.D. HOLE BLANKING GROMMET
TRANSFORMER GASKET
M3 x 6mm SCREW
M4 x 12mm SCREW
M5 x 70mm BOLT
M5 x 20mm HEX HEAD BOLT BLACK
M6 x 60mm BOLT
SFTP TORX SCREW NO.6x6mm BK
TORX SCREW NO.4x9mm + WASHER
33
34
35
36
37
38
39
40
41
42
HJ4A00A
HJ4C00D
HL4SB
HL5EB
L882AY
L884TX
L911AY
L915CA
L919CA
L929AY
M4 NUT
M4 WAISTED NUT
M4 SHAKE PROOF WASHER
M5 WASHER BLACK
A85 POWERAMP PCB
TRANSFORMER
RD
3 CHANNEL PCB
SWITCH TO POWERAMP CABLE ASSY
RD
SWITCH TO 3 CHANNEL CABLE ASSY
P35 SWITCH PCB
REAR PANEL (FOR LINK BAR)
UNDER TRANSFORMER
PCB’S
EARTHING SCREW
HEATSINK BOLTS
TRANSISTORS TO HEATSINK
TRANSFORMER
CHASSIS TO SUB PANEL
COMPONENTS TO REAR PANEL +
COVER TO REAR PANEL + REAR
PANEL TO CHASSIS
EARTHING NUT
EARTH
EARTH
HEATSINK BOLT (AT THE FRONT)
CHASSIS FLOOR
CHASSIS FLOOR
CHASSIS FLOOR
L882AY TO L929AY
WA8511A
L884TX
WA85Q1A
WFA35P 1A
100V
L880TX
SILVER
E058AY
E839CP
HA4V06S
BLACK
E058AYB
E839CPB
HA4V06B
WHERE USED
FRONT OF CHASSIS
COVER (SIDE) TO CHASSIS
ON L882AY (NEAR SWITCH)
FITTED TO REAR PANEL
CHASSIS REAR
CHASSIS FLOOR
ON CHASSIS FLOOR UNDER POWER
SUPPLY PCB
CHASSIS FLOOR
BASE OF CHASSIS
CHASSIS
HEATSINK
HEATSINK
HEATSINKS
HEATSINK
SUB PANEL
QTY
1
1
4
2
1
1
1
1
1
1
6
1
1
1
6
1
2
1
1
1
400m
m
2
1
22
1
5
6
1
4
16
1
1
1
1
1
1
1
2
1
1
ARCAM
All parts can be ordered via spares@arcam.co.uk
Pembroke Ave, Waterbeach, Cambridge, CB5 9PB, ENGLAND
TEL: +44(0) 1223 203 203
FAX: +44(0) 1223 863 384
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