Service Manual
A32
Issue 1.0
FMJ A32, P35 & P35/3
Amplifiers
ARCAM
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
2A410
2N622
2D210
CERD 100N 63V -20% +80% RA
ELST 22U 63V
PPRO 1N0 5% 63V RA
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
2P710AS ELEC 100U 25V SILMIC
2P710AS ELEC 100U 25V SILMIC
2K410
PEST 100N 63V 10%
2K410
PEST 100N 63V 10%
2K410
PEST 100N 63V 10%
2K410
PEST 100N 63V 10%
2D147W
2D110W
2D247N
2D310
2D310
2K510
2D213N
2D147W
2D147W
2U610
2D110N
2D210
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
2N622
2D210
PPRO 1N0 5% 63V RA
2P710AS ELEC 100U 25V SILMIC
2P710AS ELEC 100U 25V SILMIC
2K410
PEST 100N 63V 10%
2K410
PEST 100N 63V 10%
2K410
PEST 100N 63V 10%
2K410
PEST 100N 63V 10%
2D147W
2D110W
2D247N
2D310
2D310
2K510
2D213N
2D147W
2D147W
2U610
2D110N
2D210
3A4148
3A4148
3A4148
3A4148
3A4148
3A4148
5B071
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
5B071
L870PB_2 PRINTED CIRCUIT BOARD
1H133
1H110
1H110
1H110
1H110
1H110
1H347
1H312
1H312
1H356
1H410
1H410
1H410
1H315
1H522
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
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
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
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
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
1
2
3
4
5
6
7
8
D
C
B
A
D
C
B
A
LEFT CHANNEL
L870C2_2.0.SCH
+15V
Q_5
Q_1
Q_3
SK1
PHONO2HG
LEFT IN
LEFT OUT
SK2
1
1
2
3
4
5
6
7
8
0V_SIG
Q_2
EMC
C1
RIGHT CHANNEL
L870C3_2.0.SCH
100N CD
Q_4
Q_6
RIGHT IN
RIGHT OUT
0V_SIG
AMPCT8
Q_8
Q_7
0V_SIG
-15V
0V_HF
DRAWING TITLE
PCB1
EL1
A85 PHONO STAGE - TOP LEVEL
PCB
Update Box
Circuit Diagram
UPDATE_BOX
L870PB_2
2 3 4 2 5
Notes:
01_1070
00_1051
JAG
JAG
17/4/01
updated pcb and scm
2
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
22/3/01
PRODUCTION ISSUE
1
ECO No. INITIALS
Date Printed
G:\DATA\ECO\ECO AGENDA\01_1070 l870 A85 PHONO ISSUE2\L870_2.0.ddb - L870c1_2.0.PRJ
DATE
DESCRIPTION OF CHANGE
ISSUE
Drawn by:
JBR
Filename
Cambridge CB5 9PB
Sheet 1 of 3
DRAWING NO. L870C1
23-Apr-2001
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
+15V
Q_102
+
C102
100U SILMIC
C104
100N PE
C119
D
C
B
A
0V_HF
R101
100R MF
0V_SIG
D
C
B
A
R100
R102
330R MF
100R MF
100P PP
C101
TR100
BC556B
TR102
BC556B
TR103
1N0 PP
BC556B
C110
TR101
BC556B
+ C100
22U EL
4N7 PP
C120
1N0 PP
C112
R109
12K MF
TR108
TR109
BC546B
BC546B
10N PP AX
C111
R115
R110
12K MF
15K MF
10N PP AX
R118
22R MF
LEFT IN
R112
D100
100K MF
1N4148
C106
100N PE
SW100B
4PCO
C113
C105
100N PE
C115
1N3 PP
R116
LEFT OUT
1U0 PE
2M2 MF
R119
22R MF
TR106
2SA1085
TR107
IC100
3
R122
39K MF
2SA1085
R117
2M2 MF
C118
Q_101
R111
6
2
56K MF
10U NP
TL071CD
R124
5K6 MF
SW100D
4PCO
R113
100K MF
0V_SIG
R108
47K MF
TR104
TR105
BC556B
BC556B
C109
100P PPW
R104
100R MF
C108
470P PPW
R114
10R MF 100K MF
R105
100R MF
R123
C117
470P PPW
C116
0V_SIG
0V_SIG
470P PPW
TR112
BC546B
TR113
BC546B
TR110
BC546B
TR111
BC546B
TR114
BC546B
D101
1N4148
D102
1N4148
R106
100R MF
C107
100N PE
+
R120
22R MF
R121
22R MF
0V_HF
C103
100U SILMIC
0V_SIG
Q_103
-15V
DRAWING TITLE
A85 PHONO STAGE - LEFT CHANNEL
Circuit Diagram
2 3 4 2 5
Notes:
01_1070
00_1051
JAG
JAG
17/4/01
updated pcb and scm
2
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
22/3/01
PRODUCTION ISSUE
1
ECO No. INITIALS
Date Printed
DATE
DESCRIPTION OF CHANGE
ISSUE
Drawn by:
JBR
Filename
Cambridge CB5 9PB
Sheet 2 of 3
DRAWING NO. L870C2
G:\DATA\ECO\ECO AGENDA\01_1070 l870 A85 PHONO ISSUE2\L870_2.0.ddb - L870C2_2.0.SCH 23-Apr-2001
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
+15V
Q_202
+
C202
100U SILMIC
C204
100N PE
C219
D
C
B
A
0V_HF
R201
100R MF
0V_SIG
D
C
B
A
R200
R202
330R MF
100R MF
100P PP
C201
TR200
BC556B
TR202
BC556B
TR203
1N0 PP
C210
BC556B
TR201
BC556B
4N7 PP
C220
+ C200
22U EL
1N0 PP
C212
R209
12K MF
TR208
TR209
BC546B
BC546B
10N PP AX
C211
R215
R210
12K MF
15K MF
10N PP AX
R218
22R MF
RIGHT IN
R212
D200
100K MF
1N4148
C206
100N PE
SW100A
4PCO
C213
C205
100N PE
C215
R216
RIGHT OUT
1N3 PP
1U0 PE
2M2 MF
R219
22R MF
TR206
2SA1085
TR207
IC200
3
R222
39K MF
2SA1085
R217
2M2 MF
Q_201
R211
6
2
56K MF
TL071CD
C218
10U NP
SW100CR224
4PCO 5K6 MF
R213
100K MF
0V_SIG
R208
47K MF
TR204
TR205
BC556B
BC556B
C208
C209
R204
100R MF
100P PPW
R214
10R MF 100K MF
R205
R223
100R MF
470P PPW
C217
470P PPW
C216
470P PPW
0V_SIG
0V_SIG
TR212
BC546B
TR213
BC546B
TR210
BC546B
TR211
BC546B
TR214
BC546B
D201
1N4148
D202
1N4148
R206
100R MF
C207
100N PE
+
R220
22R MF
R221
22R MF
0V_HF
C203
0V_SIG
100U SILMIC
Q_203
-15V
DRAWING TITLE
A85 PHONO STAGE - RIGHT CHANNEL
Circuit Diagram
2 3 4 2 5
Notes:
01_1070
00_1051
JAG
JAG
17/4/01
updated pcb and scm
2
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
22/3/01
PRODUCTION ISSUE
1
ECO No. INITIALS
Date Printed
DATE
DESCRIPTION OF CHANGE
ISSUE
Drawn by:
JBR
Filename
Cambridge CB5 9PB
Sheet 3 of 3
DRAWING NO. L870C3
G:\DATA\ECO\ECO AGENDA\01_1070 l870 A85 PHONO ISSUE2\L870_2.0.ddb - L870C3_2.0.SCH 23-Apr-2001
1
2
3
4
5
6
7
8
Amplifier + PSU
Board
L882
Contents
ꢀ
ꢀ
ꢀ
Circuit description
Component overlay
Parts list
ꢀ
Circuit diagrams
rails will vary with mains input and load conditions. The
current is around 20mA per relay.
Amplifier & PSU Circuit Description
Refer to L882 circuit diagrams
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.
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
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.
ꢀ
ꢀ
ꢀ
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
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
ꢀ
ꢀ
ꢀ
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.
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.
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).
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.
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.
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.
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).
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.
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
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.
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.
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.
The input to the amplifier is limited to ±5.4V via back-to-
back 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.
TR203 and TR202 are a complementary Darlington pair
which turn on mains relay RLY200 when activated by a
signal from the microprocessor.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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
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
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.
dependent on system bandwidth to
a
first order
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.
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).
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.
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.
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.
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.
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!)
R338 and R339 are to loosely couple the outputs of the pre-
driver 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.
Sheet 4 is an identical copy of sheet 3 so I will not
describe it separately.
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, fast-
responding 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.
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
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
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
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
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
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
F200
F200
F200
F201
F201
F201
F202
C12207
F022
8S004
F022
8S004
FUSE 20mm 2A AS
INS COVER PCB FUSEHOLDER
FUSEHOLDER 20mm PCB
INS COVER PCB FUSEHOLDER
FUSEHOLDER 20mm PCB
FUSE 20mm 2A AS
C12207
C3501
FUSE R452 T500mA
HS200
HS200
IC200
IC201
F008
F006
5M393AD
5D7805
HEATSINK TO220 8.6 DEGC/W
HEATSINK CLIP TO220 13/8.6 DC/W
IC COMPARATOR SM DUAL LM393A
IC VREG POS 7805
L882 Amplifier and PSU Board Parts List Issue 3.0
Designator Part
Description
IC202
IC300
IC400
L200
L300
L400
PCB
5J7414D
5B072D
5B072D
7D327
7D002C
7D002C
L882PB_3
8K6201
8K6201
8K6201
8K6201
1H010
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
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
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
1A110
1A110
RES SM W4 1% 100R 1206
RES SM W4 1% 100R 1206
1.00E+133 RES CF 1W 330R 5%
1.00E+133 RES CF 1W 330R 5%
1.00E+110 RES CF 1W 100R 5%
1.00E+110 RES CF 1W 100R 5%
1A122
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
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
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
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
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
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
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%
R448
R449
R450
R451
R452
R453
R454
R455
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
RLY100
RLY101
RLY200
RV300
RV400
SH200
SK100
SK101
SK102
SK103
SK104
SK105
SK106
SK107
SK200
SK201
SK202
SK203
SK204
SK205
SW100
SW200
A207
A219
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
6F110
6F110
E5402
8D418G
8D418G
8K2404
8K7014
8D225
8D301
8K2404
8K2404
8K2306
8D302
8Q003
8A001
8K2308
8K2406
A1008
A1404
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
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
1T002
4B179
4B179
4B179
THERMISTOR SIEMENS B59008
NPN TRANS MP BD179
NPN TRANS MP BD179
NPN TRANS MP BD179
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT497 TRANS LF SS N SM FMMT497
4A849B
4A856B
4A856B
TRANS LF SS N SM BC849B
TRANS LF SS P SM BC856B
TRANS LF SS P SM BC856B
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT497 TRANS LF SS N SM FMMT497
4CSAP15N TRANS POWER NPN SAP15N
4CSAP15P
TRANS POWER PNP SAP15P
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT497 TRANS LF SS N SM FMMT497
4CSAP15N TRANS POWER NPN SAP15N
4CSAP15P
TRANS POWER PNP SAP15P
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT497 TRANS LF SS N SM FMMT497
7A9301
TRANSFORMER 3VA 9V+9V TYPE 9301
1
2
3
4
5
6
7
8
L882C3
0V_SIG
L882C3_4.1.SCH
L SIG
VIPROT_L
DCPROT_L
LS L
0V_TRIG
0V_D
5
8
6
7
0V_HF_R
0V_LS_R
0V_LS_L
0V_PSU
INPUT
0V_SIG
0V_LS
0V_HF
VPOS
VNEG
VIPROT
DCPROT
OUTPUT
D
C
B
A
0V_SIG
0V_LS_L
0V_HF_L
+49V
D
C
B
A
TP121
1
2
L882C2
L882C2_4.1.SCH
0V_D
0V_PSU
0V_HF_L
-49V
+5V_D
+49V
-49V
THERMPROT
VIPROT
AC PRESENT
DCPROT
REMOTE
TRIGGER
0V_D
+5V(D)
VPOS
VNEG
SP100
STAR_8
0V_PSU
PWRON
VIPROT_L
VIPROT_R
0V_TRIG
DCPROT_L DCPROT_uC
DCPROT_R
STANDBY
VIPROT_L
VIPROT_R
0V_TRIG
DCPROT_L
DCPROT_R
THPROT_uC
VIPROT_uC
AC_PRES
L882C4
L882C4_4.1.SCH
R SIG
VIPROT_R
DCPROT_R
LS R
INPUT
0V_SIG
0V_LS
0V_HF
VPOS
VNEG
VIPROT
DCPROT
OUTPUT
RC5 IN
TRG IN
0V_SIG
0V_LS_R
0V_HF_R
+49V
-49V
+49V
SW100A
2PCO
LS L
RLY100C
RLY G5Z-2A-E
RLY101C
RLY G5Z-2A-E
D100
1N4003F
D101
1N4003F
TP101
L SIG
R SIG
SK106
PL100
1
2
3
4
0V_LS_L
LS R
TP102
SK104B
1
SK104A
SK102
AMPCT4
TP118
TR101
BD179
R101
1
2
3
4
F
F
TR100
BD179
SPKR1 ON
SPKR2 ON
TP100
4
5
SK107
100R SM
R103
FROM PREAMP
1
2
3
4
EMC
N
N
330R 1W CF
R104
SK105
0V_SIG
2
3
1
C100
TP119
R102
AMPCT4
1N0 SM
330R 1W CF
100R SM
PHONO4G
PHONO4G
TP120
PL101
HPSKT
AMPCT4
6
7
R105
R106
0V_SIG
100R 1W CF 100R 1W CF
R107
220R SM
R108
220R SM
0V_SIG
SW100B
2PCO
0V_D
INTEGRATED / PRE-POWER
MODE SELECT SWITCH
SK100A
SK100B
Bot+
RLY100A
RLY101A
LS L
Top+
TP111
TP113
RLY G5Z-2A-E
TP115
RLY G5Z-2A-E
+5V_D
+49V
PCB
0V_LS_L
PCB
Top-
Bot-
R100
SK103
CAMCON_G
CAMCON_G
L882PB_4
EL
1
2
3
4
5
6
7
8
10R MF
EARTH LEAD
8M101
STANDBY
SPKR1 ON
SPKR2 ON
THERMPROT
VIPROT
TP103
TP104
TP105
TP106
TP107
TP108
TP109
TP110
TP117
SK101A
Top+
SK101B
Bot+
RLY100B
RLY101B
EARTH LEAD
LS R
TP112
TP114
TP116
RLY G5Z-2A-E
RLY G5Z-2A-E
9
DCPROT
10
11
12
13
14
AC PRESENT
TRIGGER
REMOTE
0V_D
0V_LS_R
Top-
Bot-
CAMCON_G
CAMCON_G
FFC 14W 2.54MM VER
8K7014
DRAWING TITLE
A85 amplifier and PSU - top sheet
Circuit Diagram
2 3 4 2 5
Notes:
02_E062
02_E035
JBR
JBR
20/3/02
LDO REG FITTED TO IC201
FUSE VALUES UPRATED TO T4A
4.1
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
4/2/2002
4.0
ECO No. INITIALS
Date Printed
DATE
DESCRIPTION OF CHANGE
ISSUE
Drawn by:
Filename
L882C1_4.1.PRJ
Sheet 1 of 4
Cambridge CB5 9PB
L882C1
DRAWING NO.
J Reckless
20-Mar-2002
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
NEUTRAL
SK204
TP203
4
3
2
1
8
7
6
5
HS200
TO220HS08REG
D
C
B
A
D
C
B
A
TX200
0V
1
9VRMS
IC201
L4940V5
+5V_D
SK203
IEC3 NO RIVETS
MOLEXPWR8
RLY200A
F202
TP204
D202
5
9V
I
O
Vin
Vout
+5V(D)
TP205
D200
1N4003F
T750mA SM
1N4003F
DPDT5V
NF
LIVE
SW200B
VOL SEL SLIDE
VR200
VDR 115V
N
E
L
C207
C225
100N CD
C226
100N CD
F200
T4A
TP202
TP201
+
C228
1000u 10V
3N3 MAINS
C224
100N CD
SH200
EMCMAINS
2 115V
+
0V
3
6
C227
C205
EMC Shield
7
3N3 MAINS
3300u 25V
9V
C206
3N3 MAINS
NEUTRAL
LIVE
SW200A
VOL SEL SLIDE
RLY200B
D201
1N4003F
D203
1N4003F
TP200
NEUTRAL
TP206
LIVE
NF
VR201
VDR 115V
DPDT5V
C208
0V_D
SK202
CAGECLAMP1
0V
BC200
TOOLING4.1
F201
T4A
8
TP207
TP210
3N3 MAINS
4 115V
TX 3VA 9301
EARTH
C234
0V_D
MAINS WIRING AND AUXILIARY SUPPLY
220N X2 CLASS
R231
1M5 VR25
+5V_D
9VRMS
R219
1K8 SM
IC202E
R220
TR204
BC849B
11
10
AC_PRES
10R SM
+49V
74HC14D
R211
10K SM
TP208
VPOS
D206
BAS16W SM
+
C229
22U EL
BR200
BRGBU8D
SK205
+
+
1
2
3
4
5
6
C209
10,000u 63V
C211
100N PC
SK200
3
2
1
6
5
4
3
2
~
~
0V_PSU
C210
10,000u 63V
0V_PSU
0V_D
MICROPROCESSOR SIGNALS INTERFACE
AMPCT6
C212
100N PC
+5V_D
TP209
MOLEXPWR6
VNEG
POWER AMP SUPPLY
TH200
PTH90DEG
C201
C202
IC202G
74HC14D
IC202F
100N SM 100N SM
R221
-49V
13
12
THPROT_uC
10R SM
R205
1K0 SM
74HC14D
CARRIER FILTER AND DEMODULATOR
+5V_D
R209
10K SM
R223
10K SM
0V_D
TRG IN
IC200A
2
3
1
R226
R228
SK201A
+5V_D
IC200C
LM393A SM
+
C233
10U EL
470R SM
100K SM
TP211
Near to PCB
C232
LM393A SM
DZ204
4V7 350MW SM
100N SM
R227
1K0 SM
L200
27mH
R224
1K8 SM
IC202A
C200
680P PP
R229
100K SM
TR205
BC856B
JACK3.5X2
R201
R213
1
3
2
VIPROT_L
C203
100N SM
MODULATED RC5
REMOTE CONTROL INPUT
1K0 SM
4K7 SM
C214
10N SM
74HC14D
IC202B
VIPROT_uC
C230
10N SM
R230
1K5 SM
R202
R214
R208
10K SM
4
R206
1K0 SM
VIPROT_R
IC200B
C218
10N SM
1K0 SM
4K7 SM
C215
10N SM
C219
10N SM
5
6
74HC14D
7
RC5 IN
R222
10K SM
C231
1N0 SM
LM393A SM
R225
1K8 SM
0V_D
0V_D
+5V_D
0V_TRIG
+49V
IC202C
TR206
BC856B
R203
R215
5
6
DCPROT_L
DCPROT_R
C204
100N SM
R218
10K SM
1K0 SM
4K7 SM
C216
10N SM
+5V_D
74HC14D
TR200
BD179
IC202D
DCPROT_uC
RLY200C
DPDT5V
R204
R216
D205
BAS16W SM
TR201
FMMT497
+
9
8
R207
1K0 SM
C223
10U EL
C213
10N SM
DZ207
15V 350MW SM
C220
100N SM
1K0 SM
4K7 SM
C217
10N SM
C221
10N SM
74HC14D
TRIGGER OUTPUT
APPROX 13.5VDC
60mA MAX CURRENT
R217
10R SM
TP212
R200
1K0 SM
SK201B
TR202
FMMT597
STANDBY RELAY CONTROL
R210
10K SM
+
0V_D
0V_D
C222
Far from PCB
10U EL
JACK3.5X2
DRAWING TITLE
0V_TRIG
TR203
FMMT497
R212
A85 amplifier - power supply and microcontroller interface
0V_TRIG
PWRON
CAMCON_G
SK101C
4K7 SM
C235
Circuit Diagram
CHASS
2
3 4 2
5
Notes:
02_E062
02_E035
JBR
JBR
20/3/02
LDO REG FITTED TO IC201
4.1
0V_D
1N0 SM
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
4/2/2002
FUSE VALUES UPRATED TO T4A
4.0
ECO No. INITIALS
Date Printed
DATE
DESCRIPTION OF CHANGE
ISSUE
Drawn by:
J Reckless
Filename
L882C2_4.1.SCH
Sheet 2 of 4
Cambridge CB5 9PB
L882C2
DRAWING NO.
20-Mar-2002
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
VPOS
D
C
B
A
D
C
B
A
R319
100R SM
R315
100R SM
R316
100R SM
R300
10K SM
PRE DRIVER
PNP CURRENT MIRROR
TR310
FMMT497
TR300
FMMT597
TR301
FMMT597
R301
10K SM
+
R321
22R SM
TR302
FMMT597
C300
100U EL
DZ300
15V 350MW SM
TR309
FMMT497
TR321
FMMT597
OUTPUT STAGE
V-I PROTECTION
VI PROTECT
R338
150R SM
R329
4K7 SM
R305
10K SM
SIGNAL TO MICRO
D301
BAS16W SM
C307
TP307
R333
0V_HF
TR318
SAP15N
R334
22K SM
VIPROT
3K3 SM
100P SM
DZ305
4V7 350MW SM
TR311
FMMT497 C317
R306
10K SM
+
C305
10U EL
TP305
R341
D303
1N4003F
TR312
FMMT497
TR313
FMMT497
DC SERVO
R347
R349
BOOTSTRAP
330R SM
100R SM
R345
100R SM 0R0 SM
100R SM
470N PE
IC300B
+
R325
1K0 SM
R343
C302
100U EL 100V
C310
100N SM
R330
ADJ BIAS
RV300
6
7
0V_HF
1M0 SM
5
PL300
1
2
+
C303
100U EL
0V_SIG
R340
100K SM
R328
4K7 SM
TL072CD
0V_SIG
100R PSET
R351
R352
470R 2W MF 5%
10R MF
D300
BAS16W SM
MEASURE
BIAS
TP302
R331
INPUT FILTER
V TO I AMP
1K5 SM
0V_SIG
L300
2U2H LAC SMALL
(SET TO 16mV)
R324
IC300A
3
2
INPUT
TP304
R322
OUTPUT
R332
1
1K0 SM
470R 2W MF 5%
R353
DZ302
DC OFFSET SIGNAL
TO MICRO
1K8 SM
4V7 350MW SM
TL072CD
R327
22K SM
22R SM
R350
5R6 2W CF
R355
6K8 SM
DCPROT
R303
10K SM
TR322
FMMT497
+
+
C318
C304
DZ303
C316
470P PPW
C312
10N SM
ZOBEL NETWORK
C313
10U EL
100U EL
4V7 350MW SM
R337
22R SM
TR305
FMMT597
C311
100N PC
C319
100N PE
DC OFFSET
DETECTION
R326
1K0 SM
R344
R346
100R SM 0R0 SM
R304
10K SM
0V_SIG
+
C306
TP303
TR303
R354
1K0 SM
C309
100N SM
0V_SIG
TR304
FMMT597
100U EL 100V
0V_LS
R348
100R SM
D304
1N4003F
0V_SIG
R308
22K SM
TP306
R342
330R SM
BOOTSTRAP
R302
10K SM
100N SM
0V_HF
FMMT597
R307
10K SM
0V_HF
0V_LS
TP308
C308
R336
22K SM
R335
3K3 SM
C314
100N SM
D302
BAS16W SM
TR319
SAP15P
TR316
FMMT497
100P SM
R339
150R SM
R310
4K7 SM
R313
DZ306
4V7 350MW SM
C320
100U NP
0V_SIG
TR320
FMMT497
R314
10K SM
DZ301
15V 350MW SM
OUTPUT STAGE
10K SM
V-I PROTECTION
+
C315
100N SM
0V_HF
TR306
FMMT597
R323
22R SM
C301
100U EL
0V_HF
0V_HF
TR314
FMMT497
TR315
FMMT497
R309
10K SM
TR307
FMMT597
TR308
FMMT597
NPN CURRENT MIRROR
PRE DRIVER
R317
100R SM
R318
100R SM
R311
10K SM
TR317
FMMT497
R320
100R SM
R312
10K SM
VNEG
DRAWING TITLE
A85 amplifier - power output stage left
Circuit Diagram
2
3 4 2
5
Notes:
02_E062
02_E035
JBR
JBR
20/3/02
LDO REG FITTED TO IC201
4.1
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
4/2/2002
FUSE VALUES UPRATED TO T4A
4.0
ECO No. INITIALS
Date Printed
DATE
DESCRIPTION OF CHANGE
ISSUE
Drawn by:
J Reckless
Filename
L882C3_4.1.SCH
Sheet 3 of 4
Cambridge CB5 9PB
L882C3
DRAWING NO.
20-Mar-2002
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
VPOS
D
C
B
A
D
C
B
A
R419
100R SM
R415
100R SM
R416
100R SM
R400
10K SM
PRE DRIVER
PNP CURRENT MIRROR
TR410
FMMT497
TR400
FMMT597
TR401
FMMT597
R401
10K SM
+
R421
22R SM
TR402
FMMT597
C400
100U EL
DZ400
15V 350MW SM
TR409
FMMT497
TR421
FMMT597
OUTPUT STAGE
V-I PROTECTION
VI PROTECT
R438
150R SM
R429
4K7 SM
R405
10K SM
SIGNAL TO MICRO
D401
BAS16W SM
C407
TP407
R433
0V_HF
TR418
SAP15N
R434
22K SM
VIPROT
3K3 SM
100P SM
DZ405
4V7 350MW SM
TR411
FMMT497 C417
R406
10K SM
+
C405
10U EL
TP405
R441
D403
1N4003F
TR412
FMMT497
TR413
FMMT497
DC SERVO
R447
R449
BOOTSTRAP
330R SM
100R SM
R445
100R SM 0R0 SM
100R SM
470N PE
IC400B
+
R425
1K0 SM
R443
C402
100U EL 100V
C410
100N SM
R430
ADJ BIAS
RV400
6
7
0V_HF
1M0 SM
5
PL400
1
2
+
C403
100U EL
0V_SIG
R440
100K SM
R428
4K7 SM
TL072CD
0V_SIG
100R PSET
R451
R452
470R 2W MF 5%
10R MF
D400
BAS16W SM
MEASURE
BIAS
TP402
R431
INPUT FILTER
V TO I AMP
1K5 SM
0V_SIG
L400
(SET TO 16 mV)
R424
IC400A
3
2
INPUT
TP404
R422
OUTPUT
R432
1
1K0 SM
2U2H LAC SMALL
DC OFFSET SIGNAL
TO MICRO
470R 2W MF 5%
R453
1K8 SM
TL072CD
DZ402
R427
22K SM
22R SM
R450
5R6 2W CF
4V7 350MW SM
R455
6K8 SM
DCPROT
R403
10K SM
ZOBEL NETWORK
TR422
FMMT497
+
+
C418
C404
DZ403
C412
10N SM
10U EL
100U EL
4V7 350MW SM
C416
470P PPW
R437
22R SM
TR405
FMMT597
C411
100N PC
C419
100N PE
DC OFFSET
DETECTION
R426
1K0 SM
R444
R446
100R SM 0R0 SM
R404
10K SM
0V_SIG
C413
TP403
TR403
R454
1K0 SM
C409
100N SM
0V_SIG
+
TR404
FMMT597
C406
0V_LS
R448
100R SM
D404
1N4003F
0V_SIG
R408
22K SM
100U EL 100V
TP406
R442
330R SM
R402
10K SM
100N SM
BOOTSTRAP
0V_HF
FMMT597
R407
10K SM
0V_HF
0V_LS
C408
R436
22K SM
TP408
R435
3K3 SM
C414
100N SM
D402
BAS16W SM
TR419
SAP15P
TR416
FMMT497
100P SM
R439
150R SM
R410
4K7 SM
R413
DZ406
4V7 350MW SM
C420
100U NP
0V_SIG
TR420
FMMT497
R414
10K SM
DZ401
15V 350MW SM
OUTPUT STAGE
10K SM
V-I PROTECTION
+
C415
100N SM
0V_HF
TR406
FMMT597
R423
22R SM
C401
100U EL
0V_HF
0V_HF
TR414
FMMT497
TR415
FMMT497
R409
10K SM
TR407
FMMT597
TR408
FMMT597
NPN CURRENT MIRROR
PRE DRIVER
R417
100R SM
R418
100R SM
R411
10K SM
TR417
FMMT497
R420
100R SM
R412
10K SM
VNEG
DRAWING TITLE
A85 amplifier - power output stage right
Circuit Diagram
2
3 4 2
5
Notes:
02_E062
02_E035
JBR
JBR
20/3/02
LDO REG FITTED TO IC201
4.1
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
4/2/2002
FUSE VALUES UPRATED TO T4A
4.0
ECO No. INITIALS
Date Printed
DATE
DESCRIPTION OF CHANGE
ISSUE
Drawn by:
J Reckless
Filename
L882C4_4.1.SCH
Sheet 4 of 4
Cambridge CB5 9PB
L882C4
DRAWING NO.
20-Mar-2002
1
2
3
4
5
6
7
8
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
2C018
2C018
2C410
2C410
2C410
2C410
2C410
2C410
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
C9
2C410
2C410
2M610
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
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
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
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
D2
D3
DC1
DC2
DISP1
IC1
IC2
IC5
IC6
IC7
IC8
IC11
LED1
LED2
3D001
LED GREEN 5MM
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
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
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
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
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
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
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
F195
F195
F195
F195
F195
F195
F195
F195
F195
F163
F163
LED SPACER
STICKY PAD S/A 10 X 15mm
STICKY PAD S/A 10 X 15mm
IR RX SUPPORT PAD
E822AP
E822AP
A1505
A1505
A1505
A1505
A1505
A1505
A1505
A1505
A1505
A1505
A1505
A1505
A1505
A1505
A1505
A1505
A1505
A1211
7X040
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
1
2
3
4
5
6
7
8
A32 FMJ DISPLAY PCB
D
C
B
A
D
C
B
A
L928CT_B.1
L928CT_2_B.3.SCH
MICRO
FD_1
FD_2
FIDUCIAL FIDUCIAL
FIX7
FIX2
FIX10
FIX5
FIX6
FIX13
FIXING HOLE 3F.I5XING HOLE 3F.I5XING HOLE 3.5
FIXING HOLE 3F.I5XING HOLE 3F.I5XING HOLE 3.5
C39
1N0 SM
CHASSIS 1
(BY SK3)
C38
1N0 SM
C40
1N0 SM
C41
1N0 SM
C43
C44
0V_D
1N0 SM
1N0 SM
0V_D
0V_D
0V_D
0V_D
0V_D
FIX1
FIX8
FIX9
FIX3
FIX11
FIX12
FIXING HOLE 3F.I5XING HOLE 3F.I5XING HOLE 3F.I2XING HOLE 3.5
FIXING HOLE 3.5 FIXING HOLE 3.2
C45
1N0 SM
C46
1N0 SM
C47
1N0 SM
CHASSIS 2
(BY SK1)
C37
1N0 SM
C48
1N0 SM
C49
1N0 SM
0V_D
0V_D
0V_D
CHASSIS 3
(BY SK2)
0V_D
0V_D
0V_D
PCB1
PCB
L928PB_B
DRAWING TITLE
A32 FMJ AMP DISPLAY PCB
WAF
26/9/01
10/9/01
9/08/01
STICKY PADS RENUMBERED
PRE PRODUCTION RELEASE
UPDATED PROTOTYPE
INITIAL PROTOTYPE
B.3
B.2
JBR
WAF
CL
Circuit Diagram
2 3 4 2 5
Notes:
B.0
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
25/04/01
A.0
ECO No. INITIALS
Date Printed
DATE
DESCRIPTION OF CHANGE
ISSUE
Drawn by:
CL
Filename
Cambridge CB5 9PB
Sheet 1 of 2
L928CT1
DRAWING NO.
J:\Released_Documents\Native_format_files\Protel_DDB\L928_B.3.Ddb - Documents\L928CT1_10_-BO.3c.Pt-R2J001
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
SP7
SP8
SP6
SP3
SP10
SP9
SP1
SP4
SP2
SP5
SPACER F195SPACER F195SPACER F195SPACER F195SPACER F195SPACER F195SPACER F195SPACER F195SPACER F195SPACER F195
PHONO/
AUX
+5V
AV
MODE
RECORD
TONE
DVD
DOWN
UP
ENTER
POWER
SELECT
CD
TUNER
VCR
TAPE
SP2
SP1
Q2
BC847B
Q1
BC847B
R1
10K SM
SW6
R2
10K SM
SW12
R3
10K SM
SW11
R4
10K SM
SW8
R5
10K SM
SW7
R6
10K SM
SW13
R7
10K SM
SW14
R8
10K SM
SW15
R68
10K SM
SW17
R9
10K SM
SW16
R10
10K SM
SW1
R11
10K SM
SW4
R12
10K SM
SW2
R13
10K SM
SW5
R14
10K SM
SW3
R15
10K SM
SW10
R16
10K SM
SW9
R17
330R SM
R18
330R SM
R19
330R SM
R20
330R SM
R21
330R SM
R22
330R SM
R25
330R SM
R24
330R SM
R23
330R SM
R31
330R SM
D
C
B
A
D
C
B
A
TACTSW A1505 TACTSW A1505 TACTSW A1505 TACTSW A1505 TACTSW A1505 TACTSW A1505 TACTSW A1505 TACTSW A1505 TACTSW A1505 TACTSW A1505TACTSW A1505 TACTSW A1505 TACTSW A1505 TACTSW A1505 TACTSW A1505 TACTSW A1505 TACTSW A1505
Q_65
LED7
Q_66
LED8
Q_67
LED6
Q_68
LED3
Q_69
Q_70
LED9
Q_71
LED1
Q_72
LED4
Q_73
LED2
Q_74
LED5
LED10
R29
10K SM
R30
10K SM
R33
330R SM
R34
150R SM
0V_D
LED GREEN
LED GREEN
LED GREEN
LED GREEN
LED GREEN
LED GREEN
LED GREEN
LED GREEN
LED GREEN
LED GREEN
LED11
IC7B
5
6
7
+5V
2V7
0V5
LED RED/GRN 3MM
DISP1
B1013
F1 to F2 = 4Vac 150mA
VDD2 = 40Vdc 20mA
+5V
Q_21
R36
10K SM
Q_22
R39
2K2 SM
SP101
LM393A SM
DOUBLE SIDED
STICKY PAD
10 X 15MM
R35
0V_D
+5V
+5V
Graphics Display
0V_D
R74
10K SM
LEFTAUDIO
10K SM
STICKY PAD DS 10X15MM
SP102
10U EL SM
C11
R40
4K7 SM
R47
4K7 SM
IC6B
IC8A
+5V
0V_D
R73
DOUBLE SIDED
STICKY PAD
10 X 15MM
+
Q_59
2V7
+5V
IRIN
R50
5
6
3
TRANSMIT
RECEIVE
SAMHOLD
SAMTX2
10K SM
IRIN
Q4
2V7
7
1
SAMDATA
10K SM
Q_34
R43
100K SM
+5V
2
SAMBUSY
STICKY PAD DS 10X15MM
BC847B
Q_35
DC1
R41
100K SM
+5V
LM393A SM
R38
1K2 SM
LM393A SM
R46
1K2 SM
DISPLAY CRADLE
E916PM
+5V
VFD_VDD2
R37
10K SM
R45
10K SM
IC6A
IC8B
0V5
2
0V5
6
IC7A
LM393A SM
Q3
R76
10K SM
IROUT
BC847B
DISPLAY CRADLE E916PM
DC2
Q_115
SAMRX2
3
2
1
7
R49
10K SM
1
3
0V_D
5
0V_D
+5V
0V_D
R75
DISPLAY CRADLE
E916PM
10K SM
Q_54
LM393A SM
LM393A SM
SP
Q_53
R44
Q_82
Q_49
DISPLAY CRADLE E916PM
R42
100K SM
2
IC11A
AD8532 SM
O/P
O/P
IR RX
SUPPORT PAD
0V_D
100K SM
C6
100N SM
+5V
Q_47
+5V
3
2
Q_48
R58
+5V
1
C9
IR RX SUPPORT PAD
RX1
R52
0V_D
F1CLOCK
Q_79
0R0 SM
Q_80
SBX1610-52/PIC-26043TM2
SP103
R56
10K SM
100R SM
100N SM
PLACE ONE ON TOP OF
THE OTHER UNDER RX1
0V_D
IR RX
Q_50
Programming adaptor
5
6
SUPPORT PAD
SW18
R59
0V_D
PR_GND
PR_TXD
7
SK4
ALPS_ENCODER
R53
1
2
PHASEA
PHASEB
F2CLOCK
Q_78
PR_VCC
PR_RXD
Q_58
Q_57
0R0 SM
2
4
6
8
10
12
14
1
3
5
7
9
11
13
A
B
Q_81
RECEIVE
TRANSMIT
RESPIN
IR RX SUPPORT PAD
100R SM
R57
10K SM
IC11B
AD8532 SM
Q_55
VPROG
PB0
PR_VPP
PR_PMODE
PR_MD
PR_RESET
SAMHOLD
3
C
+5V
0V_D
HEADER 7X2HORIZ
+
C14
C13
C3
100N SM
0V_D
10U EL SM
+5V
+5V
0V_D
100N SM
SK2
0V_D
+5V
1
IC1
Q_19
C17
2
3
4
5
SAMDATA
100N SM
SAMBUSY
+5V
+5V
D2
BAS16W SM
Q_20
R26
Q_56
0V_D
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
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
Vcc
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB7
MD2
MD1
MD0
+5V
PB0
10K SM
AMPCT5
R55
10K SM
SEL7
SEL6
SEL5
SEL4
SEL3
SEL2
SEL1
VPROG
0V_D
STANDBY
To power amp / PSU
SK1
P6.6/LWR
P6.5/HWR
P6.4/RD
P6.3/AS
Vcc
+SUP
Q_121
SP1ON
SP2ON
THERMPROT
C1
18P SM
Q_51
Q_37
Q_38
14
13
12
11
10
9
8
7
6
5
C60D 100PX4 SM
C60C 100PX4 SM
C60B 100PX4 SM
C60A 100PX4 SM
C61D 100PX4 SM
C61C 100PX4 SM
C61B 100PX4 SM
C61A 100PX4 SM
C62D 100PX4 SM
C62C 100PX4 SM
C62B 100PX4 SM
C62A 100PX4 SM
C63D 100PX4 SM
D3
BAS16W SM
X1
16MHZ SM
STANDBY
SP1ON
XTAL
EXTAL
Vss
NM1
RES
STBY
Q_122
Q_123
Q_124
Q_125
Q_126
Q_127
Q_128
0V_D
C2
18P SM
+5V
+
Q_52
Q_46
Vpp/RESO
Vss
SP2ON
R64
C12
100N SM
+
DISPDAT
DISPCLK
THERMPROT
VIPROT
DCPROT
ACPRESENT
C33
220U EL
C34
220U EL
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
H8/3048F
TRANSMIT
RECEIVE
RESPIN
100R SM
C4
100N SM
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
R65
+5V
0V_D
4
3
2
1
SAMTX2
SAMRX2
BUT17
IC2
Vcc
Res
Q_45
3
2
IRIN
100R SM
R67
(FIT CLOSE TO SK1)
Q_129
R66
DISPBLK
DISPLAT
Q_43
C63C 100PX4 SM
C63B 100PX4 SM
C63A 100PX4 SM
100R SM
Q_39
C7
4
1
TONEID
SDATA
BUT9
BUT8
BUT7
BUT6
BUT2
IND3
Q_86
100R SM
Gnd
Gnd
Q_44
FFC 14W 2.54MM HOR
Q_87
Q_88
Q_89
Q_90
Q_91
0V_D
DS1233 SM
SLOAD
SCLK
100N SM
D4/P4.4
D5/P4.5
D6/P4.6
C31
10P SM
C32
10P SM
0V_D
CHASSIS 2
Q_42
0V_D
0V_D
0V_D
0V_D
H8/3048F
Q_98
0V_D
+5V
R51
100R SM
Q5
BD179 NPN TO-126
To preamp board
SK3
+SUP
VFD_VDD2
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
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
Q_1
Q_2
Q_3
Q_4
Q_5
Q_6
Q_7
Q_8
Q_9
SEL1
Q_23
Q_41
+5V
+5V
SEL2
SEL3
SEL4
SEL5
SEL6
SEL7
SEL8
SEL9
Q_40
R54
3K3 MF
Q_64
C5
100N SM
+
R32
10K SM
+
C28
10U EL SM
C29
100U EL SM
D1
IC6C
IC7C
C16
100N SM
0V_D
IC8C
LM393A SM
IC11C
AD8532 SM
Q_75
ZENER 400MW 33V
C10
C15
100N SM
C25
100N SM
LM393A SM
LM393A SM
100N SM
IC5
24C02 SM
+
Q_10 LEFTAUDIO
Q_116
C26
10U EL SM
4
8
Q_11
Q_12
Q_117
Q_14 TONEID
Q_118
Q_15
Q_119
Q_16
Q_120
Q_17
MUTE
TONE
VSS
VDD
0V_D
C8
100N SM
0V_D
SDATA
SLOAD
SCLK
DRAWING TITLE
0V_D
A32 FMJ AMP DISPLAY PCB
WAF
JBR
WAF
CL
26/9/01
10/9/01
9/08/01
STICKY PADS RENUMBERED
PRE PRODUCTION RELEASE
UPDATED PROTOTYPE
INITIAL PROTOTYPE
B.3
B.2
FFC 22W 1MM HOR
Circuit Diagram
2 3 4 2 5
0V_D
Notes:
B.0
CHASSIS 1
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
A.0
25/04/01
0V_D
ECO No. INITIALS
Date Printed
DATE
DESCRIPTION OF CHANGE
ISSUE
Drawn by:
Filename
Cambridge CB5 9PB
Sheet 2 of 2
L928CT2
DRAWING NO.
CL
10-Oct-2001
J:\Released_Documents\Native_format_files\Protel_DDB\L928_B.3.Ddb - Documents\L928CT_2_B.3.SCH
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Preamplifier
Board
L937
Contents
ꢀ
ꢀ
ꢀ
Circuit description
Component overlay
Parts list
ꢀ
Circuit diagrams
excursion which wastes power and may damage the drive
units.
Pre-amplifier circuit description
Refer to L937 circuit diagrams
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.
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.
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.
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
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.
multiplexers. In addition, there is
a
simple resistor-
capacitor 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.
Volume control
Z107 is a VSDVC electronic volume control IC. It works, in
conjunction with an external op-amp, by varying the feed-
forward 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.
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.
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.
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.
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.
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.
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.
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.
The voltage regulators are discrete compound emitter
followers. I will describe the +15V supply as the negative is
essentially an exact mirror image.
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.
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
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.
power down.
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
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
2C210
2D147W
2D147W
2D147W
2C410
2C410
2C410
2C410
2C110
2C110
2N710
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
2P610CC ELEC 10U 50V CERAFINE
2K447
2K447
2D222W
2C022
PEST 470N 63V 10%
PEST 470N 63V 10%
WIMA FKP2 2N2 63V CAP
MLC 22P 50V NPO 5% SM
2P610CC ELEC 10U 50V CERAFINE
2P610CC ELEC 10U 50V CERAFINE
2C410
2C310
2N610
2C210
2D147W
2D147W
2D147W
2C410
2C410
2C410
2C410
2C110
2C110
2N710
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
2P610CC ELEC 10U 50V CERAFINE
2K447
2K447
2D222W
2C022
PEST 470N 63V 10%
PEST 470N 63V 10%
WIMA FKP2 2N2 63V CAP
MLC 22P 50V NPO 5% SM
2P610CC ELEC 10U 50V CERAFINE
2P610CC ELEC 10U 50V CERAFINE
2C210
2D147W
2D147W
2D147W
2C410
2C410
2C410
2C410
2K410
2C022
2C022
2K447
2K447
2C410
2C410
2N610
2C410
2C410
2N710
2C022
2C022
2C210
2D147W
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
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
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
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
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
3AV99W
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
3AV99W
3AV99W
3AV99W
3AS16W
3AV99W
3AV99W
3BS1D
3BS1D
3AS16W
3AS16W
3AS16W
3BS1D
3BS1D
3AS16W
3CW315V ZENER 15V OW35 SM SOT23
3CW315V ZENER 15V OW35 SM SOT23
C3751
C3751
FUSE R452 T750mA
FUSE R452 T750mA
L937PB_1 PRINTED CIRCUIT BOARD
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
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
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
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
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
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
1A410
1A410
1A822
1A822
1A822
1A247
1A310
1A133
1A212
1A147
1A133
1A122
A216
8D225
8D225
8D225
8D225
8D226
8K8022B
8K8330
8K2404
8K2408
8K2304
8K6604
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
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
8-WAY AMP CT CONN
MOLEX MINI FIT HCS 4 WAY
4-WAY FR LOCK CONN
5S408DY IC 8 TO 1 MUX DG408DY SO16
5S408DY IC 8 TO 1 MUX DG408DY SO16
5S408DY IC 8 TO 1 MUX DG408DY SO16
5S408DY IC 8 TO 1 MUX DG408DY SO16
5S408DY IC 8 TO 1 MUX DG408DY SO16
5S408DY IC 8 TO 1 MUX DG408DY SO16
5S413DY IC QUAD SPST CMOS SW SO16
5AVSDVC IC AUDIO DIGITAL VOL SM
5A1844
5B072D
5B072D
5B072D
5B072D
5B072D
5B072D
5B2134
5B2134
5B2134
5D317T
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
1
2
3
4
D
C
B
A
D
C
B
A
Main signal path
L937C2_1.1.SCH
Power supply
L937C3_1.1.SCH
USE EXCLUDE NF WHEN USING RUNOUT SHEET PROGRAM
DRAWING TITLE
Integrated amplifier preamp
PCB1
PCB
Circuit Diagram
2 3 4 2 5
Notes:
01_E014
01_1142
JBR
JBR
28/11/01
Fuses uprated to 2A
1.1
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
L937PB_1
14/8/01
First production release
1.0
ECO No. INITIALS
Date Printed
DATE
DESCRIPTION OF CHANGE
ISSUE
Drawn by:
JBR
Filename
Cambridge CB5 9PB
Sheet 1 of 3
L937C1
DRAWING NO.
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
1
2
3
4
1
2
3
4
5
6
7
8
D100
BAV99W DUAL SM
D105
BAV99W DUAL SM
+15V
-15V
+5V
+15V
+15V
1
-15V
D103
BAV99W DUAL SM
Z100
Z109A
TL072 SM
AUX L
CD L
TUNER L
AV L
4
5
6
13
8
R110
2K2 SM
X0
X1
X2
X3
X4
X5
X6
X7
V+
D
SK2A
+15V
CDL1
R100
CDL
SK4B
Z111A
TL072 SM
CD INPUT
1
CD L
3
2
0V_SIG
Z112_3
R108
TAPEO1
Z112A
7
TAPE OUTPUT
1K0 SM
Z111_3
R112
22K SM
C104
100N SM
Z112B
F
DVD L
12
11
10
9
R106
1M0 SM
3
2
Z111_1
TL072 SM
47R SM
C108
100P SM
R114
C101
470P FKP2
F
R103
100K SM
1
3
2
TL072 SM
Z112_1
C117
VCR IN L
MODULE L
1
5
6
+5V
22K SM
Z112_7
Z106_14
C105
100N SM
N
+
0V_SIG
R111
2K2 SM
R113
22K SM
7
C110
100U EL
CDR1
C100
1N0 SM
N
+
0V_SIG
TAP0
TAP1
TAP2
+5V
Z108D
17
Z108A
14
C120
10U EL
C118
100N SM
0V_SIG
CDR
2
1
16
15
0V_SIG
0V_SIG
TAPE02
C115
10U CERAFINE
EN
A0
A1
A2
-15V
TAPE 0
TAPE 1
TAPE 2
Z108E
PHONO4G
+15V
R119
R101
+
0V_SIG
CD R
PHONO4G
C111
22K SM
D
C
B
A
D
C
B
A
22P SM
R118
1K0 SM
Z108_19
10U CERAFINE
0V_SIG
SCLK 13
SDATA 12
1
8
11
SCLK
SDATA
TONEID
CLK
DIN
RST DOUT
PS
R/W
C102
470P FKP2
-15V R104
100K SM
14
3
22K SM
GND
V-
R120
22K SM
R121
22K SM
TONEID
9
C113
C114
CFKP2 63V 2N2
D101
BAV99W DUAL SM
470N PE
0V_SIG
DG408DY
5
6
R204
10K SM
+15V
Z111_7
IC DS1844
-15V
+15V
+15V
7
-15V
7
D104
BAV99W DUAL SM
+
0V_SIG
-15V
Z101
R115
2K7 SM
R117
5K6 SM
C116
Z109B
TL072 SM
Z111B
TL072 SM
AUX R
CD R
TUNER R
AV R
4
5
6
13
8
10U CERAFINE
C106
100N SM
X0
X1
X2
X3
X4
X5
X6
X7
V+
D
R122
D102
BAV99W DUAL SM
+15V
SK2B
5
6
R109
Z115_1B
2R2 SM
0V_TONEID
C119
10N SM
7
C112
C107
100N SM
DVD R
12
11
10
9
R107
1M0 SM
0V_SIG
47R SM
C109
100P SM
R124
0V_SIG
-15V
VCR IN R
470N PE
C192
TUNL1
TUNL
TUNER L
R102
MODULE R
R116
2K7 SM
TUNER INPUT
2R2 SM
+5V
1K0 SM
F
0V_SIG
2
1
16
15
0V_SIG
+5V
0V_SDATA
EN
A0
A1
A2
C103
470P FKP2
R105
100K SM
TAPE 0
TAPE 1
TAPE 2
470N PE
+5V
0V_SIG
TAPE0
R123
TAPE1
TAPE2
N
0V_SIG
R135
2K2 SM
0V_SIG
D111
2R2 SM
TUNR1
BAV99W DUAL SM
Z113A
TL072 SM
0V_SIG
TUNR
14
3
0V_SCLK
GND
V-
Z114A
TL072 SM
PHONO4G
+15V
Z113_3
R138
R125
R137
22K SM
Z114B
TL072 SM
TUNER R
3
2
0V_SIG
Z114_3
SK100
R151
Z113_1
R139
22K SM
0V_SIG
DG408DY
Z102
1
3
2
Z114_1
LISTEN 0
1
2
3
4
5
6
7
8
9
R147
1K0 SM
22K SM
C138
-15V
+15V
+15V
1
-15V
1
5
LISTEN 1
LISTEN 2
VCR 0
VCR 1
VCR 2
TAPE 0
TAPE 1
TAPE 2
D109
BAV99W DUAL SM
R152
22K SM
Z114_7
R144
Z106_11
22K SM
C122
+
-15V R128
100K SM
R136
2K2 SM
7
R148
Z110A
TL072 SM
C131
100U EL
22K SM
470P FKP2
AUX L
CD L
4
5
6
13
8
22K SM
Z108B
7
Z108C
4
6
R153
X0
X1
X2
X3
X4
X5
X6
X7
V+
D
22K SM
VCR OUTPUT
SK5B
VCRO1
C136
10U CERAFINE
R149
+15V
22K SM
D106
BAV99W DUAL SM
TUNER L
AV L
3
2
R154
R133
22K SM
+
7
22K SM
R150
C132
10U CERAFINE
22K SM
0V_SIG
-15V
DVD L
12
11
10
9
R131
1M0 SM
22P SM
R143
R155
C125
100N SM
47R SM
C129
100P SM
Z108_3
22K SM
F
TAPE IN L
0V_SIG
10
D107
BAV99W DUAL SM
22K SM
+15V
MODULE L
R145
22K SM
R146
22K SM
11
12
13
14
15
16
17
18
19
20
21
22
C126
100N SM
0V_SIG
C134
470N PE
C135
N
+5V
Z116_1B
CFKP2 63V 2N2
2
1
16
15
0V_SIG
0V_SIG
VCR02
5
6
MUTE*
EN
A0
A1
A2
Z113_7
0V_SIG
VCR 0
VCR 1
VCR 2
7
TONE*
-15V
VCR01
VCR11
VCR21
+
SK3A
1
R140
2K7 SM
R142
5K6 SM
0V_D
C137
10U CERAFINE
PHONO4G
AVL1
AVL
AV L
R126
Z113B
TL072 SM
AV INPUT
TONEID
1K0 SM
F
14
3
0V_TONEID
0V_SDATA
0V_SLOAD
0V_SCLK
SDATA
GND
V-
C123
R129
100K SM
C133
470P FKP2
0V_SIG
SLOAD
N
0V_SIG
0V_SIG
DG408DY
AVR1
C121
1N0 SM
-15V
+15V
+15V
7
-15V
470N PE
C193
SCLK
D110
BAV99W DUAL SM
0V_SIG
AVR
Z103
R141
2K7 SM
Z110B
TL072 SM
AUX R
CD R
TUNER R
AV R
DVD R
TAPE IN R
4
5
6
13
8
FFC22V1MM
PHONO4G
X0
X1
X2
X3
X4
X5
X6
X7
V+
D
R127
0V_SIG
AV R
5
6
470N PE
1K0 SM
R134
7
SK101
1
2
3
4
5
6
7
8
C124
+15V
-15V R130
100K SM
12
11
10
9
R132
1M0 SM
0V_SIG
AUX L
47R SM
C130
100P SM
470P FKP2
AUX R
+15V
D108
BAV99W DUAL SM
MODULE R
+5V
CD L
0V_SIG
-15V
2
1
16
15
0V_SIG
C127
100N SM
EN
A0
A1
A2
0V_SIG
VCR 0
VCR 1
VCR 2
CD R
VCR0
VCR1
D112
BAV99W DUAL SM
+15V
TUNER L
TUNER R
AV L
9
C128
100N SM
0V_SIG
VCR2
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
14
3
C148
GND
V-
-15V
SK3B
DVDL1
DVDL
DVD L
R156
0V_SIG
DG408DY
22P SM
R178
DVD INPUT
-15V
+15V
AV R
1K0 SM
F
Z104
+15V
R170
22K SM
C140
R159
100K SM
AUX L
CD L
TUNER L
AV L
DVD L
TAPE IN L
VCR IN L
MODULE L
4
5
6
13
8
DVD L
R162
22K SM
2
X0
X1
X2
X3
X4
X5
X6
X7
V+
D
22K SM
470P FKP2
+
R171
C190
10U EL
22K SM
N
0V_SIG
DVD R
D122
BAV99W DUAL SM
R163
DVDR1
Z115_1A
C150
22K SM
7
1
+5V
+15V
-15V
R172
Z115A
3
R185
22K SM
+
0V_SIG
DVDR
12
11
10
9
TAPE IN L
TAPE IN R
VCR IN L
VCR IN R
R164
C191
10U EL
22K SM
+
+
0V_SIG
D121
BAV99W DUAL SM
R173
C157
22R SM
PHONO4G
+15V
R157
C154
10U EL
22K SM
C155
100N SM
DVD R
OPA2134PA SM
R165
100U EL
C156
100N SM
22K SM
1K0 SM
+15V
Z107_1
+5V
470N PE
Z115B
-15V
R183
C141
-15V R160
100K SM
2
1
16
15
6
5
0V_SIG
3
LFO
EN
A0
A1
A2
R180
470P FKP2
LISTEN 0
LISTEN 1
LISTEN 2
7
Z106
0V_SIG
1M0 SM
C143
100N SM
LIST0
LIST1
LIST2
/TONE
+15V
TONE*
1
2
3
4
5
6
7
8
16 TONE*
C158
22P SM
100K SM
SEL1 SEL2
D113
BAV99W DUAL SM
C147
100N PE
MODULE L
MODULE R
15
14
2
3
SK102
OPA2134PA SM
+15V
C144
100N SM
0V_SIG
D1
S1
D2
S2
V+
VL
S3
D3
SK102_1
R186
0V_SIG
-15V
14
3
C149
1
1
2
3
4
Z117A
GND
V-
R188
0V_SIG
0V_SIG
FFC30V SM
47R SM
Z107_4
+
-15V
4
2
D114
BAV99W DUAL SM
C188
-15V
LIN
LMO
RFO
10K SM
+15V
SK4A
0V_SIG
R174
DG408DY
22P SM
R179
13
14
0V_SIG
0V_MODULE
OPA2134PA SM
10U EL
V-
-15V
+15V
+5V
12
5
0V_SIG
SK102_3
LGND
C152
100N SM
C153
100N SM
+
Z105
AMPCT4
TO POWER AMP I/P
C189
GND
S4
22K SM
AUX R
CD R
TUNER R
AV R
DVD R
TAPE IN R
VCR IN R
MODULE R
4
5
6
13
8
0V_SIG
C159
22P SM
R166
10U EL
Z116_1A
C151
22K SM
X0
X1
X2
X3
X4
X5
X6
X7
V+
D
22K SM
11
10
9
0V_SIG
R182
R175
TAPEIL1
TAPEIL
Z107_13
R158
22K SM
TAPE INPUT
1
TAPE IN L
2
3
0V_SIG
13
12
15
6
5
R167
RIN
RMO
R187
22K SM
+15V
7
1
-15V
7
RLY100A
RLY100B
R176
1K0 SM
Z116A
Z117B
D4
22K SM
F
12
11
10
9
0V_SIG
TONE*
R168
47R SM
RGND
22K SM
C142
470P FKP2
R161
100K SM
TONE*
R177
SEL4 SEL3
DG413DY
RLY DPDT 5V SM RLY DPDT 5V SM
22K SM
C145
100N SM
OPA2134PA SM
OPA2134PA SM
R169
22K SM
N
0V_SIG
0V_SIG
100R SM
0V_SIG
0V_SIG
TAPEIR1
C139
1N0 SM
+5V
470N PE
Z116B
Z107
VSDVC
R184
C146
100N SM
0V_SIG
TAPEIR
0V_SIG
2
1
16
15
6
5
+5V
EN
A0
A1
A2
R199
LISTEN 0
LISTEN 1
LISTEN 2
7
1M0 SM
PHONO4G
+15V
LISTEN0
LISTEN1
LISTEN2
R189
0V_SIG
TAPE IN R
100K SM
R200
C167
100N PE
-15V
1K0 SM
D120
BAS16W SM
R181
10K SM
+
-
RLY100C
RLY DPDT 5V SM
OPA2134PA SM
2R2 SM
R201
C161
+
-15V R192
100K SM
14
3
0V_SDATA
C187
10U EL
GND
V-
470P FKP2
0V_SIG
0V_SIG
2R2 SM
R202
D115
BAV99W DUAL SM
0V_SIG
DG408DY
+15V
0V_SLOAD
0V_SCLK
+15V2
-15V
+15V
+5V
0V_SIG
-15V
SK103
C186
2R2 SM
+15V1
C168
100N SM
C172
100N SM
C176
100N SM
C180
100N SM
1
2
3
4
5
6
7
8
Q100
BC849B
D116
BAV99W DUAL SM
D118
BAV99W DUAL SM
AUXR1
R203
4K7 SM
+15V
+15V
-15V
AUX R
AUX L
100N SM
MUTE*
0V_SIG
Z109C
TL072 SM
Z110C
TL072 SM
Z111C
TL072 SM
Z112C
AUXL1
-15V1
TL072 SM
SK5A VCRIL1
SK6
F
0V_SIG
C169
100N SM
0V_SIG
0V_SIG
0V_SIG
VCRIL
AUXIL1
AUXL
R190
R195
VCR INPUT
1
VCR IN L
1
AUX L
AUX INPUT
C173
100N SM
C177
100N SM
C181
100N SM
1K0 SM
1K0 SM
-15V2
C162
F
AMPCT8
-15V
0V_D
470P FKP2
R193
100K SM
R197
100K SM
+15V
C165
470P FKP2
0V_SIG
-15V
N
N
0V_SIG
0V_SIG
VCRIR1
AUXIR1
C160
1N0 SM
C164
1N0 SM
C170
100N SM
C174
100N SM
C178
100N SM
C182
100N SM
C184
DRAWING TITLE
Integrated amplifier preamp - main signal path
100N SM
0V_SIG
VCRIR
0V_SIG
AUXR
AUX R
0V_HF
PHONO4G
+15V
PHONO2G
+15V
R191
R196
0V_SIG
VCR IN R
0V_SIG
Z113C
TL072 SM
Z114C
TL072 SM
Z115C
Z116C
Z117C
1K0 SM
1K0 SM
Circuit Diagram
2
3 4 2
5
C163
C166
470P FKP2
-15V R194
100K SM
-15V R198
100K SM
0V_SIG
0V_SIG
0V_SIG
0V_SIG
0V_SIG
Notes:
470P FKP2
01_E014
01_1142
ECO No. INITIALS
Date Printed 28-Nov-2001
JBR
28/11/01
14/8/01
DATE
Fuses uprated to 2A
First production release
DESCRIPTION OF CHANGE
1.1
1.0
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
C171
100N SM
C175
100N SM
C179
100N SM
C183
100N SM
C185
JBR
D117
BAV99W DUAL SM
D119
BAV99W DUAL SM
100N SM
ISSUE
0V_SIG
0V_SIG
-15V
Drawn by:
Filename
Cambridge CB5 9PB
Sheet 2 of 3
DRAWING NO. L937C2
J:\Change_Control\ECO_AGENDA\01_E014 Fuse changes on A32 preamp\L937_1.1.ddb - Documents\Schematic\L937C2_1.0.SJCBH R
1
2
3
4
5
6
7
8
1
2
3
4
D302
D304
BAS16W SM
Q305
BAS16W SM
LM317T
Z301
+15V
+15V3
+5V
+5V
2SA1964
I
O
Vin
Vout
D
C
B
A
D
C
B
A
Q306
SK300
MOLEXPWR4
BC846B
D305
BAS16W SM
UR+
R303
470R SM
D300
S1D
D301
S1D
Q300
J112
+
C300
1000u 35V
+3.75V
C304
100N SM
F300
AC1
+
+
R300
330R SM
R302
1K2 SM
C306
470U EL 25V
+
D310+
C303
3300u 25V
C305
10U EL
T2A SM
C307
470N PE
C308
100N SM
D310
15V 350MW SM
R307
220R SM
C314
1N0 PP
+
+
C302
220U EL
+15V SK301
C312
C309
100N SM
1
2
3
4
C315
1N0 PP
220U EL
D311
15V 350MW SM
F301
AC2
0V_PSU
+
-15V
0V_PSU
C313
3300u 25V
T2A SM
IDC4S
Q303
J112
D311-
0V_MODULE
D306
S1D
D307
S1D
+
C310
1000u 35V
R304
330R SM
SP300
0V_PSU
0V_SIG
STAR POINT 4
Q307
BC856B
UR-
-15V3
0V_HF
0V_MODULE
-15V
Q301
2SC5248
D308
0V_SIG
BAS16W SM
DRAWING TITLE
Integrated amplifier preamp - power supply
Circuit Diagram
2 3 4 2 5
Notes:
01_E014
01_1142
JBR
JBR
28/11/01
Fuses uprated to 2A
1.1
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
14/8/01
First production release
DESCRIPTION OF CHANGE
1.0
ECO No. INITIALS
DATE
ISSUE
Drawn by:
Date Printed
Filename
Cambridge CB5 9PB
Sheet 3 of 3
L937C3
DRAWING NO.
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
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
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%
2N610
2K410
2V710
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
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
PB
PCB
PL300
R100
R101
R102
R103
R104
R105
R106
R107
R300
R301
R302
R303
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
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
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
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
A213
6F110
8K7014
8D226
8D418G
8K2304
1T002
4B179
4B179
NPN TRANS MP BD179
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
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT497 TRANS LF SS N SM FMMT497
4CSAP15N TRANS POWER NPN SAP15N
4CSAP15P
TRANS POWER PNP SAP15P
4AFMMT497 TRANS LF SS N SM FMMT497
4AFMMT597 TRANS LF SS P SM FMMT597
4AFMMT497 TRANS LF SS N SM FMMT497
1
2
3
4
5
6
7
8
+5V_D
TP102
SK100
1
2
TP103
3
4
5
6
7
8
9
10
11
12
13
14
D
C
B
A
0V_D
D
C
B
A
SPKR1 ON
SPKR2 ON
THERMPROT
VIPROT1
TP104
TP105
TP106
TP107
TP108
DCPROT1
+5V_D
+5V_D
R107
0V_SIG
SP100
TH100
PTH90DEG
0V_D
FFC 14W 2.54MM VER
2R2 SM
C100
100N SM
+
C101
0V_D
IC100G
74HC14D
C102
100U EL
IC100E
PIN 1 TO THE LEFT AS YOU LOOK FROM THE FRONT
TP116
100N SM
11
10
12
THERMPROT
0V_LS
0V_HF
STAR POINT 8
R100
1K0 SM
74HC14D
IC100F
0V_PSU
13
74HC14D
0V_D
IC100A
IC100B
R101
+49V
1
23
4
8
VIPROT1
1K0 SM
C103
10N SM
74HC14D
IC100C
74HC14D
IC100D
RLY101B
RLY SPST SPKR
RLY100B
D100
1N4003F
RLY SPST SPKR
D101
R102
5
69
DCPROT1
1N4003F
1K0 SM
C104
10N SM
74HC14D
74HC14D
SK101
TP109
1
L911C2_1
L911C2_1.1.SCH
TR101
BD179
R105
F
TR100
BD179
SPKR1 ON
SPKR2 ON
INPUT
0V_SIG
0V_LS
0V_HF
VPOS
VNEG
VIPROT
DCPROT
OUTPUT
0V_D
RLY101A
100R SM
TP111
SK102A
SK102B
EMC
C105
TP112
RLY100A
TP113
N
+49V
-49V
Top+
Top-
Bot+
Bot-
R106
1N0 SM
RLY SPST SPKR
RLY SPST SPKR
100R SM
PHONO2G
TP110
0V_SIG
R103
R104
220R SM
0V_HF
0V_LS
220R SM
0V_LS
0V_D
+49V
TP100
BR100
BRGBU8D
TP114
+
+
C106
10,000u 63V
PB
C108
100N PC
PCB
3
2
~
~
L911PB_1
C107
10,000u 63V
0V_PSU
SK103
C109
100N PC
MOLEXPWR4
TP101
DRAWING TITLE
TP115
POWER AMP SUPPLY
AP85 third channel - top level
Circuit Diagram
23425
-49V
Notes:
01_1101
01_1018
JR
JR
4/6/01
DC OFFSET CHANGES
PRODUCTION ISSUE
1.1
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
30/1/01
1.0
ECO No. INITIALS
Date Printed
DATE
DESCRIPTION OF CHANGE
Sheet 1 of 2
ISSUE
Drawn by:
J Reckless
Filename
Cambridge CB5 9PB
L911C1
DRAWING NO.
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
7
8
1
2
3
4
5
6
7
8
VPOS
D
C
B
A
D
C
B
A
R319
100R SM
R315
100R SM
R316
100R SM
R300
10K SM
PRE DRIVER
PNP CURRENT MIRROR
TR310
FMMT497
TR300
FMMT597
TR301
FMMT597
R301
10K SM
+
R321
22R SM
TR302
FMMT597
C300
100U EL
DZ300
15V 350MW SM
TR309
FMMT497
TR321
FMMT597
R338
150R SM
OUTPUT STAGE
V-I PROTECTION
R329
4K7 SM
R305
10K SM
VI PROTECT
SIGNAL TO MICRO
D301
BAS16W SM
C307
R333
TP307
0V_HF
TR318
SAP15N
R334
22K SM
VIPROT
3K3 SM
100P SM
DZ305
4V7 350MW SM
+
TR311
FMMT497 C317
R306
10K SM
C305
10U EL
TP305
R341
D303
1N4003F
TR312
FMMT497
TR313
FMMT497
DC SERVO
R347
R349
BOOTSTRAP
330R SM
100R SM
R345
100R SM 0R0 SM
100R SM
+
470N PE
R325
1K0 SM
R343
C302
100U EL 100V
C310
100N SM
R330
6
IC300B
ADJ BIAS
7
0V_HF
1M0 SM
5
+
PL300
C303
0V_SIG
RV300
100R PSET
R340
100K SM
1
2
100U EL
R328
4K7 SM
TL072CD
0V_SIG
R351
R352
470R 2W
5R6 2W CF
D300
BAS16W SM
TP302
MEASURE
BIAS
R331
INPUT FILTER
R324
V TO I AMP
1K5 SM
0V_SIG
IC300A
L300
2U2H LAC SMALL
3
2
INPUT
TP304
OUTPUT
R332
1
1K0 SM
DZ302
DC OFFSET SIGNAL
TO MICRO
470R 2W
R353
1K8 SM
4V7 350MW SM
TL072CD
R322
22R SM
R327
22K SM
R355
6K8 SM
R350
5R6 2W CF
DCPROT
R303
10K SM
+
+
TR322
FMMT497
C318
C304
DZ303
C316
470P PPW
C312
10N SM
ZOBEL NETWORK
10U EL
100U EL
4V7 350MW SM
R337
22R SM
TR305
FMMT597
C311
100N PC
C319
100N PE
DC OFFSET
DETECTION
R326
1K0 SM
R344
R346
100R SM 0R0 SM
R304
10K SM
0V_SIG
+
C313
C306
TP303
C309
100N SM
0V_SIG
R354
1K0 SM
TR304
FMMT597
100U EL 100V
0V_LS
R348
100R SM
D304
1N4003F
0V_SIG
R308
22K SM
TP306
R342
BOOTSTRAP
TR303
FMMT597
R302
10K SM
100N SM
0V_HF
R307
10K SM
330R SM
0V_HF
0V_LS
TP308
C308
R336
22K SM
R335
3K3 SM
C314
100N SM
D302
BAS16W SM
TR319
SAP15P
TR316
FMMT497
100P SM
R339
150R SM
R310
4K7 SM
R313
DZ306
4V7 350MW SM
C320
100U NP
0V_SIG
TR320
FMMT497
R314
10K SM
DZ301
15V 350MW SM
OUTPUT STAGE
10K SM
V-I PROTECTION
+
C315
100N SM
0V_HF
TR306
FMMT597
R323
22R SM
C301
100U EL
0V_HF
0V_HF
TR314
FMMT497
TR315
FMMT497
R309
10K SM
TR307
FMMT597
TR308
FMMT597
NPN CURRENT MIRROR
PRE DRIVER
R317
100R SM
R318
100R SM
R311
10K SM
TR317
FMMT497
R320
100R SM
R312
10K SM
VNEG
DRAWING TITLE
AP85 third channel - output stage
Circuit Diagram
23425
Notes:
01_1101
01_1018
JR
JR
4/6/01
DC OFFSET CHANGES
PRODUCTION ISSUE
1.1
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
30/1/01
1.0
ECO No. INITIALS DATE
Date Printed
4-Jun-2001
DESCRIPTION OF CHANGE
Sheet 2 of 2
ISSUE
Drawn by:
J Reckless
Filename
L911C2_1.1.SCH
Cambridge CB5 9PB
DRAWING NO. L911C2
1
2
3
4
5
6
7
8
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
230V
L813RC
115V
100V
SILVER
BLACK
DESCRIPTION
HANDY REMOTE 3 DIVA/DIVA SERIES CR389
TRANSF A85 100V
WHERE USED
QTY
1
1
1
1
1
4
L907TX
E045AY
E838CP
E839AY
HA4V06S
E045AYB
E838CPB
E839AYB
HA4V06B
FRONT PANEL ASSEMBLY
COVER
LARGE VOLUME KNOB
M4 x 6mm Screw
39
35
COVER TO CHASSIS
54
2
3
N/A
N/A
E046AY
E804HK
E804MI
REAR PANEL ASSEMBLY
HEAT SINK
MAINS INSULATOR
1
1
1
4
ON CHASSIS FLOOR UNDER POWER
SUPPLY PCB
5
6
8
9
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
CHASSIS
FOOT
HEAT SHUNT
1
6
1
1
1
1
1
1
4
1
1
2
1
1
1
1
3
ON CHASSIS FLOOR
E850MC
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
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
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
FOAM TAPE
400mm
1
2
31
2
3
4
1
4
20
1
1
1
3
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
TRANSISTORS TO HEATSINK
TRANSFORMER
EARTHING NUT
EARTH
EARTH
HEATSINK SCREWS
E878MC TO L870AY
BLANKING PLATES
M4 WAISTED NUT
M4 SHAKE PROOF WASHER
M5 WASHER BLACK
PLASTIC SNAP RIVET
SNAP RIVET BLACK PLASTIC
HL5EB
HP008
HP008
1
4
A32 General Assembly Parts List E047rs_2
ITEM
A
B
230V
L813RC
115V
100V
L907TX
L894AY
L915TX
SILVER
BLACK
DESCRIPTION
HANDY REMOTE 3 DIVA/DIVA SERIES CR389
TRANSF A85 100V
WHERE USED
QTY
1
1
1
1
1
1
1
1
1
1
1
1
50
28
31
30
32
33
34
53
29
27
L870AY
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
THROUGH REAR PANEL
L882AY
L914CA
L914TX
L915CA
L916CA
L917CA
L918CA
L928AY
L937AY
WA8511A
A32 PREAMP PCB
P35 General Assembly Parts List E078rs_2
ITEM
230V
115V
100V
SILVER
E058AY
E838CP
HA4V06S
BLACK
DESCRIPTION
FASCIA ASSEMBLY
COVER
M4 x 6mm Screw
2-WAY JUMPER SOCKET 0.1” M7571-05
CONNECTOR 14MM LINK BAR P2148
WHERE USED
FRONT OF CHASSIS
QTY
1
1
4
2
1
1
2
3
4
5
E058AYB
E838CPB
HA4V06B
COVER (SIDE) TO CHASSIS
ON L882AY (NEAR SWITCH)
FITTED TO REAR PANEL
8K004
8K006
7
8
9
E060AY
E804HK
E804MI
REAR PANEL ASSEMBLY
HEAT SINK
MAINS INSULATOR
CHASSIS REAR
CHASSIS FLOOR
ON CHASSIS FLOOR UNDER POWER
SUPPLY PCB
1
1
1
10
11
12
13
14
15
16
17
18
19
20
21
E820CH
E822PM1
E861MC
E879SL
E907MC
E912MC
E920MC
E938MC
F022
CHASSIS
FOOT
1
6
1
1
1
4
1
1
BASE OF CHASSIS
REAR PANEL
CHASSIS
HEATSINK
HEATSINK
3RD 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
HEATSINK
ON CHASSIS FLOOR
2
1
1
F037
F038
F164
TOP OF TRANSFORMER
ON TOP OF TRANSFORMER
FRONT PANEL TO COVER
400m
m
2
1
17
1
3
4
1
4
22
23
24
25
26
27
28
29
30
F200
E83001
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
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
HA3V06A
HA4A12B
HA5K70A
HA5L20B
HA6K60A
HE6V06B
HF4V09B
16
31
32
33
34
35
36
37
38
HJ4A00A
HJ4C00D
HL4SB
M4 NUT
M4 WAISTED NUT
1
1
1
1
1
1
1
1
EARTH
EARTH
M4 SHAKE PROOF WASHER
M5 WASHER BLACK
A85 POWERAMP PCB
TRANSFORMER
DISPLAY TO POWERAMP CABLE ASSY
P35 SWITCH PCB
HL5EB
HEATSINK BOLT (AT THE FRONT)
CHASSIS FLOOR
CHASSIS FLOOR
L882AY TO L929AY
SUB PANEL
L882AY
L884TX
L915CA
L929AY
WA8511A
L884TX
L894AY
L880TX
P35/3 Channel General Assembly Parts List E079rs_2
ITEM
230V
115V
100V
SILVER
E058AY
E839CP
HA4V06S
BLACK
DESCRIPTION
FASCIA ASSEMBLY
COVER
WHERE USED
FRONT OF CHASSIS
QTY
1
1
2
3
4
5
7
8
9
E058AYB
E839CPB
HA4V06B
1
4
2
1
1
1
1
M4 x 6mm Screw
COVER (SIDE) TO CHASSIS
ON L882AY (NEAR SWITCH)
FITTED TO REAR PANEL
CHASSIS REAR
CHASSIS FLOOR
ON CHASSIS FLOOR UNDER POWER
SUPPLY PCB
8K004
8K006
E060AY
E804HK
E804MI
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
CHASSIS FLOOR
1
1
6
1
1
1
6
1
2
1
BASE OF CHASSIS
CHASSIS
HEATSINK
HEATSINK
HEATSINKS
HEATSINK
CONFIGURATION LABEL
KOOL PAD
3RD 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
1
1
400m
m
2
1
22
1
5
6
1
4
24
25
26
27
28
29
30
31
32
F200
E83001
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
REAR PANEL (FOR LINK BAR)
UNDER TRANSFORMER
PCB’S
EARTHING SCREW
HEATSINK BOLTS
HA3V06A
HA4A12B
HA5K70A
HA5L20B
HA6K60A
HE6V06B
HF4V09B
TRANSISTORS TO HEATSINK
TRANSFORMER
CHASSIS TO SUB PANEL
COMPONENTS TO REAR PANEL +
COVER TO REAR PANEL + REAR
PANEL TO CHASSIS
EARTHING NUT
16
33
34
35
36
37
38
39
40
41
42
HJ4A00A
HJ4C00D
HL4SB
M4 NUT
M4 WAISTED NUT
M4 SHAKE PROOF WASHER
M5 WASHER BLACK
1
1
1
1
1
1
1
2
1
1
EARTH
EARTH
HL5EB
HEATSINK BOLT (AT THE FRONT)
CHASSIS FLOOR
CHASSIS FLOOR
CHASSIS FLOOR
L882AY TO L929AY
L882AY
L884TX
L911AY
L915CA
L919CA
L929AY
WA8511A
L884TX
WA85Q1A
A85 POWERAMP PCB
TRANSFORMER
L880TX
3RD CHANNEL PCB
SWITCH TO POWERAMP CABLE ASSY
SWITCH TO 3RD CHANNEL CABLE ASSY
P35 SWITCH PCB
WFA35P 1A
SUB PANEL
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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