A85
DiVA A85, P85 & P85/3
Amplifi ers
Service Manual
ARCAM
ARCAM
Issue 2.0
Contents List
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Contents list
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Circuit description
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Service guide
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Circuit diagrams
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Component overlays
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Circuit board parts list
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General assembly parts list
Pre-amplifier circuit description
The A85 preamplifier is a high-performance, DC coupled design
with microprocessor control of input select, two independent tape
loops, electronic volume control, tone bypass and electronic tone
control.
It features a discrete power supply and low-noise linear circuitry to
obtain very good distortion and noise performance, suitable for
high quality source material such as CD or DVD-A.
Input switching
Each of the inputs has a pair of diodes to the ±15V rails to prevent
static spikes from causing damage to the CMOS multiplexers. In
addition, there is a simple 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.
Z104 and Z105 are the main input select multiplexers, which are
configured in a ‘virtual earth’ unity gain arrangement with Z115
and Z116. This arrangement is slightly lower distortion than the
‘normal’ one, at the cost of a slightly higher noise floor. It is an
inverting configuration, which is restored to correct polarity by the
inverting electronic volume control which follows.
Z115B and Z116B are integrating servos, which take out any DC
from the input signal before the following stages. The servos are 2-
pole, with a passive 2
nd
pole being formed by R180 and C147 (for
the left channel) to remove broadband noise from the output of the
servo and improve speed of response.
Z100 thru Z103 are the input selectors for the 2 tape loops. These
are normal non-inverting selectors which are buffered before being
passed on to the phono sockets.
Z109A output is decoupled by R108 which is included in the
feedback path. Local high frequency feedback occurs around C108
to allow the tape loop output to be very low impedance, whilst
being stable into a capacitive load such as may be presented by a
screened interconnect cable. This is the same for all tape outputs.
Z106 is configured as a double pole changeover switch, used to
select the tone controls. The tone controls are bypassed when not
required so that the noise and distortion can be minimised.
Tone control circuit
The tone control circuit is a non-inverting one, using a gyrated
‘bell’ filter for the bass and a simple shelving filter for the treble.
Left channel description
The input is attenuated by 6dB and biased to a voltage of +2.5V
DC by C111, R113, R112, R110, R111 and C110. This is so the
signals fall within the 0 - 5VDC required by the digital
potentiometer Z108.
Z111B and its associated components form an active equivalent of
a series resonant LCR circuit. This has an impedance minimum of
5.4k at around 80Hz with Q=0.7 The reason the bass is done as a
band-boost filter rather than a shelving filter is so that you can
boost the ‘real’ bass without causing lots of sub-audio loudspeaker
cone excursion which wastes power and may damage the drive
units.
The digital pots Z108D and Z108A control the bass and treble
respectively. This is done by moving the wiper connected to the
frequency-sensitive impedance between the non-inverting and
inverting terminals of Z112A, effectively changing the ratio of
feedback boost and feed-forward attenuation of the circuit at the
desired frequencies, thus providing a EQ gain control that is
symmetrical on a logarithmic scale, with the use of a linear pot.
Z112B provides the 6dB of gain necessary to bring the nominal
signal level back to unity. C116 and C117 remove the 2.5VDC
offset from the output, to prevent clunks when the tone controls
are activated.
Z108 is controlled by a simple 3-wire serial interface from the
microprocessor. Each of the digital lines has its own ground return
to minimise electromagnetic interference. They are connected
together only at the GND pin of the IC.
Volume control
Z107 is a VSDVC electronic volume control IC. It works, in
conjunction with an external op-amp, by varying the 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.
Z117 is the output op-amp. Its outputs are decoupled via R186,
R187, C158 and C159 so that it has a low output impedance but
can drive cable capacitance without oscillation. R186 and R187
are included in the audio frequency feedback loop to reduce output
impedance when driving ‘difficult’ cables.
RLY100 is a mute relay which shunts the preamp output to
ground. This is to prevent thumps and squeals when the units is
powered up or down.
Power supply
The transformer winding is connected to SK300. The voltage is
rectified and smoothed by D300, D301, D306, D307 and C300,
C310. The unregulated voltage should be around ±27VDC. F300
and F301 are secondary fuses, as the low power preamp winding
would not blow the primary fuses if short circuited.
The voltage regulators are discrete compound emitter followers. I
will describe the +15V supply as the negative is essentially an
exact mirror image.
Q300 and R300 act as a constant current source, supplying around
7mA into D310. C302 and C314 reduce ripple and broadband
noise on the zener diode. Q305 and Q306 form a complementary
Darlington NPN transistor which is configured as an emitter
follower, producing the +15VDC at its output. C303 is to provide
bulk charge storage and to reduce the AC output impedance of the
power supply. D302 prevents reverse bias of the supply during
power down.
Z301 is a conventional LM317 type circuit to drop the +15V rail
down to +5V for the tone and volume control circuits.
Star point SP300 explicitly connects the differently named ground
nets together at one point, to minimise hum.
Amplifier & PSU Circuit Description
L882PB is the printed circuit board that provides the power supply
and output stage amplifiers for the A85 integrated and power
amplifiers.
Its function is to:
1. Drive the loudspeakers(!)
2. Provide an (always on) auxiliary 5VDC supply for the micro
controller and display interface
3. Receive logic signals from the micro controller to turn on
the main amplifier supply relay (mains) and connect either
pair of speaker output sockets
4. Send logic signals to the micro controller pertaining to the
state of the amplifiers (short circuit protection, DC offset
protection, thermal protection)
5. Receive and demodulate RC5 remote style control codes via
the rear panel jack and transmit them to the micro controller
6. Send a 12V trigger output via the rear panel jack for control
of an auxiliary power amp when the unit is on
7. Receive a 12V trigger input from the rear jack (for use in the
power amp only version)
8. Drive a pair of headphones via attenuating resistor networks
The power amplifier is a symmetrical, class B, bipolar junction
transistor output, current-feedback design (of which more later)
with DC-coupled signal and feedback paths, featuring an active
integrating voltage servo to control DC offsets.
It features ‘instantaneous’ safe operating area protection in
addition to sending a signal to the micro to turn off the output
relays in the event of user or thermal overload. Since it is a DC-
coupled design, the unit senses DC at the output and triggers the
micro to turn off the loudspeaker relays in the event of excessive
levels (possibly due to a faulty source component or short circuit
output transistor).
The output stage uses Sanken specialised ‘audio amplifier’ power
bipolar Darlington transistors which are optimised for use with this
type of topology. Consequently the unit has excellent measured
performance in terms of noise, slew rate, output impedance and
distortion (harmonic and intermodulated) and is essentially load
invariant (to a first order the measured performance is independent
of the load impedance).
L882 Circuit Sheet 1
The audio input to the amplifier is connected to SK102 (which
connects to the output of the preamp PCB). This signal is passed
on via SK104A which forms the preamp out connection to the
outside world.
SK104B provides the power amp input connection, with switch
SW100 selecting between pre / power and integrated modes. The
unit is wired as a preamp / power amp combination with the switch
depressed, allowing the user to insert a processor or other function
(e.g. graphic EQ) between the output of the preamp and the input
of the power amp. With the switch in the ‘out’ position the power
amp input socket is ignored and the input to the power amp is
connected internally to the output of the preamp. PL100 and
PL101 are ‘handbag’ links fitted to the power amp only version to
connect both pairs of phono sockets in parallel for daisy chaining
(as there is no preamp output on a power amp).
Relays RLY100 and RLY101 switch the two pairs of loudspeaker
output sockets and are controlled by the micro lines describes
above. Transistors TR100 and TR101 operate in ‘constant current
sink’ mode which allow relay current to be approximately constant
although the main power supply rails will vary with mains input
and load conditions. The current is around 20mA per relay.
Star point SP100 is the ground ‘mecca’ for the entire amplifier
(comprising all three PCBs within the unit). All of the separately
named grounds are joined explicitly at this point. Different named
grounds are used to ensure that no two ‘different’ grounds share
copper, which could compromise the noise, distortion or crosstalk
performance of the amplifier.
The loudspeaker output signals are passed to socket SK106 which
connects to SK107 and onto the headphone output via the
attenuation resistors R103 thru R106.
The hierarchy containing the other sheets is self explanatory. Each
of the port names shown on the top sheet connects to the port of
the same name on the lower sheets.
L882 Circuit Sheet 2
This sheet contains the power supplies, the rear panel jack socket
trigger circuits, the standby relay control and the ‘interface’
circuits between the output signals of the power amplifiers and the
inputs expected by the micro processor.
The mains input enters the unit at SK203, with capacitors C205
and C206 acting as conducted RF suppression. The earth
connection is passed on to the chassis (for safety reasons the
chassis metalwork remains connected to mains power earth at all
times). Switch SW200 is the voltage selector switch, allowing the
unit to be operated in 230V or 115V mains countries by switching
the dual-primary mains transformers between series and parallel
winding. Varistors VR200 and VR201 act to prevent over-voltage
surges from damaging the unit. If the user selects 115V operation
and then connects the unit to a 230V supply, the varistors will go
to a low impedance and blow the primary fuses. Any very high
voltage line transients will also be suppressed, helping to eliminate
transformer isolation breakdown.
Relay RLY200 switches the primary side of the mains transformer,
allowing the micro to control the on / off status of the amplifier. Its
contacts are snubbed by capacitors C207 and C208 (to eliminate
switching spark transients and prolong relay lifespan). The primary
windings of the toroidal mains transformer connect to SK204.
PCB mounted transformer TX200 is powered all the time that
mains is present on SK203, irrespective of the on / off status of the
amplifier. This is to ensure that the micro processor is always
operational and can thus control the mains switching for the main
amplifier. Secondary fuse F202 limits the current in the event of a
failure mode, as the short circuit primary current of TX200 would
be insufficient to blow the mains fuses.
Diodes D200 thru D203, C227 and IC201 provide the 5VDC
supply which powers the micro and display PCB and the relay
coils. C224 is to reduce diode noise being transmitted back
through the leakage capacitance of TX200.
The mains transformer secondary winding is connected to SK200.
This is a centre tapped winding, and is used with full bridge
rectifier BR200 to produce the main positive and negative supplies
for the power amp. C209 and C210 are the large reservoir
capacitors, with C211 and C212 acting as high frequency
decouplers. The main power supply rails and ground are accessible
on SK205 for future module expansion.
The circuitry around SK201A and IC200 is to receive and
demodulate remote control commands sent in via the rear panel
jack socket. This is for multi-room applications.
L200 and C200 form a parallel resonant circuit at approximately
37kHz. The output from this bandpass filter is passed into IC200A
where it is ‘chopped’ and fed to IC200B to provide the output
signal.
SK201B is a 13VDC signal trigger output which is active
whenever the amplifier is powered up. R218 and DZ207 / C223
provide a reference voltage which is buffered by TR200. TR201
and R217 act as a current limit and prevent damage due to a short
circuit on the output of SK201B. The maximum current is
approximately 65mA.
TR203 and TR202 are a complementary Darlington pair which
turn on mains relay RLY200 when activated by a signal from the
microprocessor.
TR204 and its associated components are to detect whenever AC
mains is present at the IEC socket. This is to notify the
microprocessor if the user has unplugged the mains cord, so that it
can take the necessary action (muting all the outputs and switching
off the mains relay). The reservoir capacitors should last at least 4
mains cycles which gives the microprocessor plenty of time for a
controlled shutdown.
TR204 forms a monostable circuit. Each cycle of AC turns on
TR204 via R211. TR204 then ‘shunts’ C229 ensuring that it is
kept at a low potential. If more than one mains cycle is missing,
then R219 charges up C229 sufficiently to trigger Schmitt inverter
IC202E thus passing on a logic signal to the microprocessor. The
use of a Schmitt inverter for IC202 is to ensure that the micro
receives ‘clean’ logic levels - the hysteresis voltage (about 0.5V) is
sufficient to prevent circuit noise from producing a string of
‘ghost’ signals when analogue levels are near the threshold point.
TH200 is a positive tempco thermistor placed adjacent to the
heatsink on which the output transistors are mounted. When the
temperature of the thermistor exceeds 90 degrees Celsius the
thermistor goes to a high impedance and so the input to IC202F
goes low. This triggers a HIGH output to the micro indicating
thermal overload.
The VI protection signals from the left and right channels pass into
IC202A and IC202B respectively, to be ‘cleaned up’ via the
Schmitt trigger. They are then NOR’d using TR205 which sends a
HIGH signal to the micro in the event of either channel suffering a
short circuit or current overload. Exactly the same approach is
used for the DC fault lines using IC202C and IC202D.
L882 Circuit Sheet 3
This is the main audio power amplifier circuit. The amplifier is a
class B design, which uses SAP ‘audio’ transistors in a
symmetrical current feedback configuration. Input and feedback
paths are DC coupled and there is an active integrating servo to
remove DC offsets from the output.
The basic principle of operation is follows:
The input signal is amplified by a factor of 2 in IC300A. This
drives a 44 impedance to ground causing the supply pin currents
to change with the signal level. These changing supply pin currents
are then ‘reflected’ by a pair of complementary Wilson mirrors
and passed on to a series of buffer transistors before being
connected to the load. The ‘feedback current’ flows back from the
output terminal via R331 and R332 and attempts to provide the
current necessary to allow IC300A to swing its output without
drawing excessive current from its supply pins, thus making the
change in supply current very small indeed. This is why the term
‘current feedback’ is used - it is the current flowing in the
feedback resistors that sets the overall gain of the amplifier.
IC300B acts as an inverting integrator and its purpose is to remove
DC from the loudspeaker output. Any positive DC offset will
cause the output of IC300B to go negative, thus increasing the
current in its negative supply pin and pulling the output voltage
back towards zero. R330 and C317 set the time constant of this
integrator (0.47 seconds) so that audio frequency components are
ignored and only DC and subsonic frequencies are removed.
The input to the amplifier is limited to ±5.4V via back-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.
R324, R327 and C316 act as an input filter - this is a first order
low pass filter with a corner frequency of around 340kHz to
prevent RF signals from being injected into the front end of the
amplifier. The corner frequency was chosen such that the phase
shift introduced is less than 5 at 20kHz (considered by the AES
to be the minimum perceptible relative amount by the human ear).
The input impedance of the amplifier is 23kW at DC, falling to
around 14kW at 20kHz.
Operational amplifier IC300A is acting as a non-inverting gain of
2, driving the input signal into a 44W impedance to ground via
R322 and R337. Its output voltage will be an accurate
amplification of its input voltage (i.e. the signal on pin 1 should
look identical to that on pin 3 but at twice the amplitude). The op-
amp is used in a slightly unusual configuration here, in that its
power supply pins are used as a (current) output, and its output pin
is used as a (current) feedback.
Transistors TR311 and TR303 supply the ±15V rails to the op-
amp, and act as cascades to pass its supply pin currents through to
the current mirrors, which sit at a potential too high for the op-amp
to be connected directly.
TR300, TR301 and TR321 form a PNP Wilson current mirror,
which reflects the current sunk by the positive supply pin of
IC300. Likewise TR314, TR315 and TR320 form an NPN Wilson
current mirror, which reflects the current sourced by the negative
supply pin of IC300.
R315 thru R318 provide emitter degeneration of approximately
300mV for the current mirrors (as they pass about 3mA DC in
quiescent conditions), to ensure accurate operation independent of
the small variations between the transistors in the current mirrors.
They also ensure that the current passing down the next stage is
reasonably constant as the internal temperature of the amplifier
changes, swamping out small thermal variations in the V
BE
of the
mirror transistors.
R319 and R320 slightly decouple the rails to the current mirrors
from the main power rails of the amplifier, to allow the bootstrap
circuit to operate. The bootstrap consists of C302 and C306 with
metal film power resistors R352 and R353. The bootstrap is
provided to allow the power supply rails of the current mirrors to
go up and down slightly with the output signal into the
loudspeaker. This enables the driver stage to fully saturate the
output transistors and thus give the greatest power output and best
thermal efficiency for any given power rail voltage. The voltage on
the ‘inside’ end of R319 and R320 will vary by about 12 volts
peak to peak at full output power, rising above the main power
rails during signal peaks.
C307 and C308 with R333 and R335 provide the compensation
necessary to ensure stability when the loop is closed. They are
Miller capacitors which dramatically reduce the transimpedance
(i.e. current to voltage gain) of the current mirrors at high
frequencies. The present value of 47pF provides for a unity gain
open loop bandwidth of around 75MHz, whilst ensuring a closed
loop gain margin of around 6dB (note that gain margin in a current
feedback design is not dependent on system bandwidth to a first
order approximation). R333 and R335 provide a ‘zero’ in the open
loop frequency response which is tailored to give the best time
domain performance (i.e. to make high frequency square waves
look square with minimal ringing or overshoot).
DZ304 and C311 provide a fixed 4.7V bias voltage to allow the
following stages to operate correctly. C311 is there to ensure that
both halves of the following stage receive an equal AC signal
component at high frequency.
TR310 and TR307 are the ‘pre-driver’ transistors, which act to
buffer the outputs from the preceding stage and drive the
Darlington output power transistors. TR309 and R321 act as a
current limit, to ensure that the emitter current of TR310 does not
exceed 30mA in a fault condition. TR306 and R323 provide the
same function for TR307.
R338 and R339 are to loosely couple the outputs of the 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.
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 h
FE
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
V
BE
versus temperature characteristic of the power transistors,
allowing for easy, fast-responding and reasonably accurate control
of quiescent current (one of the major headaches of class B
amplifier design!)
RV300 is for fine trimming of the quiescent current. PL300
provides a convenient measuring point for this, which is short-
circuit protected in the event of a slip with the multimeter probe!
All of the remaining circuitry to the right of TR318 and TR319 is
essentially for output stage protection...
Transistors TR312 and TR304, along with the network of resistors
and capacitors to which they are connected, provide instantaneous
overload protection of the output stage. This is a conventional
single slope VI protection scheme, which allows much greater
current to be delivered into a rated load than into a short circuit.
The values allow for 18A peak delivery (at clip) into a purely
resistive load, 7A peak (at clip) into a purely capacitive load and
around 4A peak into a short circuit. R345, C303, R346 and C304
allow these values to be doubled for short transient bursts
(approximately 2.7 milliseconds) so that impulsive musical
transients can be delivered cleanly with minimal risk of damaging
the output transistors.
TR313, TR302 and their associated components send a signal to
the microprocessor when the instantaneous protection circuits are
having to work ‘hard’ to prevent amplifier overload. This instructs
the micro that the user is severely abusing the amplifier and will
switch off the loudspeaker relays to prevent possible permanent
damage. In reality, if you short circuit the outputs at any
appreciable volume level, this circuit will trigger and the
microprocessor will turn off the loudspeaker relays and send a
signal to the user.
R308, R314 and C320 form a low pass filter from which the DC
detection circuits can sense excessive DC at the loudspeaker
outputs. If there is any positive DC present, then TR316 will turn
on, which turns on TR305 and thus activates the DC protection
line to the micro, turning off the loudspeaker relays.
If there is any negative DC present, then TR308 will turn on,
which turns on TR317 which then turns on TR305 in turn, causing
the same effect.
R350 and C319 are the Zobel network which is provided to ensure
the amplifier ‘sees’ a constant and resistive load at very high
frequencies, to aid stability, although the amplifier will be stable
without the Zobel fitted.
C313 locally couples the ‘high frequency’ and loudspeaker ground
returns together at the output to overcome the effects of track
inductance back to the star point. C309 couples the ‘high
frequency’ and signal grounds together at the input for the same
reason.
D303 and D304 are ‘flyback’ diodes to protect the output
transistors from reverse bias when the amplifier is heavily clipped
into an inductive load (such as a loudspeaker voice coil!)
Sheet 4 is an identical copy of sheet 3 so I will not describe it
separately.
L870 Phono Circuit Description
The Phono board is a simple single stage RIAA amplifier. It
consists of two channels of high gain amplification, and switching
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:
Amplifier
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 the same in all respects.
The amplifier is a small signal class A voltage feedback amplifier
with switchable gain. The input consists of an actively loaded
differential pair of very low noise PNP transistors (TR106,107).
These transistors are very specific and should only be replaced
with identical parts with the E grade high gain. TR100 & TR101
form a current source for the pair, which sets the quiescent current
for the entire amplifier. The active load consists of TR110 &
TR111, which forms part of a differential current mirror with
TR112,113 & 114. 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:
C101,110,111,112,119,120,&R115,112. C115 is used to correct
between MM & MC gains as the amplifier is non-inverting.
SW100 switches between MM & MC. Two poles of the switch
change between the different loading required for each type of
cartridge: R108 & C109 for MM, and added in parallel for MC
R104 & C108. The other two poles change the feedback resistor
value to alter the gain. MM: R105 and 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) & 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 startup 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
(TR104,105,108,109). The quiescent current is set up by D100
and R118,119.
Closed loop stability is achieved with C116,117, giving
symmetrical slewing capability.
SK103 connects to the micro controller and display PCB.
The 14 pin connector is numbered as follows:
No Name Type Description
1 +5V_D O/P 5 volt digital supply (for micro)
2 0V_D O/P Digital ground
3 +49V O/P Main power supply for VFD (via fusible resistor)
4 STANDBY I/P Mains relay control signal (HIGH = ON)
5 SPKR1 ON I/P Speaker 1 relay control signal (HIGH = ON)
6 SPKR2 ON I/P Speaker 2 relay control signal (HIGH = ON)
7 THERMPROT O/P Over temperature protect (HIGH = FAULT)
8 VIPROT O/P Short circuit protect (HIGH = FAULT)
9 DCPROT O/P DC offset protect (HIGH = FAULT)
10 AC PRESENT O/P Indicates AC mains is plugged in (HIGH = ON)
11 TRIGGER O/P 12V DC trigger input (HIGH = ON)
12 REMOTE O/P Demodulated RC5 remote input from rear panel
13 0V_D O/P Spare digital ground pin
14 +5V_D O/P Spare 5 volt digital supply pin
The ground naming convention is as follows:
Name Description
0V_D Digital ground (used for micro processor circuitry, display and interface)
0V_LS_R Right channel loudspeaker ground return
0V_SIG Signal ground (this is the ‘clean’ precision reference ground)
0V_PSU Power supply ground (high current pulses for the large reservoir caps)
0V_TRIG Ground return for the jack socket trigger and remote control circuit
0V_HF_R Decoupling ‘noisy’ ground for the right channel power amp
0V_LS_L Left channel loudspeaker ground return
0V_HF_L Decoupling ‘noisy’ ground for the left channel power amp
A85, P85, P85/3 Service Guide
Build History
ECO
Number
Date Description of Change
00_1089 02/10/00 A85 – Fascia position changed to prevent display buttons sticking
00_1129 01/11/00 A85, P85, P85/3 – Improved stability under heavy clipping of amplifier R345,
R346, R445, R446 changed from 100R to 0R link
C307, C308, C407, C408 changed from 47P to 100P capacitors
00_1138 27/11/00 A85, P85, P85/3 – C303, C304, C403 changed from 10uF to 100uf capacitors –
this prevents protection circuit from operating when driving a 4 ohm load at
low frequency
01_1030 23/02/01 A85, P85, P85/3 – RV300, RV400 changed to 220R presets to make it easier to
adjust the bias settings
01_1068 11/04/01 A85, P85, P85/3 – New output device clamp fitted to heatsink
01_1101 04/06/01 A85, P85, P85/3 – Sensitivity of DC offset detection circuit reduced – Power
amp cct R308, R408 changed to 22K - R314, R414 changed to 10K
PSU surface mount fuse F202 up rated from 500mA to 750mA
01_1142 22/08/01 A85 – Preamp board upgraded from L866 to L937
01_1178 12/10/01 A85, P85, P85/3 – Speaker terminals changed from Camcon to 4mm binding
post
01_E014 28/11/01 A85 – Preamp board fuses F300, F301 up rated to 2A surface mount
02_E033 31/01/02 A85 – Extra pad F038 fitted under TX to stop TX coming loose in transit
02_E035 04/02/02 A85, P85, P85/3 – Main 20mm fuse rating changed to 4AT
Software History
ECO
Number
Date Version Description of Change
01_1072 18/04/01 1.1 Remote standby action changed from turning unit completely off
to putting unit into standby
01_1095 21/05/01 1.2 Delay added to start H8 start up routine (volume control chip)
01_1167 12/09/01 1.3 Volume chip read/write protocol changed
01_1179 26/10/01 2.0 Added the processor mode option
01_E011 23/11/01 2.1 Corrected the welcome message saving fault. This fault was
introduced with version 2.0 software
02_E048 15/02/02 2.2 Corrected the processor loop volume jump when v/c adjusted
Current Fuse Ratings (20/02/02)
Fuse Position Fuse Rating
Main Supply fuses - A85, P85, P85/3 2 x 4AT 20mm (Arcam part number C12406)
PSU fuse F202 - A85, P85, P85/3 750mA surface mount (Arcam part number C3751)
Preamp fuses F300, F301 – A85 2A surface mount (Arcam part number C3202)
Quiescent Current Setting
Left channel Measure points indicated on PCB -
Adjust RV300 for 8.5mV cold or 12 mV when warm
Right channel Measure points indicated on PCB -
Adjust RV400 for 8.5mV cold or 12 mV when warm
Fault Diagnostics
Hints & Tips
!
To check software version press PHONO, TUNER, DVD buttons on the front panel
simultaneously.
!
On issue 2 phono boards only, fit Kapton insulation tape to the phono stage PCB (rear panel
end) to prevent track shorting to chassis.
!
Check all fuses are the correct rating.
!
Check DC offset alterations are fitted as per ECO 01_1101
!
To isolate a fault between the pre or power amp section press the PRE/PWR button on the
rear panel to separate the two sections.
!
Check R100 on amp/psu board is not shorting to the track underneath (through plated via).
Fault Action
No power Check fuses
Check power supply rails
Unit functions ok but no audio Check preamp fuses
Check RL100A (volume control mute relay)
Check +5V supply rail
Check mute signal line
Volume control locks up Check software version is 2.0 or higher
DC offset Check equipment connected to amp for DC on the audio leads
Check alterations as per ECO 01_1101 have been fitted
Unit fails to respond to commands Check ribbon cable from display to main board
Check ribbon cable from display to preamp board
Unit gets very hot Check power stage IQ settings
1 2 3 4 5 6 7 8
A
B
C
D
87654321
D
C
B
A
ISSUE
DRAWING NO.
23425
DRAWING TITLE
Drawn by:
DATE
Filename
ECO No. DESCRIPTION OF CHANGE
L882C1_3.2.PRJ
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
A85 amplifier and PSU - top sheet
Circuit Diagram
L882C1
J Reckless
6-Jun-2001
INITIALS
Date Printed
1 4Sheet of
Notes:
Top+
Top-
SK100A
CAMCON_G
Bot+
Bot-
SK100B
CAMCON_G
Top+
Top-
SK101A
CAMCON_G
Bot+
Bot-
SK101B
CAMCON_G
D100
1N4003F
D101
1N4003F
1 2
34
5 6
78
SP100
STAR_8
EMC
1
N
F
SK104A
PHONO4G
N
F
SK104B
PHONO4G
0V_SIG
0V_SIG
0V_SIG
1
2
3
SW100A
2PCO
4
5
6
SW100B
2PCO
C100
1N0 SM
1
2
3
4
SK102
AMPCT4
STANDBY
SPKR1 ON
SPKR2 ON
THERMPROT
VIPROT
DCPROT
AC PRESENT
L SIG
R SIG
SPKR1 ON
SPKR2 ON
THERMPROT
VIPROT
AC PRESENT
DCPROT
LS L
LS R
L SIG
0V_SIG
0V_LS_L
0V_HF_L
+49V
-49V
+5V_D
+49V
-49V
0V_D
0V_PSU
R SIG
0V_SIG
0V_LS_R
0V_HF_R
+49V
-49V
0V_TRIG
LS L
0V_LS_L
0V_LS_R
LS R
+49V
0V_D
VIPROT_L
DCPROT_L
DCPROT_L
VIPROT_R
DCPROT_R
DCPROT_R
VIPROT_L
VIPROT_R
STANDBY
+49V
+5V_D
0V_D
0V_PSU
0V_LS_R
0V_HF_R
0V_LS_L0V_HF_L
0V_D
0V_TRIG
0V_SIG
R103
330R 1W CF
R104
330R 1W CF
R105
100R 1W CF
R106
100R 1W CF
1
2
3
4
SK106
AMPCT4
LHC
2
RHC
3
1
4
L
5
6
R
7
SK105
HPSKT
1
2
3
4
SK107
AMPCT4
LS L
LS R
0V_LS_L
REMOTE
REMOTE
FROM PREAMP
INTEGRATED / PRE-POWER
MODE SELECT SWITCH
TRIGGER
TRIGGER
TP102
TP101
TP100
TP103
TP104
TP105
TP106
TP107
TP108
TP109
TP110
TP117
TP111 TP113 TP115
TP112 TP114 TP116
0V_D +5V(D)
VPOS
VNEG
0V_PSU
PWRON
THPROT_uCVIPROT_L
VIPROT_R VIPROT_uC
AC_PRES0V_TRIG
DCPROT_L
DCPROT_R
DCPROT_uC
RC5 IN
TRG IN
L882C2
L882C2_3.2.SCH
INPUT
0V_SIG
VIPROT
DCPROT
OUTPUT0V_LS
0V_HF
VPOS
VNEG
L882C3
L882C3_3.2.SCH
INPUT
0V_SIG
VIPROT
DCPROT
OUTPUT0V_LS
0V_HF
VPOS
VNEG
L882C4
L882C4_3.2.SCH
RLY100A
RLY G5Z-2A-E
RLY100B
RLY G5Z-2A-E
RLY100C
RLY G5Z-2A-E
RLY101A
RLY G5Z-2A-E
RLY101B
RLY G5Z-2A-E
RLY101C
RLY G5Z-2A-E
TR100
BD179
TR101
BD179
R101
100R SM
R102
100R SM
R107
220R SM
R108
220R SM
PCB
PCB
L882PB_3
TP118
TP119
TP120
TP121
1
2
3
4
5
6
7
8
9
10
11
12
13
14
SK103
FFC 14W 2.54MM VER
8K7014
EARTH LEAD
8M101
EL
EARTH LEAD
1
2
PL100
1
2
PL101
00_1086 JR 19/9/00 NO CHANGE TO THIS SHEET
2.0
R100
10R MF
00_1115 JR 16/10/00 NO CHANGE TO THIS SHEET
00_1129 JR 1/11/00 NO CHANGE TO THIS SHEET
2.1
2.2
00_1138 JR 27/11/00 NO CHANGE TO THIS SHEET
2.3
00_1134 MGM 17/11/00 NO CHANGE TO THIS SHEET
2.4
01_1101 JR 6/4/01 POWER SUPPLY FUSES AND DC OFFSET 3.2
1 2 3 4 5 6 7 8
A
B
C
D
87654321
D
C
B
A
ISSUE
DRAWING NO.
23425
DRAWING TITLE
Drawn by:
DATE
Filename
ECO No. DESCRIPTION OF CHANGE
L882C2_3.2.SCH
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
A85 amplifier - power supply and microcontroller interface
Circuit Diagram
L882C2
J Reckless
6-Jun-2001
INITIALS
Date Printed
2 4Sheet of
Notes:
L
N
E
N E L
SK203
IEC3 NO RIVETS
BC200
TOOLING4.1
Green
1
SK202
CAGECLAMP1
C205
3N3 MAINS
C206
3N3 MAINS
Far from PCB
SK201B
JACK3.5X2
Near to PCB
SK201A
JACK3.5X2
SW200B
VOL SEL SLIDE
SW200A
VOL SEL SLIDE
C208
3N3 MAINS
C207
3N3 MAINS
Vin
I
GND
G
Vout
O
IC201
7805
D203
1N4003F
D201
1N4003F
D202
1N4003F
D200
1N4003F
C225
100N CD
C226
100N CD
VR201
VDR 115V
VR200
VDR 115V
+
1
~
2
-
4
~
3
BR200
BRGBU8D
LIVENEUTRAL
EARTH
EMC Shield
SH200
EMCMAINS
NEUTRAL
LIVE
LIVE
NEUTRAL
0V_D
+5V(D)
0V_D
0V_PSU
VPOS
VNEG
0V_PSU
+49V
+5V_D
0V_D
PWRON
-49V
+5V_D
TH200
PTH90DEG
+5V_D
0V_D
THPROT_uC
VIPROT_L
VIPROT_R
+5V_D
0V_D
VIPROT_uC
0V_D
9VRMS
+5V_D
0V_D
9VRMS
+
C229
22U EL
AC_PRES
+
C227
3300u 25V
+
C228
1000u 10V
2
3
4
6
7
8
1 5
SK204
MOLEXPWR8
1
2
3
4
5
6
SK200
MOLEXPWR6
D206
BAS16W SM
TR204
BC849B
R211
10K SM
R220
10R SM
R200
1K0 SM
TR202
FMMT597
D205
BAS16W SM C213
10N SM
TR203
FMMT497
DZ207
15V 350MW SM
+
C223
10U EL
+
C222
10U EL
R210
10K SM
+49V
0V_TRIG
0V_TRIG
1 2
IC202A
74HC14D
3 4
IC202B
74HC14D
1011
IC202E
74HC14D
1213
IC202F
74HC14D
C214
10N SM
C215
10N SM
R213
4K7 SM
R214
4K7 SM
TR205
BC856B
R206
1K0 SM
C218
10N SM
C203
100N SM
DCPROT_L
DCPROT_R
+5V_D
0V_D
DCPROT_uC
0V_D
5 6
IC202C
74HC14D
89
IC202D
74HC14D
C216
10N SM
C217
10N SM
R215
4K7 SM
R216
4K7 SM
TR206
BC856B
R207
1K0 SM
C220
100N SM
C204
100N SM
14
7
IC202G
74HC14D
C201
100N SM
C202
100N SM
R205
1K0 SM
R221
10R SM
C224
100N CD
R219
1K8 SM
R212
4K7 SM
TR201
FMMT497
TRIGGER OUTPUT
APPROX 13.5VDC
60mA MAX CURRENT
R201
1K0 SM
R202
1K0 SM
R203
1K0 SM
R204
1K0 SM
C219
10N SM
C221
10N SM
MAINS WIRING AND AUXILIARY SUPPLY
POWER AMP SUPPLY
MICROPROCESSOR SIGNALS INTERFACE
HS
HS200
TO220HS08REG
1
2
3
4
5
6
SK205
AMPCT6
RLY200A
DPDT5V
RLY200B
DPDT5V
RLY200C
DPDT5V
115V
115V
6
4
2
1 0V
5
8
9V
0V
9V
3
7
0V
TX200
TX 3VA 9301
TR200
BD179
R217
10R SM
R218
10K SM
STANDBY RELAY CONTROL
R227
1K0 SM
DZ204
4V7 350MW SM
R228
100K SM
L200
27mH
C200
680P PP
3
2
1
IC200A
LM393A SM
R223
10K SM
R229
100K SM
R209
10K SM
R224
1K8 SM
R230
1K5 SM
5
6
7
IC200B
LM393A SM
84
IC200C
LM393A SM
R225
1K8 SM
C231
1N0 SM
R208
10K SM
C232
100N SM
0V_TRIG
+5V_D
RC5 IN
CARRIER FILTER AND DEMODULATOR
C230
10N SM
MODULATED RC5
REMOTE CONTROL INPUT
+
C233
10U EL
R222
10K SM
TRG IN
TP206
TP200
TP207
TP203
TP201
TP202
TP210
TP204
TP205
TP208
TP209
TP211
TP212
+
C209
10,000u 63V
+
C210
10,000u 63V
R226
470R SM
C211
100N PC
C212
100N PC
F200
AS2A
F201
AS2A
CHASS
SK101C
CAMCON_G
C235
1N0 SM
C234
220N X2 CLASS
R231
1M5 VR25
00_1086 JR 19-9-00 R231, C234, C235 ADDED FOR EMC 2.0
NF
NF
00_1115 JR 16/10/00
00_1129 JR 1/11/00 NO CHANGE TO THIS SHEET
NO CHANGE TO THIS SHEET 2.1
2.2
00_1138 JR 27/11/00 NO CHANGE TO THIS SHEET 2.3
00_1134 MGM 17/11/00 NO CHANGE TO THIS SHEET
2.4
01_1101 JR 6/4/01 POWER SUPPLY FUSES AND DC OFFSET 3.2
F202
T750mA SM
1 2 3 4 5 6 7 8
A
B
C
D
87654321
D
C
B
A
ISSUE
DRAWING NO.
23425
DRAWING TITLE
Drawn by:
DATE
Filename
ECO No. DESCRIPTION OF CHANGE
L882C3_3.2.SCH
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
A85 amplifier - power output stage left
Circuit Diagram
L882C3
J Reckless
6-Jun-2001
INITIALS
Date Printed
3 4Sheet of
Notes:
R324
1K0 SM
TR300
FMMT597
TR301
FMMT597
R315
100R SM
R316
100R SM
R319
100R SM
TR314
FMMT497
TR315
FMMT497
R317
100R SM
R318
100R SM
R320
100R SM
R322
22R SM
0V_SIG
C317
470N PE
0V_SIG
0V_SIG
INPUT
0V_SIG
R350
5R6 2W CF
C319
100N PE
0V_HF 0V_LS
C313
100N SM
R341
330R SM
R342
330R SM
R343
100R SM
R344
100R SM
R345
0R0 SM
R346
0R0 SM
R334
22K SM
R336
22K SM
D301
BAS16W SM
D302
BAS16W SM
TR312
FMMT497
TR304
FMMT597
TR313
FMMT497
TR302
FMMT597
DZ305
4V7 350MW SM
0V_HF
VIPROT
C320
100U NP
TR305
FMMT597
DZ306
4V7 350MW SM
0V_HF
DCPROT
OUTPUT
0V_LS
0V_HF
VPOS
VNEG
0V_HF
0V_HF
DZ300
15V 350MW SM
DZ301
15V 350MW SM
C309
100N SM
C310
100N SM
C314
100N SM
0V_SIG
0V_SIG
D304
1N4003F
D303
1N4003F
R302
10K SM
R327
22K SM
RV300
100R PSET
C312
10N SM
1
2
PL300
BIAS
R325
1K0 SM
R326
1K0 SM
ADJ BIAS
D300
BAS16W SM
R300
10K SM
R309
10K SM
R305
10K SM
R306
10K SM
+
C305
10U EL
MEASURE
TR318
SAP15N
TR319
SAP15P
R301
10K SM
C315
100N SM
R347
100R SM
R349
100R SM
R348
100R SM
R340
100K SM
DZ302
4V7 350MW SM
DZ303
4V7 350MW SM
3
2
1
84
IC300A
TL072CD
5
6
7
IC300B
TL072CD
R328
4K7 SM
0V_HF
0V_SIG
TR311
FMMT497
TR303
FMMT597
TR310
FMMT497
TR307
FMMT597
C307
100P SM
C308
100P SM
INPUT FILTER V TO I AMP
DC SERVO
PNP CURRENT MIRROR
NPN CURRENT MIRROR
PRE DRIVER
PRE DRIVER
OUTPUT STAGE
OUTPUT STAGE
V-I PROTECTION
V-I PROTECTION
VI PROTECT
SIGNAL TO MICRO
DC OFFSET
DETECTION
DC OFFSET SIGNAL
TO MICRO
ZOBEL NETWORK
TR316
FMMT497
TR308
FMMT597
TR317
FMMT497
R311
10K SM
R312
10K SM
R313
10K SM
R303
10K SM
R304
10K SM
R307
10K SM
R310
4K7 SM
R329
4K7 SM
+
C300
100U EL
+
C301
100U EL
R338
150R SM
R339
150R SM
R308
22K SM
R314
10K SM
TR309
FMMT497
TR306
FMMT597
R323
22R SM
R321
22R SM
TP302
TP303
TP304
TP307
TP308
TP305
TP306
R337
22R SM
R331
1K5 SM
R332
1K8 SM
R330
1M0 SM
R333
3K3 SM
R335
3K3 SM
L300
2U2H LAC SMALL
R351
10R MF
C316
470P PPW
C311
100N PC
+
C318
10U EL
TR321
FMMT597
TR320
FMMT497
+
C302
100U EL 100V
+
C306
100U EL 100V
R352
470R 2W MF 5%
R353
470R 2W MF 5%
BOOTSTRAP
BOOTSTRAP
(SET TO 16mV)
00_1086 JR 19/9/00 NO CHANGE TO THIS SHEET 2.0
00_1115 JR 16/10/00 R338 R339 CHANGED TO 150R
00_1129 JR 1/11/00 R345 R346 C307 C308 VALUE CHANGES
2.1
2.2
+
C303
100U EL
+
C304
100U EL
00_1138 JR 27/11/00 C303 C304 FROM 10U TO 100U 2.3
00_1134 MGM 17/11/00 NO CHANGE TO THIS SHEET
2.4
TR322
FMMT497
R354
1K0 SM
R355
6K8 SM
01_1101 JR 6/4/01 POWER SUPPLY FUSES AND DC OFFSET 3.2
1 2 3 4 5 6 7 8
A
B
C
D
87654321
D
C
B
A
ISSUE
DRAWING NO.
23425
DRAWING TITLE
Drawn by:
DATE
Filename
ECO No. DESCRIPTION OF CHANGE
L882C4_3.2.SCH
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
A85 amplifier - power output stage right
Circuit Diagram
L882C4
J Reckless
6-Jun-2001
INITIALS
Date Printed
4 4Sheet of
Notes:
R424
1K0 SM
TR400
FMMT597
TR401
FMMT597
R415
100R SM
R416
100R SM
R419
100R SM
TR414
FMMT497
TR415
FMMT497
R417
100R SM
R418
100R SM
R420
100R SM
R422
22R SM
0V_SIG
R430
1M0 SM
R431
1K5 SM
R432
1K8 SM
C417
470N PE
0V_SIG
0V_SIG
INPUT
0V_SIG
R450
5R6 2W CF
C419
100N PE
0V_HF 0V_LS
C413
100N SM
R441
330R SM
R442
330R SM
R443
100R SM
R444
100R SM
R445
0R0 SM
R446
0R0 SM
R434
22K SM
R436
22K SM
D401
BAS16W SM
D402
BAS16W SM
TR412
FMMT497
TR404
FMMT597
TR413
FMMT497
TR402
FMMT597
DZ405
4V7 350MW SM
0V_HF
VIPROT
C420
100U NP
TR405
FMMT597
DZ406
4V7 350MW SM
0V_HF
DCPROT
OUTPUT
0V_LS
0V_HF
VPOS
VNEG
0V_HF
0V_HF
DZ400
15V 350MW SM
DZ401
15V 350MW SM
C409
100N SM
C410
100N SM
C414
100N SM
0V_SIG
0V_SIG
D404
1N4003F
D403
1N4003F
R402
10K SM
R427
22K SM
RV400
100R PSET
C412
10N SM
1
2
PL400
BIAS
R425
1K0 SM
R426
1K0 SM
ADJ BIAS
D400
BAS16W SM
R400
10K SM
R409
10K SM
R405
10K SM
R406
10K SM
+
C405
10U EL
MEASURE
TR418
SAP15N
TR419
SAP15P
R401
10K SM
C415
100N SM
R447
100R SM
R449
100R SM
R448
100R SM
R440
100K SM
DZ402
4V7 350MW SM
DZ403
4V7 350MW SM
3
2
1
84
IC400A
TL072CD
5
6
7
IC400B
TL072CD
R428
4K7 SM
0V_HF
0V_SIG
TR411
FMMT497
TR403
FMMT597
TR410
FMMT497
TR407
FMMT597
C407
100P SM
C408
100P SM
INPUT FILTER V TO I AMP
DC SERVO
PNP CURRENT MIRROR
NPN CURRENT MIRROR
PRE DRIVER
PRE DRIVER
OUTPUT STAGE
OUTPUT STAGE
V-I PROTECTION
V-I PROTECTION
VI PROTECT
SIGNAL TO MICRO
DC OFFSET
DETECTION
DC OFFSET SIGNAL
TO MICRO
ZOBEL NETWORK
TR416
FMMT497
TR408
FMMT597
TR417
FMMT497
R411
10K SM
R412
10K SM
R413
10K SM
R403
10K SM
R404
10K SM
R407
10K SM
R410
4K7 SM
R429
4K7 SM
+
C400
100U EL
+
C401
100U EL
R438
150R SM
R439
150R SM
R408
22K SM
R414
10K SM
TR409
FMMT497
TR406
FMMT597
R423
22R SM
R421
22R SM
(SET TO 16 mV)
TP402
TP403
TP404
TP405
TP406
TP407
TP408
R437
22R SM
R433
3K3 SM
R435
3K3 SM
R451
10R MF
C416
470P PPW C411
100N PC
+
C418
10U EL
TR421
FMMT597
TR420
FMMT497
+
C402
100U EL 100V
+
C406
100U EL 100V
R452
470R 2W MF 5%
R453
470R 2W MF 5%
BOOTSTRAP
BOOTSTRAP
00_1086 JR 19/9/00 NO CHANGE TO THIS SHEET 2.0
00_1115 JR 16/10/00 R438 R439 CHANGED TO 150R
00_1129 JR 1/11/00 R435 R436 C407 C408 VALUE CHANGES
2.1
2.2
+
C403
100U EL
+
C404
100U EL
00_1138 JR 27/11/00 C403 C404 FROM 10U TO 100U 2.3
L400
2U2H LAC SMALL
00_1134 MGM 17/11/00 L300 L400 CHANGED TO 7D002C
2.4
TR422
FMMT497
R454
1K0 SM
R455
6K8 SM
01_1101 JR 6/4/01 POWER SUPPLY FUSES AND DC OFFSET 3.2
1 2 3 4 5 6 7 8
A
B
C
D
87654321
D
C
B
A
ISSUE
DRAWING NO.
DRAWING TITLE
Drawn by:
DATE
Filename
ECO No. DESCRIPTION OF CHANGE
J:\ECO_wip\L886 DV88 Display board correct R4 cock-up\L8863\L8863.0a.ddb - L886_3.0a.sch
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
DVD DISPLAY PCB
Circuit Diagram
L886_3
PG17-Nov-2000
INITIALS
Date Printed
1 1Sheet of
Notes:
SW1
1
SW2
2
SW3
3
SW4
4
SO
5
SI
6
VSS
7
SCK
8
CS
9
K1
10
K2
11
K3
12
K4
13
VDD
14
S1
15
S2
16
S3
17
S4
18
S5
19
S6
20
S7
21
S8
22
S9
23
S10
24
S11
25
S12/G11
26
VEE
27
S13/G10
28
S14/G9
29
S15/G8
30
S16/G7
31
G6
32
G5
33
G4
34
G3
35
G2
36
G1
37
VDD
38
L4
39
L3
40
L2
41
L1
42
VSS
43
OSC
44
Z1
BU2872AK
F1
1
F1
2
G1
5
G2
6
G3
7
G4
8
G5
9
G6
10
G7
11
S1
25
S2
26
S3
27
S4
28
S5
29
S6
30
S7
31
S8
32
S9
33
S10
34
S11
35
S12
36
S13
37
S14
38
S15
39
F2
42
F2
43
DISP1
DISP SSV-07MS09
R1
10K SM
R2
10K SM
R3
10K SM
K3
K4
(was POWER)
(was MENU)
D1
BAS16W SM
D2
BAS16W SM
D3
BAS16W SM
D4
BAS16W SM
SW1
SKIP>
SW2
<SKIP
SW3
PAUSE
SW4
PLAY
SW5
STOP
SW6
OPEN
SW7
FWD>>
SW8
<<RWD
F2F1
G1
G2
G3
G4
G5
G6
G7
SEG8
SEG7
SEG6
SEG5
SEG4
SEG3
SEG2
SEG1
SEG9
SEG10
SEG11
SEG12
SEG13
SEG14
SEG15
K2
Q1
BC856B
Q2
BC847B
R6
1K0 SM
On=Green
Standby=red
+5V
HDCD
+5V
STBLED
R5
470R SM
1
2
3
4
5
6
7
8
SK1
FFC8H SM
1
2
3
4
5
6
SK2
AMPCT6H
SO
SI
SCK
CS
+5V
VKK
+5V
R7
33K SM
+
C5
10U EL SM
+
C6
10U EL SM
+5V
CATHODE BIAS CCT
VKK = -19.5V
F1= -13.9V
F2 = -9.6V
Pwr in
SO
IRIRQ
CS
SCK
SI
DATA I/O
Photo Strip
PS
PHOTO_STRIP
Detail
Drilling
DD2
DRILL_DWG
Paper Marker
A2 Horizontal
DD3
DD_A3H
Paper Marker
A2 Vertical
DD4
DD_A3V
FD_1
FIDUCIAL
FD_2
FIDUCIAL
FIX4
FIXING HOLE
FIX3
FIXING HOLE
FIX2
FIXING HOLE
FIX1
FIXING HOLE
FR4, 1 OZ Cu
PCB MATERIAL
DD1
FR4_1OZ
Q_1
Q_2
Q_3
Q_4
Q_5
Q_6
Q_7
Q_8
Q_9
Q_10
Q_11
Q_12
Q_13
Q_14
Q_23
Q_24
Q_25
Q_26
Q_27
Q_28
Q_29
Q_30
R8
4K7 SM
+5V
Q_18
R
G
LED1
LED RED/GRN 3MM
PCB
PCB
L886PB_3
HDCDLED
Q3
BC847B
Q4
BC847B
R10
10K SM
R9
10K SM
R11
10K SM
R12
10K SM
IRIRQ
F2
VKK_CK
VKK_D
R14
4K7 SM
R15
1K0 SM
Q5
BC856B
Q6
BC846B
CLK
3
D
2
SD
4
CD
1
Q
5
Q
6
Z2A
74HC74 SM
VKKIN VKK
+5V
CLK
11
D
12
SD
10
CD
13
Q
9
Q
8
Z2B
74HC74 SM
VCC
14
GND
7
Z2C
74HC74 SM
+5V
R13
1M0 SM
Layout by
Cliff
DD6
CLOGO
Update Box
EL1
UPDATE_BOX
F1
VKKIN
C7
100N SM
C3
100N SM
C2
100N SM
C4
1N0 SM
C8
100N SM
C1
100N SM
LED2
LED GREEN3.1MM
CL 31/07/00 PRODUCTION RELEASE 1.0
R16
1K0 SM
+5V
VKK
D5
BZX284-C5V6
CL 23/08/00 MINOR MODIFICATIONS 2.0
PG00_1082 14/09/00 Change RX1 to l/p part, test pad changes, display clip, R4 VALUE 3.0
VKK switching CCT
Test pad change for issue 3:
Q_23= SO (was STBLED)
Q_9=SI (was GND)
VFD CLIP
E874PM
E882PM
LC1
DVD DISPLAY CLIP
VFD CLIP
E874PM
E882PM
LC2
DVD DISPLAY CLIP
Display clips: PCB footprint is called E882PM
This footprint will accept either E874PM (current clip)
or E882PM (new clip not designed yet)
This part type currently calls for p/n E874PM, change to E882PM when new clip is available
+5V
3
O/P
2
GND
1
Case
Case
O/P
GND +5V
DUAL FOOTPRINT
RX1
SBX1610-52/PIC-26043TM2
IR RX
SUPPORT PAD
SP1
IR RX SUPPORT PAD
PG 17/11/00 Correct error R4 is 1206 not 0805 3.0a
R4
220R SM
1 2 3 4
A
B
C
D
4321
D
C
B
A
ISSUE
DRAWING NO.
23425
DRAWING TITLE
Drawn by:
DATE
Filename
ECO No. DESCRIPTION OF CHANGE
J:\Change_Control\ECO_AGENDA\01_E014 Fuse changes on A32 preamp\L937_1.1.ddb - Documents\Schematic\L937C1_1.0.PRJ
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
Integrated amplifier preamp
Circuit Diagram
L937C1
JBR
28-Nov-2001
INITIALS
Date Printed
1 3Sheet of
Notes:
Main signal path
L937C2_1.1.SCH
Power supply
L937C3_1.1.SCH
USE EXCLUDE NF WHEN USING RUNOUT SHEET PROGRAM
PCB
PCB1
L937PB_1
01_1142 JBR 14/8/01 First production release 1.0
01_E014 JBR 28/11/01 Fuses uprated to 2A 1.1
1 2 3 4 5 6 7 8
A
B
C
D
87654321
D
C
B
A
ISSUE
DRAWING NO.
23425
DRAWING TITLE
Drawn by:
DATE
Filename
ECO No. DESCRIPTION OF CHANGE
J:\Change_Control\ECO_AGENDA\01_E014 Fuse changes on A32 preamp\L937_1.1.ddb - Documents\Schematic\L937C2_1.0.SCH
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
Integrated amplifier preamp - main signal path
Circuit Diagram
L937C2
JBR28-Nov-2001
INITIALS
Date Printed
2 3Sheet of
Notes:
EMC
1
N
F
SK2A
PHONO4G
C100
1N0 SM
0V_SIG
0V_SIG
R100
1K0 SM
R101
1K0 SM
R103
100K SM
R104
100K SM
D100
BAV99W DUAL SM
+15V -15V
0V_SIG
0V_SIG
D101
BAV99W DUAL SM
+15V -15V
N
F
SK2B
PHONO4G
0V_SIG
R102
1K0 SM
R125
1K0 SM
R105
100K SM
R128
100K SM
D102
BAV99W DUAL SM
+15V -15V
0V_SIG
0V_SIG
D106
BAV99W DUAL SM
+15V -15V
EMC
1
N
F
SK3A
PHONO4G
C121
1N0 SM
0V_SIG
0V_SIG
R126
1K0 SM
R127
1K0 SM
R129
100K SM
R130
100K SM
D107
BAV99W DUAL SM
+15V -15V
0V_SIG
0V_SIG
D108
BAV99W DUAL SM
+15V -15V
N
F
SK3B
PHONO4G
0V_SIG
R156
1K0 SM
R157
1K0 SM
R159
100K SM
R160
100K SM
D112
BAV99W DUAL SM
+15V -15V
0V_SIG
0V_SIG
D113
BAV99W DUAL SM
+15V -15V
EMC
1
N
F
SK4A
PHONO4G
C139
1N0 SM
0V_SIG
0V_SIG
R158
1K0 SM
R189
1K0 SM
R161
100K SM
R192
100K SM
D114
BAV99W DUAL SM
+15V -15V
0V_SIG
0V_SIG
D115
BAV99W DUAL SM
+15V -15V
EMC
1
N
F
SK5A
PHONO4G
0V_SIG
R190
1K0 SM
R191
1K0 SM
R193
100K SM
R194
100K SM
D116
BAV99W DUAL SM
+15V -15V
0V_SIG
0V_SIG
D117
BAV99W DUAL SM
+15V -15V
CD INPUT
TUNER INPUT
AV INPUT
DVD INPUT
TAPE INPUT
VCR INPUT
C160
1N0 SM
0V_SIG
C164
1N0 SM
0V_SIG
0V_SIG
R195
1K0 SM
R196
1K0 SM
R197
100K SM
R198
100K SM
D118
BAV99W DUAL SM
+15V -15V
0V_SIG
0V_SIG
D119
BAV99W DUAL SM
+15V -15V
EMC
1
N
F
SK6
PHONO2G
AUX INPUT
CD L
CD R
TUNER L
TUNER R
AV L
AV R
DVD L
DVD R
TAPE IN L
TAPE IN R
VCR IN L
VCR IN R
AUX L
AUX R
AUX L
CD L
TUNER L
AV L
DVD L
VCR IN L
MODULE L
0V_SIG
AUX R
CD R
TUNER R
AV R
DVD R
VCR IN R
MODULE R
0V_SIG
TAPE 0
TAPE 1
TAPE 2
TAPE 0
TAPE 1
TAPE 2
+15V
+15V-15V
-15V
0V_SIG
0V_SIG
C104
100N SM
C105
100N SM
+15V
-15V
3
2
1
Z109A
TL072 SM
84
Z113C
TL072 SM
R106
1M0 SM
0V_SIG
R108
47R SM
D103
BAV99W DUAL SM
+15V -15V
N
F
SK4B
PHONO4G
0V_SIG
5
6
7
Z109B
TL072 SM
R107
1M0 SM
0V_SIG
R109
47R SM
D104
BAV99W DUAL SM
+15V -15V
3
2
1
Z110A
TL072 SM
R131
1M0 SM
0V_SIG
R133
47R SM
D109
BAV99W DUAL SM
+15V -15V
5
6
7
Z110B
TL072 SM
R132
1M0 SM
0V_SIG
R134
47R SM
D110
BAV99W DUAL SM
+15V -15V
N
F
SK5B
PHONO4G
0V_SIG
+15V
+15V-15V
-15V
-15V
-15V
C108
100P SM
C109
100P SM
C129
100P SM
C130
100P SM
AUX L
CD L
TUNER L
AV L
DVD L
TAPE IN L
MODULE L
0V_SIG
AUX R
CD R
TUNER R
AV R
DVD R
TAPE IN R
MODULE R
VCR 0
VCR 1
VCR 2
VCR 0
VCR 1
VCR 2
0V_SIG
0V_SIG
0V_SIG
TAPE OUTPUT
VCR OUTPUT
C106
100N SM
C107
100N SM
+15V
-15V
0V_SIG
C125
100N SM
C126
100N SM
+15V
-15V
0V_SIG
C127
100N SM
C128
100N SM
+15V
-15V
0V_SIG
AUX L
CD L
TUNER L
AV L
DVD L
TAPE IN L
VCR IN L
MODULE L
AUX R
CD R
TUNER R
AV R
DVD R
TAPE IN R
VCR IN R
MODULE R
LISTEN 0
LISTEN 1
LISTEN 2
LISTEN 0
LISTEN 1
LISTEN 2
0V_SIG
0V_SIG
C143
100N SM
C144
100N SM
+15V
-15V
0V_SIG
C145
100N SM
C146
100N SM
+15V
-15V
0V_SIG
84
Z114C
TL072 SM
R170
22K SM
R162
22K SM
R171
22K SM
R163
22K SM
R172
22K SM
R164
22K SM
R173
22K SM
R165
22K SM
R174
22K SM
R166
22K SM
R175
22K SM
R167
22K SM
R176
22K SM
R168
22K SM
R177
22K SM
R169
22K SM
+15V
+15V
R178
22K SM
C148
22P SM
R179
22K SM
C149
22P SM
5
6
7
Z115B
OPA2134PA SM
5
6
7
Z116B
OPA2134PA SM
84
Z116C
OPA2134PA SM
0V_SIG
0V_SIG
R183
1M0 SM
R184
1M0 SM
R199
100K SM
R180
100K SM
0V_SIG
0V_SIG
+5V
+5V
+5V
+5V
+5V
+5V
X0
4
X1
5
X2
6
X3
7
X4
12
X5
11
X6
10
X7
9
EN
2
A0
1
A1
16
A2
15
V-
3
D
8
GND
14
V+
13
Z100
DG408DY
X0
4
X1
5
X2
6
X3
7
X4
12
X5
11
X6
10
X7
9
EN
2
A0
1
A1
16
A2
15
V-
3
D
8
GND
14
V+
13
Z101
DG408DY
X0
4
X1
5
X2
6
X3
7
X4
12
X5
11
X6
10
X7
9
EN
2
A0
1
A1
16
A2
15
V-
3
D
8
GND
14
V+
13
Z102
DG408DY
X0
4
X1
5
X2
6
X3
7
X4
12
X5
11
X6
10
X7
9
EN
2
A0
1
A1
16
A2
15
V-
3
D
8
GND
14
V+
13
Z103
DG408DY
X0
4
X1
5
X2
6
X3
7
X4
12
X5
11
X6
10
X7
9
EN
2
A0
1
A1
16
A2
15
V-
3
D
8
GND
14
V+
13
Z104
DG408DY
X0
4
X1
5
X2
6
X3
7
X4
12
X5
11
X6
10
X7
9
EN
2
A0
1
A1
16
A2
15
V-
3
D
8
GND
14
V+
13
Z105
DG408DY
LIN
4
LGND
5
RGND
12
RIN
13
LMO
2
RMO
15
AVCC
1
DVCC
7
LFO
3
RFO
14
DGND
11
XCS
6
DATA
9
CCLK
10
XMUTE
8
AGND
16
Z107
VSDVC
0V_SIG
C186
100N SM
+5V
+
C154
10U EL
C155
100N SM
C156
100N SM
0V_SIG
0V_SIG
+5V
SCLK
SDATA
SLOAD
0V_SIG
0V_SIG
R200
2R2 SM
R201
2R2 SM
R202
2R2 SM
0V_SCLK
0V_SLOAD
0V_SDATA
C158
22P SM
C159
22P SM
0V_SIG
0V_SIG
SEL1
1
S2
14
D1
2
V+
13
S1
3
S3
11
V-
4
GND
5
VL
12
S4
6
D3
10
D4
7
SEL3
9
D2
15
SEL4
8
SEL2
16
Z106
DG413DY
+15V-15V
0V_SIG
+5V
TONE*
TONE*
TONE*
TONE*
C152
100N SM
0V_SIG
C153
100N SM
R186
47R SM
R187
47R SM
R185
22R SM
+
C157
100U EL
R110
2K2 SM
R111
2K2 SM
+
C110
100U EL
R112
22K SM
0V_SIG
R113
22K SM
+
C111
10U CERAFINE
+5V
3
2
1
Z111A
TL072 SM
5
6
7
Z112B
TL072 SM
3
2
1
Z112A
TL072 SM
5
6
7
Z111B
TL072 SM
84
Z109C
TL072 SM
84
Z110C
TL072 SM
+
C117
10U CERAFINE
R121
22K SM
R119
22K SM
R120
22K SM
+
C116
10U CERAFINE
0V_SIG
D105
BAV99W DUAL SM
0V_SIG
R114
22K SM
R118
22K SM
1618
17
Z108D
DS1844
1519
14
Z108A
DS1844
R115
2K7 SM
R116
2K7 SM
0V_SIG
R117
5K6 SM
R135
2K2 SM
R136
2K2 SM
+
C131
100U EL
R137
22K SM
0V_SIG
R138
22K SM
+
C132
10U CERAFINE
+5V
3
2
1
Z113A
TL072 SM
5
6
7
Z114B
TL072 SM
3
2
1
Z114A
TL072 SM
5
6
7
Z113B
TL072 SM
+
C138
10U CERAFINE
R146
22K SM
R144
22K SM
R145
22K SM
+
C137
10U CERAFINE
0V_SIG
D111
BAV99W DUAL SM
0V_SIG
R139
22K SM
R143
22K SM
62
7
Z108B
DS1844
53
4
Z108C
DS1844
R140
2K7 SM
R141
2K7 SM
0V_SIG
R142
5K6 SM
84
Z111C
TL072 SM
84
Z112C
TL072 SM
+15V
+15V
-15V
-15V
C169
100N SM
C168
100N SM
C172
100N SM
C173
100N SM
C176
100N SM
C177
100N SM
C180
100N SM
C181
100N SM
0V_SIG 0V_SIG 0V_SIG 0V_SIG
C170
100N SM
C171
100N SM
C174
100N SM
C175
100N SM
C178
100N SM
C179
100N SM
C182
100N SM
C183
100N SM
C184
100N SM
C185
100N SM
0V_SIG 0V_SIG 0V_SIG 0V_SIG 0V_SIG
PS
1
R/W
8
DOUT
11
RST
9
DIN
12
CLK
13
VCC
20
GND
10
Z108E
IC DS1844
+5V
SDATA
SCLK
TONEID
C118
100N SM
+
C120
10U EL
0V_SIG
C119
10N SM
R122
2R2 SM
0V_TONEID
C115
22P SM
C136
22P SM
0V_SDATA
0V_SCLK
R124
2R2 SM
R123
2R2 SM
R151
22K SM
R147
22K SM
R152
22K SM
R148
22K SM
R153
22K SM
R149
22K SM
R154
22K SM
R150
22K SM
R155
22K SM
LISTEN 0
LISTEN 1
LISTEN 2
VCR 0
VCR 1
VCR 2
TAPE 0
TAPE 1
TAPE 2
TONE*
0V_TONEID
TONEID
0V_SDATA
SDATA
0V_SLOAD
SLOAD
0V_SCLK
SCLK
1
2
3
4
SK102
AMPCT4
0V_SIG
1
2
3
4
5
6
7
8
SK103
AMPCT8
+15V
0V_SIG
-15V
AUX R
AUX L
TO PHONO PCB
TO POWER AMP I/P
TO MICRO / DISPLAY PCB
3
2
1
Z115A
OPA2134PA SM
3
2
1
Z116A
OPA2134PA SM
3
2
1
Z117A
OPA2134PA SM
5
6
7
Z117B
OPA2134PA SM
84
Z115C
OPA2134PA SM
84
Z117C
OPA2134PA SM
RLY100A
RLY DPDT 5V SM
RLY100B
RLY DPDT 5V SM
+
-
RLY100C
RLY DPDT 5V SM
D120
BAS16W SM
Q100
BC849B
R203
4K7 SM
MUTE*
0V_D
+5V
MUTE*
0V_D
+
C187
10U EL
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
SK101
FFC30V SM
0V_MODULE
AUX L
AUX R
CD L
CD R
TUNER L
TUNER R
AV L
AV R
DVD L
DVD R
TAPE IN L
TAPE IN R
VCR IN L
VCR IN R
MODULE L
MODULE R
TO PLUG IN MODULE PCB
+5V
R188
10K SM
0V_SIG
0V_HF
D121
BAV99W DUAL SM
D122
BAV99W DUAL SM
+15V -15V
C113
470N PE
C134
470N PE
C150
470N PE
C151
470N PE
+
C188
10U EL
+
C189
10U EL
+15V
-15V
0V_SIG
+
C190
10U EL
+
C191
10U EL
+15V
-15V
0V_SIG
R204
10K SM
C112
470N PE
C192
470N PE
C133
470N PE
C193
470N PE
C101
470P FKP2
C102
470P FKP2
C103
470P FKP2
C122
470P FKP2
C123
470P FKP2
C124
470P FKP2
C140
470P FKP2
C141
470P FKP2
C142
470P FKP2
C161
470P FKP2
C162
470P FKP2
C163
470P FKP2
C165
470P FKP2
C166
470P FKP2
C114
CFKP2 63V 2N2
C135
CFKP2 63V 2N2
CDL1 CDL
CDR
CDR1
TUNL1
TUNR1
TUNL
TUNR
AVL1
AVR1
AVL
AVR
DVDL1
DVDR1
DVDL
DVDR
TAPEIL1
TAPEIR1
TAPEIL
TAPEIR
VCRIL1
VCRIR1
VCRIL
VCRIR
AUXL
AUXR
+15V1
-15V1
AUXL1
AUXR1
LISTEN2
LISTEN1
LISTEN0
LIST2
LIST1
LIST0
VCR2
VCR1
VCR0
VCR21
VCR11
VCR01
TAPE2
TAPE1
TAPE0
TAP2
TAP1
TAP0
TAPEO1
TAPE02
VCRO1
VCR02
Z115_1A
Z116_1A
/TONE
Z107_4
Z107_13
Z107_1
SK102_1
SK102_3
Z116_1B
Z113_3
Z111_3
Z115_1B
Z111_1
Z111_7
Z108_19
Z112_3
Z112_1
Z112_7
TONEID
SDATA
SCLK
Z106_11Z114_7
Z114_1
Z114_3
Z108_3
Z113_7
Z113_1
AUXIL1
AUXIR1
Z106_14
+15V2
-15V2
R182
100R SM
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
SK100
FFC22V1MM
C147
100N PE
C167
100N PE
01_1142 JBR 14/8/01 First production release 1.0
R181
10K SM
01_E014 JBR 28/11/01 Fuses uprated to 2A 1.1
1 2 3 4
A
B
C
D
4321
D
C
B
A
ISSUE
DRAWING NO.
23425
DRAWING TITLE
Drawn by:
DATE
Filename
ECO No. DESCRIPTION OF CHANGE
J:\Change_Control\ECO_AGENDA\01_E014 Fuse changes on A32 preamp\L937_1.1.ddb - Documents\Schematic\L937C3_1.0.SCH
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
Integrated amplifier preamp - power supply
Circuit Diagram
L937C3
JBR
28-Nov-2001
INITIALS
Date Printed
3 3Sheet of
Notes:
1
2
3
4
SK300
MOLEXPWR4
+
C300
1000u 35V
+
C310
1000u 35V
D302
BAS16W SM
D308
BAS16W SM
Vin
I
ADJ
A
Vout
O
Z301
LM317T
D305
BAS16W SM
D304
BAS16W SM
R303
470R SM
+
C305
10U EL
C304
100N SM
R302
1K2 SM
R307
220R SM
+15V
-15V
+5V
0V_PSU
SP300
STAR POINT 4
0V_PSU
0V_SIG
0V_HF 0V_MODULE
+
C306
470U EL 25V
C307
470N PE
C308
100N SM
C309
100N SM
Q301
2SC5248
Q305
2SA1964
+
C302
220U EL
+
C312
220U EL
Q300
J112
Q303
J112
R300
330R SM
R304
330R SM
+
C303
3300u 25V
+
C313
3300u 25V
D310
15V 350MW SM
D311
15V 350MW SM
Q306
BC846B
Q307
BC856B
1
2
3
4
SK301
IDC4S
+15V
-15V
0V_PSU
0V_MODULE
AC1
AC2
UR+
UR-
D311-
D310+
+15V3
+5V
+3.75V
0V_SIG
-15V3
C314
1N0 PP
C315
1N0 PP
D300
S1D
D301
S1D
D306
S1D
D307
S1D
01_1142 JBR 14/8/01 First production release 1.0
01_E014 JBR 28/11/01 Fuses uprated to 2A 1.1
F300
T2A SM
F301
T2A SM
1 2 3 4 5 6 7 8
A
B
C
D
87654321
D
C
B
A
ISSUE
DRAWING NO.
23425
DRAWING TITLE
Drawn by:
DATE
Filename
ECO No. DESCRIPTION OF CHANGE
J:\Completed_Projects\A85 (Mary)\mary display\L865_2\l865_2.0 dbase.ddb - Documents\L865_2.0.PRJ
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
MARY AMP DISPLAY PCB
Circuit Diagram
L865C1
JBR
8-Jan-2002
INITIALS
Date Printed
1 2Sheet of
Notes:
L865C2_2.0
L865C2_2.0.SCH
FIX7
FIXING HOLE
FIX2
FIXING HOLE
FIX10
FIXING HOLE
FIX4
FIXING HOLE
FIX5
FIXING HOLE
FIX6
FIXING HOLE
FIX1
FIXING HOLE
FIX8
FIXING HOLE
FD_1
FIDUCIAL
FD_2
FIDUCIAL
A85 DISPLAY PCB
MICRO
PCB
PCB1
L865PB_2
Update Box
(Small)
UDB
UPDATE_SML
FIX9
FIXING HOLE
FIX3
FIXING HOLE
FIX11
FIXING HOLE
CHASSIS 1
CHASSIS 2
CHASSIS 3
(BY SK3)
(BY SK1)
(BY SK2)
C39
1N0 SM
C45
1N0 SM
C40
1N0 SM
C41
1N0 SM
C42
1N0 SM
C43
1N0 SM
C44
1N0 SM
C46
1N0 SM
C47
1N0 SM
C49
1N0 SM
C48
1N0 SM
0V_D
0V_D 0V_D 0V_D 0V_D 0V_D
0V_D0V_D
0V_D0V_D
0V_D
ISSUE 1.1
00_1103 JBR SW1 TO SW10 CHANGED29 SEP 2000 1.1
EDD IR DUAL FOOTPRINT ADDED19/07/2001 2.0
1 2 3 4 5 6 7 8
A
B
C
D
8
7
6
5
4
3
2
1
D
C
B
A
ISSUE
DRAWING NO.
23425
DRAWING TITLE
Drawn by:
DATE
Filename
ECO No. DESCRIPTION OF CHANGE
J:\Completed_Projects\A85 (Mary)\mary display\L865_2\l865_2.0 dbase.ddb - Documents\L865C2_2.0.SCH
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
MARY AMP DISPLAY PCB
Circuit Diagram
L865C2
JBR
8-Jan-2002
INITIALS
Date Printed
2 2Sheet of
Notes:
Vcc
1
PB0
2
PB1
3
PB2
4
PB3
5
PB4
6
PB5
7
PB6
8
PB7
9
Vpp/RESO
10
Vss
11
TxD0/P9.0
12
TxD1/P9.1
13
RxD0/P9.2
14
RxD1/P9.3
15
IRQ4/SCK0/P9.4
16
IRQ5/SCK1/P9.5
17
D0/P4.0
18
D1/P4.1
19
D2/P4.2
20
D3/P4.3
21
Vss
22
D4/P4.4
23
D5/P4.5
24
D6/P4.6
25
D7/P4.7
26
D8/P3.0
27
D9/P3.1
28
D10/P3.2
29
D11/P3.3
30
D12/P3.4
31
D13/P3.5
32
D14/P3.6
33
D15/P3.7
34
Vcc
35
A0/P1.0
36
A1/P1.1
37
A2/P1.2
38
A3/P1.3
39
A4/P1.4
40
A5/P1.5
41
A6/P1.6
42
A7/P1.7
43
Vss
44
A8/P2.0
45
A9/P2.1
46
A10/P2.2
47
A11/P2.3
48
A12/P2.4
49
A13/P2.5
50
P2.6/A14
51
P2.7/A15
52
P5.0/A16
53
P5.1/A17
54
P5.2/A18
55
P5.3/A19
56
Vss
57
P6.0/WAIT
58
P6.1/BREQ
59
P6.2/BACK
60
CLKOUT
61
STBY
62
RES
63
NM1
64
Vss
65
EXTAL
66
XTAL
67
Vcc
68
P6.3/AS
69
P6.4/RD
70
P6.5/HWR
71
P6.6/LWR
72
MD0
73
MD1
74
MD2
75
AVcc
76
Vref
77
P7.0/AN0
78
P7.1/AN1
79
P7.2/AN2
80
P7.3/AN3
81
P7.4/AN4
82
P7.5/AN5
83
P7.6/AN6/DA0
84
P7.7/AN7/DA1
85
AVss
86
P8.0/IRQ0
87
P8.1/IRQ1
88
P8.2/IRQ2
89
P8.3/IRQ3
90
P8.4/CS0
91
Vss
92
PA0
93
PA1
94
PA2
95
PA3
96
PA4
97
PA5
98
PA6
99
PA7
100
H8/3048F
Z1
H8/3048F
Gnd
1
Res
2
Vcc
3
DS1233
Gnd
4
Z2
DS1233 SM
R1
10K SM
R2
10K SM
R3
10K SM
R4
10K SM
R5
10K SM
R6
10K SM
R7
10K SM
R8
10K SM
R9
10K SM
R10
10K SM
R11
10K SM
R12
10K SM
R13
10K SM
R14
10K SM
R15
10K SM
R16
10K SM
0V_D
SW12 SW11
TACTSW SM
SW13
TACTSW SM
SW14
TACTSW SM
SW15
TACTSW SM
SW16
TACTSW SM
R17
1K5 SM
R18
1K5 SM
R19
1K5 SM
R21
1K5 SM
R22
1K5 SM
R25
1K5 SM
BUT1
BUT2
BUT3
BUT4
BUT5
BUT6
BUT7
BUT8
BUT9
BUT10
BUT11
BUT12
BUT13
BUT14
BUT15
BUT16
0V_D
C1
18P SM
C2
18P SM
Programming adaptor
+5V
0V_D
+5V
+5V
D2
BAS16W SM
+5V
R26
10K SM
+5V
IND1
IND2
IND3
IND4
IND5
IND6
IND7
IND8
IND9
IND10
0V_D
+5V
R27
10K SM
R2810K SM
R34
150R SM
R33
330R SM
0V_D
+5V
0V_D
+5V
To preamp board
SEL1
SEL2
SEL3
SEL4
SEL5
SEL6
SEL7
SEL8
SEL9
LEFTAUDIO
MUTE
TONE
TONEID
SDATA
SLOAD
SCLK
0V_D
PHASEA
PHASEB
+5V
PHASEA
PHASEB
+5V
0V_D
A0
1
A1
2
A2
3
VSS
4
SDA
5
SCL
6
WP
7
VDD
8
Z5
24C02 SM
0V_D
R32
10K SM
+5V
DISPCLK
DISPDAT
DISPDAT
DISPCLK
0V_D
F1 to F2 = 4Vac 150mA
VDD2 = 40Vdc 20mA
+5V
DISPLAT
DISPBLK
3
2
1
Z6A
LM393A SM
5
6
7
Z6B
LM393A SM
84
Z6C
LM393A SM
C3
100N SM
C4
100N SM
0V_D
0V_D
C5
100N SM
0V_D
DISPBLK
DISPLAT
BUT9
BUT8
BUT7
BUT6
BUT2
IND3
BUT3
BUT1
IND1
BUT5
IND2
BUT4
IND12
IND11
BUT16
IND6
BUT15
IND5
BUT10
IND7
BUT12
IND9
BUT14
IND4
BUT11
IND8
BUT13
C6
100N SM
C7
100N SM
C8
100N SM
C9
100N SM
C10
100N SM
0V_D
+5V
R35
10K SM
R36
10K SM
R37
10K SM
R38
1K2 SM
R39
2K2 SM
R40
4K7 SM
+5V
+5V
+5V
0V_D
0V_D
+
C11
10U EL SM
R41
100K SM
R42
100K SM
0V_D
+5V
R43
100K SM
R44
100K SM
3
2
1
Z7A
LM393A SM
5
6
7
Z7B
LM393A SM
84
Z7C
LM393A SM
0V52V7
2V7
0V5
3
2
1
Z8A
LM393A SM
5
6
7
Z8B
LM393A SM
84
Z8C
LM393A SM
R45
10K SM
R46
1K2 SM
R47
4K7 SM
0V5
2V7
+5V
+5V
0V_D
0V_D
R480R0 SM
SCLK
SLOAD
SDATA
TONEID
SEL1
SEL2
SEL3
SEL4
SEL5
SEL6
SEL7
SEL8
SEL9
MUTE
TONE
+
C14
10U EL SM
C15
100N SM
0V_D
C16
100N SM
1
2
3
4
5
SK2
AMPCT5
SAMTX2
SAMRX2
SAMRX2
SAMTX2
SAMBUSYSAMDATA
+5V
0V_D
IND10
C17
100N SM
0V_D
D3
BAS16W SM
R55
10K SM
+5V
VFD_VDD2
3
2
1
Z11A
AD8532 SM
5
6
7
Z11B
AD8532 SM
84
Z11C
AD8532 SM
C25
100N SM
DCPROT
VIPROT
F1CLOCK
F2CLOCK
STANDBY
SP1ON
SP2ON
THERMPROT
+5V
0V_D
F1CLOCK
F2CLOCK
Vin
I
GND
G
Vout
O
Z12
7815
C27
100N SM
+SUP VFD_VDD2
+
C28
10U EL SM
0V_D
R56
10K SM
R57
10K SM
Q_19
Q_20
D5
BAS16W SM
R58
0R0 SM
R59
0R0 SM
R64
100R SM
R65
100R SM
R66
100R SM
R67
100R SM
C31
10P SM
C32
10P SM
0V_D
R49
10K SM
R50
10K SM
+5V
SAMHOLD
SAMHOLD
R51
100R SM
Q_54
R20
1K5 SM
R23
1K5 SM
R24
1K5 SM
R31
1K5 SM
R
G
LED11
LED RED/GRN 3MM
Q1
BC847B
Q2
BC847B
R29
10K SM R30
10K SM
0V_D
IND11
IND12
ISSUE 1.1
R68
10K SM
BUT17
BUT17
0V_D
+5V
+SUP
STANDBY
SP1ON
SP2ON
THERMPROT
VIPROT
DCPROT
ACPRESENT
ACPRESENT
0V_D
R69
2R2 SM
R70
2R2 SM
R71
2R2 SM
R72
2R2 SM
0V_D
IRIN
Q3
BC847B
Q4
BC847B
R73
10K SM
R74
10K SM
R75
10K SM
R76
10K SM
0V_D
+5V
IRIN
IRIN
IROUT
C12
100N SM
(FIT CLOSE TO SK1)
+5V
0V_D
+
C33
220U EL
+
C34
220U EL
SAMDATA
SAMBUSY
IRIN
C
3
B
2
A
1
4
5
SW18
ALPS_ENCODER
SW17
A1506
D4
22V 350MW SM
LED7
LED GREEN3.1MM
LED8
LED GREEN3.1MM
LED6
LED GREEN3.1MM
LED3
LED GREEN3.1MM
LED10
LED GREEN3.1MM
LED9
LED GREEN3.1MM
LED1
LED GREEN3.1MM
LED4
LED GREEN3.1MM
LED2
LED GREEN3.1MM
LED5
LED GREEN3.1MM
RECEIVE
TRANSMIT
TRANSMIT
TRANSMIT
RECEIVE
RECEIVE
RESPIN
RESPIN
PB0
PB0
VPROG
VPROG
1
2
3
4
5
6
7
8
9
10
11
12
13
14
SK1
FFC 14W 2.54MM HOR
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
SK3
FFC 22W 1MM HOR
To power amp / PSU
0V_D
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
CHASSIS 1
C60A 100PX4 SM
C60B 100PX4 SM
C60C 100PX4 SM
C60D 100PX4 SM
C61A 100PX4 SM
C61B 100PX4 SM
C61C 100PX4 SM
C61D 100PX4 SM
C62A 100PX4 SM
C62B 100PX4 SM
C62C 100PX4 SM
C62D 100PX4 SM
C63A 100PX4 SM
C63B 100PX4 SM
CHASSIS 2
+
C29
100U EL SM
R52
100R SM
R53
100R SM
LEFTAUDIO
+
C26
10U EL SM
C55C 100PX4 SM
C55D 100PX4 SM
C63C 100PX4 SM
C63D 100PX4 SM
X1
16MHZ SM
F1
1
F1
2
F1
3
SIN
4
VDD1
5
SOUT
6
LAT
7
BLK
8
CLK
9
VSS
10
VSS
11
VDD2
12
F2
15
F2
16
F2
17
Graphics Display
DISP1
B1013
12
34
56
78
910
1112
1314
SK4
HEADER 7X2HORIZ
STICKY PAD
DOUBLE SIDED
10 X 15MM
SP1
STICKY PAD DS 10X15MM
STICKY PAD
DOUBLE SIDED
10 X 15MM
SP2
STICKY PAD DS 10X15MM
Q_122
Q_123
Q_124
Q_125
Q_126
Q_127
Q_128
Q_129
Q_120
Q_119
Q_118
Q_117
Q_121
SW6
A1509
SW8
A1509
SW7
A1509
SW1
A1509
SW4
A1509
SW2
A1509
SW5
A1509
SW3
A1509
SW9
A1509
SW10
A1509
00_1103 JBR 29 SEP 2000 SW1 TO SW10 CHANGED
+5V
3
O/P
2
GND
1
Case
Case
O/P
GND +5V
RX1
SBX1610-52/PIC-26043TM2
DISPLAY CRADLE
E916PM
DC1
DISPLAY CRADLE E916PM
DISPLAY CRADLE
E916PM
DC2
DISPLAY CRADLE E916PM
EDD IR DUAL FOOTPRINT ADDED19/07/2001 2.0
1 2 3 4 5 6 7 8
A
B
C
D
87654321
D
C
B
A
ISSUE
DRAWING NO.
23425
DRAWING TITLE
Drawn by:
DATE
Filename
ECO No. DESCRIPTION OF CHANGE
G:\DATA\ECO\ECO AGENDA\01_1070 l870 A85 PHONO ISSUE2\L870_2.0.ddb - L870c1_2.0.PRJ
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
A85 PHONO STAGE - TOP LEVEL
Circuit Diagram
L870C1
JBR23-Apr-2001
INITIALS
Date Printed
1 3Sheet of
Notes:
1
EMC
SK1
PHONO2HG
0V_SIG
0V_SIG
LEFT IN LEFT OUT
LEFT CHANNEL
L870C2_2.0.SCH
RIGHT IN RIGHT OUT
RIGHT CHANNEL
L870C3_2.0.SCH
1
2
3
4
5
6
7
8
SK2
AMPCT8
+15V
-15V
0V_HF0V_SIG
Q_1
Q_2
Q_3
Q_4
Q_5
Q_6
Q_7 Q_8
PCB
PCB1
L870PB_2
Update Box
EL1
UPDATE_BOX
C1
100N CD
00_1051 JAG 22/3/01 PRODUCTION ISSUE 1
01_1070 JAG 17/4/01 updated pcb and scm 2
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