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ALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUALALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUAL
Arcam Alpha One/ 7R/ 8R/ 8P Amplifier Service Manual
Issue 1 Serial Number 001 - (Paul Newton/ Haider Bahrani Sept ‘98)
Circuit Description
The Alpha One / 7R/8R and 8P share a common
pcb. The circuits are very similar and the main
differences are the remote volume facility and extra
power output on the 7R and 8R and a switch to
bypass the phono stage to enable its use as an extra
line level input and the AV processor switch on the
Alpha 8R integrated amplifier. The 8P power
amplifier utilises the same power amplifier circuit as
the Alpha 8R integrated amplifier.
Power Supplies
The ac output of the toroidal mains transformer is
rectified and smoothed by D201-204 and C204, 205.
This is then regulated to +/-15V by Z201, 202 to
power the phono and tone control stages and the
d.c. servo.
The Alpha 7R and 8R transformers have an extra
tapping which is used for the remote volume circuit.
The ac in is regulated to 5V by zener D902 and
associated components and this is then used to
power the microcontroller Z901 and remote receiver.
Phono Stage (Not applicable to Alpha One)
The phono stage consists of a dual opamp Z305, one
opamp per channel. The RIAA equalization is
achieved by the feedback components R703, 704,
702 and C704, 705, 702 on left channel (R603 etc.
as above for Right channel). R703 determines the
gain and C703 the low frequency roll off.
On the Alpha 8R this stage can be bypassed by use
of switch SW302 to enable use as an extra line input.
Tone Controls
source for the differential input stage.
The output devices are 'n' channel mosfets SMF045.
Zener diodes D103,104 limit the voltage swing within
safe limits for the output devices & fusible resistors
R105, 106 provide overcurrent damage to the
devices.
A proportion of the output current appears across the
protection network R41,42. If this becomes too high
Q17 is turned on and mutes the output. High D.C.
levels at the output will also mute the output. There
are no output fuses on the Alpha One, 7R and
8R/8P amplifiers. The muting is done by the mute ic
Z303 and its associated compontents. The mute
operates on switch on/off and if an over current or
over voltage condition occurs. The power led glows
amber when the mute circuit is operative and glows
green in normal use.
Removing the Alpha One/ 7R/ 8R/ 8P Transformer
The toroidal transformer is extremely well secured to
the main pcb with a double sided adhesive gasket.
To remove the transformer you must break this
adhesive bond by cutting through the gasket. This
will be easier if the transformer is warm.
Use a cheese wire under the transformer, pulling
backwards and forwards under tension to gradually
cut through. Once most of the adhesive is cut, you
should be able to pull the transformer away from the
pcb.
A less satisfactory substitute for cheese wire is to use
some 22 gauge tinned copper wire, stretched first to
remove kinks, and two temporary handles.
Alpha One/7R/ 8R/ 8P Quiescent Current (IQ)
Settings
The tone control stage is based around Z304 a dual
op amp.
The range of the controls is set by R507, 508 for the
bass pot RV302 and R509, 510 for the treble pot
RV303.
The tone controls and balance pot can be bypassed
by use of the direct switch, SW304.
Power Amplifier
The input to the power amplifier from previous stages
is fed to the differential input of Q112 and Q113.
Q110 and Q111 form a constant current
When replacing the output transistors of the above
amplifiers it is important to reset the quiescent
current (IQ) to the correct value to prevent the
amplifier blowing again.
The IQ should be checked and set by following the
procedure below:
From cold and with no load or signal connected
Turn both IQ presets (RV1 and RV101) down to
minimum (fully anticlockwise) and set the voltage
drop across resistor R1 (R101 for right hand channel)
to between 3.0 and 3.5mV for the Alpha One and 7R
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ALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUALALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUAL
amps or between 2.3 and 2.8mV for the Alpha 8R/8P
amps.
Leave the unit for 1 minute and reset to these values
if required.
Leave the unit for a further 5 minutes and reset if
required.
The IQ is now set and the unit can be connected to
speakers and fully checked out.
TEST POINT VOLTAGES
Test Point DC Voltage Alpha One DC Voltage Alpha 7R DC Voltage Alpha 8R/8P
1 32.8V 35V 37V
Disassembly For Servicing
1. Remove the top cover and front panel.
2. Remove 2 screws securing the sub front to the
chassis sides and 3 screws holding the
subfront to the chassis base.
3. Remove 1 screw holding the pcb to the
chassis. This can be found near to the mains
inlet socket.
4. Remove 5 screws from the rear panel, one at
each end and 3 along the bottom edge.
5. Remove the transformer bolt.
6. Release the PCB pillar located near to the
serial number on the pcb.
The pcb, with the rear panel, transformer and
subfront attached, can now be pulled backwards out
of the unit.
2 27.8V 29V 31V
3 15V 15V 15V
4 -32.8V -35V -37V
5 27.8V -29V -31V
6 -15V -15V -15V
7 N/A 0.09V 0.09V
8 N/A 0.10V 0.10V
9 0.3V 0.27V 0.27V
10 3.4V 3.2V 2.9V
11 32.8V 35V 37V
12 -3V -2.7V -2.5V
13 32.8V -35V -37V
Between 14 & 15 3.0 -3.5mV 3.0-3.5mV 2.3-2.8mV
16 (protection off) 0.0V 0.0V
16 (protection on) 0.6V 0.6V
17 0.0V 0.0V
18 0.0V 0.0V
19 0.0V 0.0V
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ALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUALALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUAL
Test Point DC Voltage Alpha One DC Voltage Alpha 7R DC Voltage Alpha 8R/8P
20 0.0V 0.0V 0.0V
21 (protection off) 1.6V 1.6V 1.6V
21 (protection on) 5.0V 5.0V 5.0V
22 0.58V 0.17V 0.17V
23 3.4V 3.1V 3.1V
24 -3V -2.7V -2.7V
25 -26V -29V -29V
Between 26 & 27 3.4mV 3.4mV 2.5mV
28 (muted) 35V 35V 35V
28 (protection off) 1V 1V 1V
29 N/A 5V 5V
30 N/A 10.5 10.5V
31
N/A 0V 0V
(volume going up)
31
N/A 5V 5V
(volume going down)
32
N/A 0V 0V
(volume going up)
32
N/A 5V 5V
(volume going down)
PARTS LISTS
The parts for all the units are as the Alpha 7 except where shown.
REF Description Part No Product
C1 ELST 100U 100V 2N710B 7R
C2 PEST 47N 63V 10% 2K347 7R
C3 PCRB 100N 100V 5% RA
C4 PEST 47N 63V 10% 2K347 7R
C5 PSTY 33P 160V ENCAP
C7 PPRO 4N7 63V 5% RA 2D247N 7R
C8 PPRO 100P 63V 5% RA 2D110N 7R
C9 ELST 100U 25V 2N710 A1
C10 ELST 22U 20V OSCON 2P622 7R
C10 ELST 22U 63V ELECT 2N622 A1
C11 ELST 100U 100V 2N710B 7R
C12 ELST 100U 100V 2N710B 7R
C13 PEST 15N 63V 10% 2K315 7R
C14 PEST 15N 63V 10% 2K315 7R
5mm
1PF%
2H410 7R
2F033 7R
C15 SUPPR CAP 4N7 250V 2K247 7R
C16 ELST 100U 25V 2N710 7R
C17 CERD 470P 63V 20% RA 2A147 7R
C18 CERD 1N0 63V 20% RA 2A210 7R
C19 ELST 100U 25V 2N710 7R
C20 CERD 470P 63V 20% RA 2A147 7R
C21 CERD 10N 63V 20% RA 2A310 7R
C22 CERD 10N 63V 20% RA 2A310 7R
C23 SUPPR CAP 4N7 250V 2K247 7R
C24 PPRO 4N7 63V 5% RA 2D247N 7R
C25 PCRB 100N 100V 5% RA
C26 PCRB 100N 100V 5% RA
C27 ELST 220U 16V 2N722 7R
C28 PCRB 100N 100V 5% RA
5mm
5mm
5mm
2H410 7R
2H410 7R
2H410 7R
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ALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUALALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUAL
C29 ELST 1U0 50V 20% RA 2N510 8R
C30 ELST 22U 63V ELECT 2N622 7R
C30 ELLL 47U 10V ELECT 2R647 A1
C30 ELEC 10U 25V CERAFINE 2P610CC 8R
C101 ELST 100U 100V 2N710B 7R
C102 PEST 47N 63V 10% 2K347 7R
C103 PCRB 100N 100V 5% RA
C104 PEST 47N 63V 10% 2K347 7R
C105 PSTY 33P 160V ENCAP
C107 PPRO 4N7 63V 5% RA 2D247N 7R
C108 PPRO 100P 63V 5% RA 2D110N 7R
C109 ELST 100U 25V 2N710 A1
C110 ELST 22U 20V OSCON 2P622 7R
C110 ELST 22U 63V ELECT 2N622 A1
C111 ELST 100U 100V 2N710B 7R
C112 ELST 100U 100V 2N710B 7R
C113 PEST 15N 63V 10% 2K315 7R
C114 PEST 15N 63V 10% 2K315 7R
C116 ELST 100U 25V 2N710 7R
C117 CERD 470P 63V 20% RA 2A147 7R
C118 CERD 1N0 63V 20% RA 2A210 7R
C119 ELST 1U0 50V 20% RA 2N510 7R
C120 CERD 470P 63V 20% RA 2A147 7R
C121 ELST 1U0 50V 20% RA 2N510 7R
C122 ELST 100U 25V 2N710 7R
C123 ELST 100U 25V 2N710 7R
C124 PPRO 4N7 63V 5% RA 2D247N 7R
C125 PCRB 100N 100V 5% RA
C126 PCRB 100N 100V 5% RA
C127 ELST 220U 16V 2N722 7R
C128 PCRB 100N 100V 5% RA
C130 ELST 22U 63V ELECT 2N622 7R
C130 ELLL 47U 10V ELECT 2R647 A1
C130 ELEC 10U 25V CERAFINE 2P610CC 8R
C200 CERD 1N0 63V 20% RA 2A210 7R
C201 SUPPR CAP 4N7 250V 2K247 7R
C204 ELST 10m 50V RA 32mm 2N910 7R
C204 ELST 6M8 35V RA 2N868 A1
C205 ELST 10m 50V RA 32mm 2N910 7R
5mm
1PF%
5mm
5mm
5mm
2H410 7R
2F033 7R
2H410 7R
2H410 7R
2H410 7R
C205 ELST 6M8 35V RA 2N868 A1
C206 PCRB 100N 100V 5% RA
C207 PCRB 100N 100V 5% RA
C208 PPRO 4N7 63V 5% RA 2D247N 7R
C209 PPRO 4N7 63V 5% RA 2D247N 7R
C210 ELST 10U 50V 2N610 7R
C211 ELST 10U 50V 2N610 7R
C212 CERD 10N 63V 20% RA 2A310 7R
C213 CERD 10N 63V 20% RA 2A310 7R
C214 CERD 10N 63V 20% RA 2A310 7R
C215 CERD 10N 63V 20% RA 2A310 7R
C216 CERD 10N 63V 20% RA 2A310 7R
C217 CERD 10N 63V 20% RA 2A310 7R
C301 CERD 10N 63V 20% RA 2A310 7R
C302 CERD 10N 63V 20% RA 2A310 7R
C502 PCRB 100N 100V 5% RA
C303 CERD 1N0 63V 20% RA 2A210 7R
C304 CERD 1N0 63V 20% RA 2A210 7R
C305 CERD 47P 63V -20% +80%RA2A047 7R
C306 CERD 47P 63V -20% +80%RA2A047 7R
C401 ELST 10U 50V 2N610 7R
C402 PEST 220N 63V 10% 2K422 7R
C402 PCRB 100N 100V 5% RA
C403 PCRB 100N 100V 5% RA
C403 PEST 220N 63V 10% 2K422 7R
C404 PPRO 4N7 63V 5% RA 2D247N 7R
C404 2N2 PP 2D222 A1
C405 ELST 10U 50V 2N610 7R
C406 CERD 100P 63V 20% RA 2A110 7R
C407 CERD 100P 63V 20% RA 2A110 7R
C408 CERD 10P 63V 20% RA 2A010 7R
C501 ELST 10U 50V 2N610 7R
C502 PEST 220N 63V 10% 2K422 7R
C503 PEST 220N 63V 10% 2K422 7R
C503 PCRB 100N 100V 5% RA
C504 PPRO 4N7 63V 5% RA 2D247N 7R
C504 2N2 PP 2D222 A1
C505 ELST 10U 50V 2N610 7R
5mm
5mm
5mm
5mm
5mm
5mm
2H410 7R
2H410 7R
2H410 A1
2H410 A1
2H410 A1
2H410 A1
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ALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUALALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUAL
C506 CERD 100P 63V 20% RA 2A110 7R
C507 CERD 100P 63V 20% RA 2A110 7R
C508 CERD 10P 63V 20% RA 2A010 7R
C601 PPRO 100P 63V 5% RA 2D110N 7R
C602 CERD 47P 63V 20% RA 2A047 7R
C603 ELST 22U 63V 2N622 7R
C604 PPRO 4N7 63V 5% RA 2D247N 7R
C605 PPRO 1N3 63V 5% RA 2D213N 7R
C606 ELST 10U 50V 2N610 7R
C701 PPRO 100P 63V 5% RA 2D110N 7R
C702 CERD 47P 63V 20% RA 2A047 7R
C703 ELST 22U 63V 2N622 7R
C704 PPRO 4N7 63V 5% RA 2D247N 7R
C705 PPRO 1N3 63V 5% RA 2D213N 7R
C706 ELST 10U 50V 2N610 7R
C801 PPRO 100P 63V 5% RA 2D110N 7R
C802 PPRO 100P 63V 5% RA 2D110N 7R
C803 ELST 10U 50V 2N610 7R
C804 ELST 10U 50V 2N610 7R
C805 CERD 10N 63V 20% RA 2A310 7R
C806 CERD 10N 63V 20% RA 2A310 7R
C901 CERD 10N 63V 20% RA 2A310 7R
C902 ELST 220U 16V 2N722 7R
C903 CERD 10N 63V 20% RA 2A310 7R
C904 CERD 10N 63V 20% RA 2A310 7R
C905 CERD 10N 63V 20% RA 2A310 7R
C906 CERD 10N 63V 20% RA 2A310 7R
C907 ELST 1M0 25V 2N810 7R
C1000 CERD 10N 63V 20% RA 2A310 7R
CL1 ALPHA AMP 7/8 HEATSINK
CL2 ALPHA AMP 7/8 HEATSINK
D1 RECTIFIER 1N4003F 1A
D2 ZENER 10V 400MW 3C11004 7R
D3 ZENER 10V 400MW 3C11004 7R
D4 ZENER 10V 400MW 3C11004 7R
D5 SSDIODE 1N4148 75V 3A4148 7R
D6 RECTIFIER 1N4003F 1A
D7 SSDIODE 1N4148 75V 3A4148 7R
D8 RECTIFIER 1N4003F 1A
CLAMP
CLAMP
200V
200V
200V
E82201 7R
E82201 7R
3B4003 7R
3B4003 8R
3B4003 7R
D9 RECTIFIER 1N4003F 1A
D10 ZENER 5V6 400MW 3C05604 8R
D101 RECTIFIER 1N4003F 1A
D102 ZENER 10V 400MW 3C11004 7R
D103 ZENER 10V 400MW 3C11004 7R
D104 ZENER 10V 400MW 3C11004 7R
D105 RECTIFIER 1N4003F 1A
D106 RECTIFIER 1N4003F 1A
D107 RECTIFIER 1N4003F 1A
D108 ZENER 5V6 400MW 3C05604 7R
D201 ULTRAFAST RECTIFIER
D202 ULTRAFAST RECTIFIER
D203 ULTRAFAST RECTIFIER
D204 ULTRAFAST RECTIFIER
D801 ZENER 5V6 400MW 3C05604 7R
D802 ZENER 4V7 400MW 3C04704 7R
D803 SSDIODE 1N4148 75V 3A4148 7R
D901 RECTIFIER 1N4003F 1A
D902 ZENER 5V6 400MW 3C05604 7R
D903 RECTIFIER 1N4003F 1A
D904 ZENER 5V6 400MW 3C05604 7R
D905 SSDIODE 1N4148 75V 3A4148 7R
EL1 FUSE CLIP WCK-180-01A F062 7R
FS201 INS COVER PCB
FS201 FUSE 20mm 1.25A AS C12126 7R
FS201 FUSEHOLDER 20mm PCB 8S004 7R
FS202 FUSEHOLDER 20mm PCB 8S004 7R
FS202 INS COVER PCB
HS1 ALPHA AMP 7/8 HEATSINK E81801 7R
HS1 SIL PAD - 25 X 12.5mm E817MC 7R
HS1 ALPHA AMP 7/8 HS CLIP E810MC 7R
HS2 SIL PAD - 25 X 12.5mm E817MC 7R
HS2 ALPHA AMP 7/8 HEATSINK E81801 7R
HS2 ALPHA AMP 7/8 HS CLIP E810MC 7R
HS3 SIL PAD - 25 X 12.5mm E817MC 7R
200V
200V
200V
200V
200V
DIODE UF5403 3A
DIODE UF5403 3A
DIODE UF5403 3A
DIODE UF5403 3A
200V
200V
FUSEHOLDER
FUSEHOLDER
3B4003 7R
3B4003 7R
3B4003 7R
3B4003 7R
3B4003 7R
3B5403F 7R
3B5403F 7R
3B5403F 7R
3B5403F 7R
3B4003 7R
3B4003 7R
F022 7R
F022 7R
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ALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUALALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUAL
HS3 ALPHA AMP 7/8 HEATSINK E81801 7R
HS3 ALPHA AMP 7/8 HS CLIP E810MC 7R
HS4 SIL PAD - 25 X 12.5mm E817MC 7R
HS4 ALPHA AMP 7/8 HS CLIP E810MC 7R
HS4 ALPHA AMP 7/8 HEATSINK E81801 7R
L1 INDUCT 2U2 12x20mm 7D002B 7R
L101 INDUCT 2U2 12x20mm 7D002B 7R
LED201 LED RED/GREEN 5MM 3D002 7R
LK19 RES MF W4 3K3 1% 1H233 7R
LK19A A8R AMP MBD TO AV
LK20 RES MF W4 3K3 1% 1H233 7R
LK311 7-WAY RIBBON 250mm L825CA 7R
LK805 JUMPER 3 WAY x 125mm L815CA 7R
LK901 JUMPER 8-WAY LEAD L809CA 7R
LK902 JUMPER 3 WAY x 125mm L815CA 7R
MS MAINS SWITCH SPACER E66901 7R
PCB PRINTED CIRCUIT BOARD L846PB 7R
Q1 TRANS PWR MOSFET
Q2 TRANS PWR MOSFET
Q3 TRANS LF SS P BC556B 4A556 7R
Q4 TRANS LF SS N BC546B 4A546 7R
Q5 TRANS LF SS P BC556B 4A556 7R
Q6 TRANS LF SS P BC556B 4A556 7R
Q7 TRANS LF SS P BC556B 4A556 7R
Q8 TRANS LF SS N BC546B 4A546 7R
Q9 TRANS LF SS N BC546B 4A546 7R
Q10 TRANS LF SS N BC547B 4A547 7R
Q11 TRANS LF SS N BC547B 4A547 7R
Q12 TRANS LF SS N BC547B 4A547 7R
Q13 TRANS LF SS N BC547B 4A547 7R
Q14 TRANS LF SS P BC557B 4A557 7R
Q15 TRANS LF SS N BC546B 4A546 7R
Q16 TRANS LF SS P BC557B 4A557 7R
Q17 TRANS LF SS N BC546B 4A546 7R
Q18 TRANS LF SS N BC546B 4A546 7R
Q19 TRANS LF SS P BC556B 4A556 7R
Q101 TRANS PWR MOSFET
Q102 TRANS PWR MOSFET
Q103 TRANS LF SS P BC556B 4A556 7R
SWITCH CABLE
IRF540/SMF045
IRF540/SMF045
IRF540/SMF045
IRF540/SMF045
L835CA 8R
4K045 7R
4K045 7R
4K045 7R
4K045 7R
Q104 TRANS LF SS N BC546B 4A546 7R
Q105 TRANS LF SS P BC556B 4A556 7R
Q106 TRANS LF SS P BC556B 4A556 7R
Q107 TRANS LF SS P BC556B 4A556 7R
Q108 TRANS LF SS N BC546B 4A546 7R
Q110 TRANS LF SS N BC547B 4A547 7R
Q111 TRANS LF SS N BC547B 4A547 7R
Q112 TRANS LF SS N BC547B 4A547 7R
Q113 TRANS LF SS N BC547B 4A547 7R
Q114 TRANS LF SS P BC557B 4A557 7R
Q115 TRANS LF SS N BC546B 4A546 7R
Q116 TRANS LF SS P BC557B 4A557 7R
Q117 TRANS LF SS N BC546B 4A546 7R
Q118 TRANS LF SS N BC546B 4A546 7R
Q119 TRANS LF SS N BC546B 4A546 7R
Q120 TRANS LF SS N 2SC2547 4A2546 7R
PL1 16 WAY DIL PIN HEADER 8K6316 8P
R1A RES MO 3W 5% 0R22
R1 RES MO 3W 5% 0R22
R2 RES CF W2 4R7 5% 1D847 7R
R3 RES CF W4 5% 2R2 1B822 7R
R4 RES MF FU W3 100R 5%
R5 RES MF FU W3 100R 5%
R6 RES MF FU W3 100R 5%
R7 RES MF FU W3 470R 5%
R8 RES MF FU W3 470R 5%
R9 RES MF FU W3 470R 5%
R10 RES MF FU W3 470R 5%
R11 RES MF FU W3 470R 5%
R12 RES MF FU W3 470R 5%
R13 RES MF W4 1% 1K0 1H210 7R
R14 RES MF W4 1% 1K0 1H210 7R
R15 RES CF W4 5% 1K0 1B210 7R
R16 RES MF W4 1% 2K7 1H227 7R
R17 RES MF W4 1% 5K6 1H256 7R
R18 RES MF W4 1% 2K7 1H227 7R
KOASPR3
KOASPR3
NFR25
NFR25
NFR25
NFR25
NFR25
NFR25
NFR25
NFR25
NFR25
1Q922 7R
1Q922 7R
1G110 7R
1G110 7R
1G110 7R
1G147 7R
1G147 7R
1G147 7R
1G147 7R
1G147 7R
1G147 7R
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ALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUALALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUAL
R19 RES CF W4 5% 5K6 1B256 7R
R20 RES MF W4 1% 15K 1H315 7R
R21 RES MF W4 1% 100R 1H110 7R
R22 RES MF W4 1% 120R 1H112 7R
R23 RES MF W4 1% 2K7 1H227 7R
R24 RES MF W4 1% 2K7 1H227 7R
R25 RES MF W4 1% 330R 1H133 7R
R26 RES MF FU W3 470R 5%
R27 RES MF FU W3 470R 5%
R28 RES MF W4 18K 1% 1H318 7R
R29 RES MF W4 1% 1K2 1H212 7R
R30 RES MF W4 1% 33K 1H333 7R
R31 RES CF W4 5% 1K0 1B210 A1
R32 RES MF W4 1% 33K 1H333 A1
R33 RES MF W4 1% 680K 1H468 A1
R34 RES MF W4 1% 1K0 1H210 7R
R34 RES MF W4 1K6 1% 1H216 A1
R35 RES MF W4 1% 33K 1H333 7R
R36 RES MF FU W3 100R 5%
R39 RES MF W4 18K 1% 1H318 7R
R40 RES MF W4 1% 33K 1H333 A1
R41 RES MF FU W3 470R 5%
R42 RES MF W4 1% 620R 1H162 7R
R43 RES MF W4 1% 22K 1H322 8R
R44 RES MF W4 1% 68K 1H368 7R
R45 RES MF W4 18K 1% 1H318 7R
R46 RES MF W4 1% 150R 1H115 7R
R47 RES MF W4 1% 4K7 1H247 7R
R48 RES MF W4 1% 47K 1H347 7R
R49 RES CF 1W 330R 5% 1E133 7R
R50 RES CF W2 100R 5% 1D110 7R
R51 RES MF W4 1% 15K 1H315 7R
R52 RES MF W4 1% 3K9 1H239 7R
R53 RES MF W4 18K 1% 1H318 7R
R54 RES MF W4 1% 68K 1H368 7R
R55 RES MF W4 1% 22K 1H322 7R
R56 RES MF W4 1% 22K 1H322 7R
R57 RES CF 1W 2K7 5% 1E227 8R
R58 RES MF W4 1% 1K8 1H218 7R
NFR25
NFR25
NFR25
NFR25
1G147 7R
1G147 7R
1G110 7R
1G147 7R
R61 RES MF W4 18K 1% 1H318 7R
R62 RES MF W4 18K 1% 1H318 7R
R63 RES MF W4 1% 56K 1H356 8R
R64 RES MF W4 1% 56K 1H356 8R
R70 RES MF W4 1% 680R 1H168 7R
R101A RES MO 3W 5% 0R22
R101 RES MO 3W 5% 0R22
R102 RES CF W2 4R7 5% 1D847 7R
R103 RES CF W4 5% 2R2 1B822 7R
R104 RES MF FU W3 100R 5%
R105 RES MF FU W3 100R 5%
R106 RES MF FU W3 100R 5%
R107 RES MF FU W3 470R 5%
R108 RES MF FU W3 470R 5%
R109 RES MF FU W3 470R 5%
R110 RES MF FU W3 470R 5%
R111 RES MF FU W3 470R 5%
R112 RES MF FU W3 470R 5%
R113 RES MF W4 1% 1K0 1H210 7R
R114 RES MF W4 1% 1K0 1H210 7R
R115 RES CF W4 5% 1K0 1B210 7R
R116 RES MF W4 1% 2K7 1H227 7R
R117 RES MF W4 1% 5K6 1H256 7R
R118 RES MF W4 1% 2K7 1H227 7R
R119 RES CF W4 5% 5K6 1B256 7R
R120 RES MF W4 1% 15K 1H315 7R
R121 RES MF W4 1% 100R 1H110 7R
R122 RES MF W4 1% 120R 1H112 7R
R123 RES MF W4 1% 2K7 1H227 7R
R124 RES MF W4 1% 2K7 1H227 7R
R125 RES MF W4 1% 330R 1H133 7R
R126 RES MF FU W3 470R 5%
R127 RES MF FU W3 470R 5%
R128 RES MF W4 18K 1% 1H318 7R
R129 RES MF W4 1% 1K2 1H212 7R
KOASPR3
KOASPR3
NFR25
NFR25
NFR25
NFR25
NFR25
NFR25
NFR25
NFR25
NFR25
NFR25
NFR25
1Q922 7R
1Q922 7R
1G110 7R
1G110 7R
1G110 7R
1G147 7R
1G147 7R
1G147 7R
1G147 7R
1G147 7R
1G147 7R
1G147 7R
1G147 7R
7
Page 8
ALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUALALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUAL
R130 RES MF W4 1% 33K 1H333 7R
R131 RES CF W4 5% 1K0 1B210 A1
R132 RES MF W4 1% 33K 1H333 A1
R133 RES MF W4 1% 680K 1H468 A1
R134 RES MF W4 1% 1K0 1H210 7R
R134 RES MF W4 1K6 1% 1H216 A1
R135 RES MF W4 1% 33K 1H333 7R
R136 RES MF FU W3 100R 5%
R139 RES MF W4 18K 1% 1H318 7R
R140 RES MF W4 1% 33K 1H333 A1
R141 RES MF FU W3 470R 5%
R142 RES MF W4 1% 620R 1H162 7R
R145 RES MF W4 18K 1% 1H318 7R
R146 RES MF W4 1% 150R 1H115 7R
R147 RES MF W4 1% 4K7 1H247 7R
R149 RES CF 1W 330R 5% 1E133 7R
R150 RES CF W2 100R 5% 1D110 7R
R151 RES MF W4 1% 15K 1H315 7R
R152 RES MF W4 1% 3K9 1H239 7R
R153 RES MF W4 1% 47K 1H347 7R
R154 RES MF W4 1% 47K 1H347 7R
R155 RES MF W4 1% 47K 1H347 7R
R156 RES MF FU W3 470R 5%
R157 RES MF W4 1% 100K 1H410 7R
R158 RES MF W4 1% 47K 1H347 7R
R159 RES MF W4 1% 100K 1H410 7R
R160 RES MF W4 10K 1% 1H310 7R
R161 RES CF 1W 1K0 5% 1E210 7R
R161 RES CF 1W 330R 5% 1E133 A1
R162 RES MF W4 1% 47K 1H347 7R
R163 RES MF W4 1% 33K 1H333 7R
R164 RES MF W4 18K 1% 1H318 7R
R165 RES MF W4 1% 47K 1H347 7R
R166 RES CF 1W 2K7 5% 1E227 7R
R167 RES CF 1W 2K7 5% 1E227 7R
R170 RES MF W4 1% 680R 1H168 7R
R201 RES MF FU W3 470R 5%
R202 RES MF FU W3 470R 5%
NFR25
NFR25
NFR25
NFR25
NFR25
1G110 7R
1G147 7R
1G147 7R
1G147 7R
1G147 7R
R203 RES MF FU W3 470R 5%
R204 RES MF FU W3 470R 5%
R205 RES MF FU W3 470R 5%
R206 RES MF FU W3 470R 5%
R207 RES MF W4 1% 100R 1H110 7R
R401 RES MF W4 1% 1K8 1H218 7R
R402 RES MF W4 1% 47K 1H347 7R
R403 RES MF W4 1% 2K2 1H222 7R
R404 RES MF W4 6K8 1% 1H268 7R
R405 RES MF W4 1% 4K7 1H247 7R
R406 RES MF W4 1% 220R 1H122 7R
R406 RES MF W4 470R 1% 1H147 A1
R407 RES MF W4 1% 4K7 1H247 7R
R407 RES MF W4 12K 1% 1H312 A1
R408 RES MF W4 1% 4K7 1H247 7R
R408 RES MF W4 12K 1% 1H312 A1
R409 RES MF W4 3K3 1% 1H233 7R
R409 RES MF W4 6K8 1% 1H268 A1
R410 RES MF W4 3K3 1% 1H233 7R
R410 RES MF W4 6K8 1% 1H268 A1
R411 RES MF W4 1% 4K7 1H247 7R
R411 RES MF W4 10K 1% 1H310 A1
R412 RES MF W4 1% 10K 1H310 7R
R412 RES MF W4 18K 1% 1H318 A1
R415 RES MF W4 3K3 1% 1H233 7R
R416 RES MF W4 1% 1K8 1H218 7R
R501 RES MF W4 1% 1K8 1H218 7R
R502 RES MF W4 1% 47K 1H347 7R
R503 RES MF W4 1% 2K2 1H222 7R
R504 RES MF W4 6K8 1% 1H268 7R
R505 RES MF W4 1% 4K7 1H247 7R
R506 RES MF W4 1% 220R 1H122 7R
R506 RES MF W4 470R 1% 1H147 A1
R507 RES MF W4 1% 4K7 1H247 7R
R507 RES MF W4 12K 1% 1H312 A1
R508 RES MF W4 1% 4K7 1H247 7R
R508 RES MF W4 12K 1% 1H312 A1
R509 RES MF W4 3K3 1% 1H233 7R
R509 RES MF W4 6K8 1% 1H268 A1
NFR25
NFR25
NFR25
NFR25
1G147 7R
1G147 7R
1G147 7R
1G147 7R
8
Page 9
ALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUALALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUAL
R510 RES MF W4 3K3 1% 1H233 7R
R510 RES MF W4 6K8 1% 1H268 A1
R511 RES MF W4 1% 4K7 1H247 7R
R511 RES MF W4 10K 1% 1H310 A1
R512 RES MF W4 1% 10K 1H310 7R
R512 RES MF W4 18K 1% 1H318 A1
R515 RES MF W4 3K3 1% 1H233 7R
R516 RES MF W4 1% 1K8 1H218 7R
R601 RES MF W4 1% 47K 1H347 7R
R602 RES MF W4 1% 470R 1H147 7R
R603 RES MF W4 1% 680K 1H468 7R
R604 RES MF W4 1% 56K 1H356 7R
R605 RES MF W4 1% 820R 1H182 7R
R701 RES MF W4 1% 47K 1H347 7R
R702 RES MF W4 1% 470R 1H147 7R
R703 RES MF W4 1% 680K 1H468 7R
R704 RES MF W4 1% 56K 1H356 7R
R705 RES MF W4 1% 820R 1H182 7R
R801 RES MF W4 1% 4K7 1H247 7R
R801 RES MF W4 560R 1% 1H156 8P
R802 RES MF W4 1% 100K 1H410 7R
R802 RES MF W4 3K9 1% 1H239 8P
R803 RES MF W4 1% 2K4 1H224 7R
R804 RES MF W4 1% 5K6 1H256 7R
R805 RES MF W4 1% 4K7 1H247 7R
R805 RES MF W4 560R 1% 1H156 8P
R806 RES MF W4 1% 100K 1H410 7R
R806 RES MF W4 3K9 1% 1H239 8P
R807 RES MF W4 1% 2K4 1H224 7R
R808 RES MF W4 1% 5K6 1H256 7R
R809 RES MF W4 1% 100K 1H410 7R
R810 RES MF W4 1% 100K 1H410 7R
R811 RES MF W4 1% 220R 1H122 7R
R812 RES MF W4 1% 220R 1H122 7R
R813 RES MF W4 1% 22K 1H322 7R
R814 RES MF W4 1% 22K 1H322 7R
R815 RES MF W4 1% 1K2 1H212 7R
R816 RES MF W4 1% 1K2 1H212 7R
R817 RES MF W4 18K 1% 1H318 7R
R818 RES MF W4 1% 8K2 1H282 8P
R819 RES MF W4 1% 8K2 1H282 8P
R901 RES MF FU W3 1R0 5%
R902 RES MF W4 1% 100R 1H110 7R
R903 RES MF W4 1% 100R 1H110 7R
R904 RES MF W4 1% 1K8 1H218 7R
R905 RES MF W4 1% 4K7 1H247 7R
RLY1 RELAY G5Z-2A-E 24V A207 7R
RLY2 RELAY 960 OHM 51SB12T A205 8R
RV1 10K PSET 6F310 7R
RV101 10K PSET 6F310 7R
RV301 POT 20KA* 2 LOG A 6A320L A1
RV302 POT 10KB* 2 LIN 6A310E 7R
RV303 POT 10KB* 2 LIN 6A310E 7R
RV304 POT 10KB* 2 LIN 6A310E 7R
RV901 POT 20KA DUAL 18MM
RX1 REMOTE CONTROL
SK1 CAMCON BINDING POST
SK1 CANCON BINDING POST
SK2 CAMCON BINDING POST
SK2 CANCON BINDING POST
SK3 STEREO JACK PCB 8D301 7R
SK4 CAGE CLAMP 16A 3 WAY
SK5 CAGE CLAMP 16A 1 WAY
SK6 CAGE CLAMP 16A 2WAY
SK7 CAGE CLAMP 16A 3 WAY
SK201 IEC MAINS CONN PCB INSPX8A001 7R
SK301 PHONO SKT 4-WAY EMC 8D224 7R
SK301 PHONO SKT 4-WAY EMC
SK302 PHONO SKT 4-WAY EMC 8D224 7R
SK302 PHONO SKT 4-WAY EMC
SK303 PHONO SKT 4-WAY EMC 8D224 7R
SK303 PHONO SKT 4-WAY EMC
SK304 PHONO SKT 4-WAY EMC 8D224 7R
SK304 PHONO SKT 4-WAY EMC
SW1 SWITCH SLIDE 2WAY C/O
NFR25
MOTORISED
RECEIVER SBX1610-62
4WAY NICKEL
4WAY GOLD
4WAY NICKEL
4WAY GOLD
ARC001-236
ARC003-236
236-402/000-009
ARC004-236
GOLD
GOLD
GOLD
GOLD
PANEL MNT PCB
1G810 7R
6A360M 7R
B2103 7R
8D418 7R
8D418G 8R/8P
8D418 7R
8D418G 8R/8P
8Q001 7R
8Q003 7R
8Q005 7R
8Q004 7R
8D225 8R/8P
8D225 8R/8P
8D225 8R/8P
8D225 8R/8P
A1403 8R
9
Page 10
ALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUALALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUAL
SW201 SW PUSH MAINS
SW302 SW PUSH 4PCO A1013 8R
SW305 SWITCH SRBU 150 44A A1202 7R
SW305 SWITCH 4POLE SRBU
TX1 ALPHA 7 AMP MULTI
TX1 ALPHA 1/5.2
TX1 ALPHA 8 AMP MULTI
VOLMOT JUMPER 2 W LEAD APL5 1Y271 7R
X901 CER RESON CST4.19MG
Y1 TX WIRE RESTRAINT F185 7R
Y2 TX WIRE RESTRAINT F185 7R
Z201 IC VREG POS 7815 5D7815 7R
Z202 IC VREG NEG 7915 5D7915 7R
Z300 IC AUDIO DUAL 4560D 5B4560 7R
Z301 IC AUDIO DUAL NE5532N 5A5532 A1
Z302 IC AUDIO DUAL 4560D 5B4560 7R
Z303 IC COMPARITOR TA7317P 5M7317 7R
Z304 IC AUDIO DUAL 4560D 5B4560 7R
Z305 IC AUDIO DUAL NE5532N 5A5532 7R
Z305 IC AUDIO DUAL OP275 5B275 8R
Z801 IC HCMOS PC74HC4052P
Z901 IC SOCKET 18 PIN 0.3'' 8S018 7R
Z901 IC CMOS MICRO
Z902 MOTOR DRIVER 5Q6109 5Q6109 7R
SDDSA32MZU
5WAY
VOLTAGE TRANSFORM
TRANSFORMER 230V
VOLTAGE TRANSFORM
4.19MHz
ONLY
PIC16C54XT/P
A1007 7R
A1212 8R
L835TX 7R
L841TX A1
L833TX 8R/8P
7W002 7R
5F4052P 7R
5H16C54X 7R
10
Page 11
87654321
D
LK1001
LINK10NP
LK1002
LINK10NP
LK1003
LINK10NP
LK1004
LINK10NP
LK1005
LINK10NP
LK1006
LINK10NP
LK1007
LINK10NP
LK1008
LINK10NP
LK1009
LINK10NP
LK1010
LINK10NP
LK1011
LINK10NP
LK1012
LINK10NP
LK1013
LINK10NP
LK1014
LINK10NP
LK1015
LINK10NP
LK1016
LINK10NP
LK1017
LINK10NP
LK1018
LINK10NP
LK1019
LINK10NP
LK1020
LINK10NP
LK1021
LINK10NP
LK1023
LINK10NP
LK1024
LINK10NP
LK1025
LINK10NP
LK1026
LINK10NP
LK1027
LINK10NP
LK1028
LINK10NP
LK1029
LINK10NP
LK1030
LINK10NP
LK1031
LINK10NP
LK1032
LINK10NP
LK1033
LINK10NP
LK1034
LINK10NP
LK1035
LINK10NP
LK1036
LINK10NP
LK1037
LINK10NP
LK1038
LINK10NP
LK1039
LINK10NP
LK1041
LINK10NP
LK1042
LINK10NP
LK1043
LINK10NP
LK1044
LINK10NP
LK1045
LINK10NP
LK1046
LINK10NP
LK1047
LINK10NP
LK1048
LINK10NP
LK1049
LINK10NP
LK1050
LINK10NP
LK1051
LINK10NP
LK1052
LINK10NP
LK1053
LINK10NP
LK1054
LINK10NP
LK1055
LINK10NP
LK1056
LINK10NP
LK1057
LINK10NP
LK1058
LINK10NP
LK1059
LINK10NP
LK1060
LINK10NP
LK1062
LINK10NP
LK1063
LINK10NP
LK1064
LINK10NP
LK1065
LINK10NP
LK1066
LINK10NP
LK1067
LINK10NP
LK1068
LINK10NP
LK1069
LINK10NP
LK1070
LINK10NP
LK1071
LINK10NP
LK1072
LINK10NP
LK1073
LINK10NP
LK1074
LINK10NP
LK1075
LINK10NP
LK1076
LINK10NP
LK1077
LINK10NP
LK1078
LINK10NP
LK1079
LINK10NP
LK1080
LINK10NP
LK1081
LINK10NP
LK1082
LINK10NP
LK1083
LINK10NP
LK1084
LINK10NP
LK1085
LINK10NP
LK1086
LINK10NP
LK1087
LINK10NP
LK1088
LINK10NP
LK1089
LINK10NP
LK1090
LINK10NP
LK1091
LINK10NP
LK1092
LINK10NP
LK1093
LINK10NP
LK1094
LINK10NP
LK1095
LINK10NP
LK1096
LINK10NP
LK1097
LINK10NP
LK1098
LINK10NP
LK1099
LINK10NP
LK1100
LINK10NP
LK1101
LINK10NP
LK1102
LINK10NP
LK1103
LINK10NP
LK1104
LINK10NP
LK1105
LINK10NP
LK1106
LINK10NP
LK1107
LINK10NP
LK1108
LINK10NP
LK1109
LINK10NP
LK1110
LINK10NP
LK1111
LINK10NP
LK1112
LINK10NP
LK1113
LINK10NP
LK1114
LINK10NP
LK1115
LINK10NP
LK1116
LINK10NP
LK1117
LINK10NP
LK1118
LINK10NP
LK1119
LINK10NP
LK1120
LINK10NP
LK1121
LINK10NP
LK1122
LINK10NP
LK12
LINK10NP
LK13
LINK10NP
LK1125
LINK10NP
LK14
LINK10NP
LK1127
LINK10NP
LK1128
LINK10NP
LK1129
LINK10NP
LK1130
LINK10NP
LK1131
LINK10NP
LK1132
LINK10NP
LK1133
LINK10NP
LK1134
LINK10NP
LK1135
LINK10NP
D
LK1136
LINK10NP
LK1137
LINK10NP
LK1138
LINK10NP
C
MAINS_N
MAINS_E
MAINS_L
SK201
IEC3
C15
4N7 MAINS
MAINS INPUT
N E L
N
E
L
C23
4N7 MAINS
MAINS SWITCH
PD2
TOOLING
PD3
TOOLING
FS201
AS1A25
PD4
TOOLING
C200
1N0 CD
SELECT VOLTAGE
BY FITTING FS201
OR FS202
T2
PD5
TOOLING
T3
3
Orange
2
Dark Grey
1
Blue
PD7
TOOLING
PD8
TARGET1
230V
115V
TX1
PD9
TARGET1 Y2
9Vac
Orange
Blue
Orange
Grey
Grey
CAGECLAMP2
1
2
3
SK6
PD10
TOOLING
1
2
OR1
BLUE1
ACLT1
GREY2
PD11
TOOLING
GREY1
PD12
TOOLING
D203
UF5403
D204
UF5403
PD13
TOOLING
TP1
+
PD14
TOOLING
+37V
C204
10M EL 50V
PSUP
Y1
TX WIRE CLIP
C206
100N PC
POWRE
TX WIRE CLIP
R204 470R FU
R205 470R FU
R206 470R FU
TP2
C208
4N7 PP
Z201
7815
I
Vin
GND
G
Vout
O
P15V
P15V
+
C210
10U EL
TP3
C
B
PD1
TOOLING
A1007
SW201A
T1
W10
Chassis Earth Point,
Use correct screw and washer.
SW201B
A1007
C201
4N7 MAINS
FS202
AS2A5_115V
GREEN
FIT ONLY ONE FUSE
SK4
CAGECLAMP3
BLUE2
SK5
1
Green
CAGECLAMP1
SCREEN
L833TX
SK7
CAGECLAMP3A
OR2
ACSENSE
D201
UF5403
D202
UF5403
+
C205
10M EL 50V
TP4
-37V
C207
100N PC
NSUP
R201
470R FU
R202
470R FU
R203
470R FU
C209
4N7 PP
I
Z202
TP5
7915
Vin
G
GND
Vout
O
N15V
+
C211
10U EL
TP6
N15V
B
R207
100R MF
MS
MAINS SW SPACER
MAINS_SW_SPACER
EL1
Spare Fuse Clip
FUSE CLIP
BARCD
BARCODE LABEL
BARCODE
Test point for service engineers are shown as
See additional service documentation for details.
DD3
Drilling Detail
Issue Box
DD_ISSUE
DD4
PCB MATERIAL
CEM1, 2 OZ Cu
CEM1_20Z
TP28
PS
Photo Strip
PHOTO_STRIP
DD
Drilling
Detail
DRILL_DWG
DD1
A1 Horizontal
Paper Marker
DD_A1H
DD2
A1 Vertical
Paper Marker
DD_A1V
EL2
Update Box_2
UPDATE_BOX_2
A
W12
DRAWING TITLE
ALPHA 1,7, 8 & 8P AMP
WAF
WAF
WARNING SAFETY CRITICAL COMPONENT
REPLACE WITH IDENTICAL PART
1 2 3 4 5 6 7 8
WAF
PCB
L846PB
PCB
23425
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
Circuit Diagram
Notes:
POWER SUPPLY
Filename
J:\FILES\Products\A1_7_8_8P AMPS\Issue_2\L846C2_3.SCH
LJW
LJW 12-05-9898_1025
ECO No. DESCRIPTION OF CHANGE
Date Printed
INITIALS
22-Sep-1998
DATE
Initial release
Drawn by:
LJW
2 7Sheet of
DRAWING NO.
A
2LISTENING APPROVAL29-05-9898_1029
1
ISSUE
L846C2_2
Page 12
14
87654321
D
C
B
PHINL
SK301A
N
EMC
F
1
PHONO4G
PHINR
PHINE
10
11
SW302D
4PCO
LK701
10MM LINK
100P PP
7
8
SW302C
4PCO
LK601
10MM LINK
12
12
C701
9
12
C601
100P PP
R701
47K MF
R601
47K MF
C702
47P CD
R702
470R MF
C703
+
22U EL
C602
47P CD
R602
470R MF
C603
+
22U EL
Z305A
NE5532
3
2
R703
680K MF
C704
4N7 PP
5
6
R603
680K MF
C604
4N7 PP
LK19B
L835CA
1
2
1
2
36
SW1
SLIDE2H
5
4
LK19B TO LK19A ON MAIN BOARD
SLIDER SWITCH FOR AV
1
TP7
R704
56K MF
C705
1N3 PP
SW302B
4PCO
Z305B
NE5532
7
R604
56K MF
SW302A
4PCO
FITTED BY HAND
ON ALPHA 1 AMP ONLY
TP8
C605
1N3 PP
4
5
6
1
2
3
+
C606
+
10U EL
LK8
MINI_LK
C706
10U EL
12
10MM LINK
LK9
ON ALPHA 1 AMP ONLY
MINI_LK
12
10MM LINK
R705
820R MF
LK702
FITTED BY HAND
R605
820R MF
LK602
LK19A
L835CA
1
2
LK19A TO SNAP OFF BOARD FOR SLIDER SWITCH
VCRL TUNL COL AVL
VCR TUNER CD AV/DVD TAPE IN
SK301B
PHONO4G
N
N
EMC
F
C303
1N0 CD
VCRR TUNR COR AVR TAPR
F
SK302A
PHONO4G
1
15
16
17
18
N
F
SK302B
PHONO4G
13
SW305C
ROTARY4H
MCLR
R43
22K MF
D10
5V6 400MW
10
9
8
N
EMC
F
SK303A
PHONO4G
3
4
5
R57
2K7 1W CF
11
12
SW305B
7
ROTARY4H
N
F
1
SK303B
PHONO4G
2
1
SW305A
ROTARY4H
6
+37V
C29
+
1U0 EL
C304
1N0 CD
TAPL
D6
1N4003F
4
SW301B
2PCO
R501
1K8 MF
TAPE OUT
8P - LINK
N
EMC
F
1
SK304A
PHONO4G
R401
1K8 MF
RLY2C
RLY 51SB12T
5
6
8P ONLY
LK804
10MM LINK
1 2
PREAMP OUT
8P - PWR IN
TAPEOL
TAPEOR
LK803
1 2
10MM LINK
8P ONLY
SW301A
2PCO
1
2
N
F
SK304B
PHONO4G
LK11
10MM LINK
3
1 2
PREOR
PREOUTR
R505
4K7 MF
PREOL
R59
2K2 MF
C305
47P CD
PREOUTL
LK10
10MM LINK
1 2
CUT WHEN CIM FITTED
SIGE
CUT WHEN CIM FITTED
R405
4K7 MF
R44
68K MF
R502
47K MF
RV301B
20K LOG POT
2K2 MF
C306
47P CD
10MM LINK
R60
LK15
1 2
R55
22K MF
LK16
10MM LINK
R54
68K MF
R402
47K MF
RV301A
20K LOG POT
VOLL
RLY2B
RLY 51SB12T
D
C
VOLR
RLY2A
RLY 51SB12T
1 2
R56
22K MF
B
A
Z305C
NE5532
23
22
21
20
19
P15V
C301
N15V
10N CD
C302
10N CD
Key to component numbers:
0xx Power amp L
1xx Power amp R
2xx Power supply
3xx ICs / Switches
4xx Tone / balance L
5xx Tone / balance R
6xx MM phono L
7xx MM phono R
8xx Pre amp output L&R
9xx Remote control
DRAWING TITLE
ALPHA 1, 7, 8 & 8P AMP
23425
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
Notes:
Filename
J:\FILES\Products\A1_7_8_8P AMPS\Issue_2\L846C3_3.SCH
Circuit Diagram
PHONO & INPUTS
84
24
SW305D
ROTARY4H
98_1029 29-05-98 LISTENING APPROVAL
ECO No. DESCRIPTION OF CHANGE
Date Printed
LK901A
1
2
3
4
5
6
7
8
L809CA
LJW
LJW98_1025
INITIALS
22-Sep-1998
12-05-98
DATE
Initial release
Drawn by:
LJW
PL1
1 2
3 4
5 6
7 8
9 10
11 12
13 14
15 16
DIL16 VPLG
3 7Sheet of
DRAWING NO.
A
2
1
ISSUE
L846C3_2
1 2 3 4 5 6 7 8
Page 13
87654321
D
VOLR
R516
1K8 MF
C507
100P CD
Z300A
4560D
3
2
R503
2K2 MF
R504
6K8 MF
5
6
R403
2K2 MF
Z300B
4560D
R404
6K8 MF
7
C401
+
10U EL
R406
220R MF
R407
4K7 MF
C402
220N PE
Tone controls :
8dB cut and boost
R409
BASS
RV302B
10K LIN POT
R411
4K7 MF
C404
4N7 PP
R408
4K7 MF
C403
220N PE
R410
Z304A
3
2
4560D
C408
10P CD
D
TP18
C405
1
+
10U EL
R412
10K MF
R62
18K MF
R415
3K3 MF
RV304B
10K LIN POT
BALANCE
TONOL
R507
4K7 MF
C502
220N PE
C501
1
+
10U EL
R506
220R MF
Tone controls :
8dB cut and boost
R509
BASS
RV302A
10K LIN POT
R511
4K7 MF
C504
4N7 PP
R508
4K7 MF
C503
220N PE
R510
Z304B
5
6
4560D
C508
10P CD
R416
VOLL
1K8 MF
C407
TP17
C505
7
+
10U EL
R61
18K MF
R512
10K MF
R515
3K3 MF
100P CD
RV304A
10K LIN POT
BALANCE
TONOR
C
VOLR
VOLL
LK19
1 2
10MM LINK
TONOR
LK20
1 2
10MM LINK
TONOL
R63
56K MF
R64
56K MF
56SW304B
4
2PCO
3
2
SW304A
1
2PCO
R801
4K7 MF
(560R MF in 8P)
C801
100P PP
3K3 MF
C406
100P CD
R802
100K MF
(3k9 MF in 8P)
RV303A
10K LIN POT
TREBLE
Pot arrow shows max boost
Z302A
3
2
4560D
R804
5K6 MF
R803
2K4 MF
3K3 MF
1
TP19
C803
+
10U EL
12
14
15
11
Z801A
1Y0
1Y1
1Y2
1Y3
1Z
13
R811
220R MF
3K3 MF
C506
100P CD
RV303B
10K LIN POT
TREBLE
Pot arrow shows max boost
R819
8K2 MF
3K3 MF
R818
8K2 MF
8P ONLY8P ONLY
C
PWRIR
PWRIL
*** NOTE! ***
PCB has two links,
LK801, LK802 in place of
R818 and R819.
THE RESISTORS SHOULD BE
FITTED ON THE 8P - NOT THE LINKS.
PREOUTR
B
R805
4K7 MF
(560R MF in 8P)
P15V
C802
100P PP
R806
100K MF
(3k9 MF in 8P)
Z302B
5
6
4560D
R807
2K4 MF
R808
5K6 MF
8
7
GND
16
Z801B
P74HC4052
VDD
TP20
C805
10N CD
P15V
R815
1K2 MF
D801
5V6 400MW
C804
+
10U EL
R809
100K MF
R817
18K MF
R810
100K MF
TP21
1
2Y0
5
2Y1
2
2Y2
4
2Y3
6
INH
9
S1
10
S0
P74HC4052
D803
1N4148
3
2Z
VEE
PREMUTEPREP
7
R812
220R MF
R813
22K MF
PREOUTL
R814
22K MF
FIT LINKS AS BELOW
B
LINK 1 7 8 8P
1
2
3
4
5
6
7
601
602
701
702
803
804
A
84
Z300C
4560D
84
Z302C
4560D
84
Z304C
4560D
N15V
C212
10N CD
C213
10N CD
C214
10N CD
C215
10N CD
C216
10N CD
C217
10N CD
PREG
C806
10N CD
PREMUTE
D802
4V7 400MW
PREN
DRAWING TITLE
R816
1K2 MF
ALPHA 1, 7, 8 & 8P AMP
A
Circuit Diagram
23425
N15V
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
Notes:
TONE CONTROL
Filename
J:\FILES\Products\A1_7_8_8P AMPS\Issue_2\L846C4_3.SCH
LJW
LJW
ECO No. DESCRIPTION OF CHANGE
Date Printed
INITIALS
22-Sep-1998
12-05-9898_1025 1
DATE
LISTENING APPROVAL29-05-9898_1029
Initial release
Drawn by:
LJW
4 7Sheet of
DRAWING NO.
2
ISSUE
L846C4_2
1 2 3 4 5 6 7 8
Page 14
+37V
87654321
D
C
PWRIL
2
3
R32
33K MF
C10
+
22U EL OS
+
10U CERAFINE
PWRIL
R40
33K MF
R31
1K0 CF
Z301A
NE5532
680K MF
C30
AMPEL
C9
+
100U EL
1
R33
R34
1K MF
100P PP
TP9
SRVOL
R38
680K MF
C8
R37
47K MF
47N PE
R30
33K MF
C6
R24
2K7 MF
Q16
BC557B
C7
4N7 PP
R25
330R MF
Q13
BC547B
LK18
10MM LINK
1 2
R19
5K6 CF
R23
2K7 MF
Q12
BC547B
R70
680R MF
C25
100N PC
Q7
BC556B
C24
4N7 PP
C5
33P PS
R20
15K MF
R22
120R MF
+
C27
220U EL
R15
1K0 CF
R39
18K MF
TP10
R17
5K6 MF
R51
15K MF
R52
3K9 MF
10K PSET
BC546B
RV1
Q15
R12
470R FU
Q6
BC556B
Q4
BC546B
C4
47N PE
Place Q15 by hsk.
C14
15N PE
R9
470R FU
Q3
BC556B
R10
470R FU
R13
1K0 MF
R14
1K0 MF
R11
R26
+
C11
100U EL 100V
470R FU
100R MF
C28
100N PC
Q14
BC557B
D3
10V 400MW
R21
Q1
IRF540
100R FU
470R FU
R5
R7
100R FU
D2
10V 400MW
C1
100U EL 100V
+
4R7 W2 CF
TP11
D1
1N4003F
R4
C2
47N PE
R2
C3
100N PC
SK3
HPSKT
PROT_OP_L
L1
2U2H LAC SMALL
R3
2R2 CF
R35
33K MF
L
LHC
RHC
R
RLY1A
RLY G5Z-2A-E
PD6
TOOLING
PD6
4
5
2
3
1
6
7
OP_L
SPLE
PREMUTE
SK3_7
R150
100R W2 CF
C17
470P CD
C18
1N0 CD
100R W2 CF
SPLD
SP2_SEND_L
SK1A
SK1C
CAMCON_G
CAMCON_G
HPR
HPE
HPL
R49
330R 1W CF
R149
330R 1W CF
R50
Top+
Top-
CHASS
SW99A
2PCO
1
2
12
LK1
10MM LINK
4
5
SW99B
2PCO
3
10MM LINK
1 2
6
SP2_RETN_L
SW99_3
SW99_2
LK7
C20
470P CD
LK311
1
2
3
4
5
6
7
L825CA
LK311A
1
2
3
4
5
6
7
L825CA
SPLS
SK1B
Bot+
Bot-
CAMCON_G
D
SP2_SEND_L
SP2_RETN_L
SP2_RETN_R
SP2_SEND_R
OP_L
OP_R
C
B
P15V
Q11
BC547B
R29
1K2 MF
Q10
BC547B
1N4148
C13
15N PE
D5
R28
18K MF
C12
+
100U EL 100V
Q9
BC546B
R16
2K7 MF
TP12
Q8
BC546B
R18
2K7 MF
470R FU
Q5
BC556B
R8
470R FU
R27
470R FU
-37V
R6
100R FU
D4
10V 400MW
R1A
0R22 3W MO
Q2
IRF540
TP14
R1
0R22 3W MO
TP15
IQ2L
IQ1L
R41
470R FU
R42
620R MF
R36
100R FU
R46
150R MF
+
C16
100U EL
D8
1N4003F
Q17
BC546B
R45
18K MF
C26
100N PC
R47
4K7 MF
Q18
BC546B
VI_CH2
Q19
BC556B
R48
47K MF
C19
+
100U EL
B
A
84
N15V
Z301C
NE5532
C21
10N CD
C22
10N CD
CL1
E82201
HS1
E81801
HS2
E81801
CL2
E82201
HS3
E81801
HS4
E81801
TP13
DRAWING TITLE
ALPHA 1, 7, 8 & 8P AMP
23425
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
Notes:
Filename
J:\FILES\Products\A1_7_8_8P AMPS\Issue_2\L846C5_3.SCH
Circuit Diagram
LEFT CHANNEL
R53
18K MF
98_1029 29-05-98 LISTENING APPROVAL
98_1025
ECO No. DESCRIPTION OF CHANGE
Date Printed
LJW
INITIALS
22-Sep-1998
Initial release
DATE
Drawn by:
LJW
TP16
5 7Sheet of
DRAWING NO.
VI_PROTECT
A
2
1LJW 12-05-98
ISSUE
L846C5_2
1 2 3 4 5 6 7 8
Page 15
+37V
87654321
D
C
B
PWRIR
PWRIR
R131
1K0 CF
Z301B
6
5
R132
33K MF
NE5532
C110
+
22U EL OS
+
C130
10U CERAFINE
AMPER
R140
33K MF
C109
+
100U EL
R133
680K MF
R134
1K MF
100P PP
7
C108
SRVOR
R138
680K MF
TP22
R137
47K MF
47N PE
R130
33K MF
Q111
BC547B
C106
R124
2K7 MF
Q116
BC557B
C107
4N7 PP
R125
330R MF
Q113
BC547B
LK118
10MM LINK
1 2
R129
1K2 MF
5K6 CF
R123
2K7 MF
R170
680R MF
C125
100N PC
Q110
BC547B
R119
4N7 PP
Q112
BC547B
C124
R120
15K MF
R122
120R MF
+
C127
220U EL
D7
1N4148
R115
1K0 CF
Q107
BC556B Q106
R139
18K MF
TP23
C105
33P PS
R151
15K MF
10K PSET
R128
18K MF
Q119
BC546B
R117
5K6 MF
Q115
BC546B
R152
3K9 MF
RV101
TP24
BC556B
BC546B
C104
47N PE
Q108
BC546B
R112
470R FU
Q104
Q105
BC556B
C114
15N PE
Q103
BC556B
R110
470R FU
R113
1K0 MF
R114
1K0 MF
R111
470R FU
R108
470R FU
+
C111
100U EL 100V
R109
470R FU
D104
10V 400MW
R126
470R FU
R121
100R MF
C128
100N PC
D103
10V 400MW
R106
100R FU
R101A
0R22 3W MO
Q101
IRF540
R105
100R FU
Q114
BC557B
TP26
100U EL 100V
R107
470R FU
+37V
D102
10V 400MW
C101
Q102
IRF540
R101
0R22 3W MO
D101
1N4003F
R104
100R FU
C102
47N PE
+
2U2H LAC SMALL
R102
4R7 W2 CF
C103
100N PC
IQ1R
L101
R103
2R2 CF
R135
33K MF
R141
470R FU
VI_PROTECT
PROT_OP_L
RLY1B
RLY G5Z-2A-E
CHASSIS
EARTH
R136
100R FU
OP_R
PD6
PROTIN
C118
1N0 CD
D9
1N4003F
R153
47K MF
R154
47K MF
SPRD
C117
470P CD
R145
18K MF
Q117
BC546B
ACDET
SP2_SEND_R
SK2A
Top+
10MM LINK
Top-
CAMCON_G
SK2C
CHASS
CAMCON_G
SPRE
12
LK2
LED201
G
R
LED RED/GRN
R160
10K MF
D106
1N4003F
D105
1N4003F
R156
470R FU
ACSENSE
R158
47K MF
R159
100K MF
TP25
R155
47K MF
C119
+
1U0 EL
R157
100K MF
C122
100U EL
+
1K0 1W CF
SK3_7
MUTE
1
12
8
2
IN1
C123
+
100U EL
SP2_RETN_L PREMUTE
R147
4K7 MF
R165
47K MF
LK805A
1
2
3
L815CA
VI_CH2
3
IN2
Z303
TA7317P
R164
18K MF
LK805
1
2
3
L815CA
PWR
V-
4
5
-37V
SP2_RETN_R
RC
9
V+
FB
0V
7
C121
1U0 EL
D108
5V6 400MW
6
O
+
R163
33K MF
C120
Q120
2SC2547
R162
47K MF
PROTE
R166
2K7 1W CF
10MM LINK
FIT ALL
BUT HK
LK4
1 2
10MM LINK
+37V
R167
2K7 1W CF
D107
1N4003F
SPRS
SK2B
Bot+
RLY1C
RLY G5Z-2A-E
SW99_2
SW99_3
R161
12
LK3
LK5
10MM LINK
PROT
D
LK5 & LK6 FIT
FOR HK ONLY
12
LK6
10MM LINK
C
B
A
C113
15N PE
C112
+
100U EL 100V
R116
2K7 MF
R118
2K7 MF
R127
470R FU
TP27
IQ2R
-37V
DRAWING TITLE
ALPHA 1, 7, 8 & 8P AMP
23425
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
R142
620R MF
C116
100U EL
R146
150R MF
+
Circuit Diagram
Notes:
RIGHT CHANNEL
Filename
J:\FILES\Products\A1_7_8_8P AMPS\Issue_2\L846C6_3.SCH
Q118
BC546B
C126
100N PC
LISTENING APPROVAL29-05-9898_1029
98_1025 1
ECO No. DESCRIPTION OF CHANGE
Date Printed
INITIALS
22-Sep-1998
12-05-98LJW
DATE
Initial release
Drawn by:
LJW
470P CD
6 7Sheet of
Bot-
CAMCON_G
DRAWING NO.
ISSUE
L846C6_2
A
2LJW
1 2 3 4 5 6 7 8
Page 16
87654321
REPLACE WITH IDENTICAL PART
D
C
ACLT1
W11
R901
1R0 FU
C901
10N CD
MOTE
D901
1N4003F
C902
220U EL
R902
100R MF
+5V
100R MF
+
D903
1N4003F
TP29
R903
C903
10N CD
D902
5V6 400MW
+5V
R904
1K8 MF
LK902A
1
2
3
C904
10N CD
REMO
D904
5V6 400MW
+5V
R58
1K8 MF
3
5
4
6
9
Z901
PIC16C54XT
17
RA0
18
RA1
1
RA2
2
RA3
3
RTCC
4
MCLR
OSC1
TP30
CC1
MC1
REF
MC2
CC2
Z902
BA6109
7
VCC1
MOTOR DRIVER
VOLUME DRIVE
RB0
RB1
RB2
RB3
RB4
RB5
RB6
RB7
OSC2
VSS
VDD
8
VCC2
6
7
8
9
10
11
12
13
MD1
GND
MD2
2
1
10
D905
1N4148
+
C907
1M0 25V
C905
10N CD
R905
4K7 MF
VOLM1
VOLM2
C906
10N CD
TP31
VOLMOT
1Y271
1 2
TP32
MUTE
MOTSUP
+
LK901
L809CA
+ -
1
2
3
4
5
6
7
8
RV901C
6A360M
C1000
10N CD
VOLUME POT SNAP OFF BOARD
RV901A
6A360M
RV901B
6A360M
VOLMOTA
1Y271
1 2
D
RV901D
7
9
Case
6A360M
C
B
L815CA
LK17
10MM LINK
MCLR
5
16
X901
12
CST4.19MG
15
14
P5V
+5v
RX1
SBX1610-52
3
B
GND
1
+5V
Case
O/P
2
LK902
1
2
3
L815CA
A
W13
WARNING SAFETY CRITICAL COMPONENT
DRAWING TITLE
ALPHA 1, 7, 8 & 8P AMP
-
23425
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
-
Notes:
Filename
J:\FILES\Products\A1_7_8_8P AMPS\Issue_2\L846C7_3.SCH
Circuit Diagram
REMOTE CONTROL
REMOTE SENSOR SNAP OFF BOARD
LJW 298_1029 29-05-98 LISTENING APPROVAL
98_1026 Initial release
ECO No. DESCRIPTION OF CHANGE
Date Printed
LJW
INITIALS
22-Sep-1998
DATE
Drawn by:
LJW
7 7Sheet of
DRAWING NO.
A
112-05-98
ISSUE
L846C7_2
1 2 3 4 5 6 7 8
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