Arcam ALPHA ONE User manual

H / P P S E MANALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUAL
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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
powerthemicrocontrollerZ901andremotereceiver.
Phono Stage (Not applicable to Alpha One)
Thephonostageconsistsofa 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
ofswitch SW302 to enableuse as an extraline input.
Tone Controls
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
Theinputtothepoweramplifierfrompreviousstages
is fed to the differential input of Q112 and Q113.
Q110 and Q111 form a constant current
source for the differential input stage.
Theoutput devices are 'n' channelmosfets SMF045.
ZenerdiodesD103,104limitthevoltage swing within
safe limits for the output devices & fusible resistors
R105, 106 provide overcurrent damage to the
devices.
Aproportionof the output current appearsacross 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.
RemovingtheAlphaOne/7R/8R/8PTransformer
Thetoroidal transformer is extremely wellsecured 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.
Alesssatisfactorysubstituteforcheesewireistouse
some 22 gauge tinned copper wire, stretched first to
remove kinks, and two temporary handles.
Alpha One/7R/ 8R/ 8P Quiescent Current (IQ)
Settings
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
dropacrossresistorR1(R101 for righthandchannel)
to between 3.0 and 3.5mV for the Alpha One and 7R

H / P P S E MANALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUAL
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ampsor between2.3 and 2.8mVfor 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.
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.
TEST POINT VOLTAGES
Test Point DC Voltage Alpha One DC Voltage Alpha 7R DC Voltage Alpha 8R/8P
132.8V 35V 37V
227.8V 29V 31V
315V 15V 15V
4-32.8V -35V -37V
527.8V -29V -31V
6-15V -15V -15V
7N/A 0.09V 0.09V
8N/A 0.10V 0.10V
90.3V 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

H / P P S E MANALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUAL
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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
(volume going up) N/A 0V 0V
31
(volume going down) N/A 5V 5V
32
(volume going up) N/A 0V 0V
32
(volume going down) N/A 5V 5V
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
5mm 2H410 7R
C4 PEST 47N 63V 10% 2K347 7R
C5 PSTY 33P 160V ENCAP
1PF% 2F033 7R
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
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
5mm 2H410 7R
C26 PCRB 100N 100V 5% RA
5mm 2H410 7R
C27 ELST 220U 16V 2N722 7R
C28 PCRB 100N 100V 5% RA
5mm 2H410 7R

H / P P S E MANALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUAL
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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
5mm 2H410 7R
C104 PEST 47N 63V 10% 2K347 7R
C105 PSTY 33P 160V ENCAP
1PF% 2F033 7R
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
5mm 2H410 7R
C126 PCRB 100N 100V 5% RA
5mm 2H410 7R
C127 ELST 220U 16V 2N722 7R
C128 PCRB 100N 100V 5% RA
5mm 2H410 7R
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
C205 ELST 6M8 35V RA 2N868 A1
C206 PCRB 100N 100V 5% RA
5mm 2H410 7R
C207 PCRB 100N 100V 5% RA
5mm 2H410 7R
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
5mm 2H410 A1
C303 CERD 1N0 63V 20% RA 2A210 7R
C304 CERD 1N0 63V 20% RA 2A210 7R
C305 CERD 47P 63V -20% +80%
RA 2A047 7R
C306 CERD 47P 63V -20% +80%
RA 2A047 7R
C401 ELST 10U 50V 2N610 7R
C402 PEST 220N 63V 10% 2K422 7R
C402 PCRB 100N 100V 5% RA
5mm 2H410 A1
C403 PCRB 100N 100V 5% RA
5mm 2H410 A1
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
5mm 2H410 A1
C504 PPRO 4N7 63V 5% RA 2D247N 7R
C504 2N2 PP 2D222 A1
C505 ELST 10U 50V 2N610 7R

H / P P S E MANALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUAL
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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 HEATS NK
CLAMP E82201 7R
CL2 ALPHA AMP 7/8 HEATS NK
CLAMP E82201 7R
D1 RECT FIER 1N4003F 1A
200V 3B4003 7R
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 RECT FIER 1N4003F 1A
200V 3B4003 8R
D7 SSDIODE 1N4148 75V 3A4148 7R
D8 RECT FIER 1N4003F 1A
200V 3B4003 7R
D9 RECT F ER 1N4003F 1A
200V 3B4003 7R
D10 ZENER 5V6 400MW 3C05604 8R
D101 RECT F ER 1N4003F 1A
200V 3B4003 7R
D102 ZENER 10V 400MW 3C11004 7R
D103 ZENER 10V 400MW 3C11004 7R
D104 ZENER 10V 400MW 3C11004 7R
D105 RECT F ER 1N4003F 1A
200V 3B4003 7R
D106 RECT F ER 1N4003F 1A
200V 3B4003 7R
D107 RECT F ER 1N4003F 1A
200V 3B4003 7R
D108 ZENER 5V6 400MW 3C05604 7R
D201 ULTRAFAST RECT F ER
DIODE UF5403 3A 3B5403F 7R
D202 ULTRAFAST RECT F ER
DIODE UF5403 3A 3B5403F 7R
D203 ULTRAFAST RECT F ER
DIODE UF5403 3A 3B5403F 7R
D204 ULTRAFAST RECT F ER
DIODE UF5403 3A 3B5403F 7R
D801 ZENER 5V6 400MW 3C05604 7R
D802 ZENER 4V7 400MW 3C04704 7R
D803 SSDIODE 1N4148 75V 3A4148 7R
D901 RECT F ER 1N4003F 1A
200V 3B4003 7R
D902 ZENER 5V6 400MW 3C05604 7R
D903 RECT F ER 1N4003F 1A
200V 3B4003 7R
D904 ZENER 5V6 400MW 3C05604 7R
D905 SSDIODE 1N4148 75V 3A4148 7R
EL1 FUSE CLIP WCK-180-01A F062 7R
FS201 INS COVER PCB
FUSEHOLDER F022 7R
FS201 FUSE 20mm 1.25A AS C12126 7R
FS201 FUSEHOLDER 20mm PCB 8S004 7R
FS202 FUSEHOLDER 20mm PCB 8S004 7R
FS202 INS COVER PCB
FUSEHOLDER F022 7R
HS1 ALPHA AMP 7/8 HEATS NK 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 HEATS NK E81801 7R
HS2 ALPHA AMP 7/8 HS CLIP E810MC 7R
HS3 SIL PAD - 25 X 12.5mm E817MC 7R

H / P P S E MANALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUAL
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HS3 ALPHA AMP 7/8 HEATS NK E81801 7R
HS3 ALPHA AMP 7/8 HS CL P E810MC 7R
HS4 S L PAD - 25 X 12.5mm E817MC 7R
HS4 ALPHA AMP 7/8 HS CL P E810MC 7R
HS4 ALPHA AMP 7/8 HEATS NK E81801 7R
L1 NDUCT 2U2 12x20mm 7D002B 7R
L101 NDUCT 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
SWITCH CABLE L835CA 8R
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 MA NS SWITCH SPACER E66901 7R
PCB PR NTED CIRCUIT BOARD L846PB 7R
Q1 TRANS PWR MOSFET
RF540/SMF045 4K045 7R
Q2 TRANS PWR MOSFET
RF540/SMF045 4K045 7R
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
RF540/SMF045 4K045 7R
Q102 TRANS PWR MOSFET
RF540/SMF045 4K045 7R
Q103 TRANS LF SS P BC556B 4A556 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
KOASPR3 1Q922 7R
R1 RES MO 3W 5% 0R22
KOASPR3 1Q922 7R
R2 RES CF W2 4R7 5% 1D847 7R
R3 RES CF W4 5% 2R2 1B822 7R
R4 RES MF FU W3 100R 5%
NFR25 1G110 7R
R5 RES MF FU W3 100R 5%
NFR25 1G110 7R
R6 RES MF FU W3 100R 5%
NFR25 1G110 7R
R7 RES MF FU W3 470R 5%
NFR25 1G147 7R
R8 RES MF FU W3 470R 5%
NFR25 1G147 7R
R9 RES MF FU W3 470R 5%
NFR25 1G147 7R
R10 RES MF FU W3 470R 5%
NFR25 1G147 7R
R11 RES MF FU W3 470R 5%
NFR25 1G147 7R
R12 RES MF FU W3 470R 5%
NFR25 1G147 7R
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

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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%
NFR25 1G147 7R
R27 RES MF FU W3 470R 5%
NFR25 1G147 7R
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%
NFR25 1G110 7R
R39 RES MF W4 18K 1% 1H318 7R
R40 RES MF W4 1% 33K 1H333 A1
R41 RES MF FU W3 470R 5%
NFR25 1G147 7R
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
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
KOASPR3 1Q922 7R
R101 RES MO 3W 5% 0R22
KOASPR3 1Q922 7R
R102 RES CF W2 4R7 5% 1D847 7R
R103 RES CF W4 5% 2R2 1B822 7R
R104 RES MF FU W3 100R 5%
NFR25 1G110 7R
R105 RES MF FU W3 100R 5%
NFR25 1G110 7R
R106 RES MF FU W3 100R 5%
NFR25 1G110 7R
R107 RES MF FU W3 470R 5%
NFR25 1G147 7R
R108 RES MF FU W3 470R 5%
NFR25 1G147 7R
R109 RES MF FU W3 470R 5%
NFR25 1G147 7R
R110 RES MF FU W3 470R 5%
NFR25 1G147 7R
R111 RES MF FU W3 470R 5%
NFR25 1G147 7R
R112 RES MF FU W3 470R 5%
NFR25 1G147 7R
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%
NFR25 1G147 7R
R127 RES MF FU W3 470R 5%
NFR25 1G147 7R
R128 RES MF W4 18K 1% 1H318 7R
R129 RES MF W4 1% 1K2 1H212 7R

H / P P S E MANALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUAL
8
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%
NFR25 1G110 7R
R139 RES MF W4 18K 1% 1H318 7R
R140 RES MF W4 1% 33K 1H333 A1
R141 RES MF FU W3 470R 5%
NFR25 1G147 7R
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%
NFR25 1G147 7R
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%
NFR25 1G147 7R
R202 RES MF FU W3 470R 5%
NFR25 1G147 7R
R203 RES MF FU W3 470R 5%
NFR25 1G147 7R
R204 RES MF FU W3 470R 5%
NFR25 1G147 7R
R205 RES MF FU W3 470R 5%
NFR25 1G147 7R
R206 RES MF FU W3 470R 5%
NFR25 1G147 7R
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

H / P P S E MANALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUAL
9
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%
NFR25 1G810 7R
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
MOTORISED 6A360M 7R
RX1 REMOTE CONTROL
RECEIVER SBX1610-62 B2103 7R
SK1 CAMCON BIND NG POST
4WAY NICKEL 8D418 7R
SK1 CANCON B ND NG POST
4WAY GOLD 8D418G 8R/8P
SK2 CAMCON BIND NG POST
4WAY NICKEL 8D418 7R
SK2 CANCON B ND NG POST
4WAY GOLD 8D418G 8R/8P
SK3 STEREO JACK PCB 8D301 7R
SK4 CAGE CLAMP 16A 3 WAY
ARC001-236 8Q001 7R
SK5 CAGE CLAMP 16A 1 WAY
ARC003-236 8Q003 7R
SK6 CAGE CLAMP 16A 2WAY
236-402/000-009 8Q005 7R
SK7 CAGE CLAMP 16A 3 WAY
ARC004-236 8Q004 7R
SK201 IEC MAINS CONN PCB NS
PX 8A001 7R
SK301 PHONO SKT 4-WAY EMC 8D224 7R
SK301 PHONO SKT 4-WAY EMC
GOLD 8D225 8R/8P
SK302 PHONO SKT 4-WAY EMC 8D224 7R
SK302 PHONO SKT 4-WAY EMC
GOLD 8D225 8R/8P
SK303 PHONO SKT 4-WAY EMC 8D224 7R
SK303 PHONO SKT 4-WAY EMC
GOLD 8D225 8R/8P
SK304 PHONO SKT 4-WAY EMC 8D224 7R
SK304 PHONO SKT 4-WAY EMC
GOLD 8D225 8R/8P
SW1 SWITCH SLIDE 2WAY C/O
PANEL MNT PCB A1403 8R

H / P P S E MANALPHA ONE/7R/8R/8P AMPLIFIER SERVICE MANUAL
10
SW201 SW PUSH MA NS
SDDSA32MZU A1007 7R
SW302 SW PUSH 4PCO A1013 8R
SW305 SWITCH SRBU 150 44A A1202 7R
SW305 SWITCH 4POLE SRBU
5WAY A1212 8R
TX1 ALPHA 7 AMP MULTI
VOLTAGE TRANSFORM L835TX 7R
TX1 ALPHA 1/5.2
TRANSFORMER 230V L841TX A1
TX1 ALPHA 8 AMP MULTI
VOLTAGE TRANSFORM L833TX 8R/8P
VOLMOT JUMPER 2 W LEAD APL5 1Y271 7R
X901 CER RESON CST4.19MG
4.19MHz 7W002 7R
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
ONLY 5F4052P 7R
Z901 IC SOCKET 18 P N 0 3'' 8S018 7R
Z901 IC CMOS MICRO
PIC16C54XT/P 5H16C54X 7R
Z902 MOTOR DRIVER 5Q6109 5Q6109 7R

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:\FILES\Products\A1_7_8_8P AMPS\Issue_2\L846C2_3.SCH
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
ALPHA 1,7, 8 & 8P AMP
Circuit Diagram
L846C2_2
LJW
22-Sep-1998
INITIALS
Date Printed 2 7Sheet of
Notes:
L
N E
NEL
SK201
IEC3
C201
4N7 MAINS
FS201
AS1A25
+C204
10M EL 50V
+C205
10M EL 50V
C206
100N PC
C207
100N PC
PSUP
POWRE
NSUP
R204 470R FU
R205 470R FU
R206 470R FU
R201
470R FU
R202
470R FU
R203
470R FU
C208
4N7 PP
C209
4N7 PP
+C210
10U EL
+C211
10U EL
P15V
N15V
Vin
I
GND
G
Vout O
Z201
7815
Vin
I
GND G
Vout O
Z202
7915
P15V
N15V
+37V
-37V
SW201B
A1007
SW201A
A1007
SELECT VOLTAGE
BY FITTING FS201
OR FS202
MAINS INPUT
MAINS SWITCH
FIT ONLY ONE FUSE
W12
Chassis Earth Point,
W10
Use correct screw and washer.
R207
100R MF
MAINS_N
MAINS_E
MAINS_L
MAINS SW SPACER
MS
MAINS_SW_SPACER
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
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
LK1077
LINK10NP
LK1078
LINK10NP
LK1079
LINK10NP
LK1080
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
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
WARNING SAFETY CRITICAL COMPONENT
REPLACE WITH IDENTICAL PART
T1
T2
T3
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
LK1125
LINK10NP
LK1127
LINK10NP
LK1128
LINK10NP
LK1129
LINK10NP
LK1130
LINK10NP
LK1131
LINK10NP
LK1132
LINK10NP
LK1133
LINK10NP
LK1134
LINK10NP
LK1135
LINK10NP
LK1136
LINK10NP
LK1137
LINK10NP
LK1138
LINK10NP
PD1
TOOLING
PD2
TOOLING PD3 TOOLING PD4 TOOLING PD5 TOOLING Y1 TX WIRE CLIP
PD8
TARGET1 PD9 TARGET1 Y2
TX WIRE CLIP
PD10
TOOLING PD11 TOOLING
LK1062
LINK10NP
Test point for service engineers are shown as
See additional service documentation for details.
FS202
AS2A5_115V
230V
115V
9Vac
SCREEN
TX1
L833TX
TP1
TP2
TP3
TP4
TP5
TP6
TP28
C200
1N0 CD
D201
UF5403
D202
UF5403
D203
UF5403
D204
UF5403
Blue
1Dark Grey
2Orange
3
SK4
CAGECLAMP3
Green
1
SK5
CAGECLAMP1
Grey 1
Grey 2
SK6
CAGECLAMP2
Orange 1
Blue 2
Orange 3
SK7
CAGECLAMP3A
WAF
WAF
WAF
GREY1
GREY2
GREEN
OR1
OR2
BLUE1
BLUE2
LK1081
LINK10NP
LK1076
LINK10NP
LJW
LJW 12-05-9898_1025
Photo Strip
PS
PHOTO_STRIP
1
Issue Box
Drilling Detail
DD3
DD_ISSUE
Update Box_2
EL2
UPDATE_BOX_2
BARCODE LABEL
BARCD
BARCODE
Spare Fuse Clip
EL1
FUSE CLIP
LK12
LINK10NP
LK13
LINK10NP
LK14
LINK10NP
PD7
TOOLING PD12 TOOLING PD13 TOOLING PD14 TOOLING
POWER SUPPLY
Paper Marker
A1 Horizontal
DD1
DD_A1H
Paper Marker
A1 Vertical
DD2
DD_A1V
Detail
Drilling
DD
DRILL_DWG
C15
4N7 MAINS
C23
4N7 MAINS
PCB
PCB
L846PB
CEM1, 2 OZ Cu
PCB MATERIAL
DD4
CEM1_20Z
ACSENSE
Initial release
2LISTENING APPROVAL29-05-9898_1029
ACLT1

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:\FILES\Products\A1_7_8_8P AMPS\Issue_2\L846C3_3.SCH
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
ALPHA 1, 7, 8 & 8P AMP
Circuit Diagram
L846C3_2
LJW
22-Sep-1998
INITIALS
Date Printed 3 7Sheet of
Notes:
1 2 3
SW301A
2PCO
4 5 6
SW301B
2PCO
12 LK701
10MM LINK
12
LK702
10MM LINK
3
21
Z305A
NE5532
C701
100P PP
R701
47K MF
R702
470R MF
C702
47P CD
+
C703
22U EL
R703
680K MF
R704
56K MF
C704
4N7 PP
C705
1N3 PP
R705
820R MF
+
C706
10U EL
12 LK601
10MM LINK
12
LK602
10MM LINK
C601
100P PP
R601
47K MF
R602
470R MF
C602
47P CD
+
C603
22U EL
R603
680K MF
R604
56K MF
C604
4N7 PP C605 1N3 PP
R605
820R MF
+
C606
10U EL
1
2
3
SW302A
4PCO
4
5
6
SW302B
4PCO
7 8 9
SW302C
4PCO
10 11 12
SW302D
4PCO
5
67
Z305B
NE5532
C301
10N CD
C302
10N CD
N15V
P15V
PHINE
VCRL TUNL COL AVL
VCRR TUNR COR AVR TAPR
TAPL
SIGE
R401
1K8 MF
R501
1K8 MF
R402
47K MF
R502
47K MF
RV301A
20K LOG POT
RV301B
20K LOG POT
VCR TUNER CD AV/DVD TAPE IN TAPE OUT
PREAMP OUT
8P - PWR IN
8P - LINK
1 2
LK804
10MM LINK
1 2
LK803
10MM LINK
8P ONLY
8P ONLY
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
EMC
1
N
F
SK301A
PHONO4G
N
F
SK301B
PHONO4G
EMC
1
N
F
SK302A
PHONO4G
N
F
SK302B
PHONO4G
EMC
1
N
F
SK303A
PHONO4G
N
F
SK303B
PHONO4G
EMC
1
N
F
SK304A
PHONO4G
N
F
SK304B
PHONO4G
C303
1N0 CD C304
1N0 CD
TAPEOL
TAPEOR
PREOR
PREOL
PHINR
PHINL
1
2
3
4
5
6
7
8
LK901A
L809CA
84
Z305C
NE5532
TP7
TP8
R505
4K7 MF
R405
4K7 MF
C305
47P CD
C306
47P CD
LK8
MINI_LK
FITTED BY HAND
ON ALPHA 1 AMP ONLY
LK9
MINI_LK
ON ALPHA 1 AMP ONLY
FITTED BY HAND
1
LJW
LJW98_1025 12-05-98
1
2
3
4
5
6
SW305A
ROTARY4H
12
11
10
9
8
7SW305B
ROTARY4H
13
14
15
16
17
18
SW305C
ROTARY4H
RLY2A
RLY 51SB12T
RLY2B
RLY 51SB12T
RLY2C
RLY 51SB12T
R44
68K MF
R55
22K MF
R57
2K7 1W CF +C29
1U0 EL
D6
1N4003F
+37V
1 2
3 4
5 6
7 8
9 10
11 12
13 14
15 16
PL1
DIL16 VPLG
1 2
LK10
10MM LINK
1 2
LK11
10MM LINK
R54
68K MF
R56
22K MF
24
23
22
21
20
19
SW305D
ROTARY4H
R43
22K MF
D10
5V6 400MW
1 2
LK15
10MM LINK
1 2
LK16
10MM LINK
PHONO & INPUTS
1 2 36
5 4
SW1
SLIDE2H
LK19B TO LK19A ON MAIN BOARD LK19A TO SNAP OFF BOARD FOR SLIDER SWITCH
1 2
LK19B
L835CA
1 2
LK19A
L835CA
SLIDER SWITCH FOR AV
R59
2K2 MF
R60
2K2 MF
CUT WHEN CIM FITTED
CUT WHEN CIM FITTED
VOLL
VOLR
Initial release
2
PREOUTR
PREOUTL
98_1029 29-05-98 LISTENING APPROVAL
MCLR

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:\FILES\Products\A1_7_8_8P AMPS\Issue_2\L846C4_3.SCH
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
ALPHA 1, 7, 8 & 8P AMP
Circuit Diagram
L846C4_2
LJW
22-Sep-1998
INITIALS
Date Printed 4 7Sheet of
Notes:
1
2
3
SW304A
2PCO
4
5
6
SW304B
2PCO
R801
4K7 MF
R805
4K7 MF
C801
100P PP
C802
100P PP
R802
100K MF
R806
100K MF
R803
2K4 MF
R807
2K4 MF
R808
5K6 MF
R804
5K6 MF
R811
220R MF
R812
220R MF
1Y0
12
1Y1
14
1Y2
15 1Y3
11
2Y0
1
2Y1
52Y2
22Y3
4
INH
6
S1
9S0
10
2Z 3
VEE 7
1Z 13
Z801A
P74HC4052
VDD 16
GND
8
Z801B
P74HC4052
+
C803
10U EL
+
C804
10U EL
R809
100K MF
R813
22K MF R814 22K MF
R810
100K MF
D801
5V6 400MW
D802
4V7 400MW
R815
1K2 MF
R816
1K2 MF
P15V
N15V
C805
10N CD
C806
10N CD
R817
18K MF D803
1N4148
8P ONLY8P ONLY
R506
220R MF
R507
4K7 MF R508 4K7 MF
R509
3K3 MF
R510
3K3 MF
R512
10K MF
RV302A
10K LIN POT
RV303A
10K LIN POT
C502
220N PE C503 220N PE
R511
4K7 MF
R504
6K8 MF
+
C501
10U EL
R503
2K2 MF
RV304A
10K LIN POT
+
C505
10U EL
R515
3K3 MF
BASS
TREBLE
BALANCE
8dB cut and boost
Tone controls :
R406
220R MF
R407
4K7 MF R408
4K7 MF
R409
3K3 MF
R410
3K3 MF
R412
10K MF
RV302B
10K LIN POT
RV303B
10K LIN POT
C402
220N PE C403 220N PE
R411
4K7 MF
R404
6K8 MF
+
C401
10U EL
R403
2K2 MF
RV304B
10K LIN POT
+
C405
10U EL
R415
3K3 MF
BASS
TREBLE
BALANCE
8dB cut and boost
Tone controls :
Pot arrow shows max boost Pot arrow shows max boost
C212
10N CD
C213
10N CD
C214
10N CD
C215
10N CD
P15V
N15V
PREMUTEPREP
PREN
PREG
R516
1K8 MF
R416
1K8 MF
3
21
Z304A
4560D
5
67
Z304B
4560D
3
21
Z302A
4560D
5
67
Z302B
4560D
C504
4N7 PP
TP17
TP18
TP19
TP20
TP21
(560R MF in 8P)
(3k9 MF in 8P)
(560R MF in 8P)
(3k9 MF in 8P)
R819
8K2 MF R818 8K2 MF
*** NOTE! ***
PCB has two links,
LK801, LK802 in place of
R818 and R819.
THE RESISTORS SHOULD BE
FITTED ON THE 8P - NOT THE LINKS.
C407
100P CD
C507
100P CD
C216
10N CD
C217
10N CD
C406
100P CD
C508
10P CD C408 10P CD
C506
100P CD
LINK 1 7 8 8P
2
3
4
5
6
7
601
701
803
804
602
702
FIT LINKS AS BELOW
3
21
Z300A
4560D
5
67
Z300B
4560D
84
Z300C
4560D
84
Z302C
4560D
84
Z304C
4560D
1
LJW
LJW
12-05-9898_1025 1
TONE CONTROL
C404
4N7 PP
R61
18K MF R62 18K MF
1 2
LK19
10MM LINK
1 2
LK20
10MM LINK
R63
56K MF
R64
56K MF
VOLR
VOLR
VOLL
VOLL
TONOR TONOL
PWRIR
PWRIL
PREOUTR
PREOUTL
Initial release
2
PREMUTE
LISTENING APPROVAL29-05-9898_1029
TONOL
TONOR

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:\FILES\Products\A1_7_8_8P AMPS\Issue_2\L846C5_3.SCH
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
ALPHA 1, 7, 8 & 8P AMP
Circuit Diagram
L846C5_2
LJW
22-Sep-1998
INITIALS
Date Printed 5 7Sheet of
Notes:
R31
1K0 CF
R40
33K MF
R24
2K7 MF R19 5K6 CF
R23
2K7 MF
Q16
BC557B Q7
BC556B Q6
BC556B
Q3
BC556B
+
C9
100U EL
R32
33K MF
3
21
Z301A
NE5532
84
Z301C
NE5532
R33
680K MF
C6
47N PE
R38
680K MF
R37
47K MF
SRVOL
Q13
BC547B
Q12
BC547B
Q4
BC546B
Q8
BC546B
Q9
BC546B
Q10
BC547B
Q11
BC547B
Q5
BC556B
R30
33K MF
C8
100P PP
R25
330R MF
C7
4N7 PP
C5
33P PS
R20
15K MF
R22
120R MF
R28
18K MF
R29
1K2 MF
C4
47N PE
R17
5K6 MF
R16
2K7 MF
R8
470R FU
R12
470R FU
R9
470R FU
C14
15N PE
+C11
100U EL 100V
R26
470R FU
R5
100R FU
D3
10V 400MW
D4
10V 400MW
R6
100R FU
R10
470R FU
R11
470R FU
R14
1K0 MF
AMPEL
R15
1K0 CF
R27
470R FU
-37V
R7
470R FU
R1
0R22 3W MO
R1A
0R22 3W MO
Q1
IRF540 D1
1N4003F
+37V
R4
100R FU
+
C1
100U EL 100V
C2
47N PE
D2
10V 400MW
R3
2R2 CF
C17
470P CD
R2
4R7 W2 CF
C3
100N PC
Q2
IRF540
C13
15N PE
+
C12
100U EL 100V
P15V
N15V
R18
2K7 MF
Q15
BC546B
R52
3K9 MF
RLY1A
RLY G5Z-2A-E
LHC 2
RHC 3
1
4
L5
6
R7
SK3
HPSKT
1 2 3
SW99A
2PCO
4 5 6
SW99B
2PCO
R49
330R 1W CF
R149
330R 1W CF
R150
100R W2 CF R50 100R W2 CF
C20
470P CD
C18
1N0 CD
R41
470R FU
R42
620R MF
+C16
100U EL
R45
18K MF
R35
33K MF
R47
4K7 MF
R48
47K MF
+
C19
100U EL
Q14
BC557B
R21
100R MF
C21
10N CD
C22
10N CD
Place Q15 by hsk.
Q17
BC546B
Q18
BC546B
Q19
BC556B
Top+
Top-
SK1A
CAMCON_G
Bot+
Bot-
SK1B
CAMCON_G
CHASS
SK1C
CAMCON_G
L1
2U2H LAC SMALL
PWRIL
IQ1L
IQ2L
SPLD
SPLE
HPL
HPR
HPE
SPLS
1
2
3
4
5
6
7
LK311
L825CA
HS1
E81801
HS2
E81801
HS3
E81801
HS4
E81801
R53
18K MF
1
2
3
4
5
6
7
LK311A
L825CA
CL1
E82201
CL2
E82201
R13
1K0 MF
R46
150R MF
TP9
TP10
TP12
TP11
TP13
TP14
TP15
TP16
PD6
PD6
TOOLING
1 2
LK7
10MM LINK
+
C10
22U EL OS
12
LK1
10MM LINK
98_1025
LJW
1LJW 12-05-98 Initial release
D5
1N4148
+C27
220U EL
C25
100N PC
R39
18K MF
C24
4N7 PP
C28
100N PC
C26
100N PC
D8
1N4003F
R34
1K MF
1 2
LK18
10MM LINK
RV1
10K PSET
LEFT CHANNEL
R70
680R MF R51
15K MF
+ C30
10U CERAFINE
R36
100R FU
PWRIL
PROT_OP_L
OP_L
SP2_SEND_L
SP2_RETN_L
VI_CH2
VI_PROTECT
2
PREMUTE
SK3_7
SW99_3
SW99_2
SP2_SEND_L
SP2_SEND_R
SP2_RETN_R
SP2_RETN_L
OP_L
OP_R
98_1029 29-05-98 LISTENING APPROVAL

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:\FILES\Products\A1_7_8_8P AMPS\Issue_2\L846C6_3.SCH
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
ALPHA 1, 7, 8 & 8P AMP
Circuit Diagram
L846C6_2
LJW
22-Sep-1998
INITIALS
Date Printed 6 7Sheet of
Notes:
R131
1K0 CF
R140
33K MF
R124
2K7 MF R119 5K6 CF
R123
2K7 MF
Q116
BC557B
Q107
BC556B Q106
BC556B
Q103
BC556B
+
C109
100U EL
R132
33K MF
5
67
Z301B
NE5532
R133
680K MF
C106
47N PE
R138
680K MF
R137
47K MF
SRVOR
Q113
BC547B
Q112
BC547B
Q104
BC546B
Q108
BC546B
Q119
BC546B
Q110
BC547B
Q111
BC547B
Q105
BC556B
R130
33K MF
C108
100P PP
R125
330R MF
C107
4N7 PP
C105
33P PS
R120
15K MF
R122
120R MF
R128
18K MF
R129
1K2 MF
C104
47N PE
R117
5K6 MF
R116
2K7 MF
R108
470R FU
R112
470R FU
R109
470R FU
C114
15N PE
+C111
100U EL 100V
R126
470R FU
R105
100R FU
D103
10V 400MW
D104
10V 400MW
R106
100R FU
R110
470R FU
R111
470R FU
R114
1K0 MF
R113
1K0 MF
AMPER
R115
1K0 CF
R127
470R FU
-37V
R107
470R FU
R101
0R22 3W MO
R101A
0R22 3W MO
Q101
IRF540
D101
1N4003F
+37V
R104
100R FU
+
C101
100U EL 100V
C102
47N PE
D102
10V 400MW
R103
2R2 CF C117
470P CD
R102
4R7 W2 CF
C103
100N PC
Q102
IRF540
C113
15N PE
+
C112
100U EL 100V
R118
2K7 MF
Q115
BC546B
R152
3K9 MF
RLY1B
RLY G5Z-2A-E
RLY1C
RLY G5Z-2A-E
C120
470P CD
C118
1N0 CD
R141
470R FU
R142
620R MF
+
C116
100U EL
R145
18K MF
R135
33K MF
R147
4K7 MF
Q114
BC557B
R121
100R MF
PWR 1
IN1
2
IN2
3
0V
4
V-
5
O6
FB
7
RC 8
V+ 9
Z303
TA7317P
+
C123
100U EL R165
47K MF
R154
47K MF
R153
47K MF
R155
47K MF
+
C119
1U0 EL
R157
100K MF
D105
1N4003F
R158
47K MF
Q120
2SC2547
R161
1K0 1W CF
D106
1N4003F
R160
10K MF
R159
100K MF
+
C122
100U EL
+37V
R164
18K MF
-37V
+
C121
1U0 EL
R163
33K MF
R162
47K MF 1 2
LK4
10MM LINK
D107
1N4003F
R167
2K7 1W CF
+37V
R166
2K7 1W CF
R
G
LED201
LED RED/GRN D108
5V6 400MW
Q117
BC546B
Top+
Top-
SK2A
CAMCON_G
Bot+
Bot-
SK2B
CAMCON_G
CHASS
SK2C
CAMCON_G
L101
2U2H LAC SMALL
PWRIR
IQ1R
IQ2R
SPRD
SPRE
SPRS
ACDET
PROTE
PROT
PROTIN
Q118
BC546B
1
2
3
LK805A
L815CA
1
2
3
LK805
L815CA
R146
150R MF
TP22
TP23
TP24
TP25
TP26
TP27
PD6
CHASSIS
EARTH
12 LK3
10MM LINK
12
LK2
10MM LINK
FIT ALL
BUT HK
12 LK5
10MM LINK
12 LK6
10MM LINK
LK5 & LK6 FIT FOR HK ONLY
R156
470R FU
+
C110
22U EL OS
98_1025 1
Initial release
12-05-98LJW
D7
1N4148
D9
1N4003F
C126
100N PC
C128
100N PC
R134
1K MF
+C127
220U EL
C125
100N PC
R139
18K MF
C124
4N7 PP
1 2
LK118
10MM LINK
RV101
10K PSET
RIGHT CHANNEL
R170
680R MF
+
C130
10U CERAFINE
R151
15K MF
R136
100R FU
PWRIR
VI_CH2
SP2_RETN_R
ACSENSE
2LJW
VI_PROTECT
PROT_OP_L
OP_R
SP2_SEND_R
SP2_RETN_L PREMUTE
LISTENING APPROVAL29-05-9898_1029
SK3_7
MUTE
SW99_2
SW99_3

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:\FILES\Products\A1_7_8_8P AMPS\Issue_2\L846C7_3.SCH
A & R Cambridge Ltd.
Pembroke Avenue
Denny Industrial Centre
Waterbeach
Cambridge CB5 9PB
ALPHA 1, 7, 8 & 8P AMP
Circuit Diagram
L846C7_2
LJW
22-Sep-1998
INITIALS
Date Printed 7 7Sheet of
Notes:
RA2
1
RA3
2
RTCC
3
MCLR
4
VSS
5
RB0 6
RB1 7
RB2 8
RB3 9
RB4 10
RB5 11
RB6 12
RB7 13
VDD
14
OSC2
15
OSC1
16
RA0
17 RA1
18
Z901
PIC16C54XT
3
2
1
+5V
O/P
GND Case
RX1
SBX1610-52
D904
5V6 400MW
C904
10N CD
R904
1K8 MF
C903
10N CD
R903
100R MF
R902
100R MF
+
C902
220U EL
C901
10N CD
R901
1R0 FU
D902
5V6 400MW
D901
1N4003F
D903
1N4003F +C907
1M0 25V C906
10N CD
C905
10N CD
MOTE
REMO
MOTSUP
VOLM1
VOLM2
P5V
+5V
+5v
X901
CST4.19MG
VOLUME DRIVE
MOTOR DRIVER
D905
1N4148 R905
4K7 MF
W11
W13
+5V
GND 1
MD1 2
CC1
3
REF
4
MC1
5
MC2
6
VCC1 7 VCC2 8
CC2
9MD2 10
Z902
BA6109
C1000
10N CD
1 2
VOLMOT
1Y271
1 2
VOLMOTA
1Y271
1
2
3
4
5
6
7
8
LK901
L809CA
WARNING SAFETY CRITICAL COMPONENT
REPLACE WITH IDENTICAL PART
1
2
3
LK902A
L815CA
1
2
3
LK902
L815CA
TP29
TP30
TP31
TP32
-
112-05-98
-
LJW
R58
1K8 MF
+5V
12 LK17
10MM LINK
REMOTE CONTROL
VOLUME POT SNAP OFF BOARD
REMOTE SENSOR SNAP OFF BOARD
RV901A
6A360M
RV901B
6A360M
+ -
+
RV901C
6A360M
9
7
Case
RV901D
6A360M
ACLT1
MUTE
98_1026 Initial release
LJW 298_1029 29-05-98 LISTENING APPROVAL
MCLR