ALPHA 1, 7, 8 & 8P AMP Circuit Diagram

ALPHA 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 

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 

1 

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 

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


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 

2 

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 DC Voltage Alpha One DC Voltage Alpha 7R DC Voltage Alpha 8R/8P 

1 32.8V 35V 37V 

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


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) 

31 

(volume going down) 

32 

(volume going up) 

32 

(volume going down) 

PARTS LISTS 

N/A 0V 0V 

N/A 5V 5V 

N/A 0V 0V 

N/A 5V 5V 

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 

3 

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 


C24 PPRO 4N7 63V 5% RA 2D247N 7R 

C25 PCRB 100N 100V 5% RA 

5mm 

C26 PCRB 100N 100V 5% RA 

5mm 

2H410 7R 

2H410 7R 

C27 ELST 220U 16V 2N722 7R 

C28 PCRB 100N 100V 5% RA 

5mm 

2H410 7R


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 

C126 PCRB 100N 100V 5% RA 

5mm 

2H410 7R 

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 


C204 ELST 10m 50V RA 32mm 2N910 7R 

C204 ELST 6M8 35V RA 2N868 A1 

C205 ELST 10m 50V RA 32mm 2N910 7R 

4 

C205 ELST 6M8 35V RA 2N868 A1 

C206 PCRB 100N 100V 5% RA 

5mm 

C207 PCRB 100N 100V 5% RA 

5mm 

2H410 7R 

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 

C306 CERD 47P 63V -20% +80% 

RA 

2A047 7R 

2A047 7R 

C401 ELST 10U 50V 2N610 7R 

C402 PEST 220N 63V 10% 2K422 7R 

C402 PCRB 100N 100V 5% RA 

5mm 

C403 PCRB 100N 100V 5% RA 

5mm 

2H410 A1 

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


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 

CLAMP 

CL2 ALPHA AMP 7/8 HEATSINK 

CLAMP 

D1 RECTIFIER 1N4003F 1A 

200V 

E82201 7R 

E82201 7R 

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 


200V 

3B4003 8R 

D7 SSDIODE 1N4148 75V 3A4148 7R 


200V 

3B4003 7R 

5 


200V 

3B4003 7R 

D10 ZENER 5V6 400MW 3C05604 8R 


200V 

3B4003 7R 

D102 ZENER 10V 400MW 3C11004 7R 

D103 ZENER 10V 400MW 3C11004 7R 

D104 ZENER 10V 400MW 3C11004 7R 


200V 


200V 


200V 

3B4003 7R 

3B4003 7R 

3B4003 7R 

D108 ZENER 5V6 400MW 3C05604 7R 

D201 ULTRAFAST RECTIFIER 

DIODE UF5403 3A 







3B5403F 7R 

3B5403F 7R 

3B5403F 7R 

3B5403F 7R 

D801 ZENER 5V6 400MW 3C05604 7R 

D802 ZENER 4V7 400MW 3C04704 7R 

D803 SSDIODE 1N4148 75V 3A4148 7R 


200V 

3B4003 7R 

D902 ZENER 5V6 400MW 3C05604 7R 


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 HEATSINK E81801 7R 

HS1 SIL PAD - 25 X 12.5mm E817MC 7R 

HS1 ALPHA AMP 7/8 HS CLIP E810MC 7R 




HS3 SIL PAD - 25 X 12.5mm E817MC 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 

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 MAINS SWITCH SPACER E66901 7R 

PCB PRINTED CIRCUIT BOARD L846PB 7R 

Q1 TRANS PWR MOSFET 

IRF540/SMF045 


IRF540/SMF045 

4K045 7R 

4K045 7R 

Q3 TRANS LF SS P BC556B 4A556 7R 

Q4 TRANS LF SS N BC546B 4A546 7R 

















IRF540/SMF045 


IRF540/SMF045 

4K045 7R 

4K045 7R 


6 
















Q120 TRANS LF SS N 2SC2547 4A2546 7R 

PL1 16 WAY DIL PIN HEADER 8K6316 8P 

R1A RES MO 3W 5% 0R22 

KOASPR3 

R1 RES MO 3W 5% 0R22 

KOASPR3 

1Q922 7R 

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 


NFR25 


NFR25 


NFR25 


NFR25 


NFR25 


NFR25 


NFR25 


NFR25 

1G110 7R 

1G110 7R 

1G110 7R 

1G147 7R 

1G147 7R 

1G147 7R 

1G147 7R 

1G147 7R 

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


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 


NFR25 


NFR25 

1G147 7R 

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 


NFR25 

1G110 7R 

R39 RES MF W4 18K 1% 1H318 7R 

R40 RES MF W4 1% 33K 1H333 A1 


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 

7 

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 

R101 RES MO 3W 5% 0R22 

KOASPR3 

1Q922 7R 

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 

R105 RES MF FU W3 100R 5% 

NFR25 

R106 RES MF FU W3 100R 5% 

NFR25 

R107 RES MF FU W3 470R 5% 

NFR25 

R108 RES MF FU W3 470R 5% 

NFR25 

R109 RES MF FU W3 470R 5% 

NFR25 

R110 RES MF FU W3 470R 5% 

NFR25 

R111 RES MF FU W3 470R 5% 

NFR25 

R112 RES MF FU W3 470R 5% 

NFR25 

1G110 7R 

1G110 7R 

1G110 7R 

1G147 7R 

1G147 7R 

1G147 7R 

1G147 7R 

1G147 7R 

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 

R127 RES MF FU W3 470R 5% 

NFR25 

1G147 7R 

1G147 7R 

R128 RES MF W4 18K 1% 1H318 7R 

R129 RES MF W4 1% 1K2 1H212 7R


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 

R202 RES MF FU W3 470R 5% 

NFR25 

1G147 7R 

1G147 7R 

8 

R203 RES MF FU W3 470R 5% 

NFR25 

R204 RES MF FU W3 470R 5% 

NFR25 

R205 RES MF FU W3 470R 5% 

NFR25 

R206 RES MF FU W3 470R 5% 

NFR25 

1G147 7R 

1G147 7R 

1G147 7R 

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


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 

9 

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 



RV901 POT 20KA DUAL 18MM 

MOTORISED 

RX1 REMOTE CONTROL 

RECEIVER SBX1610-62 

SK1 CAMCON BINDING POST 

4WAY NICKEL 

SK1 CANCON BINDING POST 

4WAY GOLD 

SK2 CAMCON BINDING POST 

4WAY NICKEL 

SK2 CANCON BINDING POST 

4WAY GOLD 

6A360M 7R 

B2103 7R 

8D418 7R 

8D418G 8R/8P 

8D418 7R 

8D418G 8R/8P 

SK3 STEREO JACK PCB 8D301 7R 

SK4 CAGE CLAMP 16A 3 WAY 

ARC001-236 


ARC003-236 

SK6 CAGE CLAMP 16A 2WAY 

236-402/000-009 


ARC004-236 

SK201 IEC MAINS CONN PCB INS 

PX 

8Q001 7R 

8Q003 7R 

8Q005 7R 

8Q004 7R 

8A001 7R 

SK301 PHONO SKT 4-WAY EMC 8D224 7R 

SK301 PHONO SKT 4-WAY EMC 

GOLD 

8D225 8R/8P 



GOLD 




GOLD 




GOLD 

SW1 SWITCH SLIDE 2WAY C/O 

PANEL MNT PCB 


A1403 8R


SW201 SW PUSH MAINS 

SDDSA32MZU 

A1007 7R 

SW302 SW PUSH 4PCO A1013 8R 

SW305 SWITCH SRBU 150 44A A1202 7R 

SW305 SWITCH 4POLE SRBU 

5WAY 

TX1 ALPHA 7 AMP MULTI 

VOLTAGE TRANSFORM 

TX1 ALPHA 1/5.2 

TRANSFORMER 230V 

TX1 ALPHA 8 AMP MULTI 

VOLTAGE TRANSFORM 

A1212 8R 

L835TX 7R 

L841TX A1 

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 


Z303 IC COMPARITOR TA7317P 5M7317 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 PIN 0.3'' 8S018 7R 

Z901 IC CMOS MICRO 

PIC16C54XT/P 

5H16C54X 7R 

Z902 MOTOR DRIVER 5Q6109 5Q6109 7R 

10

D 

C 

B 

A 

MAINS_N 

MAINS_E 

MAINS_L 

W12 

1 

LK1001 

LINK10NP 

LK1002 

LINK10NP 

LK1003 

LINK10NP 

LK1004 

LINK10NP 

LK1005 

LINK10NP 

LK1006 

LINK10NP 

C15 

SK201 

IEC3 

N 

4N7 MAINS 

MAINS INPUT 

N E L 

PD1 

E 

TOOLING 

LK1007 

LINK10NP 

LK1008 

LINK10NP 

LK1009 

LINK10NP 

LK1010 

LINK10NP 

LK1011 

LINK10NP 

LK1012 

LINK10NP 

L 

A1007 

R207 

100R MF 

LK1013 

LINK10NP 

LK1014 

LINK10NP 

LK1015 

LINK10NP 

LK1016 

LINK10NP 

LK1017 

LINK10NP 

LK1018 

LINK10NP 

C23 

4N7 MAINS 

MAINS SWITCH 

SW201A 

T1 

W10 

LK1019 

LINK10NP 

LK1020 

LINK10NP 

LK1021 

LINK10NP 

LK1023 

LINK10NP 

LK1024 

LINK10NP 

PD2 

TOOLING 

SW201B 

A1007 

2 

C201 

FS201 

AS1A25 

4N7 MAINS 

Chassis Earth Point, 

Use correct screw and washer. 

WARNING SAFETY CRITICAL COMPONENT 

REPLACE WITH IDENTICAL PART 

LK1025 

LINK10NP 

LK1026 

LINK10NP 

LK1027 

LINK10NP 

LK1028 

LINK10NP 

LK1029 

LINK10NP 

LK1030 

LINK10NP 

PD3 

TOOLING 

LK1031 

LINK10NP 

LK1032 

LINK10NP 

LK1033 

LINK10NP 

LK1034 

LINK10NP 

LK1035 

LINK10NP 

LK1036 

LINK10NP 

PD4 

TOOLING 

SELECT VOLTAGE 

BY FITTING FS201 

OR FS202 

FIT ONLY ONE FUSE 

MS 

LK1037 

LINK10NP 

LK1038 

LINK10NP 

LK1039 

LINK10NP 

LK1041 

LINK10NP 

LK1042 

LINK10NP 

C200 

1N0 CD 

T2 

FS202 

AS2A5_115V 

T3 

GREEN 

LK1043 

LINK10NP 

LK1044 

LINK10NP 

LK1045 

LINK10NP 

LK1046 

LINK10NP 

LK1047 

LINK10NP 

LK1048 

PD5 

TOOLING 

LINK10NP 

MAINS SW SPACER 

MAINS_SW_SPACER 

3 

LK1049 

LINK10NP 

LK1050 

LINK10NP 

LK1051 

LINK10NP 

LK1052 

LINK10NP 

LK1053 

LINK10NP 

LK1054 

2 

Dark Grey 

1 

Blue 

Orange 

3 

SK4 

CAGECLAMP3 

BLUE2 

SK5 

1 

Green 


LINK10NP 

PD7 

TOOLING 

230V 

115V 

SCREEN 

EL1 

Spare Fuse Clip 

FUSE CLIP 

WAF 

WAF 

WAF 

LK1055 

LINK10NP 

LK1056 

LINK10NP 

LK1057 

LINK10NP 

LK1058 

LINK10NP 

LK1059 

LINK10NP 

LK1060 

LINK10NP 

PD8 

TARGET1 

TX1 

L833TX 

BARCD 

LK1063 

LINK10NP 

LK1064 

LINK10NP 

LK1065 

LINK10NP 

LK1066 

LINK10NP 

LK1067 

4 

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 

DRAWING TITLE 

ALPHA 1,7, 8 & 8P AMP 

23425 

A & R Cambridge Ltd. 

Pembroke Avenue 

Denny Industrial Centre 

Waterbeach 

Cambridge CB5 9PB 

1 2 3 4 5 6 7 8 

LK1085 

LINK10NP 

LK1086 

LINK10NP 

LK1087 

LINK10NP 

LK1088 

LINK10NP 

LK1089 

LINK10NP 

LK1090 

LINK10NP 

Notes: 

LK1091 

Filename 

5 

LINK10NP 

LK1092 

LINK10NP 

LK1093 

LINK10NP 

LK1094 

LINK10NP 

LK1095 

LINK10NP 

LK1096 

LINK10NP 

+ C205 

+37V 

+ C204 

10M EL 50V 

10M EL 50V 

LK1097 

LINK10NP 

LK1098 

LINK10NP 

LK1099 

LINK10NP 

LK1100 

LINK10NP 

LK1101 

LINK10NP 

LK1102 

LINK10NP 

-37V 

PSUP 

C207 

100N PC 

NSUP 

LK1103 

LINK10NP 

LK1104 

LINK10NP 

LK1105 

LINK10NP 

LK1106 

LINK10NP 

LK1107 

LINK10NP 

LK1108 

LINK10NP 

C206 

100N PC 

Circuit Diagram 

POWRE 

LK1109 

J:\FILES\Products\A1_7_8_8P AMPS\Issue_2\L846C2_3.SCH 

LINK10NP 

LK1110 

LINK10NP 

LK1111 

LINK10NP 

LK1112 

LINK10NP 

LK1113 

LINK10NP 

LK1114 

LINK10NP 

PD9 

TARGET1 PD10 PD11 PD12 PD13 PD14 Y1 

Y2 

TOOLING TOOLING TOOLING TOOLING TOOLING TX WIRE CLIP TX WIRE CLIP 

9Vac 

BARCODE 

LK1062 

LINK10NP 

Orange 

Blue 

Orange 

PCB 

SK7 

Grey 

Grey 

SK6 

1 

2 


1 

2 

3 

CAGECLAMP3A 

BARCODE LABEL 

L846PB 

PCB 

OR1 

GREY2 

BLUE1 

OR2 

LK1076 

LINK10NP 

ACLT1 

GREY1 

LK1081 

ACSENSE 

Test point for service engineers are shown as 

See additional service documentation for details. 

DD3 

LINK10NP 

D201 

UF5403 

D202 

UF5403 

Drilling Detail 

Issue Box 

DD_ISSUE 

D203 

UF5403 

D204 

UF5403 

TP1 

DD4 

TP4 

PCB MATERIAL 

CEM1, 2 OZ Cu 

CEM1_20Z 

TP28 

PS 

POWER SUPPLY 

Photo Strip 

PHOTO_STRIP 

6 

R204 470R FU 

R205 470R FU 

R206 470R FU 

LK1115 

LINK10NP 

LK1116 

LINK10NP 

LK1117 

LINK10NP 

LK1118 

LINK10NP 

LK1119 

LINK10NP 

LK1120 

LINK10NP 

R201 

470R FU 

R202 

470R FU 

R203 

470R FU 

DD 

TP2 

Drilling 

Detail 

DRILL_DWG 

98_1029 

98_1025 

ECO No. INITIALS DATE 

DESCRIPTION OF CHANGE 

Date Printed 

LK1121 

LINK10NP 

LK1122 

LINK10NP 

LK12 

LINK10NP 

LK13 

LINK10NP 

LK1125 

LINK10NP 

LK14 

LINK10NP 

I 

C208 

4N7 PP 

Z201 

7815 

Vin 

C209 

4N7 PP 

TP5 

LJW 

22-Sep-1998 

GND 

G 

Vout O 

G 

I GND 

Vin 

Z202 

7915 

LK1127 

LINK10NP 

LK1128 

LINK10NP 

LK1129 

LINK10NP 

LK1130 

LINK10NP 

LK1131 

LINK10NP 

LK1132 

LINK10NP 

DD1 

LJW 12-05-98 

A1 Horizontal 

Paper Marker 

DD_A1H 

29-05-98 

Drawn by: 

LJW 

7 

LK1133 

LINK10NP 

LK1134 

LINK10NP 

LK1135 

LINK10NP 

LK1136 

LINK10NP 

LK1137 

LINK10NP 

LK1138 

LINK10NP 

P15V 

Vout O 

P15V 

+ C210 

10U EL 

N15V 

TP3 

+ C211 

10U EL 

DD2 

A1 Vertical 

Paper Marker 

DD_A1V 

LISTENING APPROVAL 

Initial release 

N15V 

Sheet 2 of 7 

TP6 

EL2 

DRAWING NO. 

8 

Update Box_2 

UPDATE_BOX_2 

L846C2_2 

2 

1 

ISSUE 

D 

C 

B 

A

D 

C 

B 

A 

EMC 

PHINL 

SK301A 

N 

F 

1 

PHONO4G 

PHINR 

1 

10 

2 

PHINE 

LK701 

1 

10MM LINK 

C701 

100P PP 

R701 

47K MF 

+ 

2 

C702 

47P CD 

R702 

470R MF 

C703 

22U EL 

3 

2 

Z305A 

NE5532 

R703 

680K MF 

C704 

4N7 PP 

1 

R704 

56K MF 

C705 

1N3 PP 

+ 

1 

2 

3 

C706 

10U EL 

1 

5 

Z305B 

NE5532 

7 

C606 

SW302C 

4PCO 

C602 

47P CD 

6 

10U EL 

2 

LK601 

1 

R601 

10MM LINK R603 R604 

7 

11 

SW302D 

4PCO 

8 

12 

9 

Z305C 

NE5532 

C601 

100P PP 

8 

4 

47K MF 

P15V 

N15V 

+ 

C301 

10N CD 

C302 

10N CD 

R602 

470R MF 

C603 

22U EL 

680K MF 

C604 

4N7 PP 

3 

6 

2 

5 

SW302B 

4PCO 

56K MF 

SW302A 

4PCO 

TP7 

TP8 

1 

2 

4 

5 

6 

C605 

1N3 PP 

1 

2 

3 

1 

4 

LK19B 

L835CA 

SW1 

SLIDE2H 

LK19B TO LK19A ON MAIN BOARD 

SLIDER SWITCH FOR AV 

+ 

2 

LK8 

MINI_LK 

FITTED BY HAND 

ON ALPHA 1 AMP ONLY 

LK702 

10MM LINK 

LK602 

10MM LINK 

R705 

820R MF 

LK9 

FITTED BY HAND 

ON ALPHA 1 AMP ONLY 

MINI_LK 

R605 

820R MF 

4 

VCRL TUNL COL AVL 

VCR TUNER CD AV/DVD TAPE IN 

N 

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 

F 

SK301B 

PHONO4G 

C303 

1N0 CD 

EMC 

N 

F 

LK19A 

L835CA 

1 

2 

SK302A 

PHONO4G 

1 

16 

15 

17 

N 

F 

14 

18 

SK302B 

PHONO4G 

VCRR TUNR COR AVR TAPR 

DRAWING TITLE 

ALPHA 1, 7, 8 & 8P AMP 

23425 




Waterbeach 


1 2 3 4 5 6 7 8 

13 

SW305C 

ROTARY4H 

LK19A TO SNAP OFF BOARD FOR SLIDER SWITCH 

MCLR 

Notes: 

Filename 

EMC 

5 

R43 

22K MF 

N 

F 

1 

SK303A 

PHONO4G 

D10 

5V6 400MW 

9 

4 

21 

10 

8 

3 

5 

22 

20 

11 

7 

2 

6 

23 

19 

R57 

2K7 1W CF 


TAPL 


N 

F 

12 

SW305B 

ROTARY4H 

SK303B 

PHONO4G 

1 

SW305A 

ROTARY4H 

24 

SW305D 

ROTARY4H 

+ C29 

C304 

1N0 CD 

PHONO & INPUTS 

+37V 

1U0 EL 

4 

6 

5 

SW301B 

2PCO 

R501 

1K8 MF 

TAPE OUT 

8P - LINK 

EMC 

D6 

1N4003F 

N 

F 

1 

SK304A 

PHONO4G 

R401 

1K8 MF 

SW301A 

2PCO 

1 

6 

RLY2C 

RLY 51SB12T 

8P ONLY 

LK804 

10MM LINK 

1 2 

2 

3 



Date Printed 

PREAMP OUT 

8P - PWR IN 

TAPEOL 

TAPEOR 

N 

F 

22-Sep-1998 

SIGE 

SK304B 

PHONO4G 

LK803 

1 2 

10MM LINK 


1 2 

LK11 

10MM LINK 

CUT WHEN CIM FITTED 

PREOUTR 

LK901A 

1 

2 

3 

4 

5 

6 

7 

8 

L809CA 

1 2 

LK10 

10MM LINK 

PREOR 

R505 

4K7 MF 

CUT WHEN CIM FITTED 

PREOL 

Drawn by: 

LJW 

7 

C305 

47P CD 

R405 

4K7 MF 

R502 

98_1029 LJW 29-05-98 LISTENING APPROVAL 

98_1025 LJW 12-05-98 

R59 

2K2 MF 

PREOUTL 

Initial release 

PL1 

R44 

47K MF 

68K MF 

RV301B 

20K LOG POT 

1 2 

3 4 

5 6 

7 8 

9 10 

11 12 

13 14 

15 16 

DIL16 VPLG 

C306 

47P CD 

Sheet 3 of 7 

R60 

2K2 MF 

LK15 

10MM LINK 

1 2 

R55 

22K MF 

LK16 

10MM LINK 

R54 

68K MF 

R402 

47K MF 

DRAWING NO. 

8 

RV301A 

20K LOG POT 

RLY2B 

RLY 51SB12T 

1 2 

VOLL 

VOLR 

RLY2A 

RLY 51SB12T 

L846C3_2 

R56 

22K MF 

2 

1 

ISSUE 

D 

C 

B 

A

D 

C 

B 

A 

VOLR 

8 

4 

LK19 

1 

R516 

1K8 MF 

C507 

100P CD 

1 2 

VOLR 

10MM LINK 

TONOR 

LK20 

1 2 

VOLL 

10MM LINK 

TONOL 

Z300C 

4560D 

R63 

56K MF 

8 

4 

3 

2 

R503 

2K2 MF 

Z302C 

4560D 

Z300A 

4560D 

R504 

6K8 MF 

R64 

56K MF 

8 

4 

1 

6 

5 

4 

3 

2 

1 

R801 

2 

SW304B 

2PCO 

SW304A 

2PCO 

4K7 MF 

(560R MF in 8P) 

R805 

4K7 MF 

(560R MF in 8P) 

P15V 

C501 

+ 

10U EL 

Z304C 

4560D 

N15V 

R506 

220R MF 

C212 

10N CD 

C213 

10N CD 

C801 

100P PP 

C802 

100P PP 

R507 

4K7 MF 

C502 

220N PE 

Tone controls : 

8dB cut and boost 

C214 

10N CD 

C215 

10N CD 

R509 

3K3 MF 

C406 

100P CD 

R802 

100K MF 

(3k9 MF in 8P) 

BASS 

RV302A 

10K LIN POT 

R511 

4K7 MF 

RV303A 

10K LIN POT 

TREBLE 

R804 

5K6 MF 

R803 

2K4 MF 

R808 

5K6 MF 

R807 

2K4 MF 

GND 

8 

3 

R508 

4K7 MF 

C503 

220N PE 

R510 

3K3 MF 

Pot arrow shows max boost 

3 

2 

5 

Z302A 

4560D 

Z302B 

6 

R806 

100K MF 4560D 

(3k9 MF in 8P) 

C216 

10N CD 

C217 

10N CD 

C504 

4N7 PP 

1 

7 

VDD 16 

Z801B 

P74HC4052 

PREG 

5 

6 

TP19 

TP20 

PREP 

Z304B 

4560D 

C508 

10P CD 

C805 

10N CD 

C806 

10N CD 

7 

TP17 

P15V 

N15V 

C505 

+ 

10U EL 

C803 

+ 

10U EL 

C804 

+ 

10U EL 

R815 

1K2 MF 

D801 

5V6 400MW 

D802 

4V7 400MW 

R816 

1K2 MF 

R61 

18K MF 

4 

VOLL 

R512 

10K MF 

R515 

3K3 MF 

R809 

100K MF 

R817 

18K MF 

PREN 

RV304A 

10K LIN POT 

BALANCE 

R810 

100K MF 

TP21 

R416 

1K8 MF 

DRAWING TITLE 


23425 




Waterbeach 


1 2 3 4 5 6 7 8 

TONOR 

12 

14 

15 

11 

1 

5 

2 

4 

6 

9 

10 

C407 

100P CD 

Z801A 

1Y0 

1Y1 

1Y2 

1Y3 

2Y0 

2Y1 

2Y2 

2Y3 

INH 

S1 

S0 

D803 

1N4148 

P74HC4052 

Notes: 

5 

6 

Filename 

1Z 

2Z 

5 

R404 

13 

3 

VEE 7 

PREMUTE 

PREMUTE 

Z300B 

4560D 

6K8 MF 

R403 

2K2 MF 

7 

C401 

R811 

220R MF 

R812 

R406 

220R MF 

10U EL 

+ 

220R MF 


TONE CONTROL 

R813 

22K MF 


R407 

4K7 MF 

C402 

220N PE 

R409 

6 

Tone controls : 

8dB cut and boost 

R814 

22K MF 

BASS 

RV302B 

10K LIN POT 

R411 

4K7 MF 

R819 

8K2 MF 




Date Printed 

R408 

4K7 MF 

C403 

220N PE 

R410 

3K3 MF RV303B 

10K LIN POT 

3K3 MF 

C506 

TREBLE 

100P CDPot 

arrow shows max boost 

98_1029 

C404 

4N7 PP 

LJW 

22-Sep-1998 

R818 

8K2 MF 


29-05-98 

3 

2 

PWRIR 

PWRIL 

Drawn by: 

LJW 

7 

Z304A 

4560D 

C408 

10P CD 

1 

TP18 

C405 

+ 

10U EL 

Sheet 4 of 7 

R412 

10K 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. 

PREOUTR 

PREOUTL 

FIT LINKS AS BELOW 

LINK 

1 

2 

3 

4 

5 

6 

7 

601 

602 

701 

702 

803 

804 

1 7 8 8P 


R62 

18K MF 

R415 

3K3 MF 

DRAWING NO. 

8 

RV304B 

10K LIN POT 

BALANCE 

98_1025 LJW 12-05-98 Initial release 

1 

L846C4_2 

TONOL 

2 

ISSUE 

D 

C 

B 

A

D 

C 

B 

A 

PWRIL 

R32 

1 

33K MF 

R31 

1K0 CF 

2 

3 

C10 

+ 

R40 

33K MF 

C9 

Z301A 

22U EL OS 

+ 

PWRIL 

8 

4 

+ 

100U EL 

NE5532 

R33 

C30 

680K MF 

10U CERAFINE 

AMPEL 

P15V 

N15V 

TP9 

1 

R34 

1K MF 

Z301C 

NE5532 

R38 

680K MF 

C8 

100P PP 

SRVOL 

R37 

47K MF 

C21 

10N CD 

C22 

10N CD 

C6 

47N PE 

R30 

33K MF 

Q11 

BC547B 

R24 

2K7 MF 

2 

Q16 

BC557B 

Q13 

C7 

BC547B 

4N7 PP 

R25 

330R MF 

LK18 

10MM LINK 

1 2 

R29 

1K2 MF 

Q10 

BC547B 

R19 

5K6 CF 

R23 

2K7 MF 

Q12 

BC547B 

Q7 

BC556B Q6 

BC556B 

C5 

33P PS 

R20 

15K MF 

R70 

680R MF R22 

120R MF 

C25 

100N PC 

D5 

1N4148 

C13 

15N PE + 

R28 

18K MF 

C12 

100U EL 100V 

CL1 

E82201 

HS1 HS2 

E81801 

C24 

4N7 PP 

+ C27 

220U EL 

E81801 

R15 

1K0 CF 

R39 

18K MF 

Q9 

BC546B 

R16 

2K7 MF 

3 

R17 

5K6 MF 

R51 BC546B 

15K MF Q15 

R52 

3K9 MF 

CL2 

E82201 

HS3 

E81801 

TP10 

RV1 

10K PSET 

TP12 

Place Q15 by hsk. 

Q8 

BC546B 

R18 

2K7 MF 

HS4 

E81801 

R12 

470R FU 

Q4 

BC546B 

C4 

47N PE 

Q5 

BC556B 

R8 

470R FU 

R27 

470R FU 

C14 

15N PE 

R9 

470R FU 

Q3 

BC556B 

R10 

470R FU 

R13 

1K0 MF 

R14 

1K0 MF 

R11 

470R FU 

-37V 

4 

R26 

+ C11 

470R FU 

100U EL 100V 

D4 

Q14 

BC557B 

D3 

10V 400MW 

10V 400MW 

R6 

100R FU 

TP13 

R21 

100R MF 

C28 

100N PC 

Q1 

IRF540 

R5 

100R FU 

R7 

470R FU 

R1A 

0R22 3W MO 

DRAWING TITLE 


23425 




Waterbeach 


1 2 3 4 5 6 7 8 

D2 

10V 400MW 

C1 

100U EL 100V + 

Q2 

IRF540 

TP14 

R1 

0R22 3W MO 

TP15 

IQ2L 

Notes: 

Filename 

5 

D1 

1N4003F 

R4 

100R FU 

+37V 

C2 

47N PE 

R2 

4R7 W2 CF 

C3 

100N PC 

IQ1L 

TP11 

R3 

2R2 CF 

R35 

33K MF 

R41 

470R FU 

R42 

620R MF 

SK3 

HPSKT 

L1 

2U2H LAC SMALL 

LHC 2 

RHC 3 

1 

RLY1A 


RLY G5Z-2A-E 


L 

4 

5 

6 

R 7 

PROT_OP_L 

+ C16 

SPLE 

PD6 

TOOLING 

PD6 

R36 

100R FU 

R46 

150R MF 

100U EL 

LEFT CHANNEL 

OP_L 

PREMUTE 

SK3_7 

R150 

100R W2 CF 

C18 

1N0 CD 

D8 

1N4003F 

6 

SPLD 

C17 

470P CD 

R45 

Q17 

BC546B 

18K MF 



Date Printed 

R49 

SW99A 

2PCO 

1 

330R 1W CF 

R149 

R50 

100R W2 CF 

SK1A 

Top+ 

Top- 

SK1C 

CAMCON_G 

330R 1W CF 

CHASS 

CAMCON_G 

HPR 

HPE 

HPL 

SP2_SEND_L 

98_1025 

C26 

100N PC 

R53 

18K MF 

4 

22-Sep-1998 

2 

1 

LK1 

10MM LINK 

2 

5 

SW99B 

2PCO 

3 

6 

R47 

4K7 MF 

Q18 

BC546B 

Drawn by: 

LJW 

7 

LK7 

10MM LINK 

1 2 

SP2_RETN_L 

SW99_3 

SW99_2 

C20 

470P CD 

VI_CH2 

LK311 

1 

2 

3 

4 

5 

6 

7 

L825CA 

Q19 

SK1B 

BC556B 


LJW 12-05-98 Initial release 

LK311A 

1 

2 

3 

4 

5 

6 

7 

L825CA 

SPLS 

Bot+ 

Bot- 

CAMCON_G 

TP16 

Sheet 5 of 7 

SP2_SEND_L 

SP2_RETN_L 

SP2_RETN_R 

SP2_SEND_R 

OP_L 

OP_R 

R48 

47K MF 

+ 

DRAWING NO. 

8 

C19 

100U EL 

VI_PROTECT 

L846C5_2 

2 

1 

ISSUE 

D 

C 

B 

A

D 

C 

B 

A 

PWRIR 

PWRIR 

R132 

33K MF 

1 

R131 

1K0 CF 

6 

5 

C110 

+ 

R140 

33K MF 

Z301B 

C109 

NE5532 

22U EL OS 

+ 

C130 

10U CERAFINE 

+ 

100U EL 

7 

R133 

680K MF 

AMPER 

R134 

1K MF 

C108 

100P PP 

SRVOR 

R138 

680K MF 

TP22 

R137 

47K MF 

C106 

47N PE 

R130 

33K MF 

Q111 

BC547B 

R124 

2K7 MF 

Q116 

BC557B 

Q113 

C107 

BC547B 

4N7 PP 

2 

R125 

330R MF 

R170 

680R MF 

10MM LINK 

1 2 LK118 

R129 

1K2 MF 

Q110 

BC547B 

C113 

15N PE + 

R119 

5K6 CF 

R123 

2K7 MF 

Q112 

BC547B 

C125 

100N PC 

C124 

4N7 PP 

R115 

1K0 CF 

Q107 

BC556B Q106 

BC556B 

C105 

33P PS 

R120 

15K MF 

R122 

120R MF 

+ C127 

220U EL 

D7 

1N4148 

R128 

18K MF 

C112 

100U EL 100V 

R139 

18K MF 

Q119 

BC546B 

R116 

2K7 MF 

R151 

15K MF 

TP23 

3 

R117 

5K6 MF 

Q115 

BC546B 

R152 

3K9 MF 

RV101 

10K PSET 

TP24 

Q108 

BC546B 

R112 

470R FU 

Q104 

BC546B 

C104 

47N PE 

Q105 

BC556B 

R118 

2K7 MF 

R127 

470R FU 

C114 

15N PE 

Q103 

BC556B 

R110 

470R FU 

R113 

1K0 MF 

R114 

1K0 MF 

R111 

470R FU 

R108 

470R FU 

R109 

470R FU 

R126 

4 

470R FU 

+ C111 

100U EL 100V 

D103 

10V 400MW 

R106 

100R FU 

D104 

10V 400MW 

R121 

100R MF 

C128 

100N PC 

Q101 

IRF540 

R101A 

0R22 3W MO 

TP27 

-37V 

R105 

100R FU 

Q114 

BC557B 

C101 

100U EL 100V + 

R107 

470R FU 

TP26 

DRAWING TITLE 


23425 




Waterbeach 


1 2 3 4 5 6 7 8 

+37V 

D102 

10V 400MW 

Q102 

IRF540 

D101 

1N4003F 

R104 

100R FU 

R101 

0R22 3W MO 

C102 

47N PE 

R102 

4R7 W2 CF 

C103 

100N PC 

IQ1R 

IQ2R 

Notes: 

Filename 

5 

L101 

2U2H LAC SMALL 

R103 

2R2 CF 

R135 

33K MF 

R141 

470R FU 

R142 

620R MF 

VI_PROTECT 

PROT_OP_L 

R136 

100R FU 

C116 

100U EL 

RLY1B 

RLY G5Z-2A-E 


C118 

1N0 CD 


+ 

OP_R 

PD6 

CHASSIS 

EARTH 

R146 

150R MF 

D9 

1N4003F 

RIGHT CHANNEL 

PROTIN 

R153 

47K MF 

R154 

47K MF 

SPRD 

C117 

470P CD 

Q117 

BC546B 

R145 

18K MF 

6 

ACDET 

SK2A 

Top+ 

Top- 

CAMCON_G 

SK2C 

CAMCON_G 

LED201 

SPRE 

SP2_SEND_R 

1 

LK2 

10MM LINK 

2 

CHASS 

G 

R 



Date Printed 

+ 

D105 

1N4003F 

R155 

47K MF 

C123 

100U EL 

22-Sep-1998 

+ 

R147 

4K7 MF 

R157 

100K MF 

C119 

1U0 EL 

2 

R165 

47K MF 

3 

IN1 

IN2 

Drawn by: 

LJW 

PWR 1 

V- 

5 

Z303 

TA7317P 

7 

R158 

47K MF 

RC 8 

0V 

4 

R159 

100K MF 

C122 

100U EL 

9 

V+ 

FB 

7 

+ 

O 6 

C120 

470P CD 

Sheet 6 of 7 

+37V 

R160 

10K MF 

D106 

1N4003F 

Q120 

2SC2547 

R164 

SP2_RETN_L PREMUTE 

18K MF 

LED RED/GRN 

C126 

100N PC 

98_1029 

R156 

470R FU 

LJW 

TP25 

LK805A 

1 

2 

3 

L815CA 

Q118 

BC546B 

29-05-98 

ACSENSE 

LK805 

1 

2 

3 

VI_CH2 

L815CA 

-37V 

SP2_RETN_R 

C121 

+ 

1U0 EL 

R163 

33K MF 

D108 

5V6 400MW 


MUTE 

R162 

47K MF 

R166 

SK3_7 

PROTE 

2K7 1W CF 

DRAWING NO. 

8 

RLY1C 

RLY G5Z-2A-E 

R161 

1K0 1W CF 

LK4 

1 2 

10MM LINK 

+37V 

SK2B 

1 

210MM 

LINK 

LK3 

FIT ALL 

BUT HK 

R167 

2K7 1W CF 

SPRS 

Bot+ 

Bot- 

D107 

CAMCON_G 

1 

10MM LINK 

2 

LK5 

1N4003F 


1 

L846C6_2 

SW99_2 

SW99_3 

LK5 & LK6 FIT 

FOR HK ONLY 

1 

LK6 

2 

PROT 

2 

ISSUE 

10MM LINK 

D 

C 

B 

A

D 

C 

B 

A 

1 

W13 

ACLT1 

W11 

R901 

1R0 FU 

C901 

10N CD 

MOTE 

D901 

1N4003F 

C902 

220U EL 

2 

R902 

100R MF 

+5V 

WARNING SAFETY CRITICAL COMPONENT 

REPLACE WITH IDENTICAL PART 

+ 

D903 

3 

1N4003F 

TP30 

+ C907 

1M0 25V 

TP29 

R903 

100R MF 

C903 

10N CD 

D902 

5V6 400MW 

+5V 

LK902A 

1 

2 

3 

L815CA 

C904 

10N CD 

R904 

1K8 MF 

REMO 

2 

LK17 

10MM LINK 

D904 

5V6 400MW 

1 

MCLR 

+5V 

R58 

1K8 MF 

17 

18 

1 

2 

3 

4 

Z901 

PIC16C54XT 

RA0 

16 

OSC1 

X901 

3 

5 

4 

6 

9 

RA1 

RA2 

RA3 

RTCC 

MCLR 

CST4.19MG 

CC1 

MC1 

REF 

MC2 

CC2 

Z902 

BA6109 

OSC2 

15 

VSS 

5 

7 

VCC1 

RB0 

RB1 

RB2 

RB3 

RB4 

RB5 

RB6 

RB7 

VDD 

14 

8 

VCC2 

MOTOR DRIVER 

VOLUME DRIVE 

6 

7 

8 

9 

10 

11 

12 

13 

P5V 

4 

+5v 

MD1 

GND 1 

MD2 

2 

10 

D905 

1N4148 

R905 

4K7 MF 

DRAWING TITLE 


- 

23425 

A & R 

- 

Cambridge Ltd. 



Waterbeach 


1 2 3 4 5 6 7 8 

VOLM1 

C905 

10N CD 

1 2 

VOLM2 

Notes: 

Filename 

5 

C906 

10N CD 

TP31 

VOLMOT 

1Y271 

TP32 

MUTE 

MOTSUP 


REMOTE CONTROL 


6 



Date Printed 

+ - 

+ 

22-Sep-1998 

LK901 

L809CA 

1 

2 

3 

4 

5 

6 

7 

8 

RV901C 

6A360M 

Drawn by: 

LJW 

1 

7 

C1000 

10N CD 

RX1 

SBX1610-52 

3 

+5V 

O/P 

GND Case 


RV901A 

6A360M 

RV901B 

6A360M 

1 2 

VOLUME POT SNAP OFF BOARD 

2 

VOLMOTA 

1Y271 

Sheet 7 of 7 

RV901D 

7 

9 

Case 

6A360M 

LK902 

1 

2 

3 

L815CA 

REMOTE SENSOR SNAP OFF BOARD 


2 

DRAWING NO. 

8 

L846C7_2 

1 

ISSUE 

D 

C 

B 

A

ALPHA 1, 7, 8 & 8P AMP Circuit Diagram

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