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3
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B
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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
7
Sheet
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
5
2Y2
2
2Y3
4
INH
6
S1
9
S0
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 ONLY
8P 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
PREMUTE
PREP
PREN
PREG
R516
1K8 MF
R416
1K8 MF
3
2
1
Z304A
4560D
5
6
7
Z304B
4560D
3
2
1
Z302A
4560D
5
6
7
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
2
1
Z300A
4560D
5
6
7
Z300B
4560D
8
4
Z300C
4560D
8
4
Z302C
4560D
8
4
Z304C
4560D
1
LJW
LJW
12-05-98
98_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 APPROVAL
29-05-98
98_1029
TONOL
TONOR