Beard P35 Service

Input

R2

680k

R1

2.7k

C1

330p

R31

R35

100k

Scrn

340V-350V

+

C18
680

450V

3.15V

3.15V

110V

0V

TR-Mains-P35

12 0V

TR11

D3

D1

D4

D2

R32
3R3

0V

R33
3R3

C?

270V

100n

110V

0V

12 0V

300V

+

C15
47

450V

R5

47k

C3

2.2p

350V

R7
22k

C7

100n
630V

100V

1

V1"

ECC81

2

220V

C4

100n

630V

6

1M

3

4

9

R6

100V

680R

R9
22k

C8
100n
630V

R8

C5

47p

1.5V

R3

680R

V1'

ECC81

7

8

5 9

+

C2

100

16V

R4

68R

R11

220k

3W10k

R16
10k

220k

R19

120R

R25

100R

3W

R12

V7

EL84

7

2

3

4 5

9V 9V 9V

Tr4 7805

IN GND OUT

+

C12
1000
35V

C9

35V

LK

OUT GND IN

Tr1

7805

4 5

9

7

V2

EL84

R30

100R

3W

9

R17

10k

LK

R22

120R

R20

120R

+

LK

OUT GND IN OUT GND IN

Tr2

9V

R13

10k

3

2

R26

100R

3W

V6

EL84

7

2

3

9

EL84

+

7805

V3

9

4 5

Tr5 7805

IN GND OUT IN GND OUT

LK

C13

1000

35V

C10

1000

+

35V

9V

4 5

3

2

7

R18
10k

R21

120R

R27

100R

3W

R29

100R

R23

120R

R14

10k

3W

Tr3

LK

2

3

9

+

7805

V4

EL84

7

4 5

C14

1000

35V

C11

10001000

35V

4 5

V5

EL84

Tr6 7805

LK

+

9V

3

7

F1

1A

Quick Blow

R28

100R

3W

9

OPT-UL

TR2A

R24
120R

R15

10k

1

2

3

4

5

13

12

11

10

9

Output

8

7

6

C17

100n

630V

HT Secondary
same for other
Channel

Heaters

Output and Mains transformer lead
colours varied so were not marked -

2

Mains transformer may be a drop
through type or fitted above chassis
enabling correct orientation to OPTs for
minimum hum induction - M70 PCB is
same as P35 - If you purchased a
schematic from Beard it is not likely to
reflect the build of your amplifier

R10 1.5k

C6 470p

LK is either a wire link or 1N400X diode - Each EL84 cathode current = 5V/120R with link fitted which is high - Do not use
diodes and make R19-R24 = 150R to reduce dissipation in output transformers or replace Tr1-Tr6 with 270R >1W resistors.
Connection R8-C8 is marked wrong on the drawing that Beard Audio will sell you.
LH Channel similar to RH with reference designators +100 except positions R5 and R7 which are both marked R107?
V101 LH Channel has triodes sections swapped pins 123=678 and vice versa and V105-V106-V107 = V7-V6-V5.
Input is d.c. coupled and C9-C14 are too high value for the output transformer LF response see my modified schematic.
C3 and C5 suspicious - why are they needed ? and C6 somewhat high value for a good OPT design.
C4 C7 and C8 are NOT special capacitors they may be Beard branded but that’s all.

Revision:

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Beard Audio P35 - RH Channel

12 Oct 2023

Checked:Drawn: K. Snook

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