JVC HA-NC70-J/C/E Schematics

Block diagram

Lch
ECM

Rch
ECM

R03/AAA

Battery

DC1.5V

VR1

LPF BPF

NC

Adjustment

VR2

LPF BPF

NC

Adjustment

Power

SW

LED lighting
circuit

INPUT

Lch

Rch

GND

Phase

reversal

circuit

Phase

reversal

circuit

POWER IC

LA4537M

POWER IC

LA4537M

INPUT

VOLUME

Lch-SP

Rch-SP

(No.XC029) 2-1

Standard schematic diagram

R17

330

C3

22u 6.3V

Lch

R1

2.2k

C1

+

Lch

ECM

2.2u

D3

UDZS10B

R3

33k

R5

33k

C5

0.022u

C7

0.0056u

R7
110k

Q1
2SC4081

C9

2.2u
R9

470

R11
390k

Q3

2SC4081

R13

1.5k

R15
75

2.2u

C11

VR1

10kB

R19

8.2k

LEFT Ch

NC ADJ

C13

0.1u
R21

12k

C15

0.22u

C17

0.47u

R23
270k

Q5

2SC4081

R27
680

R25
680

220u 4V

C23

2.2u

C21

2.2u

C19

R29
150

+

+

C31

10u 4V

IC1

LA4537M

1

P/SW

2

IN1

3

PRE G

4

IN2

REF5VCC

MUTE SW

OUT1

PWR G

OUT2

C25

100u 4V

R31
15k

10

9

8

7

6

+

C33

0.1u

220u 4V

C35

0.1u

C27

+

R33

2.2

R35

R37

33

4.7

Lch SPEAKER

+

C29
220u 4V

R39

2.2

C4

22u 6.3V

Rch

R18

330

R2

2.2k

C2

+

Rch

ECM

2.2u

D4

UDZS10B

R4

39k

R6

39k

C6

0.022u

C8

0.0056u

R8
110k

Q2
2SC4081

C10

2.2u

R10
470

R12
390k

Q4

2SC4081

R14

1.5k

R16
75

C12

2.2u

VR2

10kB

POWER SW

BATT
R03

1.5V

S1

R41
22k

R43
270

C38

0.0015u

Q7

2SC4081

C39

0.0015u

R42
22k

Q8

2SC4081

R44

270

C40

0.22u

D1

2R4HD-3

D2
MA2J111

+

C37

470u 4V

Use of Circuit Diagram

Notes:

1. The thick line ( ) is the B (+) power supply.

2. This circuit diagram is the r
improvement.

3. Values printed in red show the voltar
with the power switch ON.

4. Parts marked with (in the shaded ar

!

designated parts to ensure safety.

eference diagram. Cir cuits and constans ar e subject to change without notice for

es of each section measured by the tester (internal resistance 20 kOhms/V),

R30

R20

8.2k

RIGHT Ch

NC ADJ

Lch

INPUT

GND

Rch

INPUT

C14

0.1u
R22

12k

C16

0.22u

C18

0.47u

R24
270k

Q6

2SC4081

R28
680

R26
680

C24

2.2u

220u 4V

2.2u

C22

C20

+

150

+

C32

C41

0.0047

10u 4V

C42

0.0047

IC2

LA4537M

1

P/SW

MUTE SW

2

IN1

OUT1

3

PRE G

PWR G

4

IN2

OUT2

REF5VCC

INPUT VOLUME

Rch SPEAKER

220u 4V

C36

0.1u

C28

R34

2.2

R36

+

4.7

R38

33

+

10

9

8

7

6

C34

0.1u

500

VR3

ea ) are safety parts.When replacing these, be sure to use only the

C30
220u 4V

R40

2.2

Descriprion of major IC

LA4537M (IC1,IC2) : Power Amplifier

POWER

IN 1

IN 2

REF

1

SWITCH

2

3

4

5

BIAS

POWER SWITCH

PRE GND

2-2 (No.XC029)

Amp 1

Amp 2

MUTE

CIRCUIT

10

MUTE SWITCH

9

OUT 1

8

POWER GND

7

OUT 2

6

Vcc