JVC KD-2A User manual

JVC

KD-2A/B/C/E/J/U

PORLABLE

STEREO

(GASo

ETE,

DECK

No.

4151

January

1977

No.

4151

KD-2A/B/C/E/J/U

Contents

Page

Specifications

©...

0...

cee

ee

2

Features:

6:6

scdiis

a

seis

iatge

tee

se

Sie

elated

ee

hee

ea

3

Controls

and

Connections

...

0...

002

eee

eens

3

Main

parts

Location

..

2.0.2...

2000

e

eee

4

Main

Parts

Removing

Enclosure

Assembly

.......--0202

ee

eeee

5

Electrical

Parts...

0...

ce

ee

te

eee

6

Mechanical

Parts

.....---.00

0c

ee

eee

eens

7

Main

Adjustments

Electrical

Adjustment

.........00022

22

eee

8

Mechanical

Adjustment

........--

00

0e

eee

12

Maintenance

.......-

000

eee

14

Block

Diagram

2...

2.

ee

eee

ee

15

Specifications

Type

Portable

stereo

cassette

deck

Track

system

4-track,

2-channel

Cassettes

C-30,

C-60,

C-90

Tape

speed

4.8cm/sec

Frequency

response

Chrome

*1

25~

18,000Hz

(Nominal)

30~16,000Hz

(Typical)

Regular

*2

25~17,000Hz

(Nominal)

30~15,000Hz

(Typical)

Supasses

DIN

45500

*1

~~

TP-18

or

Equivalent

*2

OP-12

or

Equivalent

57dB

(from

peak

level,

weighted)

The

S/N

is

improved

by

5dB

at

1kHz

and

by

10dB

above

5kHz

with

ANRS

on.

62dB

with

ANRS

(DIN

45500,

weighted)

Effect

of

Super

ANRS

(Normal

tape)

Improvement

of

Signal-to-Noise

ratio

Improvement

of

frequency

response

Signal-to-Noise

ratio

the

same

as

with

ANRS

OVU

recording;

6dB

at

10kHz

+5VU

recording;

12dB

at

10kHz

Improvement

of

distortion

OVU

recording;

3%

or

less

at

10kHz

+5dB

recording;

3%

or

less

at

10kHz

0.09%

(WRMS)

0.20%

(DIN

45511)

Wow

and

flutter

Separation

35dB

Harmonic

distortion

1.2%

(Normal

tape

1kHz,

OVU)

Bias

:

AC

bias

(95kHz)

Erasure

:

AC

erasure

Heads

2

heads

SA

head

for

recording/playback

and

ferrite

head

for

erasure

Motor

DC

coreless

motor

2

x

30

minutes

with

the

C-60

cassette

Less

than

90

sec

(with

the

C-60

cassette)

Recording

time

Fast

Forward

time

Page

Circuit

Board

Parts

Main

Amp

Circuit

Board

Parts

List

...........+-

16

REC

Amp

Circuit

Board

..

0.0...

0.02.2

ee

ees

20

ANRS

Circuit

Board

......-.---2-

200

eee

22

Mechanical

Component

(1)

..

2.2.0.0.

002s

eens

25

Mechanical

Component

(2)

.......-.000

eee

26

Mechanical

Component

List

.............002055

27

Enclosure

Ass’y

and

Electrical

Parts

Except

Circuit

Board

Parts

(1).........2.2+05.

29

Except

Circuit

Board

Parts

(2).........-5-006-

30

Wii

AG

os

eee

ahh

eee

8

ace

lent

BS

ee

aap

se

as

Sys

32

Standard

Schematic

Diagram

.......-.

2000s

eee

33

Accessories

1...

ce

ee

te

ete

tee

ee

35

PACK

iQ

eso

'S

aces

sien

esinte

tig

Roast

da

IOS

Leta

ea

ee

hae

36

Rewind

time

Semiconductors

Input

jacks

Output

jacks

Recording

connector

(REC/PB)

Power

supply

Power

consumption

Battery

life

Dimensions

Weight

Less

than

90

sec

(with

the

C-60

cassette)

per

track

IC;

4,

Transistor;

37,

Diodes;

25,

SCR;

1

Mic

jack;

2

Max.

sensitivity;

0.2mV

(-72dBs)

Matching

impedance;

6002

(2002~2k2)

Input

jack;

2

Max.

sensitivity;

78mV

(-20dBs)

Input

impedance;

100kQ

Output

jack;

2

Output

level;

5|00mV

(fixed)

Output

impedance;

2.5k{2

Matching

impendnce;

50k{2

or

more

Headphone

jack;

1

Output

level;

0.75mW

Matching

impedance;

82

Min.

input

level;

0.2mV/kQ

Input

impedance;

2.2kQ

Output

level;

5|00mV

Output

impedance;

2.5k{2

Matching

load

impedance;

50kQ2

or

more

DC

6V

(“D”

size

CELL

x

4)

External

DC

power;

6V

AC

power;

120V,

60Hz

for

KD-2J/C

120/220/240V,

50Hz

for

KD-2A/B/E

100V,

115V

230V

50/60Hz

for

KD-2U

5.5W

(KD-2J/C)

6W

(IKD-2A/B/E/U)

Approx.

6

hours

of

continuous

recording

(on

super

type

batteries)

10-7/8

(width)

x

3-3/4

(height)

x

11-3/8

(depth)

in.

8.8

Ibs.

(including

4

batteries)

Design

and

specifications

are

subject

to

change

without

notice.

KD-2A/B/C/E/J/U

Features

Full

auto

stop.

Dual

ball

cassette

holder

Automatic

selector

of

stereo/mono

for

MIC

record.

Built-in

headphone

volume.

Input

select

switch

*

Compact

and

feather

portable

type.

*

Power-saving

design.

*

Coreless

motor.

*

Built-in

ANRS

and

Super

ANRS.

*

Sen-alloy

head.

+

+ H

Controls

and

Connections

2

®8888Oa0q8

1.

Battery

holder

18.

Left

auxiliary

output

jack

[LINE

OUT-L]

2.

ACsocket

19.

Right

auxiliary

output

jack

[LINE

OUT-R]

3.

DC

Input

jack

(DC

6V)

20.

Left

auxiliary

input

jack

[LINE

IN-L]

4,

Cassette

cover

21.

Right

auxiliary

input

jack

[LINE

IN-R]

5.

Bias

switch

[BIAS]

22.

DIN

socket

[REC/PB]

6.

Equalizer

switch

[EQ]

23.

Input

select

switch

[INPUT

SELECT]

7.

ANRS

switch

24. Left

microphone

jack

[MIC-LEFT]

8.

Tape

counter

25.

Right

microphone

jack

[MIC-RIGHT]

9.

Counter

reset

button

26.

Battery

check

button

(BATT

CH

ECK]

10.

Pause

button

[PAUSE

@ff

]

27.

Left

VU

meter

11.

Stop

button

[STOP

Bf

J

28.

Right

VU

meter

12.

Fast

forward

button

[FF

»P

]

29.

VU

meter

check

light

SW

[CHECK

LIGHT]

13.

Play

back

button

[PLAY/RECP]

30.

REC

master

volume

[REC

MASTER]

14.

Record

button

[REC]

31.

Metal

for

shoulder

strap.

15.

Rewind

button

[REW

<<

]

32.

Right

Record

level

[RIGHT

LEVEL]

16.

Headphone

jack

[PHONES]

33.

Left

Record

level

[LEFT

LEVEL]

17.

Headphone

volume

No.

4151

KD-2A/B/C/E/J/U

|

Main

Parts

Location

CON|APWN>

No.

4151

@Oe9eee

“OOOO

®

Fig.

2

Battery

contact

(+)

14.

Battery

contact

ass’y

(-)

15.

Motor

ass’y

16.

REC.

AMP

circuit

board

17.

Magnet

pulley

ass’y

18.

Pinch

roller

arm

ass’y

19.

Counter

ass’y

20.

Push

button

(Pause)

21.

Push

button

(Stop)

22.

Push

button

(FF)

23.

Push

button

(Playback)

Push

button

(Record)

Push

button

(Rewind)

R/P

head

Erase

head

Steel

ball

Supply

disc

ass’y

Take

up

disc

ass’y

Motor

circuit

board

Muting

circuit

board

ANRS

circuit

board

Main

amp

circuit

board

Power

transformer

Note;

The

circuit

board

assemblies

and

cassette

mechanism

in

this

model

will

not

be

available

as

spare

parts.

|

KD-2A/B/C/E/J/U

Main

Parts

Removing

This

cassette

deck

which

features

a

compact

design

and

performance

uses

miniatures

sized

parts

which

are

closely

arranged.

Enclosure

Assembly

Handle

Enclosure

assembly

Battery

cover

Push

the

battery

cover

the

direction

of

arrow

in

illustration

and

remove

it

to

back.

Bottom

cover

Remove

5

screws

(3¢

12mm)

and

1

screw

(3¢

14mm)

fastening

the

bottom

cover.

Top

panel

1.

Remove

the

bottom

covers

Q)

2.

Remove

5

screws

fastening

the

top

panel.

3.

Remove

to

pull

out

the

left

side

of

the

top

panel

and

to

open

in

front

of

the

front

panel

by

your

fingers.

Knobs

Pull

off

Master

knob

Record

level

knobs

Headphone

volume

knob

MIC/DIN

input

select

knob...

When

remove

the

bottom

cover,

can

be

adjusted

the

semi-fixed

resistors

on

the

main

amp

circuit

board.

Screws

5

p.c.s

=

3d,

10mm

(blue)

When

replace

the

top

panel,

do

as

same

as

(3)

Screws

4

p.c.s.

=

3¢,

16mm

When

replace

the

VU

meter

and

the

pilot

lamp,

must

be

removed

the

front

panel.

1.

Remove

the

bottom

cover

and

the

top

panel

2.

Remove

4

screws

fastening

the

handles

3.

Pull

off

in

front

the

master

knob

and

the

Record

level

knobs

4,

Pull

off

in

front

the

front

panel.

No.

4151

KD-2A/B/C/E//U

|

Electrical

Parts

Level

meter

)

Meter

bracket

®

Fig.

4

Electrical

parts

Parts

name

VU

meters

1.

Remove

the

front

panel.

Tapping

screws

=

3¢,

8mm

2.

Remove

2

screws

fastening

the

meter

bracket.

Pilot

lamp

.

Remove

the

front

panel

and

the

VU

meter

.

Remove

the

push

switches

bracket.

.

Remove

the

bushing

of

the

pilot

lamp

from

the

push

switches

bracket.

.

Remove

the

pilot

lamp

from

the

bushing

ANRS

.

Remove

2

screws

fastening

the

ANRS

Tapping

screws

=

36,

8mm

(violet)

circuit

board

circuit

board.

.

Pull

off

the

left

side

it’s

board.

REC

amp

.

Remove

2

screws

fastening

the

lever

switch

Screws

=

2.6¢,

4mm

(violet)

circuit

board

bracket.

.

Pull

out

the

connector

from

main

amp

C.

Be

carefull

to

pull

off

the

connector,

board

to

direction

of

the

arrow

in

illustration.

slowly

and

holding

the

both

sides

of

it.

(Because

it

may

be

broken

which

the

plate

is

wide)

Main

amp

.

Remove

washers

and

nuts

of

the

variable

Remove

the

main

amp

circuit

board,

after

circuit

board

resistors.

(master

volume

and

2

REC

disconnecting

the

F.P.C.

volumes.)

.

Remove

2

screws

fastening

the

jack

circuit

board

(left

side

of

it)

.

Remove

2

screws

fastening

the

shield

board

at

bottom.

Screws

=

3¢,

8mm

No.

4151

nae

|

KD-2A/B/C/E/J/U

Mechanical

Parts

Mechanical

.

Remove

6

screws

fastening

the

mechanical

ass'y

ass’y.

.

Remove

the

counter

belt.

.

Remove

the

connecting

wires

of

heads,

etc.

Motor

.

Remove

2

screws

fastening

the

shield

plate

1.

When

replace

the

motor,

replace

it’s

.

Remove

the

capstan

belt.

circuit

board

as

same.

(because

motor

.

Remove

3

screws

and

3

washers

fastening

and

it’s

circuit

board

are

pair

parts

for

the

motor.

adjustment.)

.

Remove

2

screws

fastening

the

motor

circuit

2.

Be

careful

not

to

stain

the

capstan

belt.

board.

.

Disconnect

the

wires

of

motor

circuit

board.

Flywheel

Pinch

roller

arm

ass’y

Take

up

disc

Supply

disc

Note;

1.

Don’t

dirty,

slipply

and

undue

run-out

the

capstan

belt

and

counter

belt.

.

Remove

2

screws

fastening

the

flywheel

Holder.

2.

Remove

the

flywheel

holder

from

the

mechanical

chassis.

.

Remove

the

capstan

belt.

.

Pull

out

the

flywheel.

.

Remove

‘’E”

ring

holding

the

pinch

roller

arm

ass’y.

.

Remove

spring

on

the

arm

ass‘y.

.

Remove

the

cassette

holder

.

Remove

the

counter

belt

.

Remove

“E”

ring

holding

the

take

up

disc.

.

Pull

off

the

disc

from

the

shaft.

.

Remove

the

cassette

holder

.

Remove

“E”

ring

holding

the

supply

disc.

.

Pull

off

the

disc

from

the

shaft.

When

replace

the

flywheel,

don’t

forget

to

insert

a

nylon

washer

to

it’s

shaft.

2.

Adjust

height

of

the

motor

pulley,

when

the

capstan

belt

connect

to

the

flywheel

from

the

motor

pulley,

so

that

it

will

be

parallel

to

the

chassis.

3.

When

remove

the

screw

(19),

use

the

maching

driver

to

the

screw

top

groove.

ae

eee

No.

4151

KD-2A/B/C/E/J/U

Main

Adjustments

Electrical

Adjustment

Equipment

and

measuring

instruments

used

for

adjustment.

AUDIO

Freq.

OSC

1.

V.T.V.M,

(measuring

AC

in

millivolt)

Se

—o

ATTENUATOR

2.

Audio-frequency

oscillator

\

Sy

%

aa

(range:

50—20kHz

and

output

OdBs

with

impedance

6002

)

i

-

&

ASS

dA,

‘|e

3

600

3.

Attenuator

(6002

)

i

LG

oun)

4.

Reference

tapes

for

REC/PB

Il

"

pre

TS-1

(OP-12,

C521V)

—

normal

tape

Nap

eel

<a

TS-2

(TP-18,

C402R)

—

chrome

tape

ouTaUT

LINE

a

LINE

OUT

5.

Reference

tapes

for

playback

VTT-658

(for

head

adzimuth)

VTT-656

(for

tape

speed

&

wow

flutter)

VTT-664

(1kHz

reference

level)

VTT-675N

(for

playback

frequency

response)

6.

Resistors

1002

(for

measurement

of

the

bias

current)

6002

(for

attenuator

matching)

7.

Distortion

Meter,

Band

pass

filter

When

you

adjust

following

items,

we

recommend

to

you

to

keep

doing

step

No.

1.

Electrical

Adjustment

Playback

1.

Level

meter

.

Set

the

deck

to

the

record

mode.

|

Main

amp

The

angle

of

meter

deflection

has

deflection

;

Input

1kHz

signal

(about

10dBs)

|

circuit

board

been

factory-adjusted,

but

should

from

LINE

IN

jacks.

be

adjusted

when

parts

are

.

Adjust

the

REC

volume

so

that

replaced.

LINE

OUT

become

3.5dBs.

.

Adjust

R148

and

R248

in

this

R148,

248

VU

meter

condition

it

obtain

zero

VU

(METER)

range;

O

meter

reading

.

Playback

.

Set

equalizer

switch

at

Main

amp

.

Should

be

adjusted

playback

sensitivity

“NORMAL”

position

and

turn

circuit

board

sensitivity

when

heads

are

off

ANRS

switch.

replaced.

.

Adjust

R126

and

R226

so

that

R126,

226

VU

meter

|

2.

Make

this

adjustment

after

level

meters

indicate

zero

VU

(P.B

LEVEL)

range;

0

making

sure

level

meter

deflec-

using

reference

tape

VTT-664

tion

angle

is

correct.

(1kHz)

.

Check

of

PB

Playback

the

reference

tape

VTT-

i

.

When

use

reference

tape

VTT-

frequency

675N

(1kHz)

and

check

the

OUT

675,

it’s

level

over

about

3~4

response

PUT

level

of

bach

frequency

to

Reference

frequency;

1kHz

dB

at

63Hz

compared

with

become

the

rating.

Normal

63Hz

+2dBt3dB

1kHz.

10kHz

O

+3dB/

2,

When

check

at

chrome

it’s

Chrome

63Hz

+2dB+3dB

level,

set

the

equalizer

switch

10kHz

~-4dB+3dB

at

“NORMAL”

position

to

compared

with

1kHz.

Record/playback

TS-1

use

at

normal

mode

and

TS-2

use

at

chrome

mode.

1.

Check

of

REC/

|

Input

1kHz

(OVU-20dB)

signal

Reference

frequency;

1kHz

j

Do

adjust

normal

and

chrome,

from

LINE

IN

make

recording

the

PB

frequency

blank

tape,

and

then

record

50Hz,

Normal

50Hz

O+3dB

|

Lchannel

and

R

channel.

response

10kHz

signals.

10kHz

O0+3dB

When

it’s

Ape

playback,

50Hz

or

Chrome

50Hz

0+3dB

10kHz

output

level

become

in

ratin

at

comparison

1KHz

output

level

ae.

1OkHz

O+3dB

the

reference

frequency.

(As

basic

thought,

1KHz,

50Hz

and

10KHz

output

level

become

the

flat

frequency

responce

as

same.)

No.

4151

22°8,

=

Procedure

2.

Bias

current

3.

REC/PB

level

.

Check

of

REC/PB

distortion

.

Check

of

REC/PB

signal

to

noise

ratio.

.

Check

of

erasure

ratio

Input

1kHz

and

10kHz

(OVU—20dB)]

Rec

amp

signals

from

LINE

IN

to

record

in

reference

tape.

When

playback

it’s

tape,

adjust

R

R514,

614

(normal)

and

R513,

613

(chrome)

so

that

OUT

PUT

levels

become

equal

values.

R/P

HEAD

[Easy

method]

.

Set

the

deck

to

record

mode.

.

Connect

a

1002

resistor

to

the

ground

side

(at

record

mode)

of

the

head

wire.

.

Measure

it’s

voltage.

.

Input

1kHz

(-10dBs)

signal

from

LINE

IN,

adjust

the

REC

master

volume

so

that

LINE

OUT

level

become

—8dBs.

.

Make

recording

in

such

a

way

that

the

level

meters

indicate

zero

VU

at

normal

mode

or

chrome

mode

(as

same

Left

channel

or

right

channel)

.

Playback

it

and

adjust

the

semi-

fixed

resistors

for

REC

level

so

that

the

level

meters

indicate

zero

VU.

.

Input

1kHz

(-10dBs)

signal

from

LINE

IN,

and

make

re-

cording

in

such

a

way

that

the

level

meters

indicate

zero

VU.

.

Playback

and

check

it

that

the

distortion

become

rating

less.

.

Input

1kHz

OVU

signal

from

MIC

IN,

make

recording

that

the

level

meters

indicate

zero

VU,

and

then

make

recording

at

no

signal

mode.

.

Playback

it’s

tape

and

measure

the

signal

to

noise

ratio

by

V.T.V.M.

.

Input

and

make

recording

as

same

5.

.

Continue

recording

to

up

20dB

the

signal

level.

.

Rewind

it’s

tape

and

erase

the

part

of

it.

.

Measure

output

level

to

the

re-

cording

part

ratio

the

erasing

part.

circuit

board

Normal

R514,

614

(BIAS)

Chrome

(BIAS)

Normal

33mV

Chrome

53mV

Main

amp

circuit

board

Normal

[R149,

249

REC

LEVEL]

Chrome

[R150,

250

REC

LEVEL]

Normal

3%

less

Chrome

4%

less

Normal

|

KD-2A/B/C/E/J/U

Remarks

.

Standard

method

for

bias

adjustment

of

cassette

deck

are

adjusted

the

frequency

response

at

REC/PB.

Be-

cause

the

cassette

tape

is

great

affection

to

bias

cur-

rent

of

frequency

responce

than

open-reel

tape.

When

you

measure

the

bias

curr

rent,

can

you

doing

the

easy

way

as

below.

.

If

not

correct

the

bias

cur-

rent,

frequency

responses

are

shown

as

the

too

fow

most

switable

too

high

KHz

1OKH

2

.

If

the

meter

pointer

moving

at

PB

mode

when

your

finger

touch

a

head

wire,

it’s

wire

is

ground

side

at

Rec

mode

(Because

the

head

wire

of

2

head

deck

become

opposite

polarity

at

playback

and

at

cords)

4.

Must

use

the

shield

wire.

cw

Response(dB)

The

difference

in

level

of

each

channel

is

less

than

1dB.

Make

this

adjustment

after

making

sure

bias

current,

and

REC

level.

REC

volume

at

maximum.

42dB

or

more

Chrome

42dB

or

more

When

measure

the

erasing

ratio,

connect

the

B.P.F

(Band

pass

filter)

to

the

deck

from

the

V.T.V.M.

(mitivolts)

No.

4151

KD-2A/B/C/E/J/U

Item

Procedure

7.

ANRS

.

Disconnect

the

soldering

position

|

ANRS

circuit

BIAS

CUT

of

main

circuit

board

so

that

osillator

does

not

operate.

.

Set

the

deck

to

the

record

mode.

.

Input

1kHz

-10dBs

signal

from

LINE

IN,

Adjust

the

REC

volume

so

that

LINE

OUT

be-

come

—-0.5dBs.

(not

move

the

REC

volume

position

to

finished

adjustment.)

.

Turn

R335,

435

(CONT

GAIN)

and

R340,

440

(DC

BIAS)

in

the

direction

opposite

to

the

arrow

marking

in

the

shield

board.

.

Adjust

R324

and

R424

so

that

R324,

424

level

does

not

change

when

(REC

GAIN)

ANRS

switch

is

turned

on

and

off,

and

turn

on

ANRS.

.

Input

1kHz

-50dBs

signal

from

R340,

440

LINE

IN,

Adjust

R350

and

(DC

BIAS)

440

so

that

LINE

OUT

become

—35dBs.

.

Input

5kHz

-30dBs

signal

from

R335,

435

LINE

IN

Adjust

R335,

435

so

(CONT

GAIN)

that

LINE

OUT

become

17dB.

.

Repeat

step

(5)

through

(7).

.

Turn

ANRS

switch

in

‘‘Super’’

position

when

input

10kHz

-10dBs

signal

from

LINE

IN.

Check

out

put

levels

are

~6.5dBst2dB.

.

Connect

the

position

BIAS

CUT

of

disconected

in

step

(1)

-

.

Playback

reference

tape

VTT-

R302,

402

664

and

Adjust

R302

and

R402

‘|

(PB

GAIN)

so

that

level

does

not

change

when

ANRS

is

turned

on

and

off.

Other

adjustments

Procedure

Remarks

1.

Battery

1.

Apply

exactly

DC3.8V

to

ex-

Do

not

mistake

one

polarity

for

checker

ternal

DC

jack

or

battery

contacts

the

other.

and

switch

the

deck

to

playback

or

fast

forward

mode.

.

Push

battery

check

switch

in

“CHECK”

position

and

adjust

so

that

meter

pointer

deflects

to

the

end

of

green

area.

.

Check

of

Apply

exactly

DC

6.0V

to

external

Play

back

Standard

Pilot

lamp

at

OFF

no

signal

power

con-

DC

jack

or

battery

contacts

and

200mA

or

less

165mV

Do

not

insert

cassette

tape

sumption

switch

the

deck

to

playback

or

Record

300mA

{Standard

record

mode.

or

less

(

240mA

)

Measure

the

consumption

current

as

a

such

way

by

miliampere

meter.

No.

4151

240°

2

JVC KD-2A User manual

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