Teac A-4300SX Manuale utente

MA3608X

}

"4300SX

Stereo

Tape

Deck

TEAC

CORPORATION

51031780

1.

GENERAL

DESCRIPTION

The

TEAC

A-4300SX

is

an

excellent

home

entertainment

stereo

tape

deck

built

to

semi-profes-

sional

standards,

with

3

motors,

4

heads,

foil

sensing

auto-reverse

and

index-counter

repeat.

It

operates

at

3-3/4

ips

and

7-1/2

ips,

accepts

7”

reels,

and

features

switch-controlled

Bias

and

Equal-

ization;

dual

range

VU

meter;

two

line

input

jacks

per

channel;

remote

controlled

(optional)

oper-

ation;

and

other

convenient

features.

Although

the

A-4300

SX

internally

appears

to

be

similar

to

A-4300,

significant

differences

require

that

you

consult

this

manual

before

attempting

service.

The

A-4300SX

Service

Manual/Parts

Man-

ual

contains

adjustment

and

alignment

information,

schematic

diagram,

parts

replacement

refer-

ences,

and

other

information

for

obtaining

new

parts.

TABLE

OF

CONTENTS

1.

General

Description

.................04.0.

3

2.

Specification

and

Service

Data

..............

4

3.

Tools

for

Testing

and

Maintenance............

5

4.

Partial

Disassembly

.................0--.

6

5.

Tape

Transport

Parts

Location

..............

8

6.

Head

Replacement

and

Alignment

............

9

7.

Measurement

and

Adjustment

...............

10

—MECHANICAL—

8.

Measurement

and

Adjustment

...............

13

—ELECTRICAL—

9.

Trouble-shooting

..............-2....00--

20

10.

Service

and

Maintenance

...............-..

22

11.

Simplified

Schematic

with

level

INGICALIONS

33

hee

Meals

ete

gaheds

2

ES

ae

Se

23

2.

SPECIFICATIONS

AND

SERVICE

DATA

2-1

SPECIFICATIONS

Track

System

1/4

track

2

channel

stereophonic

1/4

track

1

channel

monophonic

Heads

Four;

Erase,

Record

and

Playback

x

2

Reel

Size

7”

maximum

Tape

Speed

7-1/2

ips

and

3-3/4

ips

Motors

1

Dual-Speed

Hysteresis

Synchronous

Capstan

motor

2

Eddy

Current

Induction

Reel

motors

Input

MIC:

Specified;

-60

dB

(0.774

mV)/10k

ohms

(Level

and

Impedance)

Minimum;

—70

dB

(0.244

mV)

LINE:

Specified;

—8

dB

(308

mV)/50k

ohms

Minimum;

—18

dB

(97

mV)

DIN:

Minimum;

—38

dB

(9.75

mV)

Output

LINE:

Specified;

—8

dB

(308

mV)/10k

ohms

(Level

and

Impedance)

Maximum;

—2

dB

(615

mV)

DIN:

Maximum;

—2

dB

(615

mV)

Playback

Equalization

7-1/2

ips:

NAB

3180

yp

sec,

50

wu

sec

3-3/4

ips:

NAB

3180

p

sec,

90

pu

sec

Bias

Frequency

100k

Hz

(+5k

Hz,

push-pull

oscillator)

Power

Requirement

100,

117,

220,

240

V

AC

50/60

Hz

(General

Export

model)

117

V

AC

60

Hz

(U.S.A.

and

Canada

Model)

Weight

23

kg

(51

Ibs)

net

Power

Consumption

90

W

Dimensions

(WHD)

440

x

488

x

216

mm

(17-5/16”

x

19-1/4”

x

8-1/2”)

2-2

SERVICE

DATA

—MECHANICAL—

Tape

Speed

Deviation

and

Drift

3,000

Hz

+30

Hz,

within

15

Hz

Wow

and

Flutter

Playback:

0.18%

(RMS)

at

7-1/2

ips

0.20%

(RMS)

at

3-3/4

ips

Overall:

0.20%

(RMS)

at

7-1/2

ips

0.25%

(RMS)

at

3-3/4

ips

Pinch

Roller

Pressure

2.4

kg

(5.3

lbs)

Reel

Torque

TAKE-UP:

FWD

370

to

410

g-cm

(5.2

to

5.7

oz-inch)

REV

430

to

470

g-cm

(6.0

to

6.6

oz-inch)

BACK

TENSION:

FWD

170

to.210

g.cm

(2.4

to

2.9

oz-inch)

REV

180

to

220

g-cm

(2.5

to

3.1

oz-inch)

Brake

Torque

800

to

1,200

g-cm

(11

to

17

oz-inch)

F.F/REW

Time

160

seconds

for

1,800

foot

tape

2-3.

SERVICE

DATA

—ELECTRICAL—

Frequency

Response

Refer

to

Frequency

Response

Limits

charts

in

this

manual

Signal-To-Noise

Ratio

Overall:

48

dB

at

7-1/2

ips

46

dB

at

3-3/4

ips

Erase

Efficiency

68

dB

at

1k

Hz

signal

(Measurement

with

input

10

dB

higher

than

the

Specified

Input

level)

Cross

Talk

Rejection

40

dB

adjacent

track

at

125

Hz

Stereo

Channel

Separation

50

dB

Channel

to

Channel

at

1k

Hz

Total

Harmonic

Distortion

Overall:

1.5%

at

1k

Hz

signal

NOTE:

As

a

result

of

continuing

changes

and

improvements

during

the

production

run,

minor

differences

may

be

found

between

early

and

later

machines.

Value

of

“dB”

in

this

manual

refers

to

0

dB

=

0.775

V.

—

©@G@o

geeoes

(410mm)

4

“

6%

84

-—"

17

5

(216

mm)

(440mm)

7-103

Fig.

2-1

Dimensions

3.

TOOLS

FOR

TESTING

AND

MAINTENANCE

A

minimuth

of

the

following

tools

and

test

instruments

are

required

for

measuring

and

adjusting

to

obtain

optimum

_

ee

performance.

Regular

maintenance

tools

will

be

adequate

ghee

URAC

LESE,YAPE

for

those

not

listed

here.

If

any

test

instrument

listed

here

is

not

available,

a

close

equivalent

can

be

used.

SPRING

SCALE

.........0.0-0.

0-4

kg

(O—

8

Ibs)

0-300

g

(0-10

oz)

FLUTTER

METER

.......

Meguro

Denpa

Sokki

K.K..,

Model

MK-668A

Fig.

3-1

TEAC

Test

Tape

DIGITAL

COUNTER

.........

Range;

0

Hz—100

kHz

BANDPASS

FILTER

...TEAC

MODEL

M-206A

(1

kHz)

VTVM

(AC)

......

~.

Hewlett-Packard

Co.,

Model

400E

AF

OSCILLATOR

........----05-

10

Hz—100

kHz

ATTENUATOR

........-..----55

General

purpose

OSCILLOSCOPE

.............---

General

purpose

BLANK

TAPE........

TEAC

YTT-8023

and

YTT-8003

TEAC

TEST

TAPE

...

YTT-1003

(7-1/2

ips),

YTT-1002

(3-3/4

ips)

for

Playback

Alignment

test

YTT-2003

(7-1/2

ips),

YTT-2002

Fig.

3-2

Hex

Head

(Allen)

wrench

(3-3/4

ips)

for

Tape

Speed

and

Wow

Flutter

test

TEAC

EMPTY

REEL..........

RE-702

(2.5”

dia,

hub)

RE-701

(4”

dia,

hub)

TOOK

S

5

eee

eo

et

i

des

SE

ees

General

2

mm

nut

driver

Hex

Head

Allen

Wrench

Plastic

alignment

tool

Load

resistor

non

inductive

type

8

ohm

/

1

W

DEMAGNETIZER

..........

TEAC

E-3

or

equivalent

Fig.

3-3

Spring

Scales

4,

PARTIAL

DIS-

ASSEMBLY

4-1

REMOVING

WOODEN

SIDES

AND

REAR

PANEL

AND

BOTTOM

PANEL

See

illustration

for

complete

dis-assembly

instructions.

Most

amplifier

checks

and

adjustments

can

be

made

from

the

bottom

with

the

(bottom)

panel

removed.

These

adjustments

should

be

performed

by

experienced

technicians,

and

then

only

when

going

through

the

com-

plete

test

and

check

procedures

on

the

unit

which

is

being

tested.

Head

Base

Plate

Housing

Base

Plate

Magli:

e

Sues

ae

LUT

lee

um

lly

Ih

Wyyytll

lin,

Fig.

4-2

Head

Ass‘y

Removal

4-3

REMOVAL

OF

CAPSTAN

MOTOR

1.

Remove

the

3

screws

holding

the

capstan

motor

plate.

2.

Unsolder

the

6

wires

connecting

the

capstan

motor.

3.

Remove

the

4

screws

holding

the

capstan

motor

to

the

motor

plate.

Watch

for

the

Rupber

Cushions

(A).

4.

Loosen

the

2

set

screws

(hex

head)

in

pulley

and

lift

off

pulley

(B).

Loosen

2

set

screws

in

fan

and

remove

fan.

SOOO

MMMM}

Fig.

4-1

Removing

Wooden

Sides

and

Rear

and

Bottom

panels

4-2

HEAD

ASSEMBLY

REMOVAL

1.

Remove

the

2

screws

in

the

top

of

the

head

cover

and

lift

it

off.

2.

Remove

2

screws

holding

head

Base

plate

(with

Heads).

3.

Remove

2

mounting

nuts

through

access

slot

in

head

i :

[PPTL

Base

plate

and

dis-connect

head

wires.

See

Fig.

6-2.

4.

If

necessary,

remove

Housing

Base

plate

by

4

screws.

oe

See

Fig.

4-2.

Fig.

4-3

Capstan

Motor

Removal

4-4

REMOVAL

OF

CAPSTAN

ASSEMBLY

Dank

WwW

.

Unscrew

dust

cap(A)

on

front

panel.

.

Remove

2

screws

from

Thrust

Angle

(B).

Allow

bracket

to

drop

toward

floor

of

case.

.

Remove

capstan

belt

(C).

.

Loosen

2

screws

in

flywheel

(D)

Remove

flywheel.

.

Remove

3

screws

in

capstan

ass’y

(E).

.

Gently

move

capstan

ass’y

up

and

down

until

it

slides

out

of

panel.

NOTE:

When

replacing

flywheel,

position

flywheel

on

capstan

ass’y

shaft

so

that

end

of

shaft

protrudes

slightly

from

rear

of

flywheel.

A

clearance

of

ap-

prox.

0.01’’

must

be

maintained

between

the

end

of

the

capstan

shaft

and

the

Thrust

Angle.

Fig.

4-4

Capstan

Ass‘y

Removal

45

REMOVAL

OF

REEL

MOTOR

1.

2.

Disconnect

the

4

motor

wires

from

terminals

and

release

wire

harness

straps.

Loosen

2

set

screws

(hex

head)

in

Brake

drum(A)

and

2

in

the

Reel

Turntable

assembly(F).

Lift

off

these

parts.

.

Remove

4

screws

securing

the

Brake

Assembly(D)

to

the

motor.

Carefully

lift

off

the

Brake

Retainer(B).

Do

not

remove

wires

connected

to

the

brake

solenoid(C),

.

Remove

4

screws

securing

Reel

Motor(E)

to

chassis

through

the

front

panel.

<>

CHASSIS

FRONT

PANEL

Fig.

4-5

Reel

Motor

Removal

4-6

REMOVAL

OF

TENSION

ARMS

LEFT

AND

RIGHT

See

illustration

for

complete

dis-assembly

instructions.

NOTE:

After

re-assembly

check

clearance

to

ascertain

that

arm

moves

freely

and

is

not

binding.

Do

not

over-tighten

screws

holding

micro-switches.

Insulating

spacer

and

micro-switches

are

easily

broken

by

excess

pressure.

as

panel

Fig.

4-6

Tension

Arms

Removal

5.

TAPE

TRANSPORT

PARTS

LOCATION

—REAR

VIEW-—

Power

Brake

Solenoid

Transformer

c9

R11

RY

R10

Rectifier

PC

Board

R12

:

(

1,

:

2

ie

£

=

Brake

Solenoid

Right

Reel

Motor

Left

Reel

Motor

Cap.

Motor

R19

Cap.

Solenoid

Cap.

Beit

Freq.

Adapt

PC

Board

(C7)

Sensing

Ampl.

Cap.

Flywheel

Control

PC

Board

Control

SW

Ass’y

Fuse

Holder

NOTE:

R9,

R10

and

R11

are

adjustable

resistors

which

are

used

to

adjust

take-up

tor-

que

and

back

tension.

Refer

to

page

11

for

the

TORQUE

MEASUREMENT

procedure.

6.

HEAD

REPLACEMENT

AND

ALIGNMENT

—MECHANICAL—

6-1

HEAD

REPLACEMENT

AND

WIRING

To

replace

a

single

head

a

special

2

mm

nut

driver

is

re-

quired.

Remove

the

2

nuts

(A)

on

the

defective

head

through

the

access

hole

provided.

This

releases

the

head

from

the

mounting

plate.

Note

the

position

of

the

wires

on

the

circuit

board.

Connect

the

new

head

in

the

same

man-

er.

Replace

the

nuts

securing

the

new

head

to

the

plate.

Perform

head

alignment

before

operation.

r

aN

NUTS

(A)

{

ee

PLAYBACK

x

RECORD

REVERSE

—

i

FORWARD

Fig.

6-2

Head

Wiring

—.Rear

View

—

6-2

HEAD

ADJ.

SCREWS

AND

ALIGNMENT

8

9

i)

@

oe

©

@

dg

652°2

e

©

@

Tape

Lifters

t

Tape

Guides

va

—

eo

ose

eeepc

REVERSE

FORWARD

Toe

—~——

ERASE

RECORD

<T)

Playsack

[=>

——

@

Azimuth

adj.

screws

©

Height

and

Tilt

adj.

screws

©

Tangency

adj.

Nuts

Fig.

6-3

Head

Adjustment

Screws

and

Alignment

6-3

VISUAL

HEAD

ALIGNMENT

Since

the

propriety

of

head

alignment

affects

the

frequency

response

on

both

playback

and

recording,

the

head

align-

ment

should

be

done

carefully.

The

head

can

be

adjusted

in

TILT,

TANGENCY,

HEIGHT

and

AZIMUTH.

For

head

alignment,

perform

the

following

coarse

adjust-

ments

first.

Then

fine

alignment

should

be

accomplished

electrically

while

playing

back

the

Test

Tape.

Coarse

Adjustment:

Without

Tape

BIE

otic

3

eras

By

Height

and

tilt

screws

This

alignment

is

performed

by

viewing

from

the

side

without

tape

threaded.

Check

that

the

head

surface

is

parallel

to

the

tape

guide

surface.

With

Tape

TANGENCY

....

By

Head

mounting

Nuts

Loosen

the

head

mounting

nuts.

Adjust

the

head

so

that

the

vertical

alignment

of

the

head

gap

is

perpendicular

to

the

surface

of

the

tape,

then

tighten

the

head

mounting

Nuts.

HEIGHT

.......

By

Height

and

Tilt

screws

This

alignment

is

checked

visually

by

looking

at

the

position

of

the

head.

The

head

core

for

track-]

(inner

core)

should

be

even

with

the

inner

edge

of

the

tape.

AZIMUTH

......

By

Azimuth

adj.

Screw

Adjust

the

azimuth

adj.

screw

so

that

the

gap

of

the

head

is

perpendicular

to

the

tape

travel.

NOTE:

After

this

coarse

adjustment

is

made,

the

adj.

screws

and

the

Head

mounting

nuts

should

be

realigned

according

to

electrical

head

alignment

paragraph

which

follows

in

this

Service

Manual.

6-4

MIS-ALIGNMENT

OF

THE

HEADS

i

TILT

[3]

HEIGHT

iview

from

side

of

head)

(view

from

front

of

head)

crews

|

Adjust

by

@

Screws

TANGENCY

view

from

top

of

head)

i_()

AZIMUTH

(view

from

front

of

head)

crews

T-615

Fig.

7-3.

Head

Mis-Alignment

—Examples—

7.

MEASUREMENT

AND

ADJUSTMENT

—MECHANICAL—

7-1

PINCH

ROLLER

PRESSURE

NOTE:

Pinch

roller

pressure

is

supplied

by

the

pinch

roller

spring

arm

and

it

is

most

important

that

the

sole-

noid

plunger

be

fully

bottomed

before

taking

pressure

measurement.

.

Load

tape

or

block

the

shut-off

arm

in

the

ON

position.

2.

Attach

a

suitable

spring

scale

to

the

pinch

roller

shaft.

3.

Place

the

deck

in

the

PLAY

mode

(>),

and

holding

the

spring

scale

as

illustrated,

slowly

draw

it

away

from

the

pinch

roller.

4.

Do

not

allow

the

string

to

rub

against

the

pinch

roller.

5.

Note

the

reading

on

the

spring

scale

at

the

instant

the

pinch

roller

stops

rotating.

6.

The

scale

should

indicate

2.3

to

2.5

kg

(5.0

to

5.5

lbs).

Optimum

value

is

2.4

kg

(5.3

Ibs).

7.

If

adjustment

is

necessary,

loosen

the

3

screws

on

the

capstan

solenoid

and

position

the

solenoid

for

optimum

pressure.

8.

Adjust

solenoid-limit

position

so

that

the

gap

between

capstan

shaft

and

pinch

roller

is

approx.

7

mm

when

solenoid

is

not

actuated.

Also

make

sure

pinch

roller

shaft

does

not

contact

edit

arm

B.

Limit

is

adjusted

by

loosening

the

mounting

screw

(A),

then

sliding

limit

until

proper

position

is

obtained.

—

CAPSTAN

SOLENOID

LIMIT

Fig.

7-1

Pressure

Measurement

and

Adj.

Locations

10

7-2.

BRAKE

TORQUE

The

brake

torque

is

actuated

mechanically.

Pressure

is

set

by

the

leaf

spring

force.

While

making

these

measurements

and

adustments,

be

careful

not

to

bend

the

brake

bands.

As

brake

torque

will

change

with

cleaning,

brake

drums

and

brake

shoes

should

be

cleaned

only

when

absolutely

neces-

sary.

If

cleaning

is

required,

use

TEAC

cleaner

TZ-261B.

After

cleaning,

operate

the

brakes

by

depressing

the

play

and

STOP

buttons

several

times

to

completely

dry

out

the

brakes

before

performing

the

following

procedure.

NOTE:

Brake

adjustments

are

made

with

NO

power

con-

nected

to

the

equipment.

1.

Place

an

empty

large

hub

reel

on

the

left

reel

table,

and

fasten

one

end

of

a

30”

length

of

string

to

the

reel

anchor.

2.

Wind

several

truns

of

string

counter

clockwise

around

the

hub

and

attach

a

suitable

spring

scale

to

the

free

end

of

the

string.

3.

Take

a

reading

only

when

the

reel

is

in

steady

motion

since

the

force

required

to

overcome

static

friction

will

produce

a

false,

excessively

high

initial

reading.

4.

The

Calculated

value

should

be

800

to

1200

g-cm

(11

to

17

oz-in).

5.

If

adjustment

is

required,

loosen

the

2

screws

shown

and

position

the

brake

for

optimum

torque.

6.

The

adjustment

of

the

right

brake

is

the

same,

with

the

exception

that

rotation

is

clockwise.

(wind

string

CLOCKWISE

around

ree!

hub)

7.

See

note

at

the

top

of

page

11

for

explanation

of

torque

measurements.

Solenoid

Brake

Drum

ADJUSTMENT

SCREWS

T

H

Fig.

7-2

Torque

Measurement

and

Adjustment

Location

TORQUE

MEASUREMENT

PROCEDURE

OTE:

The

following

torque

measurements

should

be

made

with

a

spring

scale

that

is

calibrated

to

read

Torque

in

gram-cm,

for

a

7”

reel

with

a

small

reel

hub.

If

the

spring

scale

you

are

using

is

calibrated

to

read

Force

or

Weight

in

grams

the

Torque

must

be

calculated

using

the

Formula:

Torque

(in

g-cm

or

0z*in)

=

Weight

or

Force

(in

gm.

or

02.)

x

radius

of

hub

(in

cm

or

inches)

If

you

are

using

a

reel

with

other

than

the

standard

2.5”

or

6.0

cm

(approx.)

diameter

hub,

the

Torque

must

be

cal-

culated

using

the

same

formula

and

substituting

the

actual

radius

and

Weight

or

Force

reading.

All

Torque

and

Tension

measurements

must

be

made

with

the

automatic

shut-off

switch

(right

tension

arm)

held

in

the

ON

position.

Brake

Torque

Measurement

should

be

made

using

large

hub

|

reel

with

a

hub

diameter

of

4”

or

10.2

cm.

1-626

Fig.

7-3

Torque

Measurement

7-3.

TAKE-UP

TORQUE

1.

Place

the

empty

reel

and

attached

spring

scale

on

the

right

reel

table:

2.

Place

the

deck

in

the

Forward

Play

mode.

3.

Allow

the

rotation

of

the

reel

to

slowly

draw

the

scale

toward

the

hub.

4.

Hold

the

spring

scale

with

enough

force

to

allow

a

steady

reading.

5.

The

torque

calculated

valve

should

be

approx:

370

to

410

g-cm

(5.2

to

5.7

oz-inch)

6.

Repeat

the

procedure

for

the

Reverse

play.

430

to

470

g-cm

(6.0

to

6.6

oz-inch)

RRR

RSE

NRE

PD

Re

pea

ee

EE

EN

PEN

ee

ters

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canerscemiormere

i

7-4

BACK

TENSION

1.

Place

an

empty

7”

reel

with

small

hub

on

the

left

reel

table,

and

fasten

one

end

of

a

30”

length

of

string

to

the

reel

anchor.

2.

Wind

several

turns

of

string

counter-clockwise

around

the

hub.

Attach

spring

scale

to

string.

3.

Place

the

deck

in

the

Forward

Play

mode.

4.

Pull

the

scale

away

from

the

reel

against

the

motor

torque

with

a

steady,

smooth

motion.

5.

Note

the

scale

reading

while

it is

in

steady

motion.

(The

string

must

not

rub-the

reel

flanges)

6.

The

calculated

value

should

be

approx.:

170

to

210

g*cm

(2.4

to

2.9

oz-inch)

7.

Repeat

the

procedure

for

the

Reverse

Play.

Using

the

right

reel

table.

180

to

220

g+cm

(2.5

to

3.1

oz-inch)

Adjustment

Location

If

necessary,

adjust

slider

of

the

resistors

until

you

have

the

correct

scale

reading

for

optimum

torque.

Refer

to

adj.

lo-

cation

below.

REVERSE

FORWARD

TAKE-UP

TORQUE

|

TAKE-UP

TORQUE

t

=

REVERSE

uit

c

=

BACK

TENSION

FORWARD

|

®

7-5

REEL

HEIGHT

ADJUSTMENT

Reel

height

adjustment

is

required

only

if

a

motor

has

been

replaced

or

if

tape

rubs

excessively

against

the

reel.

Adjust-

ment

is

accomplished

by

FINE

ADJ.

screw

in

the

reel

turn-

table.

Reel

turntable

height

should

be

checked

using

stan-

dard

7”

reels.

With

a

tape

threaded

on

the

machine,

position

the

reel

height

for

smooth

tape

travel.

If

adjustment

is

necessary,

remove

the

reel

and

adjust

the

screw.

Then

replace

the

reel

and

re-check

the

adjustment.

1

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