Teac A-7300 User manual

SERVIGEMANUAL

GENERAL

DESCRIPTION

TEAC'S

A-7300

and

A-7300

2T

are

high

quality

stereo

tape

decks,

representing

a

New

Generation

in

the

design

and

construction

of

recording

equipment.

With

AC

reel

motors

and

Direct-Drive

Servo-cont-

rolled

DC

Motor-Capstan,

all

controlled

by

Integrated

Cir-

cuit

(IC)

Logic

Circuitry,

these

decks

provide

highly

reliable

operation

at

greatly

reduced

noise

and

heat

levels.

With

almost

all

relays

replaced

by

Logic

Circuits,

transport

control

is

quick

and

positive

and

governed

by

6

calculator-

like

buttons

on

the

control

center.

Advanced

electronics

are

also

utilized.

This

manual

is:

the

final

version

and

supersedes

manual.

PRODUCT

OF

JAPAN

SPECIFICATIONS

MECHANICAL

—

Tracks:

A-7300

4

track

2

channel

stereophonic

track

2

channel

monophonic

track

1

channel

monophonic

LS

A~7300

2T

2

track

2

channel

stereophonic

2

track

2

channel

monophonic

e

2

track

1

channel

monophonic

Heads:

Erase

X1,

Rec

X1,

Playback

X1

Reel

Size:

10-1/2"

maximum

NAB

reel

Tape

Speeds:

A-7300.....

7-1/2

ips

&

3-3/4

ips

A-7300

2T..15

ips

&

7-1/2

ips

Motors:

Direct

drive

DC

servo

capstan

motors

Xl

6-pole

eddy-current

induction

motors

for

reel

drive

X2

Wow

&

Flutter:

0.05

%

at

15

ips

(W-RMS)

0.06

%

at

7-1/2

ips

(W-RMS)

0.10

%

at

3-3/4

ips

(W-RMS)

Wow

and

flutter

measured

according

to

weighted

(W-RMS)

NAB

standard

using

TEAC

YTT-2004/2003/2002

flutter-free

tape.

Above

value

is

measured

during

playback.

Fast

Winding

Time:

Approx.

150

seconds

or

less

with

1800

ft

tape

Power

Requirement:

117

V

60

Hz

80

W

Weight:

62

lbs

(28

Kg)

net

Dimensions:

21-5/8"

(H)

17-3/8"

(W)

9-3/4"

(D)

548

(H)x440

(W)X246

(D)

mm

ELECTRICAL

——_-_-Y-TS

TST,

.————MTTTTT

O

dB=

0.

.

aa

Frequency

Response:

(Measured

at

20

dB

below

the

Spesified

level)

Refer

to

page

11,12,13

Freq.

Response

Limits

chart

Input

Impedance:

-

LINE:

50

KQor

more

MIC:

6002

(balanced)

Output

Load

Imp:

LINE

OUT:

10

KQor

more

HEADPHONE:

82

Equalization:

A-7300

7-1/2

ips...50uS

&

3180uS

(Playback)

3-3/4

ips...90u4S

&

3180uS

A-7300

2T

15

ips......50uS

&

3180

uS

7-1/2

ips...50uS

&

318048

Output

Level:

OUTPUT:

O

dB

+6

dB

+1

dB

(max.)

HEADPHONE:

-17

dB

-11

dB

+2

dB

(max.)

Input

Level:

LINE:

-8

dB

-18

dB+2

dB(min.)

MIC:

-48

dB

-58

dB+2

dB(min.)

with

ATT

(dB)

0O

(back

panel)

-38

dB

+3

dB

(min.)

with

ATT

(dB)

20

(Back

panel)

Bias

Frequency:

100

KHz

(+5

KHz:

Push-pull

Oscillator)

Crosstalk

Rejection:

40

dB

or

more,

adjacent

track

at

1

KHz

Channel

Separation:

45

dB

(4T,

2T)

or

more,

channel

to

channel

at

1

KHz

Erasure:

68

dB

(4T),

65

dB

(2T)

or

more

f

Signal-To-Noise

}

Ratio:

Better

than

53

dB

at

15

ips

(playback)

Better

than

52

dB

at

7-1/2

ips

Better

than

48 dB

at

3-3

4

ips

TAPE

TRANSPORT

PARTS

LOCATION

Adjuster

for

Back

Tension

(F.F,

REW)

Adjuster

(R-154)

for

Take

up

Adjuster

(R-155)

for

Back

Tension

C155

Reel

Motor

(L)

Reel

Motor

(R)

Reel

Motor

Drive

Unit

Power

PC

Board

Ass'y

Stabilizer

Unit

Capstan

Motor

Tape

Counter

Ass'y

-REAR

VIEW-

Fig.

1-1

Tape

Transport

Parts

Location

Terminal

A

Fig.

1-2

Control

PC

Board

2

ADJUSTMENT

OF

D.C.

Con

the

STABILIZER

UNIT)

NOTE

:

MEASUREMENT

AND

ADJUSTMENT

-"MECHANICAL-

The

TEAC

A~7300

uses

highly

reliable

AC

Motors

for

both

reel

motors,

and

a

DC

direct-drive

capstan

system.

It

should

re-

quire

a

minimum

of

mechanical

maintenance

or

adjustment.

These

adjustments

are

made

at

the

factory.

Readjustments

should

only

be

required

after

long

periods

of

operation

or

following

component

replacement.

To

prevent

damage

to

the

motor

and

control

circuitry:

1.

Remove

terminal

A

from

the

Control

PC

board.

See

Fig.

1-2.

2.

Disconnect

the

11

connector

from

the

motor

(Connector

Block).

Adjustment

Procedure

1.

Remove

the

rear

panel.

2.

Remove

terminal

A,

and

11

connector.

3.

Place

the

POWER

switch

to

"ON".

4.

Connect

a

VOM

or

VTIVM

across

the

24V

Test

Point

(Red

Lead

Socket)

and

chassis

Ground.

Adjust

VR21

if

needed

to

obtain

24V

+

0.5V

DC.

wn

6.

Adjust

VR-22

for

5V

+0.25V

DC

output

at

5V

test

point

(Pink

Lead

socket).

VR21

VR22

Decrease

Increase

Decrease

Fig.

2

Adjustment

Locations

Capstan

motor

Pink

Lead

Socket

for

5

V

11P

Connecter

Block

Red.

Lead

Socket

for

24

V

Fig.

3

Test

Points

3

CAPSTAN

SHAFT

TOLERANCE

ADJUSTMENT

1.

Check

that

the

capstan

motor

moves

©

i

: 2

Capstan

Shaft

freely

without

binding

on

the

Thrust-

‘

plate.

li

ae

2.

Check

that

the

clearance

between

the

motor

shaft

tip

and

the

Thrustplate

—-

Lock

Nut

is

between

0.1 and

0.3

millimeter.

0.10.3

mm

KA

3.

To

adjust,

first

loosen

the

locking

tolerance

@)

nut;

then

set

with

a

common screw-

Ps

x

'

Adjustment

driver

for

approx.

0.2mm

clearance.

Seraw

Check

by

observing

the

capstan

move-

for

Capstan

Shaft

ment.

4,

Tighten

the

Lock

Nut

and

secure

with

locking

paint.

Fig.

4

Shaft

Tolerance

Adj.

Location

TAPE

SPEED

ADJUSTMENT

Place

the

PITCH

CONT

to

the

OFF

position.

The

tape

speed

should

be

measured

using

TEAC

flutter

free

tape,

Model

YTT-2004

(15

ips),

YTT-2003

(7-1/2ips),

YTT-2002

(3-3/4

ips).

These

tapes

contain

a

highly

accurate

3000

Hz

tone.

Connect

a

digital

frequency

counter

to

either

line

OUTPUT

jack.

The

indicated

frequency

should

be

LOW

Speed

0

(®

3000

Hz

(+10

Hz

or

less)

for

Fig.

5

Tape

Speed

Adjusters

both

speeds.

If

necessary,

adjust

"adjustable

resistors"

on

the

CAPSTAN

MOTOR.

FLUTTER

Flutter

should

be

measured

in

Playback

mode

using

a

TEAC

flutter-

free

tape

YTT-2004

(

l5ips),

YTT-2003

(7-1/2ips),

2002

(3-3/4ips)

and

Meguro

model

ymx665B

flutter

meter.

Measurement

of

flutter

should

be

made

accordance

with

NAB

standards.

Values

obtained

with

different

standards

of

euipment

cannot

be

compared.

Flutter

should

not

exceed.

I5ips

:

0.10%

(RMS)

0.05%

(W-RMS)

7-1/2ips:

0.12%

(RMS)

0.06%

(W-RMS)

3-3/4ips:

0.15%

(RMS)

0.10%

(W-RMS)

These

figures

apply

to

any

tape

position

and

direction

(such

as

full

take-up

reel,

full

supply

reel

or

about

mid-point).

If

there

is

excessive

wow

and

flutter,

examine

the

pinch

roller,

motors,

capstan

shaft,

and

reel

rest

for

"grease",

"oil",

"dirt"

and/or

"wear".

Also

examine

the

tape

counter

assy

for

even-

ness

of

operation.

Use

to

TEST

UNIT

Tape

Speed

FLUTTER

FREE TAPE

Test

Equipment

Set-up

PINCH

ROLLER

PRESSURE

NOTE:

Pinch

roller

pressure

is

supplied

by

the

pinch

roller

solenoid

arm

and

it

is

most

important

that

the

solenoid

plungers

be

fully

bottomed

before

taking

pressure

measurement.

1.

Load

tape

or

block

the

shut-off

arm

in

the

"ON"

position.

Remove

the

Pinch

Roller

Cap.

2.

Attach

a

suitable

spring

scale

to

a

screw

inserted

in

the

pinch

roller

shaft.

3.

Place

the

unit

in

the

PLAY

mode

(

P»

),

and

holding

the

spring

scale

as

illustrated,

slowly

draw

it

away

from

the

pinch

roller.

(Do

not

allow

the

string

to

rub

against

the

pinch

roller.)

4.

Note

the

reading

on

the

spring

scale

at

the

instant

the

pinch

roller

stops

rotating.

foes)

lf

adjustment

is

necessary,

loosen

the

3

mounting

screws

on

the

capstan

solenoids

and

position

the

solenoids

for

optimum

pressure.

screw

M3

x12

Solenoid

Bracket

Decrease

Increase

Adjustment

3

Screws

Fig.

7

Adjustment

Location

The

scale

should

indicate

2

kg

+200

g

for

2T

(1.8

kg

+

200

g

for

4T).

TORQUE

MEASUREMENT

PROCEDURE

All

Torque

and

Tension

Measurement

must

be

made

with

the

automatic

shut-off

switch

(right

tension

arm)

blocked

to

the

"ON"

position.

BACK

TENSION:

Place

the

REEL

size

switch

to

the

LARGE

position.

Block

the

shut-off

arm

in

the

"ON"

position.

Install

an

empty

7"

reel

(TEAC

RE-702)

on

the

left

reel

table.

Rotate

the

reel

and

wind

several

turns

of

string

counter-clockwise

around

the

hub.

Attach

spring

scale

to

string.

.

Place

the

unit

in

the

(

»

)

play

mode.

.

Pull

the

scale

away

from

the

reel

against

the

motor

torque

with

a

steady

smooth

motion.

7.

Note

the

scale

reading

while

it is

in

steady

motion.

(

The

string

must

not

rub

the

reel

flanges.)

8.

Adjust

R-155

as

needed

to

obtain

tension

of

450

+

20

(g-cm).

(calculated

value

using

T

=

R

X

W)

9.

Repeat

all

the

above

for

the

REEL-SMALL

position.

Reading

should

be

300

(g-cm).

FWNF

an

TAKE-UP

TORQUE:

1.

Place

the

REEL

size

switch

to

the

LARGE

position,

with

empty

reel

and

attached

spring

scale

on

the

right

reel

table.

.

Place

the

unit

in

the

(

»

)

play

mode.

3.

Allow

the

rotation

of

the

reel

to

slowly

draw

the

scale

toward

the

hub.

.

Hold

the

spring

scale

with

enough

force

to

allow

a

steady

reading.

5.

It

should

be

approx.

550

+

20

(g-cm).

If

adjustment

is

necessary,

slide

the

band

on

R~154.

(The

same

resistor

is

also

used

for

SMALL

REELS).

ho

Lf

NOTE

To

measure

torque

when

using

a

reel

with

a

hub

radius

of

other

than

3.0cm

refer

to

following

table;

FORMULA

FOR

TORQUE

CALCULATION:

T

(g-cm)=

R

XW

R:

radius

of

hub

(cm)

W:

gram

R155 R154

SPECIFICATIONS

TAKEUP

TORQUE

|

BACK

TENSION

550

+20

g-cm

450t20

g-cm

300

g-cm

PLAY-

LARGE

HMI

Fig.

8

Torque

Adj.

Location

6

HEAD

ALIGNMENT

HEAD

ASSEMBLY

(head

cluster)

is

adjusted

to

very

close

tolerance

at

the

factory

and

normally

requires

only

minor

alignments

or

adjustments

after

replacement

on

the

deck.

Complete

readjustment

of

the

HEAD

ASSEMBLY

will

be

necessary

when

an

individual

head

is

replaced.

HEIGHT

ADJUSTMENT

(4

track)

RECORD

HEAD:

The

record

head

pole

should

be

above

the

edge

of

a

threaded

tape

by

the

width

of

a

thin

pencil

line.

PLAYBACK

HEAD:

The

forward

playback

head

pole

should

be

even

with

the

top

(FORWARD)

of

a

threaded

tape.

PLAYBACK

HEAD:

The

pole

of

the

reverse

head

should

be

even

with

the

bottom

(REVERSE)

of

a

threaded

tape.

ERASE

HEAD:

Erase

section

should

be

a

heavy

pencil

line

above.

NOTE

A~7300

2

track

RECORD

and

ERASE

heads

are

centered

on

the

tape.

PLAYBACK

head

forward

section

is

a

heavy

pencil

line

above

the

edge.

Refer

to

the

illustration

below.

veveeeeeeeseeegeees

(Ab)

gAZIMUTH

ADJ.

SCREWS

©

“ue

1ct

ava.

screws

4

4T

4t

For

4

track

For

2

track

T-361

Fig.

9

Head

Configuration

and

Alignment

Screws

7

HEAD

ASSEMBLY

REMOVAL

AND

REPLACEMENT

.

Remove

power

from

the

unit.

.

Move

head

assembly

cover

by

removing

2

screws

on

the

left

and

right

end

of

the

head

cover

and

then

gently

move

cover

toward

the

top

of

the

deck.

.

Remove

4

mounting

screws

from

the

head

assembly.

.

Lift

head

assembly

and

remove

the

2

jacks

and

the

9

connector

mounted

on

the

rear

of

the

head

housing.

.

Lift

off

head

assembly.

.

Loosen

2

counter~sunk

screws

(A)

from

the

rear

plate

of

the

head

assembly

and

remove

2

small

screws

(B)

from

the

top

of

the

head.

Then

slide

off

the

shield

case

(C).

-

To

replace

a

single

head,

a

nut

driver

is

required.

Remove

the

2

nuts

(D)

on

the

defective

head

through

the

access

hole

provided.

This

releases

the

head

from

the

mounting

plate.

Fo,

»?

ite

g

Head

Mount

Plate

Fig.

10

Head

Replacement

After

the

head

is

replaced

be

sure

to

replace

the

shield

case

and

tighten

the

2

counter-sunk

screws

on

the

rear

of

the

head

assembly

plate.

Also

insure

that

the

spring

on

the

head

assembly

cover

is

properly

set

in

the

slot

.on

the

head

cover

bracket.

(Ref.

to

Parts

List).

-FEATURE

COMPARISON

CHART-

eee

teresa

A-7300

2T

|

Heads

fieads

GT

2

ch

7-1/2,

3-3/4

ips

15,

7-1/2

ips

Special

Features

Index

counter

No

memory

Rewind

Memory

Rewind

ADJUSTMENT

LOCATIONS

BIAS

RECORD

STABI-

RECORD

METER

PLAY

MICL

MICR

SC

L

LINE

EO

IZER

LINE

55507460

T-340

Fig.10

Amp?

PC

Board

Locations

and

Adjustment

Points

NOTE:

All

Internal

adjustments

are

accessible

by

removing

bottom

cover.

Ref.

Nos

correspond

to

ref.

Nos

on

ELECTRICAL

ADJUSTMENT

Procedure

Charts

on

the

oscilloscope

OUTPUT

REPRODUCE

(PLAYBACK)

Fig.12

Specified

Output

Level

Position

Decrease

2dB(2T)

Decrease

peak

\

348

(A-7300)

io

A

<

B

&

wn

ie

&

io]

=

a

jo)

1}

(3

mm

OUT

During

Record

Azimuth

Adjustment,

the

oscilloscope

pattern

angle

for

SOURCE

and

TAPE

monitoring

must

be

identical

in

order

to

maintain

a

0°

phase

difference

between

them.

BIAS

307

Fig.11

Head

Alignment

Fine

Adjustment

Set-Up

Fig.13

Bias

Limits

Chart

————

ELECTRICAL

ADJUSTMENTS

!

ADJUSTING

SIGNAL

|MEASUREMENT

MODE

|

POINT

INSTRUCTIONS

Ref

Nos|

‘TEM

SOURCE

|

CONNECTION

fon

F.C.B.)

TEAC

Test

VTVM

&

Play

Playback

Tape

YTT-

Osciloscope

TAPE

Azimuth

ee

Pace

-

Eee

dicati

1003

15KHz

|

to

OUTPUT

(playback)

|

Screw

POR

ear

anna

ance

Ol

Head

:

3.Less

than

45°

out

of

phase

at

oscilloscope.

Adjustment

|

Test

Tone

jacks

on

Head

Assy

Specitied

VR-251

1.QUTPUT

control

at

the

O

VU

position

®

Output

Level

VR-252

2.

Adjust

for

O

dB

at

OUTPUT

jack.

Setting

|

400

Hz

on

Play

Line

(This

is

the

specified

output

level.)

|

0

0B

VR-301

@

Wi

Test

Tone

VR-302

1.METER

switch

to

NORMAL

for

O

VU,HIGH

for

3

+0.5

meter

!

on

Meter

VU

Reading

on

the

VU

meter

lower

scale.

Calibration

VTVM

to

ape

+

OUTPUT

jack

;

TEAC

Test

VR-203

Tape

YTT-

vr-204

(HIGH)

®

1004

on

Play

Eq

1.

Compare

the

readings

obtained

on

the

VTVM

with

response

Frequency

VR-201

(Low)

Limits

given

in

Fig.

14

Response

YTT-1003

VR-202

on

Play

Eq

1.

Adjust

to

obtain

the

specified

output

level

of

O

dB

at

Monitor

400

Hz

Veal

OUTPUT

jacks.

@

Level

~18

oB

Wego?

2.

input

selector

>

LINE

exe

(97mV)

AF

Oscillator

|

source

|

on

Mic

LR

Setting

|

to

LINE

IN

jacks

:

bee.

2

yiniaiae

cae

eae

1.METER

switch

in

NORMAL.

Level

Set

(775mV)

on

Record

Line

2.

Adjust

to

obtain

0

VU

on

the

VU

meter.

AF

Oscillator

RECORD

MODE

—

ON

sae

q

to

the

LINE

|

Oscilloscope

|

SOURCE

eee

1.Move

the

MONITER

switch

to

the

TAPE

position.

As

math

IN

jack

to

OUTPUT

&

Screw

2.

Adjust

for

maximum

Indication.

10KHz

—

28dB

|

;

I

i

Adjustment

(31m)

jack

TAPE

on

Head

Assy’

3.

Both

channels

on

the

Oscilloscope

to

be

in

Phase.

1,

Depress

REC

and

“PAUSE”

buttons

©

Bias

Trap

|

VTVM

or

L-503

2.Using

TEAC

Test

Tape

YTT-8013.

Adjustment

Oscilloscope

SOURCE

L-504

3.

BIAS

switch

to

#1

across

the

on

Record

4.RECORD

MODE

—

ON

No

signal

|

Test

Point

5.

Adjust

for

minimum.

&

ground

7

(on

the

REC

eee

5.

Adjust

L-251/252

for

minimum

bias

leakage

reading

at

P.C.B.)

;

OUTPUT

jacks

Spec.

—45

dB

or

less.

on

Play

Line

+—

r

7

KHz

VC-551

1.Using

TEAC

Test

Tape

YTT-8013.

Bias

#1

—18

4B

VC-552

2.

BIAS/EQ

switch

to

#1.

Adjustment

|

(97mV)

on

Bias

Osc

3.

Adjust

clockwise

a

decrease

2

dB

from

the

peak.

See

Fig.13

400

Hz

VR-453

1.

Using

TEAC

Test

Tape

YTT-8013.

®

Record

~8

dB

VR-454

2.BIAS/EQ

switch

to

#1.

Level

Set

(308mV)

on

Record

Line

3.

Adjust

for

0

dB

at

OUTPUT

jack.

Overall

30

Hz

VR-503

(G44)

|

1.BIAS/EQ

switch

to

#1.

a)

Frequency

to

VR-504

2.

Using

TEAC

Test

Tape

YTT-8013.

Response

28

KHz

TAPE

on

Record

3.

Adjust

for

each

channel

VTVM

to

+—

ap

pain.

|

OO

OUTPUT

VR'502

(1

ow)

|

1.

Place

the

SPEED

switch

to

LOW.

®

(31mV)

to

jack

Wieoee

2.

Adjust

for

each

channel

m

24

KHz

on

Record

‘

3

30

Hz

1.

BIAS/EQ

switch

to

#2.

@

Bias

+2

6

VR-552

2

Usin

aes

:

i

:

g

TEAC

Test

Tape

YTT-8003;

Adjusts

both

channels

Adjustment

D4

Kas

on

Bias

Osc

together.

|

11.

BIAS/EQ

switch

to

#3.

@®

:

30

Hz

|

7

2.Using

TEAC

Test

Tape

YTT-8023;

Adjusts

both

channels

Bias

#3

to

in

ae

Ose

together.

Adjustment

|

24

KHz

3.

Repeat

Overall

response

check

at

LOW,

both

speeds

refer

|

to

response

Limits

given

in

Fig.

15,16

If

the

TEAC

YTT-series

blank

test

tapes

(

8013,8003,8023

)

are

not

available

use

any

of

the

tapes

listed

on

page

12

that

require

the

same

EQ

switch

and

BIAS

switch

settings.

10

RESPONSE

IN

dB

RESPONSE

iN

dB

RESPONSE

IN

dB

FREQUENCY

RESPONSE

CHART

2T.4T

PLAYBACK

PERFORMANCE

(2T,47)

1.

Play

Test

Tape

that

matches

the

speed

of

your

deck:

U5

tps-2T

ssa

aceaee

YTT-1004

7-1/2

ips

2T,

4T...YIT-1003

3-3/4

ips

4T.......

YTT-1002

2.

Set

output

controls

to

specified

level.

Compare

output

reading

to

following

charts.

RESPONSE

IN

48

50

100

$00

"

FREQUENCY

IN

Hz

FREQUENCY

IN

He

7-\/;ips

2T

50

100

500

1K

5K

10K

20K

50K

FREQUENCY

IN

Hz

7-\yips

47

|

[

ot

reer

[th

Tey

‘a

|

tt

jj

4

sl

Ss

+

cr)

|

ia

3

ae

a

:

4

-

i

LLL

a

i

Seam

|

50

100

500

1K

5K

OK

(20K

50K

FREQUENCY

IN

Hz

Fig.14

Frequency

Response

Limits

-

Playback

-

1

——_1

K

5K

10K

20K

‘50K

50

100

500

*"

5K

70K

20K

50K

RESPONSE

IN

dB

RESPONSE

IN

dB

RESPONSE

IN

dB

FREQUENCY

RESPONSE

CHART

2T

RECORD

PERFORMANCE

(2T,4T)

r

1.

Measured

with

input

20

dB

below

the

Specified

input

level.

2.

Level

should

correspond

to

charts

below

(per

Speed

employed).

3.

Set

BIAS.

EQ

switches

to

match

the

Tape

you

are

using

per

the

chart

below:

BIAS,

EQ

#1

YTT-8013

BIAS,

EQ

#2

YTT-8003

BIAS.

EQ

#3

YTT-~8023

4.

Repeat

Frequency

Response

check

for all

speeds.

Sips

2T

"YT

T8013.

-YTT-8003

7-l\gips

2T

YTT-8018

hafarararan

Trt

RESPONSE

IN

dB

FREQUENCY

IN

Hz

7-14

ips

27

YTT-8003

RESPONSE

IN

dB

50

100

500

1K

5K

10K

20K

SOK

FREQUENCY

IN

He

FREQUENCY

IN

Hr

50

100

‘500

1K

BK

10K

20K

Recommended

BIAS

and

EQ

switch

settings

for

various

types

of

tape

1-1/2

mil

base

tape

(recommended

for

2-track

decks

only)

Type

or

model

BIASEQ|

UD-50

i

SHL-11-740B

211

1

i)

SPR-50LH

2

1200

2

FB-101

2

111

or

its

3

Equivalent

id

1

mil

base

tape

(recommended

for

2-track

or

4track

decks)

|

lisips

27

YTT-8023

tt

hatha

a

L

|

L

MAXELL

FUJI-FILM

1

|

1

Tease

FB-151

2

|2

|mMemorex

BASF

LRP

or

|LP-35LH

2

|2

|FUJI

FILM

MEMOREX

1800

2

|2

FUJI-FILM

FM-150

SCOTCH

150

or

its

equivalent

©

BRO

Rh

RO

Liilt

50

100

500

1K

5K

WK

20K

50K

FREQUENCY

IN

Hz

Fig.15

Frequency

Response

Limits

3

1/3

-

Record

-

Cont'

on

12

RESPONSE

IN

d8

RESPONSE

IN

dB

RESPONSE

IN

dB

FREQUENCY

RESPONSE

CHART

4T

RESPONSE

IN

4B

FREQUENCY

IN

Hz

3-34ips

47

YTT-8013

a

PARA

T

itor

ty

ate

4T

yrr-b013

Ht

TH

Hit

i

|

i

I

i}

Aid

SESE

ot

UT

fi

|

Ht

amu

|

[eT

ani

00

500

*

oe

10K

RESPONSE

IN

dB

50

100

500

1K

FREQUENCY

IN

Hz

7-14

ips

47

_YTT-8003

me

He

+

RESPONSE

IN

dB

50

100

500

1K

FREQUENCY

IN

Hr

cope

—

3-34ips

4T

YTT-8003

Rare

++

500

1K

FREQUENCY

IN

10K

50K

sO

100

$00

1"

5K

10K

ZOK

BOK

FREQUENCY

IN

Hz

3-S4ips

47

YTT-8023

+4

rh

T

+

i

TT

1

i

7

tit

i

|

tH

}

1

as]

+398

g

:

i

{k

ii

TT

in

1

T

Ty

H

T

—

|

{

248

!

mill

|

ti

tili

1

50

100

500

WK

5K

10K

ok

SOK

FREQUENCY

IN

Hz

Fig.

16

Frequency

Response

Limits

13

Record

-

id

i

PAN

Os

A-7300/2

TROUBLESHOOTING

se

Scan

REO

Ae

S

i

oo

ee

QSSIBLE

SOURCE

OF

TROUBL

-

Pilot

Lamps

(in

VU

Meters)

do

not

illuminate

when

power

is

applied...........cee

cence

Fuse

F701

(2A)

burned

out

-

Fuse

burns

out

(blows)

when

power

is

applied.......Defective

Power

transformer

(T151)

~

Capstan

will

not

rotate..........6..

ei

bcar'enwtenoteuereveveceyege

Specified

24V

DC

present

on

the

CAPSTAN

MOTOR

ASS'Y

J152

Pins

#1~7

Leeeecnive

CAPSTAN

ASS'Y

Specified

24V

DC

not

present

on

the

STABILIZER

UNIT

J21

Pins

#11,#12

Lonagentive

STABILIZER

UNIT

ASS'Y

or

Connector

loose

Specified

32V

DC

not

present

on

the

STABILIZER

UNIT

J21

Pins

#13,#14

Ljebeceree

D1O~D13

or

Power

transformer

(T151)

-

Transport

inoperative

in

Forward

Playback..........

Faulty

Safety

switch

(SW155)

-

Pinch

roller

fails

to

engage

completely............

Voltage

present

on

the

CAP

SOL.1

terminals

L

cap

SOL.1

Disconnected

High-Level

voltage

(approx.3V)

present

on

the

SOLENOID

DRIVE

UNIT

J121

#3

Lnefective

Q121

or

Q122

High-Level

output

voltage

not

present

on

the

CONTROL

UNIT

P41

#1

Lnefective

CONTROL

UNIT

-

Right

Reel

Motor

does

not

rotate.............+....-.Fast

Forward

OK........Defective

Q71

or

K72

High-Level

output

voltage

not

present

on

the

CONTROL

UNIT

P41

Pins

#1

or

#2

gepcekive

CONTROL

UNIT

pe

High-Level

output

voltage

present

on

the

REEL

MOTOR DRIVE

UNIT

at

H

terminal

i:

Defective

Reel

Motor

-

Neither

Reel

Motor

rotates......

ee

emcee

eer

ceeeeeee

Brakes

not

dis-engaged

Lpiseonneeted

brake

Solenoid

R

or

L,

Defective

Q125

or

Q126

High-Level

output

voltage

present

on

the

SOLENOID

DRIVE

UNIT

J21

#8

Lpefacetyva

SOLENOID

DRIVE

UNIT

High-Level

output

voltage

not

present

on

the

CONTROL

UNIT

P41

#2

lnetective

CONTROL

UNIT

-

Fast

Forward

or

Rewind

modes

inoperative

(Playback

is

OK)...........

Hapathe

Diag

..High-Level

output

voltage

not

present

on

the

CONTROL

UNIT

P41

Pins

#4,#7

lperedtive

CONTROL

UNIT

High-Level

output

voltage

present

on

the

CONTROL

UNIT

P41

#2

linefective

SOLENOID

DRIVE

UNIT

(Q125,Q126)

14

TROUBLESHOOTING

eee

POSTAL

SoU

Teouace

-MALFUNCTIOI

PPPOE

EES

Transport

inoperative

(Capstan

only

rotates)......-eeeeeee

ea

acgracanebieteces

..Specified

8V

DC

present

on

the

STABILIZER

UNIT

J21

Pins

#5,

#6

ln

Defective

STABILIZER

UNIT

Specified

8V

DC

not

present

on

the

STABILIZER

UNIT

J21

Pins

#5,

#6

Lerouley

D14~D17

or

fuse

F2

(2A)

Cannot

select

PAUSE...

.ccecec

cence

eeececeeesesess

Defective

CONTROL

UNIT

....Voltage

not

present

on

P151

at

#10

or

#11

(To

ampl.

connector)

lease

Fl

(2A),F4

(0.5A)

burned

out

Amplifier

inoperative.........

Dfelieve.S

Stace

leveré

ae

Voltage

present

on

P151

at

Pins

#10

or

#11

Lonetkeeave

Q601, Q602,

Q603

(on

AMPL.

STABILIZER

UNIT)

Playback

audio

intermittent

or

absent

a)

Both

channels

inoperative..........

seagate

reset

sce

...-Defective

Q207,

Q208,

Q209

or

associated

parts

(SOURCE

OK)

b)

Roch

or

L-Ch

inoperative.......++eseeeeeee

...-SOURCE

also

inoperative

|

Defective

Q301

or

associated

parts

SOURCE

Monitor

function

normal

Defective

Q201, Q203,

Q205,

Q207, Q251,

Q253,

Q255

or

associated

parts

Playback

sound

is

not

clear........+..+++++e+5++--High

Freq.

weak.....Dirty

head,

incorrect

Adj

of

VR201/203

Sound

distorted.....Defective

Q201,

203,

205

-

VU

Meter

inoperative

in

TAPE

Monitor

mode........Defective

Q306

or

associated

parts,

(sound

is

normal)

Faulty

VU

Meter

ass'y

-

Hum

in

playback

signal........-.eeereeeeees

.....-Defective

Playback

head

-

Intermittent

or

absence

of

audio

at

PHONES

jack...

ccc

cece

eee

ee

ese

wceeee

weeeeeee

Defective

Q303,

Q305 Q307

or

associated

parts

-

LINE

IN

signal

is

not

applied

to

SOURCE..........Defective

Q405,

Q406,

Q451,

Q453...etc

(Playback

normal)

—

WL11

not

Record.

...ccee

cc

cccccr

ence

recsessces

...-No

Erase.....Defective

K551,

Q551™~

554,

1T551

leaspecink

normal..

.++.-Sound

normal

at

SOURCE

Lnefective

Q507,

Q509,

Dirty

or

defective

recori

head

-

Recorded

sound

not

clear.

...

cece

ces

ee

cece

eeenee

.Dirty

record

head,

incorrect

Bias

Adj.

or

-

Inoperative

MIC

Recording

Detective,

Oy?

(LINE

IN

signal

normal)

.......eseeee

eee

eeeeees

.

Defective

Q401~Q404....etc

~

Hum

in

Recording

signal........-..sseeee-

weeeee.-Defective

Record

head

or

P702

connector

loose

or

heads

magnetized

Note:

Explanation

of

abbreviations

and

circuit

component

designations.

F...Fuse

D...Diode

SW...Switch

K...Relay

T...Transformer

J...Pin

jack

(Female)

Connector

P...Pin

plug

(male)

connector

High-Level

output

voltage

-Logic

true

level

approx.

+3V.

Refer

to

the

circuit

diagram

for

further

assistance

in

locating

possible

defective

circuit

components.

15

w

65

TEAC.

A-73002T

STEREO

TAPE DECK

PARTS

LIST

CONTENTS

PARTS

ORDERING

INFORMATION

PAGE

Spare

parts

are

available

through

your

nearest

TEAC

DIAGRAM

PARTS

LIST

Authorized

Service

Center

or

directly

from

the

TEAC

I.

EXPLODED

VIEW

AND

PARTS

LIST

office,

the

address

of

which

is

written

on

the

back

I.

CENTER

BASE

SECTION

cover.

When

ordering

parts,

always

include

the

fol-

(Exploded

Front

View)

....c.:ccs:e

2

3

lowing

information:

1-2,

CENTER

BASE

SECTION

{Exploded

Rear

View)

........

7

4

5,

18

1.

MODEL

4.

DESCRIPTION

1-3.

LOWER

MAIN

CHASSIS

6

7

2.

REF.

NO.

5.

UNIT

SERIAL

NO.

I-4.

AMPLIFIER

SECTION

......-.-enscseus

8

9,

18

3.

PARTS

NO.

6.

MANUAL

CODE

NO.

1-5.

TRIM

AND

CABINET

PARTS

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

10

NOTICE

REGARDING

PARTS

ORDERS

1.

Do

not

order

by

only

REF.

NO.

PC

BOARD

SECTION

Ht.

PLAY

LINE

AMP

UNIT

.................004

1

19

:

ae

:

2

AMP

STABILIZER

UNIT

1

19

2. In

some

instances,

individual

minor

parts

are

not

113.

BIAS

OSC

UNIT

..snsnncncnenn

12 19

evenable:

.

ee

Tw

MIC

MIXING

AMP

UNIT

12

20

In

such

a

case,

the

entire

assembly

including

the

mM

§

Ber

URESARAP

IAI

vie

atte

13

20

part

requested

will

be

sent

to

you.

11-6.

METER PHONE

AMP

UNIT

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

13

21

7.

PLAY

EQ

AMP

UNIT

14

21

PARTS

IDENTIFICATION

CODING

11-8.

RECORD

AMP

UNIT

........-sssssssscccsessee

14

22

Parts

are

identical

between

the

different

models

with

1-9.

SOLENOID

DRIVE

UNIT

.........s.ssssessee

15

22

the

exceptions

as

coded

by

the

designations

explained

1-10.

REEL

MOTOR

DRIVE

UNIT

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

15

23

below.

W171.

CONTROL

UNIT

.......

ee

eeeccerseeeenee

16

23

TCA

TEAC

Corporation

of

America,

U.S.A.

version

12.

STABILIZER

UNIT

7

23

only.

1-13.

POWER

SUPPLY

UNIT

..

7

24

EX

All

export

versions

(except

TCA

or

Japan).

W-14.

REWIND

STOP

UNIT

........

ee

18

24

115.

MIC.

TRANSFORMER

sss.

18

24

4T

For

decks

with

the

4

track

head

configuration

SUPPLIED

ACCESSORIES

.......csenrsnenstsnsesnssennnee

ae

perandar

ASSEMBLING

HARDWARE

CODING

LIST

For

decks

with

the

2

track

head

configuration.

(These

decks

have

2T

included

in

the

nomen-

clature,

i.e.,

A-7300-2T).

Effective:

June,

1975

Latest

Revision

No:

$124

TEAC

CORPORATION

51031520

6S

1.

EXPLODED

VIEWS

AND

PARTS

LIST

I-1,

CENTER

BASE

SECTION

(Exploded

Front

View)

3-B

M3x!0

B

M26x4

NYLON

W

SH7KO.25t

41

fos

M4x

25

eo

42

REF.

NO.

PARTS

NO.

DESCRIPTION

REMARKS

1-

55005020

Name

Plate

Assy,

Housing;

8

[A-7300]

55305111

Head

Housing

55405150

~—_

Screw,

Hinge

55405160

~—=_

Collar,

Hinge

55305121

Base,

Head

Housing

55405011

Stud,

Head

Housing

Mounting

55305390

Cushion,

Rubber

55507480

Plate,

Cover

55002271

Link

Assy,

Head

Housing

55202050

Spring,

Head

Housing

55540780

_

Anti-spoiler

=o

em

1

oP

roe

a

EO

A

WAN

-

OO

MNOoOA

WH

=

'

4-12

55507530

Plate,

Housing

Base

1-13

55440340

=

Tape

Guide,

B

1-14

55440730

~—

Tape

Guide,

C

1-15

55202020

Spring,

Head

Adjusting

1-16

55507630

—

Shield,

Jack

1-17

55540470

Shield,

A

1-18

50435070

=

Jack,

Pin;

2P

1-19

55507160

Plate,

Erase

Head

1-20

50136540

Spacer,

Erase

Head

1-21

50662030

__

Head,

Erase

(2T-2CH)

2T.

50663030

Head,

Erase

(4T-2CH)

4T

1-22

55507170

Bracket,

Head

Plate

1-23

50220500

__

Spring.

Head;

B

1-24

55305100

Plate,

Head

1-25

55507180

_—-

Head

Shield

1-26

50664520

Head,

Record

(2T-2CH)

2T

50664540

Head,

Record

(4T-2CH)

4T

1-27

50664530

~—

Head,

Playback

(2T-2CH)

2T

50664550

_—

Head,

Playback

(4T-2CH)

4T

1-28

50435040

=

Socket,

9P

(w/Clamp)

1-29

55540480

Shield,

Socket;

B

1-30

50429060

_

Clip,

Socket

Retaining:

Small

1-31

55040150

Drive

Roller

Assy

1-32

55440490

Pin,

Tape

Guide

1-33

55441240

Ring,

Tension

Arm

1-34

55040170

‘Tension

Arm,

R

1-35

55305031

Base,

Center

Mounting

1-36

50276290

Clamp,

Wire;

B

1-37

55440500

Pulley,

Drive

Roller;

2T

27

1-38

55405100

Cap.A

1-39

55040552

Tension

Arm

Assy,

L

1-40

55002051

Impedance

Roller

Assy

1-41

55440830

Spacer,

impedance

Roller

1-42

55541550

~—-Hook,

Spring:

T

1-43

55440820

Ring,

Damper

1-44

55541890

Arm,

Damper

1-45

55541900

Cushion,

Damper

Arm

1-46

50432740

Connector,

9P

(Plug)

1-47

50478430

Cord,

Head

Connection

I-2.

CENTER

BASE

SECTION

(Exploded

Rear

View)

E-2

@

2-BSB

See

2

Teac A-7300 User manual

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