Akai 4000DS Mk-II User manual

Other manuals for 4000DS Mk-II

3

This manual suits for next models

1

Table of contents

Popular Tape Deck manuals by other brands

Hitachi

Hitachi D-980MU Service manual

Teac

Teac A-6010GSL Service manual

Hitachi

Hitachi D-900BS Service manual

Kyocera

Kyocera D-611 Service manual

Kenwood

Kenwood KX-W595 instruction manual

Sony

Sony DTC-A8 Service manual

TANDBERG

TANDBERG 11 instruction manual

Teac

Teac Tascam 3030 owner's manual

Sony

Sony DTC-670 operating instructions

Teac

Teac A-3300 Service manual

Pioneer

Pioneer H-R99 KCU Service manual

Tascam

Tascam 34B operation & maintenance

Technics

Technics SV-DA10 operating instructions

Advent

Advent 201 Service manual

Pioneer

Pioneer RT-1011L Service manual

Kenwood

Kenwood KX-79CW instruction manual

Revox

Revox A77 operating instructions

Kenwood

Kenwood 1050CT instruction manual

SERVICE

mrnilML

STEREO

TAPE

DECK

MODEL

4000DS

SECTION

1

SERVICE

MANUAL

.

2

SECTION

2

PARTS

LIST

.

17

SECTION

3

SCHEMATIC

DIAGRAM.

36

SECTION

1

SERVICE

MANUAL

TABLE

OF

CONTENTS

I.

SPECIFICATIONS

.

3

II.

MEASURING

METHOD

.

4

III.

DISMANTLING

OF

TAPE

TRANSPORT

UNIT

&

AMPLIFIERS

.

6

IV.

MECHANISM

ADJUSTMENTS

.

8

V.

HEAD

ADJUSTMENTS

.I

I

VI.

AMPLIFIER

ADJUSTMENTS

.1

2

VII.

COMPOSITE

VIEWS

OF

COMPONENTS.14

I.

SPECIFICATIONS

An

asterisk

next

to

a

figure

indicates

the

minimum

guaranteed

performance.

TRACK

SYSTEM

REEL

CAPACITY

TAPE

SPEED

WOW

AND

FLUTTER

FREQUENCY

RESPONSE

AKA!

SRT

tape

Regular

tape

SIGNAL

TO

NOISE

RATIO

DISTORTION

CROSS

TALK

ERASE

RATIO

INPUTS

OUTPUTS

Mic

input

Line

input

Din

input

Line

output

Din

output

BIAS

FREQUENCY

_

BIAS

LEAK

HIGH

FREQUENCY

DEVIATION

RECORDING

CAPACITY

_

FAST

FORWARD

AND

REWIND

TIME

HEADS

Recording

Head

Playback

Head

Erase

Head

TRANSISTORS

DIODES

POWER

SUPPLY

POWER

CONSUMPTION

INSULATION

RESISTANCE

INSULATION

DURABILITY

DIMENSIONS

WEIGHT

4-track

2-channcI

stereo/monaural

system

_

Up

to

7"

reel

_

7-1/2

and

3-3/4

ips

±

2%

(*±3%)

Less

than

0.15%

(•0.22%)

RMS

at

7-1/2

ips

Less

than

0.20%

(*0.30%)

RMS

at

3-3/4

ips

30

to

23,000

Hz

(M0

to

22,000

Hz)

±

3

dB

at

7-1/2

ips

30

to

16,000

Hz

(M0

to

14,000

Hz)

±

3

dB

at

3-3/4

ips

30

to

20,000

Hz

(M0

to

20.000

Hz)

±

3

dB

at

7-1/2

ips

30

to

14,000

Hz

(M0

to

14.000

Hz)

±

3

dB

at

3-3/4

ips

Better

than

50

dB

at

7-1/2

ips

Better

than

48

dB

at

3-3/4

ips

Less

than

1.5%

(*2.0%)

at

7-1/2

ips

Less

than

2.5%

at

3-3/4

ips

Better

than

70

dB

(*60

dB)

monaural

Better

than

50

dB

(M5

dB)

stereo_

Better

than

70

dB

0.8

mV

Impedance

5

kft

70

mV

Impedance

150

kft

7

mV

1.228V

(4

±

1

dB)

using

a

250

Hz

“O’*

VU

recorded

tape

0.4V

105

kHz

±5%

_

Less

than

-30

VU

_

*

Within

2

dB

using

an

8,000

Hz

3-3/4

ips

recorded

tape

at

7-1/2

ips

60

min.

stereo

recording

using

a

1,200

ft.

tape

at

7-1/2

ips_

15

2/190

sec.

using

a

1,200

ft.

tape

at

60/50

Hz

4-pole

induction

I-speed

motor

Type:

SSM-1

Revolutions:

1,800/1,500

rpm.

at

60/50

Hz

_

In-line

4-track

2-channcl

recording

head

Type:

P4-I54

Gap:

1

micron

Impedance:

9512

±

15%

at

1,000

Hz

In-line

4

track

2-clianncl

playback

head

Type:

P4-I50

Gap:

I

micron

Impedance:

1,250ft

±15%

at

1,000

Hz

In-line

4-track

2-channcl

erase

head

Type:

E4-200

Gup:

0.6

mm

Impedance:

200ft

±5%

at

100

kHz

_

6.2SC458

LG

(C)

<D)

2.2SC97I

(2;

2.

2

SC87I

(K)

(!

■

*)

_

1

.

2

SCHW

4_

LD3I4I

___

2.

IN34A

I.

I

OIK-I

1.

IS339A

100

to

240V

A.(\.

50/60

Hz

120V

A60

Hz

lor

CSA/UL

Models

220V

A.C..

50

Hz

lor

CEE

model

35

W

More

Ilian

50

MA

_

_

I,

000V

A.C.

for

more

than

I

min.

duration

406

<W)

X

314

(11)

X

194

(D)

mm__

(15.9"

X

1

2.4"

X

7.6")

II.

4

kg

(25

lbs.)

2SC971

(2)

(3)

(red)

2SC1098

(L)

(M)

NOTE:

Specifications

subject

to

change

without

notice.

II.

MEASURING

METHOD

1.

T

APE

SPEED

DEVIATION

1

Frequency

4000DS

counter

Line

output

input

Fig.

1

As

shown

in

Figure

1,

connect

a

Frequency

Counter

to

the

Line

Output

of

Model

4000DS.

Take

a

frequency

counter

reading

at

the

beginning,

middle,

and

end

of

tape

winding

during

playback.

The

maximum

value

of

these

respective

readings

will

represent

tape

speed

deviation.

2.

W

OW

AND

FLUTTER

Vl/fMii

•mil

1

4

lai#

1

nr

4000DS

>Y()W

cIlKJ

I

inner

Meter

input

Line

output

Fig.

2

Method

A

As

shown

in

Fig.

2,

connect

the

Line

Output

of

Model

4000DS

to

the

Input

of

a

Wow

and

Flutter

Meter.

Use

a

3,000

Hz

pre-recorded

test

tape

and

take

a

wow

and

flutter

meter

reading

at

the

beginning,

middle,

and

end

of

tape

winding.

The

maximum

value

of

these

respective

readings

will

represent

the

wow

and

flutter.

Method

B

Supply

a

3,000

Hz

sine

wave

signal

from

an

Audio

Frequency

Oscillator

and

make

a

recording

on

a

blank

tape

at

the

beginning,

middle,

and

end

of

tape

winding.

Rewind

and

playback

tape.

Measure

wow

and

flutter

with

a

Wow

and

Flutter

Meter.

(The

wow

and

flutter

value

of

Method

B

will

be

close

to

twice

that

of

Method

A.)

3.

F

REQUENCY

RESPONSE

Audio

Frequency

ollt

Oscillator

put

f

.

4000DS

Line

input

Line

output

ATT.

<

High

Sensitivity

V.T.V.M.

Fig.

3

For

measuring

frequency

response,

connect

instru¬

ments

as

shown

in

Fig.

3

and

proceed

as

follows:

1)

Supply

a

1.000

Hz

sine

wave

to

the

Line

Input

of

Model

4000DS

from

an

Audio

Frequency

Oscil¬

lator

through

an

Attenuator.

Set

recorder

to

re¬

cording

mode

and

turn

recording

level

volume

control

to

maximum.

Adjust

Attenuator

to

obtain

a

+4

dB

V.T.V.M.

reading.

2)

Under

conditions

described

in

I)

above,

re-adjust

Attenuator

so

that

the

Line

Output

is-16

dB,

and

record

40

to

20,000

Hz

spot

frequencies.

3)

Rewind

tape

and

playback

from

the

beginning.

Take

V.T.V.M.

spot

frequency

readings

and

plot

values

on

a

graph.

NOTE:

When

measuring

frequency

response,

new

tape

should

be

used.

4.

S

IGNAL

TO

NOISE

RATIO

4000DS

High

Sensitivity

Line

output

V.T.V.M.

Fig.

4

As

shown

in

Fig.

4,

connect

a

High

Sensitivity

V.T.V.M.

to

the

Line

output

of

Model

4000DS.

Playback

a

250

Hz

“O”

VU

pre-recorded

test

tape

and

measure

the

output.

Then

remove

the

tape

and

measure

the

noise

level

under

the

same

condition.

Convert

each

of

the

measured

values

into

decibels.

5.

TOTAL

HARMONIC

DISTORTION

FACTOR

Fig.

5

Connect

the

measuring

instruments

as

shown

in

Fig.

5

and

record

a

1,000

Hz

sine

wave

signal

at

“O”

VU.

Playback

the

resultant

signal

and

measure

the

overall

distortion

factor.

Measure

the

noise

level

of

the

tape

recorder

without

the

tape.

Connect

the

Audio

Fre¬

quency

Oscillator

directly

to

the

distortion

meter

for

measurement

of

the

distortion

factor

of

the

oscilla¬

tor.

The

required

distortion

factor

can

be

obtained

from

the

results

of

the

above

measurement

by

the

following

formula:

do

=

d

-

dj

-

d2

where,

do

-

Required

distortion

factor

d

-

Overall

distortion

factor

d|

-

Noise

level

d

2

-

Distortion

factor

of

the

oscillator

NOTE:

When

measuring

the

distortion

factor,

new

tape

should

be

used.

7.

ERASE

RATIO

As

shown

in

Fig.

4,

connect

a

High

Sensitivity

V.T.V.M.

to

(he

Line

Output

of

Model

4000DS.

Playback

a

virgin

tape

and

take

a

V.T.V.M.

reading

of

the

output

level.

Next,

record

a

1,000

Hz

sine

wave

signal

at

+3

dB,

then

playback

this

recorded

signal

and

tape

a

V.T.V.M.

reading

of

the

output

level.

Next,

using

this

pre-recorded

tape,

record

under

a

non-input

condition

and

take

a

reading

of

the

noise

level

output

of

the

erased

signal

and

obtain

a

ratio

between

the

two

from

the

following

formula:

Er

=

20

log

^

(dB)

Where,

Er

-

Desired

erase

ratio

(dB)

Ep-

1,000

Hz

signal

output

level

E

2

—

Non-input

signal

recorded

level

E|

-

Virgin

tape

noise

output

level

6.

CROSS

TALK

(Cross

talk

between

the

tracks)

As

shown

in

Fig.

6,

first

record

a

1,000

Hz

sine

wave

signal

on

Track

No.

3

at

+3

VU

level.

Next,

record

under

a

non-input

condition.

Then,

playback

the

tape

on

Tracks

No.

3

and

4

through

the

B.P.F.(band

pass

filter

sensitivity

...

1:1)

and

obtain

a

ratio

between

the

two

from

the

following

formula:

C

=

20

log

(dB)

where,

C

-

Desired

cross

talk

ratio

(dB)

Eq

-

1,000

Hz

signal

output

level

E

2

-

1,000

Hz

cross

talk

level

El

-

Non-input

signal

recorded

level

III.

DISMANTLING

OF

TAPE

TRANSPORT

UNIT

&.

AMPLIFIERS

7<

5

r7

'5'

7d

&

*-3*

^’•S'

7

-3*

y

'S'

y

'S'

^

£

,*v

PINCH

WHEEL

CAP

In

case

of

trouble,

etc.

necessitating

disassembly,

please

disassemble

in

the

order

shown

in

photographs.

Re¬

assemble

in

reverse

order.

y

'S-

y

*F

y

'-s^-

c

s^

y

'S'

yj

s-

7

^<

7

^s

ry

^r

y

'^

y

'S'

7

^

y

^

Ky

^‘

'-‘i*

y

^

y

^i'

jj

i

»

1

A

f!

PAUSE

KNOf

TRACK

SELECTOR

KNOB

i

0-7

1

•

•

•

•

HEAD

COVER

r

r

±J\

—i

*

•

••

7-1

«

to

VIECHANISM

KNOBS

T?/“

I

AJ

IV.

MECHANISM

ADJUSTMENTS

1.

PINCH

WHEEL

ADJUSTMENT

It

is

important

that

the

pinch

wheel

shaft

be

kept

in

perfect

alignment

with

the

capstan

shaft.

Proper

pinch

wheel

pressure

is

between

1,000

and

1,150

grams

when

the

unit

is

operated

at

the

tape

speed

of

7'A

ips.

Any

deviation

from

this

specification

will

result

in

wow

and

flutter.

Check

pinch

wheel

pressure

with

a

spring

scale,

and

if

necessary,

adjust

the

pinch

wheel

load

spring.

Pig-

8

Fig.

9

2.

SUPPLY

REEL

SHAFT

ASSEMBLY

ADJUSTMENT

(See

Fig.

7

at

left)

Felt

clutch

material

(2)

is

used

between

the

lower

side

of

the

reel

table

base

plate

(I)

and

the

rewind

pulley

(3)

to

protect

recording

tape

from

excessive

tension

during

rewind

operation.

To

check

the

amount

of

friction

of

this

part,

install

a

5-inch

reel

with

a

60

mm

diameter

tape,

and

gently

pull

the

end

of

the

tape

upward

with

a

spring

scale.

Adjust

the

conical

spring

(4)

so

that

the

amount

of

tension

is

kept

between

400

and

500

grams.

Other

felt

clutch

material

(5)

is

attached

to

the

supply

roller

(6)

to

provide

proper

slippage

during

FWD

and

RFC

oper¬

ation.

The

procedure

for

checking

friction

of

this

part

is

the

same

as

the

foregoing,

and

between

80

and

100

grams

of

tension

gives

best

result.

Adjust

the

spring

(7)

just

under

the

supply

roller

(6).

When

the

unit

is

set

to

fast

forward

operation,

the

amount

of

friction

will

decrease

to

from

15

to

20

grams.

Check

to

see

whether

this

is

satisfactory.

If

not,

adjust

the

spring

plate

(8)

and

the

pressure

of

the

pulley.

(9).