Mitsubishi DA-C20 Service Manual

TUNER.PREAMPLIFIER

DA-

C20

SERVICE

MAN UAL

ArYrrrsuBrsH!

AM

/FM

STEREO

|]l]rl

MELCO SALES,

INC.

SPECIFI

CATfONS

1-(1)

FM TT]NER SECTION

(IHF)

Us$Ie sensj-tivity

MONO

STEREO

50 dB

quieting

sensj,tj-vity

MONO

STEREO

Signal to noise ratio

Frequency response

Total

harmonlc distortion

(at

I

kHz, 65 dBf)

MONO

Spurious response ratio

Image response ratio

IF response ratio

AM suppression ratio

MONO

80

atB

STEREO

75 dB

r1.2 dBf

(2.0UV)

22.7 dBt

(7.5tvl

19 .2 dBf

(5.

o'UV)

39

.2

dBf

(5ouv)

11

dB from

30 Hz

to 15 kHz

0. o5?

(r.JrDE)

o.2*

(NARROIi)

0.083

(wrDE)

0.

5r

(NARROW)

o.8

dB

(wlDE)

I.5 dB

(NARROW)

75

dB

(NARROW)

90

dB

80 dB

80 dB

55 dB

(WIDE)

50 dB

(NARROW)

STEREO

Capture

ratio

Alternate channel

selectivity 45

dB

(WIDE)

v

Stereo separation

WIDE

45

dB at 1

kHz,

35dB

at

10

kHz

-2-

NARROW

40 dB at 1

kHz, 30 dB at 10 kHz

Subcarrier

product

ratio 70 dB

SCA

rejection

ratio 70.

dB

Tuning range 88 l,lHz

to I08 I,$Iz

1-

(2)

rM TUNER SECTTON

(DrN)

Sensitivity

(at

40

kHz tleviation)

loNo

(s/N

26 alB)

STEBEO

(S^{

46 dB)

I.

2uV

32pv

Image

frequency rejection

(at

98 MIIZ)

78

dB

I!' rejection

(at

98 l{Hz) 85 dB

spurious rejection

(at

98

MHz)

90 dB

AM suppr.ession 60 alB

(WIDE)

55 dB

(NARROW)

Selectivity

40

dB

(WIDE)

(at

40

kHz

deviation,

13oo

kHz)

70 dB

(NARROW)

Signal to noise ratio

(at

40

kHz

tleviation)

!,roNo 75 dB
STEREO

'?2

dB

Total harmonic distortion

(at

1 kHz,

40

kHz aleviation)

L4ONO 0.06r

(WIDE)

0.15t

(NARROI{)

STEFEO O.O8A

(MDE)

0. 3s

(NARROW)

Stereo

sepaxation 45

dB

(WIDE)

(at

1

tiHz, 40 kHz alevi

ation)

35 dB

(NARROW)

11

dg

from

30 Hz to 15 kEz

-

3-

Frequency response

l

2-(1)

AM TUNER

SECTION

(IHF)

Usab1e

sensitivity

(bar

antenna)

45

dB

Selectivity

30

dB

l

-_/

Total

harmonic

distortion

O. 8E

Image

response

Latio

40

dB

IF

response

ratj-o

70

dB

Hr]m

and noise

50

dB

Tuning

range

525

kttz

to 1605

kHz

2.

(2)

p.J'q

TUNER

SECTION

(DIN)

Selectivity

(bar

antenna,

at

3Og

3OOUv/m

modulation,

S/N 26

dB)

Signa1

to noise

ratio

50

dB

(at

5 mVlm,

308

modulation)

Selectivity

(at

t9

kHz)

30

dB

Image

frequency

rejection

(at

I IGtz

)

40

dB

IF

rejection

(at

t MHz)

70

dB

r,.

Tota1

hamonic

distortion

O-8*

(at

308

modulation)

3

PREAMPLIFIER

SECTION

Input

sensj"

ti

vi ty/impedance

PHoNo

MC

0,1

mvlto

ohms

PHONo

MM

2.3

mv

/sC.k

ohms/l0O

pF

AUX, PLAY

1, PLAY

2

L5O

mVl5Ok

ohms

output

level/impedance

oUTPUT

1v

(rated

output)

/600

ohns

18V

(maximum

output)

REc 1,

REC

2

15O mVl6OO

ohms

PHoNES

(8

ohms

)

600

mv

(at

output

lv)

/15

ohms

650

mV

(maximum

output)

(headphone

impedance

from

8 ohms

to 16

otms

)

-

4-

l_,

Equivalent

input

noise

leve1

(IHF,

A network)

PIIONO MC

-I57

dB(v)

(47

ohns- terminated)

PHONO

MM

-136

dB(V)

(closed

circuit)

AIIX,

PLAY I, PLAY

2

-126

dB(V)

(closed

circuit)

Signal

to noise ratio

(IHF,

A network at rated

output)

PHONO MC

PHONO

MM

AUX,

PLAY I, PLAY

2

Signal to noise ratio

(DIN)

PHONO

MC

PHONO MM

AUX,

PLAY 1, PLAY 2

Total harmonic distortion

(at

rate d output

attenuator

-20

dB

v

from

20

gz

to

20

kP.z)

PHONO

MC

PHONO MM

AUX,

PLAY

1,

PIAY

2

ChaInel separation

PHONO MC, PHONO

MM

PLAY 1, PLAY 2

Tone

control

BASS

TREBT,E

77

dB

(47

ohms terminated)

84 dB

(closed

circuit)

110

dB

(closed

ci

rcuit)

72

dB

(47

ohms terminated)

73 dB

(2.2k

ohms

te

rminated)

106 dB

(closed

circuit)

92 dB

(47k

ohms/250

pF

terminated)

PHONO

MC,

PHONO

MM

crosstalk

is less than noise level at

1 kHz,

80 dB

at

20 kHz

PLAY l, PLAY 2

Crosstalk

is less than noise level at

I kHz,

IO0 dB at 20

kHz

Frequensy

response

0,0058

0.003?

0.003?

10.2

dB

from 20 Hz

to

20 kHz

(RIAA

STD)

+O

_6.S

@

from 10 Hz to I00

kHz

lI0

dB

at

100 Hz

1I0

dB

at I0 kHz

-5-

Subsonic

fi Ite r

Phono overload

1eve1

(at

t kHz

with

0.18 THD)

PHONO

MC

PHONO MM

Power consumption

Dimensions

(wxHXD)

Weight

Supplied

withr

T

shaped

antenna

18 Hz

(-6

dB/oct\

12 mv

290 mv

30w

425

x

l1o

x

292

mm

(L6-3/4

x

6-3/4

x

tL/t/2"',t

7.5 ks

(L6'L/2

I'bs\

Desiqm

and specifications are subject

to

change

without

notice

for improvements.

SERVICING

NOTES

1.

Before

connection, turn

off

the

power

supply at

all times

othemise,

the speakers are

IiabIe

to be damaged

by click

-noise

caused

when the cord if

plugged

in or out.

2. Avoid improper

connection

when tur.ntable, tuner, and R

and L of

output terminals of this

machine are incorrectly connected

or

short-circuited,

stable sound.

5-

production

cannot be achieved.

3. Correctly make input terminal

connect ion

When

pin plug

or earth

wire of

record

player

output

cord

is loosely

connected

or disconnected, hum

occurs.

Note that

the speaker

is

Ii-able to be damaged \,rrhen

such

in-

correct connection is not remedied.

Use shielded

wire for input

terminal- connection

Use

a shielded

wire of not more

than

2 m Iong for connections

to

record

player

and

trner.

In this

case, avoid

the use of longer

shielded

wire

which causes deter-

ioration

of high band

character-

istics and

easy catching

of hum

and noise,

Use

the machine

\,rith a

pin

plug

for short- c.ircuiting

use in PHONO termlnal

unused

This is intended

to

prevent

open

noise,

and click

noise caused

when

the input

selector is

switched

without connecting a turntable.

I,lhen

you

use Mitsubishi

DA-AIODC

or

DA-A15DC

in combination

with this

machine,

power

of

the

power

ampli-

fier must be

supplied

from SWITCHED

plug

sockets

of this machine.

The speaJcer

control cord

is

used

for only

Mitsubishi

power

amplifiers.

4.

-6-

DESCRIPTION

AND FUNCTION

OF

EACH PART

I

FRONT

PANEL

1F BAND

(selectivitl,

switch)

This

selectivity

switch is for choosing

the

IF

band-width

and

may be

switched

between

the

wlDE

(with

45 dB selectivity) and the NARRoW

(with

75 dB selectivity)

for

reception,

WIDE For receiving an FM broadcast

when

there

is

no interference from nearby

stations. In

Urj-s

position,

the lowest

distortion reception is obtained.

NARROW For receiving an FM broadcast in a

crohrded

broadcast area to eliminate

interference from

nearby

stations.

E

\

.....*

t-=1

tl

--------;;;::-

.:

. .'.}

S

PEAKE

RS,/OUTPUT

(Speal<er

Selection

switches)

When using

the companion

power

ampli-

fier

(DA-AloDc.

DA-A15DC)

,

the

speak-

ers

connected

to the

power

amplifier

may be

controlled

with these switches.

The

"speaker

control cable" supplied

with

the

power

amplifier must be

connected,

to utilize these

switches,

AB

I

I

For listening v,/i th

headphones.

Preamplifier outputs are

off

and no

sound will be

produced

from the speahers.

r. I

For listening

to the speakers

connected to the A terminals

on the

power

anpli

fier,

I

r

For listening

to

the

speakers

connected to

the B

terminals

on the

power

ampli fier,

r .r.

Ior listening

to

the speakers

connected

to both

A and

B

terminals

on

the

power

ampli-

fier.

SELECTOR

(rnput

selection

switch)

This

switch selects

the desired

pro-

gram

source.

PHoNo MC

This

position

is

used for

playing

a

disc on

the turn-

table

equipped

wj-

th a

MC

(moving

coil)

cartridge

and

connected to the

PHONO MC

inputs.

PNOHO

I4I{ This

position

is used

for

playing

a disc on the

turn-

table equipped

with

a MM

(moving

magnet) cartridge

and

connected to

the

PHoNo

MM inputs.

TUNER

For listening

to

programs

on the AM/FM

tuner.

AUx

For

playing

a

second

tuner,

turntable

with a high out-

put

ce

ramic

cartridqe,

taPe

deck

for

playback

use,

tele-

vision audio,

or

any

suit-

able hiqh output

sources

connected

to the AUli

inputs.

-7-

I

DISASSEMBLING

TUNER SECTION

AND PREAMPLIFIER

SECTION

]-

Removal

of

the

Top Plate

and

the

Bottom

Cover

1) After

removing

the trro

screws

indicated

as A in Fig. 1, take

off the top

plate,

pulling

it

toward

the back.

2) The cabinet

is removed by taking

off

the four screws indicated

as

B in Fig. 1 as well as the two

screws located at

the

bottom.

2. Removal of

Front

Panel

1)

Take off the two upper

panel

fixing screws indicated as

D in

Fig. 4.

2) Take off the two lower side
panel

fixing screws indicated

as C

in Fiq.

2.

3) nemove.the controls on

the

front

parrel.

(Being

of

a

hexa-

gonal

screw

type, the tuning

knob

(T

in Fig.

3)

should be're-

moved by me ans

of

a

hexagonal

screw

driver

having a 2

run

op-

posite

side.) As regards

the

rest of the knobs

and

controls

except

the

push

control.

the four

control

(v)

and

I

knobs

(I,l)

should

be

renpved by

pulling

them

out

in a forceful manner toward

this side.

4) In this

condition, the front

panel

can be taken off toward

this side.

3. Removal

of

Tuner

Section

L) Disassemble

the alunrinum inlay

of

the

tuner sectj"on by

removing

the

four screws

indicated as

E

i,n

Fig.

5.

2)

Take off the three chassis-fixing

screws

(F

in Fig. 2) of the

tuner section.

3) Remove

the

two front-chassis-

fixing screws

(G

of Fig. 5) of

the tuner section.

4) Remove

the rear-chassis-

fixing

screws

(H

of Fig. 1) of

the

tuner

section.

5)

Take off the side

panel

and

holder

assenbly screw

(J

in Fig.

4).

Fig.

I

FLq,2

Fi

g, 3

*"[.1;oanE.S

@"P

. ,9

9\

B

",@'ol

'B

B'

"6"'6

o

-'s'

i

'*'

tLr

^

ow5i,

*"

.ro ill:

-,.o.ooc

-

8-

-h

ag.

+

6) with

the right side

panel

spread

outward

from its normal

pos.ition,

lift up

the turer section and

arranqe

it

as

shown in

Fig. 6.

To

prevent

sho rt- ci

rcui

ting be-

tween

the tuner section's chassis

and

the

preamplifier's printed

ci rcu.it board,

insert a cloth or

the like in between,

7) with the set

in this

aondition,

the

front end can be adjusted.

8) To remove the

printed

circuit

board

from the chassis when re-

placing

the

parts

on it, the

follo\^7ing screws

are to be re-

mo ved.

(1)

Take off the two holder set-

screws

for meter mounting

(K

in Fig. 7) .

(2)

unscrew the two

push

switch

assenbly

screws

(L

in Fig, 7)

.

(3)

Unscrew

the two

printed

cir-

cuit board assenbly

screws

(M

in Fig.

7).

Disassembl-ing

Preampli fie

r

Section

1)

The order of

disassembly is the

same as

that for the tuner

section,

steps l) through 6).

However,

at Step

6),

the

tuner

section

should be

placed

at

the

back.

2) Remove

the two

front

chassis

fixj-ng screws

(N

in Fig. 5) of

the

preamplifier

se c ti

on.

3) Remove

the three

volume fixing

nuts

(P

of

Fig. 5) of Lhe

front

chassis section,

4) Take

off the switch assenbly

screw

(Q

of

Fig.

5)

of the

front

chassis

section.

5) Remove

the two

printed

circuit

board

(PA-66)

asse(0f,ly

s

crews

(Y

in

Fig.

4).

6) Remove

the coupling

section

(in

the direction

of R shown in

Fig.

6)

of the selector switch

and extension

shaft.

7) Lift

up the

front

chassis

and

turn

the

printed

circuit

board.

PA-67

toward this

side.

(The

condition

sho\am in Fiq'.

6)

Fig.6

Fig.5

P.C

Board

P.C Board

M

l\4

-9-

Fiq.7

Remove

the shield

plate

by un-

screwing

the

shield

Plate

assembly

screw

(S

in Fig.

5)

located

between

Pr.inted

circuit

boards

PA-66

and

PA-67.

With

the set

in

this

conditioo,

it is

possible

to

replace the

parts

provided on

printed

cir-

cuit

boards

PA-65 and

PA-67.

ADJUSTMENT

1.

Printed

Circuit

Board

(PA-6

6

)

L)

set

the

semi-fixed

resistor

vRsol

comPletelY

in the

conter-

clod(wi-se

di rection

'

2)

set

the

power

s\ri tch

to oN

position.

3)

Connect

the voltmeter

to the

ground

terminal

(34)

and the

terminal

(33)

on

+B

side and

turn

the vF50I

clockwise

(in

the arrow

direction)

to ad.just

it

so

that it

may

indicate

33!0. 5

(v)

.

4) Connect

the

voltmeter

to

the

ground

terminal

(34)

and

the ten[inal

(35)

on

-B

side

and confirm

that

it

indicates

-3311.s(v).

2. Printed Circuit

Board

(PA-57)

1) Set

the semi-fixed

resistor

VR5O1

completely

in

the cormter-

clockwise

direction.

2)

Set

the

power switch

to

oN

posltion.

3)

Connect

the

voltmeter to

the

ground

terminal

(84)

and the

tenrrinal

(83)

on

+B

side and

turn the vR60l

clockwise

(in

the arrow

direction)

to adjust

it so

that

it maY ind.icate

3310.5(v).

4) Connect

the voltmeter

to

the

gror:nd terminal

(84)

and

the terrdnal

(85)

on

-B

side

and

confirm

that

it indicates

-3311.5(v).

View seen

at

copper foil

side

The

side

whe

re the

parts

of the

printed

circuit

board

(PA-67)

are

inserted.

8)

9)

To adjust this

printed

circuit board,

the

tuner section

must be

removed.

pA-66

-

lo-

I

FM

SECTION

l. Front End

Adjustment

1) With the

signals

of

the signal

grenerator

(SG)

connected

to the

FM-ANT terminal,

take

out the

setrs output

from

test

point

r.

P.

(119).

2) With

the SGrs

frequency

set

to

87 1fr12,

turn

the dial

fully

coun te

rc lockwis

e

so

that the

turer

may indicate

the

lowest

frequency.

Adjust

the

local

oscillati-on

coil so

as to

make

the signals

generated

by the SG

maximum.

3) With

the SG's

frequency

set to

109 MHz,

turn

the dial

fu11y

clockwise

so that

the

tuner

indicator

may

show

the

maxi-

mum frequency.

Adjust

the

1ocaI

oscillation

trinuner

Ct91 in

a

manner

to ma]<e

the SGrs

signal

maximrm.

4)

Repeat

Steps

2)

and 3)

several

times

.

5) With the

SGrs frequency

set to

88 MHz,

set

the tuner

to

indicate

88

MHz

with the

dial.

Adjust

coils

L171,

LL72

and. LI73 so

as

to make

the

output

naxi mum.

6)

with the

SG's frequency

set

to

108 MHz,

set the

tuner

to indi-

cate to

108 ItrIz

with

the

dial.

Adjust triruners

TC171, TCI72

and

TC173

so as to make

the output

maximum.

.

Adjustment

of FM-MONO

1)

Set the

SG to 9 8

t"!rtz,

4OO Hz

Lo

MONO

l00A modulation

and

the

out-

put

to B0

dB.

2)

Set the

selector

s\,ritch

of the

set to

the FM

position

and the

mode

to FM-MONO/MUTING

OFF

and

SELECTI

VI TY.WI

DE .

3)

Adjust

the

secondary

side

core

(upper

side) of

T8O2

so

that

the

center meter

may

indlcate

the

center during

detuning

(

approxi-

mately

l-00 MHz).

4)

Tr:ne

the

set to

the

SG's fre-

quenc)l

(98

MHz).

Tuning,

in

this

case.

is

attained

when

the

center

meter

is

a state

in whicf-

it

indicates

the

cen

te.r.

Next,

with

the mode

switch

set

to

FM-AUTO/MIj'I1NG-ON,

adjust

VR751

so

as to

make

the

center

fieter

indicate

the

center.

5) After

connecting

a distortion

meter

to the

output

pin

Lerminal

,

adjust

the primary

side

core

(1ower

side)

of

T8O2

so

as ta

make

the

distortion

factor

minimum.

In

this

case,

if

the

center

meter

does

not

in-

dicate

the

center,

adjust

the

secondary

side

of T802

again

until

it does.

6) Adjust

T803

so

as to

mal<e

the

swing

of the

s19na1

meter

maxi-

mum.

7) Adjust

VR801

so

that

the

siqnal

meter

may

become

4.7

o]j)

the

scaIe.

3. Adjustment

of FM-MPX

1) Set

the SG

to 98 MHz,

L k:H.z

STEREO

to

L+R 902. pilot

to 10%

modulation

arld

the output

to

80

dB.

2)

Set

the

selector

switch

of the

set to

the

FM

position

and mode

to FM-MONO/MUTING-OFF

and to

SELECT]\rITY-WIDE

.

WhiIe

receiving

98

tr&tz

signals

from

the SG,

adjust

the

local

oscillation

trimmer

C191

of the

front

end

in a manner

to make

the

indicator

indicate

9g

MEz

on the

dlal

pIate.

3) Place

the set

to FM-AUTO/MIITING-

ON.

Shift

the

position

of the

indicator

to

the

feft

and right

from

98 MHz

and

confirm

that

LOCK

aid MUTING

operations

are

normal

.

4) After

turning

the

set

again

to

98 ltfr1z,

drop

the SG

output

and

adjust

VRB02

so

that

the wave-

forms

may disappear

(which

im-

plies

that

the

output

is

zero)

at

26 dB

and

re-appear

at 27

dB.

-

11

-

5)

Turn

off

the

Pilot

signal

and

modulation

signal

of

the

stereo

modulator.

with

a

frequency

counter

connected

to

Pin

(120),

adjust

the

vR

so that

the

frequ-

enqf

may

be

within

the

range

of

76!0.2

kEz.

Turn

the

pilot signal

oN and

confirm

that

the stereo

indicator

lights

up.

with the

modulation

of

the

stereo

modulator

set

to either

"R"

or

"L",

adjust

vR632

so

as

to

make

separation

maxj-mum.

THREADTNG

ON

DIAI

I

ADJUSTMENT

OF

AM

SECT]ON

I.

Tracking

Adjustment

1)

with

the

SG's

sigmal

set

to

600

kHz

and

400 I1z

to

30%

modu-

lation,

and

the

indicator

of the

set

tuned

to

60O

kHz,

adjust

the

corlrANT

(L27I)

and

Corr-osc

(T271)

so

that

the

outPut

will

may

become

maximum.

2)

with

the

SG's

sig.nal

set

to

I,4OO

kHz

and

the

indicator

of

the

set

t1med

to

I

.

400 kHz,

adjust

the

antenna

trirurcr

TC27l

and

local

oscillation

trimmer

TC272

in a

way

to

make

the

outPut

rnaximum.

3)

Repeat

f) and

2) several

times'

\i"

6)

7)

e-/

I

-L2-

PRINTED

CIRCUIT

BOARD

PA-67

i

I

I

PA-66

-

13

-

-vI -

1-

lr

lf,

E

99-Vd

PA-65

v

PA-65

-15

r-,

PA.65

PA-65

PA.65

-16-

-

AF'T-E5

lr-: ;-*.-----.,

9oo

e

e

ttut-i r

E6-l

r.

"T

I'JEE

i i

trI)

lLfli

'i'i

,J,15[

ti

'f

,,+,-+,,+-t.-

t

s€'

Ir

.,*;,i:;-'ffiu+,

5----li,imFffi

I"'"" !* ll

"

'li'-

l',;',.{lt'[l

i

i

].i,_-Iffi

r,ffiffi ffi;

ffit

1,il,fffi

,

+'t,:',-...-

:l'i-Lilqfu

"'#'-AI

Badm;Ifi

I

in-1;

r"'r

,t..,,t3i

"r[,a

rLF

=s:u,*tEEh]

'r*f

I

*;;-:"#.

+F-

'

\.{_.'*

,

-

-.

s*.1

:*:lffii"iifrJ,l,,

li:--tr

cffi

._____:i?"

rf

"r6i

-1+s-iti1,li+

l:i,l;+,tjt,a

"-ffi

, :{l .r--n

Iu.*-sl

.i /.ll:

|

:T:I:l:;"t'

i

\F

,i"':-

l1

ij,tt,

t(I-J.)

:*

"i

llll_j].]"

i l----------l

,\

F

5<

c"frf ._ji"s_;+

,". r I I

; :'i'

i

i

, ,.

-rift,.

'--*;'

l'-.-j$t--

l

-tF,

;*l*;*

--:.

r

i,.'

---:**-

*

;;

-.*t't

i

irr..,,

'.;i"

lj*.-

;

3i

il+,

E+?*-,k*i.,

r

i;l,f+J'{

etrfr1

ffi

L

j

!ffF

jr*

_J#.+"*,*,+

E

E

-ri-.*"--.

E+ffiJTiT.;

'.1"i

'".-

J-

jl.,

i*'"

r'J,r;{

"t

i{[?iEr;}

e

tf

:ft

"ii

l':

+u:il''taf

i,:=

r------------,,

Bffi1,

,::

,iffi;-"**-t

+::x

si i*rorglu: )wr:

i'"

,

t.i'1,-",

*,-ffil;;#,r,'!==--------------===i

:' :E'i;l= . .__j,

;J

..'i

#-E

effipltf

*i

i,{,=}.

''Hl

*'1i

=

^

;5'i'] -*i,

--

;

i+

-+

'

"L------------j't

+t""dr--E-

L3-?"j-"-

#4q'1*#*'I:El !i,.

^,*

i:

i:.

.r'*

.Li;

=;E_;

ff#E'S.T effiG

l'ii

6-:,*-,':;

I

i

"iirnL'*]i-*'q--=a='--

'

nt

"

aH

uffp* ,

foE:ililosF,'t**l'i'i

i

i=i''t

g,J

'

-t.**

_-;I".fl.".'ig@'-*--lJ

s-+"'ir.

i--;i

;gl

,*fu

E:i'i'ill;;'t,:,r6'ii+i

uilr,tl:ela:E

;*i

'+

H F'

3

:

qH.

,.'

l,!

:jei--H

.11

'-------

>rFo

r

O

O

B B

ELA"

-r8-

EE-if

n

SCHEMATIC

DIAGRAM

TUNER SECTIO}T

-----

l

_l

[F@

-

fAril

ttr tf r-:fl /q D

ffiWWWW

fEAL-sc

I

@

lpowER=uPPr-tl

@

-19-

@

I

B{FFEB AMPf

I

EB

3:"1"

"i:

)-

I

;,"

E

-20-

PREAMPRIFIER

SECTION

IHEAETfrPj

3e l

J;

I

,L

r:l ltt

talr

i

*f*

r-

to-..

a------o-..]

l-o +

-_ioH

Fle

srEF.o

P5

;9',

eAF

eii:

Note

:

1.

51

s2

s3

s4

s5

S6

s7

sa

SE!ECTOB

Swrtch......

...........

........phonoMc

posrrion

uur_LtLA

I E

Swrtch

.,.....,......

.....

......

source

posit@n

TAPE

MONTTOB

Swrrch.....................source

posrtion

MO-D-E

Switch.

.

"t"r"o

eo",t,on

SUASONIC

FItIEB

Swiich

...........

.........ofl posiion

ruNL

swfch..,,.......

....

......off

Poslrron

TONESwirch...............

...6nposhion

SPEAKERS/OUTPUT

S*nct

...................:a

po"n;".

2. Unit of

C and

R

(1)

C

......

...

-.non-symbot

,F

p

symboi pF

{2)

8..

non-symbot

o

K

symbol

Ko

3. The

voltage in

eath

section

is

the vatue

measured

by the

DC2OKa/V

tester.

Thb

circuit is

a basic

circuit

diirgram

and

is subiect

to

change withoot

notice

tor inproverr|ents.

-21

-

t$

-

55

-

\\(

\\\\

\

L\

I

I

+ +

rft.-?Sil

I I

=?."r1

:ffiit

-YI

---

I

qgi

rroxEl rrEi

!r;f=#*=

Ei+

i,:

EfE

YNb.l

lEEi-EHolrE

vv{b]

PARTS

LIST

PARI NO.

DESCFIPTlON

PART

IDENT]FICATION

M0714I930

Packing Bag

M07139910

Cushion

Mo7290999

r.B

M07290900

Packing Box

Mo7).4l2lo

Knob

(TiiNrNG)

MO'729O2LO

,,

(OUTPUT

LEIEL,

BASS, TREBLE,

VOLUME,

SELECTOR)

Mo7l6326O

i{eter

(SrGNAr,)

'go,

MO7L6326I "

(TrrNlNG)

M801

M071I5250

Lamp

PLItuPL4

I1O7I39480

Socket

MO7229476

Jack

(HEADPFIoNE)

J2

MO729O45O

SW-PUSh

(SEIECTTVITY,

MUTING/MODE S2O

SELECTOR)

Mo72l345O "

(POWER)

S11

M1'729O45L

Sw-Rotary

(SELECTOR)

sl

MO729O452

Si{-LEVCI

(TAPE

MONITOR, DUPLICATE)

S2,S3

M0729O453 "

(SUBSONIC

FILTER,

MODE)

S4,S5

M07290400

vR-w-A50K25

(voLUlE)

VR301,401

Mo12go4ol

vR-srD-c20K25

(BASS)

vR3

31. 4 3l

M)729O4O2

VR-W-C2OK25

(TREBLE)

VR332

,432

Mo729o4o3

vR-srD-E5K25

(owPUT

LEVEL)

vR334,434

MO129O454

Sw-Push

(TONE

ON/oFF)

s6,S7

MO7290455 "

(SPEAKERS)

S8

v

M05067315

Transistor

2SD361

Q531

Mo4o7o3o4

"

2SC71O

Q80r,802,803,804,805.806,

Bo7,

808, 809, 8lo, 811,

812

Mo51O431O "

2SCL64A

Q1O3,2O3,38L,481'

503,5 32

,

603,63L,632,

7 32,'l

33, 75L,

754,755,756u76L

Mo5lo4312 "

2SA823

Qlo\ ,134,135

,204,234,235,

336

,

33'7

,436 ,431 ,506

,533 ,

6A6

,'7

52

,753

MO5067313 "

2SC1312

Q633,634

M07085303 "

3Sx45

Ql71

Mo4o7o303

"

2SC535

QL72

M0404,6313 "

2SC46l

Q17

3

M072t5303

"

25D467

Q101,20I

M07215304

"

258561

Qlo2,2o2

Mo7r393O4

"

2SK68A

Ql.3l-

,132

,231,232

,33r

,332

,

43L, 432

Mo7l4o3o3

"

2SAA41

QL36,137

,236 ,2

37.

338,

339,

43A

,

439

,505 ,605

MO?I13310 "

2SCITOB

Q13A,23A,34O,44O

,502,602

M07128303 "

2SC1735

Q].39

,239 ,341,441

M07133304 "

2SA850

QL4O,24O

,342,442

M07141303

"

2SCl74l

Q382,442

M07137308 "

2SA854

Q383.

483 , 731

t407061304

"

2SD330

Q5O1,504,60r,604

-25-

DESC&iPTION

PART TDENTIFICATION

PART

NO.

MO4097

320

Mo7133322
M07060320

Mo7224320

M040

79

320

M05129320

MO1l4l322

M07085

320

M07151320

M04091331

M07133420

Mo7115

343

M04r37

34

3

Mo7L4L343
\107236343
M07115345
Mo7236465
Mo72L5465

Diode

IN60

"

M2308

"

as247 3

SELlO5R

"

roDr

"

Mz3o6

"

MZ3L4

"

1s2236

"

SIRBA1O

Varistor

MV- 13

R-Fuse

l/w 10-J

IC LA]222

..

TATO6IAP

"

M5

r802L

"

HA1196

"

HA1138

Relay

D801^,808

D501,60I

D).31

,L32

,133,231,232

,233,

271,272,

33L,

332, 333,

38r.

431

,432

,433 ,4A)-,731,7

32

,

752,755,7s6

D531,532.533

D5

34

D535

D 171

D101,721

DL34

,234 ,

334

,434

D7

Ot

,1O2

rc801

IC802
IC751

rc6

31

TC27L

K751

K7 31

CUSHION
tv07

r39910

PACKING

BAG

M07 t41930

PACKING

BOX

l!,107290900

MELCO

SALES,

INC.

3O3O

East

Victoraa Street,

Compton, California

90221,

U.S A.

Iet.:

1213],

537't

132,

relex: 0673278

Toll

Free:

(800)

421-1132

(Outside

of California)

r r;

iJI

'i)i':r

jo,.,

SM.8OO4-US,

PFINTED

IN JAPAN