JVC AX-A572BK Service Manual

JVC

AX-A57 2 BK

C

C

SERVICE

STEREO

INTEGRATED AMPLIFIER

AX-A5 7 2BK

MANUAL

RADIO-

KEES

s-HERTOGENBOSCF

EN

van de

BOKSHEUVELSTRAAT

TBLEVISIESERVICE

MORTEL

14

c

c

Contents

Safety

Precautions 1-2

Instruction Book 1-3

Description of Major

Disassembly

Power

Procedures 1-15

Amplifier

LSIs

1-14

Adjustment Procedures ... 1-16

Blocl(

Diagrams 1-17

Schematic

Printed Circuit Boards Insertion

Parts

Diagrams Insertion

List Insertion

No.20410

Mar.

1993

AX-A572BK

—Safety

1.

The design of this product contains special hardware and many circuits and components

specially for safety purposes. For continued protection, no changes should be made to the

original

be identical to those used in the

qualified personnel

2. Alterations of the design or circuitry of the product should not be made. Any design

alterations of the product should not be made. Any design alterations or additions

void the manufacturer's warranty and

for

personal injury or property damage resulting therefrom.

3.

Many

characteristics.

the protection afforded by them necessarily be obtained by using replacement components

rated for higher voltage, wattage, etc. Replacement parts which have these special safety

characteristics

having such features are identified by shading on the schematics and by (Aj on the Parts

List

same safety characteristics as the recommended replacement parts shown in the Parts List of

Service

4.

The leads in the products are routed and dressed with

the like to be separated from live parts,

edges

original

have been returned to

Precautions

design uniess authorized in writing by the manufacturen Replacement parts must

original

only.

electrical and mechanical parts in the products have special safety-related

These characteristics are often not evident from visual inspection nor can

are identified in the Parts List of

in the

Service

Manual

for the prevention of electric shock and fire hazard.

lead routing and

Manual.

may create shock, fire, or other hazards.

The use of a substitute repalcement which does not have the

dress

should be observed, and it should be confirmed that they

normal,

after re-assembling.

circuits.

will

further relieve the manufacture of responsibility

high

temperature parts, moving parts and/or sharp

Services

Service

Manual.

ties,

When

should be performed by

will

Electrical components

clamps, tubings, barriers and

service is required, the

5. Leakage currnet check (Electrical shock hazard testing)

After re-assembling the product, always perform an isolation check on the exposed metal

parts

of the product (antenna terminals, knobs, metal cabinet, screw heads, headphone jack,

contori shafts, etc.) to be sure the product is safe to operate without danger of electrical

shock.

Do not use a

•

Plug

the AC

measure the leakage current from each exposed metal parts of the cabinet, particularly

any exposed metal part having a return path to the chassis, to a known good earth

ground. Any leakage current must not exceed

• Alternate check method

Plug

the AC

ohms per volt or more sensitivity in the

resistor

known good earth ground.

Measure the AC voltage across the resistor

with the AC voltmeter.

Move the resistor connection to each exposed

metal part, particularly any exposed metal part

having a return path to the chassis, and

meausre the AC voltage across the resistor.

reverse

Now,

repeat

each measurement. Any voltage

measured must not exceed 0.75 V AC

This

corresponds to 0.5 mA AC

line

isolation transformer during this check.

line

cord directly into the AC outlet. Using a "Leakage Current Tester",

0.5mA

line

cord directly into the AC outlet. Use an AC voltmeter having, 1,000

following

paralleled by a 0.15 jiF AC-type capacitor between an exposed metal part and a

the plug in the AC outlet and

(r.m.s.).

(r.m.s.).

AC

(r.m.s.).

manner. Connect a

AC VOLTMETER

(Having 1000
ohms/volts,
or

more

0.15

nF AC TYPl

i50on

10W

Good earth ground

1,500ü

10 W

sensitivity.)

Place this probe

^on

each

exposed

metal

part.

—

Warning

1.

This equipment has been designed and manufactured to meet international safety standards.

2. It is the legal responsibility of the repairer to ensure that these safety standards are

maintained.

3.

Repairs must be made in accordance with the relevant safety standards.

4.

It is essential that safety critical components are replaced by approved parts.

5. If mains voltage selector is provided, check setting for

1- 2

(No.2 0 4 1 0 )

local

voltage.

AX-A572BK

Inst ruct ion

Book

Contents

IntroductionzyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA 1

About

This

Manual 1

Before

Installing

Names of Parts 2

Preparation

Connecting Stereo Equipment 3
Connecting Speakers 5

Connecting the Power Supply 6

Basic

Operation

Operating Procedure 7

Your

Amplifier

3

7

1

Names

(p

@

Selecting the Source 8

Selecting
Selecting

Adjusting the Volume and Tone 9

Adjusting
Adjusting
Reproducing More Realistic Sounds 10

Troubleshooting 11
Specifications

of

Parts

the Source You
the Source for Recording 8

the Volume 9
the Tone 10

11

Wish

to Hear 8

AX-A572BK

AX-A472BK

®

Ój)

Page

2

®

POWER

(D

BASS

(3)

TREBLE
® LOUDNESS
® MASTER VOLUME

(D

SOURCE SELECTOR
® REC SELECTOR

switch

control

control

(page

(page

switch

switch

10)

10)

(page

control

switch

(page

10)
(page

(page

8)

9)

8)

(D

CARTRIDGE

—

For the

(9) BALANCE
® SOURCE DIRECT
© SPEAKERS
@

PHONES

switch

AX-A572BK

control

switches

jack

(page

(page

only

(page
switch

(page

9)

8) zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA

9)
(page

10)

9)

(No.20410)

1-3

AX-A572BK

Preparation

Bef

ore

Starting

Basic

Connections

This

chapter

stereo

deals

with preparatory operations such as connecting the amplifier to other

equipment or speakers

before

use.

Connecting Stereo Equipment

The

left

channel of any

amplifier, and the right channel to the right-channel jack. If

stereophonic

Note:zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA

image

To ensure correct connections, insert the red plug into the red jack. (Red, by

convention represents the right channel.)

Connect

output

jacks

stereo

jacks on a

to

those

equipment to the amplifier using cables with

marked OUT

stereo

equipment must be

will not be generated.

tape

deck to the jacks marked IN

(REC).

connected

(PLAY)

to the left-channel

they

are reversed, the correct

RCA

PIN plugs. Connect the

on the amplifier, and the input

jack

of the

Notes:

•

Use the A

UXjacks

to connect audio equipment other than those detailed below. A turntable,

however cannot be connected to the

•

Connect a ground

•

For the

AX-A472BK
an MC (moving-coil type)
amplifier

or step-up transformer.

cable,

only:

iffitted

to

Any turntables incorporating a small-output cartridge such as

must

r

PHONO

AUX

jacks.

yoiir

turntable,

to the screw marked GND on the rearpanel.

be connected to this amplifier through a commercial head

Direct

-V CD

connection may result in

-vTUNERv

AUX ^— WE1 —

OUT fN

(flffi)

(PLAY)

-TSPE2/DAT
OUT IH

(BEI

(PIAÏ)

or

DAT

insufficiënt

•

volume.

deck (analogue output)

Tape deck

2

1-4(No.20410)

CD P layer (analogue output)

Tuner

Tape deck

1

Page

3

AX-A5 7 2BK

Conne cting a Graphic
Equalizer

Using the socl(et
bacl(

of the amplifier

ACOUTlfTS

UHSWIICH EO r SWITCHED-

SI
BI m m

MAXIOOW

Note:

The

provided

AC

on

nol
and Australian

on

| - SWITCHED-|

m m

I

TOTAL

OUTLETS

sockets

the

Europian

model.

the

are

model

Instead

of connecting a second

jack

of the

graphic equalizer

jacks

to the

TAPE

JVC's

S.E.A.

2/DAT

graphic equalizer is recommended.

to the

jacks

tape

deck, you can use a graphic equalizer. Connect the

TAPE

2/DAT

marked

OUT

jacks marked IN

(REC).

(PLAY),

and the

output

input

OUT

Graphic

equalizer

In

some areas you

If

your amplifier has

the

sockets.

into

The

two sockets marked

switches

of

automatically

The

socket marked

regardless of the amplifier's

ACAUTION!zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA

OUTLETS

The

socket

will

find

the

AC OUTLETS

these

sockets, you can plug the power cords

SWITCHED

are interlocked

any audio equipments connected

turn on/off as the

UNSWITCHED

POWER

POWER

provides power whenever

switch

sockets

on the

back of the amplifier.

with

the

POWER

to

these

sockets

switch

of the amplifier is turned on/off

are

the

setting.

of

other audio equipments

switch.

left

on, the

amplifier

Do not connect any equipment that consumes more power than the

capacity.

marked

The

total

capacity

UNSWITCHED

of

the

sockets

marked

SWITCHED

has a capacity of 100 watts.

If the power

equipments

is

plugged in,

is 100 watts.

AC

Page

4

(No.20410)1-5

AX-A572BK

Before

starting

Connecting

speakers

Connecting

Up

to two pairs of speakers (four speakers in total) can be connected to the amplifier.

Note:zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA

Special
an impedance of 4 to 16 ohms can be used with this amplifier. However, if two
speakers

are used at the same time, do not use speakers with an impedance lower than 8

ohms.

Connect the
(Speakers 1). If a second pair of speakers is to be used, connect them to the top row of the
SPEAKERS

Rotate the screw counterclockwise to loosen the speaker terminals, and insert the speaker
wire

as shown on the left. Tighten the screw clockwise to fasten the speaker

Important!

terminals

on the amplifier.

Speakers

care

is needed in selecting the impedance

first

pair of speakers to the

terminals. (Speakers 2).

Be sure to match the polarity of the speaker terminals with the polarity of the

i+)to(+)

bottom

row of

and (-) to (-).

of

the speakers. Only speakers with

SPEAKERS

terminals on the amplifier.

wire.

pairs

of

1-6

(No.20410)

Page

5

AX-A572BK

Bef

ore

starting

LINE

VOLTS

è

Note: Voltage selector

provided

on the

Auslralian

model.

Connec ting

the

switch

Europian

Power

is

model

not

and

Supply

ConnecHng

Check the back

Amplifiers

selector switch
required in the region where the amplifier is
a

Philips screwdriver and

supply voltage. Bear in mind incorrect setting may cause malfunction

ACAUTION!
supply.

After checking all the connections, insert power cord into an outlet.

ACAUTIONI

the

Power Supply

of

the amplifier

with a voltage

is

used

to

Be

sure

Do not handle the power cord with wet hands.

for

any switches

selector switch are available according
adjust the amplifier power requirements

set it so

to set

the

that

voltage

the

as

illustrated on the left.

to be

used.

arrowhead

selector switch before connecting

to

so

Turn

the switch using

in

"LINE ^ VOLTS"

,

the region.

as

to

meet the

or

damage.

This

voltage
voltage

indicates

the

power

the

Page

6

(No.20410)

1-7

AX-A572BK

Basic

Operation

In

order to listen

order below:

Operating Procedure

to

the source equipment after the amplifier is turned on, do as described in

AX-A572BK AX-A472BK

1.

Turning

2.

Selecting a speaker

(see page 9)

3.

Selecting a source

(see page 8)

4.

Operating

equipment

5.

AdjUSting

tone

on the power

the source

the volume and

(see page 9-10)

Press the

The

Use
The

amplifier.

Use
SELECTOR

Operate the source equipment according to their respective instruction manuals.

Use

Use

DIRECT

POWER

indicator at the side of the

the

SPEAKERS

headphones

the

SOURCE SELECTOR

the

MASTER VOLUME

the

BASS

switch

switch

to tum on the amplifier.

switch

can be used by inserting the

switch and the

and

TREBLEcontrols,BALANCEcontrol,LOUDNESS

as desired.

switch

lights up.

to

choose between the two pairs of speakers.

PHONES

switch

to select the source you

CARTRIDGE

control to adjust the volume.

switch (for

jack

to

the appropriate socket in

wish

AX-A572BK

to listen to.

only)

as desired.

switch,

Use

the

and

SOURCE

the

REC

(No.20410)

1-8

Page?

Selecting the Source

You

can select

connected to the amplifier.

Selecting

the

the

source you

Source

wish

You

to

hear

Wish

or

record from among

to

Hear

AX-A57 2BK

the

stereo equipment

Seiecting
You

Wish

Type

of

Turntable

Selecting

TAPE

1».

2/ D AT

the
to

SOURCE

the

REC

Source

Hear

SELECTOR

Source

SELECTOR

Use

TAPE

TAPEl:
PHONO:
CD:
TUNER:
AUX:

Cartridge

Use

For

set the gain of the

(moving
tridge, set the
because of

TAPE
TAPE 1 •
PHONO:

CD:
TUNER:
AUX:

the

SOURCE SELECTOR

2/DAT:

the

AX-A572BK

magnet) cartridge, set the

its

Selecting

the

REC SELECTOR

2/DAT

2/DAT:

Use this position to record from a record.

Use this position to record from a

Use this position to record from the radio.

Use this position

Use

Use

Use
Use
Use
Use
AUX

only: Before using the turntable, press the

phono

switch

to

high

output

the

Source

•

1: Use this position to record from the

Use this position to record from the

amplifier's

switch

to choose the source.

this position to listen to the
this position to listen to the
this position to listen to a record.

this position to listen to a
this position to listen to the radio.
this position

jacks.

equalizer to match the type of cartridge being used. For an

"«MC"

level,

for

switch

to

listen

switch

to

"MMM"

(depressed). If you

change the

switch

Recording

to select the source for recording.

to

record from

AUX

jacks.

tape

deck 2.

tape

deckzyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA 1.

CD.

to

equipment connected

(out). For an

detect

distortion

to the

MM

setting.

tape

deck 2 to the

tape

deck 1 to the

CD.

the

equipment connected

to the

CARTRIDGE

MC

(moving

with

an

MC

tape
tape

amplifier's

switch

and

MM

coil)

car-

cartridge

deck 1.

deck 2.

to the

Page

8

(No.20410)1-9

AX-A572BK

Adjusting the

Adjusti ng the

Selecting

Volume

MASTER

VOLUME

the

Speakers

SPEAKERSzyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA

2

Volume

You

can listen to the selected source

Note:zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA

Adjusting

Use

the

Rotating the

ft-om both

Use

the
amplifier.
position.
position. Pressing either switch again returns
deactivates

and

The

adjustments

Tone

described

the Volume

MASTER VOLUME

dial

to

the right raises the volume, and to the left lowers the

sets

of speakers and the

SPEAKERS

To activate Speakers 1, press

To

activate the Speakers

that

switches

pair of speakers.

control

to

at

any desired volume and

here

do not

affect

the

to

adjust the volume from the left and right channels.

headphones

select between

2,

press the right

changes simultaneously.

the

two pairs

the

left switch marked 1 setting

switch

the

switch

tone

recording.

of

speakers connected

marked 2 setting it to the depressed

to the not

settings.

level.

The volume

it to the

depressed position

depressed

to the

and

Adjusting
the right

Listenlng

Balance

and

to the

Headphones

between

lelt

This

insert

sound from the speakers), press

Use

the

BALANCE

appUes not only to the speaker sound but also to the

the

headphones

control to adjust the volume balance

plug into

the

PHONES

SPEAKER

of

the right and left channels.

headphone

jack. To

switch 1 and 2 to deactivate

limit

sound

sound.

to the

headphones

all

speakers.

(no

1-10(No.20410)

Page

9

AX-A572BK

Adjusting

Listening
Volume

Bass and

at Low

Level

Using a GraphiC

Treble

Equalize

Adjusting the

Use

the

BASS
high-pitched sound.
attenuates
Use

Our
The

treble settings according to the

In

order to use the loudness function, press the
mode
button not depressed), and the loudness function is cancelled.

If a graphlc equalizer

tone
equalizer, set the
switch

it. Setting the

these

dials to adjust the

ears are not sensitive to low- and high-frequency sounds when the volume is low.
Loudness control compensates for this hearing characteristic. It adjusts the bass and

(with

the button depressed). Pressing it again returns to the " M

adjustments become possible. To listen to sounds after processing by the graphic

to

TAPE 2/D

Reproducing

Tone

control to adjust a low-pitched sound and the

Tuming

REC SELECTOR

AT.

More

either

dial

to

"DEFEAT"

tone

as desired.

level.

is

connected to the

switch

Realistic

dial

to the right intensifies the sound and turning to the left

leaves bass and treble unchanged.

LOUDNESS

TAPE 2/D AT

to the desired source and the

switch

jacks

Sounds

TREBLE

on the rear panel further subtle

control to adjust a

setting it to the " . ON"

OFF"

SOURCE SELECTOR

mode

(with

the

Source

Direct

SOURCE DIRECT

function

Source

Direct function realizes amplification as close as to the original sound by shortening

the signal route. Press the

top of the
Pressing
Use
with
by
passing through the
circuit.

Notes:

function.

•

BALANCE

•

BASS

• TREBLE

switch

the

switch

this function only when a satisfactory

the

BALANCE

the

SOURCE SELECTOR

When the

control

SOURCE

control

control

SOURCE DIRECT

lights up, thereby indicating

again cancels the function and tums off the indicator.

control, the

BALANCE

BASS

switch

control

DIRECT

switch

switch

that

tone

is being reproduced requiring no adjustment

control or the

are

output

through the shortest possible

circuit

or the

is ON the following

to use this function. The indicator at the

the Source Direct function is tumed on.

TREBLE

BASS

control.

control or

switches

Input signals selected

TREBLE

and controls do not

route

without

control

Page 10

(No.20410)

1-11

AX-A572BK

Troubleshooting

Problem

Amplifier

does

not play.

No

sound from any speakers.

Sound

from one speaker only.

Howling

during record playing.

Recording

does

not work.

AX-A572BK

CD, TUNER, AUX, TAPE

1,

Possible Cause

Power

cord not plugged in.

SPEAKERS
The SOURCE SELECTOR
incorrectly.

Speaker

BALANCE
Tumtable
The REC SELECTOR

incorrectly.

switches not set correctly.

wires

not connected properly.

control may be set to one extreme.

too close to a speaker.

switch

switch

is set

has been set

Specifications

Output

Power

(lEC

268-3/DIN):

.

80 watts per channel into 8 ohms at 1 kHz

(JVC

Audio

Analysis

Total

TAPE

harmonie distortion

2/DAT

in-

SPEAKERS

PHONO

in-SPEAKERS

Damping

Power

bandwidth: 5 Hz to 50 kHz

120 watts per channel into 4 ohms at 1 kHz

halmonic

distortion.

halmonic

System):

70 watts per charmel, min.

out:

out:

Factor: 160 (1 kHz, 8 ohms)

distortion.

to 20

kHz,

with

70

watts per channel, min.

with

no more than 0.003 % total harmonie distortion.

0.003 % at 70 watts (at I kHz, 8 ohms loaded)

0.007 % at 70 watts

0.05 % at 70 watts

0.05%

total harmonie distortion)

no more than 0.007 % total harmonie distortion.

(from

(from

(IHF,

Solutions

Plug

Power cord into AC outlet.

Press

the

SPEAKERS

Select

the desired source

SELECTOR

Check

speaker
Reconnect
Adjust

Move
Set

both channels driven into 8 ohms,

if

BALANCE

speakers away from the tumtable.

the

REC SELECTOR

RMS,

both chaimels driven into 8 ohms from 20 Hz

RMS,

both channels driven into 8 ohms at 1 kHz

20 Hz to 20

20 Hz to 20 kHz, 8 ohms- loaded -30 dB volume)

switches in or out as desired.

with

the

switch.

wiring.

needed.

control so both speakers have sound.

with

with

kHz,

8 ohms loaded)

SOURCE

switch

to the desired source.

no more than 0.7% total

no more than 0.7% total

with

no more than

PHONO

overload capacity

Signal-to-noise ratio ('66

CD, TUNER, AUX, TAPE

Input

Sensitivity/Impedance (1 kHz)

CD, TUNER, AUX, TAPE

Output

Level/Impedance (1 kHz)

LOUDNESS

Frequency

(PHONO

in-TAPE

Power

1,

RIAA

requirement/Power consumption

IHF/DIN)

PHONO

(MM)

PHONO

1,

1,

TAPE

1,

Tone

(-30 dB volume):

Response (8 ohms):

TAPE

phono

Continental

(MC)

TAPE

2/DAT

PHONO

(MM):

PHONO

(MC)

TAPE

2/DAT:

TAPE

2/DAT:

control range

TREBLE:

2/DAT

REC

equalization

Europe: AC 230 voltszyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA

U.K.,

Australia:

Other

Areas;

85

dB/69

67

dB

103

dB/70

mV/47

2.5
200

HV/100

200

mV/40

200

mV /450 ohms

±8 dB

BASS:

out)

MM;

MC;

MM: ±0.3

MC: ±0.5 dB (20 Hz

at
at

±8 dB

+6

dB

at 100

Hz to 100

5

100 mV
8 mV

(with

dB

(20 Hz

AC 240 volts %, 50
AC110/127/220/240

(660

watts, maximum)

dB

dB

k ohms

ohms

k ohms

100 Hz
10 kHz

Hz, -h4 dB

kHz

(with

no more than 0.04% total harmonie distortion).

at 10

kHz

(+0

dB,

-3

dB)

no more than 0.02% total harmonie distortion).

to 20

kHz)

to

20 kHz)

"XJ

, 50

Hz/260

watts

Hz/645

watts

volts % selectable, 50/60

Hz/265

watts

Page

11

1-12(No.20410)