Harman Kardon A250 Owners Manual - Page 16

ADJUSTMENTS

Output

Tube

Balance

Controls:

There

are

two

output

tube

balance

controls

located

between

the

outpu,

tubes,

They

are

accessible

from

below

when

the

bottom

plate

is

removed

and

from

above

when

the

cage

is

removed.

These

controls

are

factory

adjusted

and

should

not

be

touched

unless

tubes,

are

changed.

If

adjustment

is

necessary

follow

the

procedure

listed

below.

1.

Set

the

volume

control

to

minimum

volume.

2.

Turn

off

all

auxiliary

equipment

connected

to

the

A250.

3.

Slowly

rotate

the

control

for

minimum

hum.

4.

If

it

is

not

possible

to

hear

hum

in

your

speakers,

set

the

balance

control

•

to

the

mid

-position.

5.

For

absolute

perfection

adjust

the

balance

control

on

an

IM

distortion

analyzer

for

minimum

intermodulation

distortion.

MAINTENANCE

AND

REPAIRS

Fuse:

In

the

event

of

a

potentially

damaging

failure

of

tubes

or

components,

the

Model

A-250

is

protected

by

a

4

ampere,

type

3AG

fuse,

located

on

the

rear

of

the

unit.

If

this

fuse

is

blown,

it

should

he

replaced

only

with

one

of

the

same

rating.

Replacing

with

a

fuse

of

higher

rating

will

not

protect

the

amplifier,

and

may

result

in

severe

damage,

which

will

not

be

covered

by

the

factory

warranty.

Repair:

Only

the

most

qualified

service

technician

should

be

employed,

as

special

equipment

and

training

is

required

to

properly

service

a

high

fi

delity

amplifier.

This

manual

contains

information

of

great

value

to

the

repairman,

and

should

be

kept

available.

Factory

Warranty

Stations

are

maintained

in

most

major

cities.

For

the

ad-

dress

of

the

nearest

one,

or

for

any

other

information

relating

ta..your

Ilarman-

Kardon

products,

-

write

to

the

attention

of

the

Customer

Service

Department,

Harman-Kardon,

Inc.,

520

Main

St.,

Westbury,

N.

Y.

Be

sure

to

include

the

model.

and

serial

number

of

the

set

in

question.

A

short

description

of

your

complete,in-

stallation

is

often

of

help

in

aswering

your

questions.

A250

REPLACEMENT

PARTS

LIST

Part

No.

Description

Price

ESCOM2727

Slide

Switch—DPDT

.40

ES10217l

7

Slide

Switch—DPDT

.70

FT2382665

Transformer

—Power

20.50

FT238266

Output

Transformer

18.75

JE2382667

Electrolytic

Cond.

500MFD/25V, 250MFD/15V

2.95

JE2382669

Electrolytic

Cond.

20MFD/450V,

150MFD/50V

2.10

JE2382668

Electrolytic

Cond.

30-20MFD/400V,

20-20MFD/300V

3.20

RVCOM2569

Balance

Pot

100

Ohm

.60

Z2382779

Selenium

Rectifier

Int.

Rec.

#BIB

3.75

ER2382722

Function

Switch

3.30

ER2382676

Mode

Switch

1.85

RV2382672

Balance

Control

—Ganged

Tandem

2.20

RV2382670

Loudness

Control

—Ganged

Tandem

2.40

RV2382673

Bass

Control

—Ganged

Tandem

2.20

RV2382671.•

Treble

Control

—Ganged

Tandem

3.50

PC2382890

Baxandall

Tone

Network

1.10

PCCOM2927

Scratch

Filter

.75

PC2382926

Equalization

Network

.90

Z2382924

Sil.

Diode,

.5

Amp/300VPIV

Int.

Rect.

#SD

-93A

or

Equiv.

3.50

PCOM2840

Knob

w/White

Line

(

Rohden

#14801-1)

.25

L2382914

Instruction

Book

2

j

L2382915

Mounting

Template

L2382920

Instruction

Sheet

,ty

238

HARMAN-KARDON,

INC.,

520

MAIN

STREET,

WESTBURY,

L.

I.,

N.

Y.

Harman Kardon A250 Owners Manual - Page 16

ADJUSTMENTS, Output, Balance, Controls, MAINTENANCE, REPAIRS, Repair, REPLACEMENT, PARTS,

Page 16 highlights