Harman Kardon 75 Owners Manual - Page 3

INSTALLATION

VENTILATION

Although

your

new

receiver

rarely

develops

high

heat,

it

is

recommended

that

you

leave

the

back

of

the

cabinet

open.

If

this

is

not

possible,

provide

several

large

holes

or

slots

as

low

and

as

high

up

in

the

cabinet

back

as

possible.

As

an

alternative,

holes

may

be

provided

in

the

sides,

bottom

or

top

of

the

cabinet.

Remember

that

really

effective

ventilation

requires

provision

for

cool

air

to

enter

at

the

bottom

and

hot

air

to

leave

at

the

top.

A

minimum

clearance

of

two

(2)

inches

should

be

allowed

on

each

side

and

in

the

rear,

between

the

chassis

and

the

cabinet,

and

three

(3)

inches

are

required

above

it.

Isolate

any

accessories

which

might

interfere

with

ventilation.

For

example,

do

not

drape

plastic

or

rubber

covered

interconnecting

cables

over

the

equip-

ment.

POWER

REQUIREMENTS

Connect

the

AC

line

cord

to

any

outlet

furnishing

117

volts,

60

Hz

AC

current.

The

voltage

may

vary

between

105

and

125

volts.

An

auxiliary

AC

power

outlet

is

provided

on

the

rear

panel

of

your

receiver.

Any

accessory

equipment

(tape

recorder,

phonograph

record

player,

etc.)

may

be

connected

to

this

receptacle

and

will

be

controlled

by

the

POWER

switch

on

the

front

panel.

FUSING

A

fuse

is

a

safety

device

used

to

protect

the

receiver

against

possible

damage

due

to

overload

or

short

circuits.

The

75+

receiver

employs

five

protective

fuses.

All

five

are

located

on

the

rear

panel.

The

AC

fuse

labeled

3A-3AG

Slo

Blo

is

used

to

protect

the

power

supply

of

the

entire

system.

The

other

four

fuses

labeled

4A-3AG

LEFT,

RIGHT,

FRONT

and

BACK,

protect

the

output

stages

of

the

receiver.

The

output

of

your

receiver

has

been

designed

to

operate

with

a

MAXI-

MUM

of

4.0

amperes

of

current

in

each

channel.

Under

certain

conditions,

it

is

possible

to

draw

more

than

4.0

amperes

through

the

output

stage

which

would,

in

turn,

blow

the

speaker

fuses.

This

could

be

caused

by

using

multiple

speaker

systems

where

the

total

impedance

falls

below

4

ohms.

(See

"CON-

NECTING

THE

SPEAKERS").

In

the

event

of

fuse

failure,

replace

ONLY

with

the

same

fuse

type

used.

NEVER

replace

with

a

fuse

of

a

higher

rating.

To

do

so

will

NOT

protect

your

receiver

and

could

result

in

severe

damage

to

it

which

will

not

be

covered

under

the

warranty

policy.

SPEAKER

PLACEMENT

(See

Fig.

1)

The

speakers

will

be

referred

to

as

LEFT

and

RIGHT,

FRONT

and

BACK.

Placement

of

the

back

speakers

will

vary

with

your

room

size,

seating

arrange-

ment

and

acoustics.

At

times,

it

may

be

advantageous

to

place

the

back

speakers

in

line

with

the

listener,

either

aiming

them

at

the

listener,

the

rear

of

the

room

or

against

the

side

wall.

It

has

been

acknowledged

that

omni-

directional

speakers

(i.e.

Harman/Kardon

HK50)

serve

well

as

back

speakers

in

a

4

-CH

setup

because

they

do

not

beam

the

sound

at

the

listener.

This

gives

the

illusion

of

far

greater

airiness

and

comes

closer

to

the

sound

at

a

live

con-

cert.

We

have

illustrated

several

ways

of

arranging

the

back

speakers.

Some

experimentation

may

be

required

before

you

obtain

optimum

sound

dispersion

and

total

surround

sound.

If

you

listen

predominantly

to

classical

music

it

is

recommended

to

reflect

the

back

speakers

off

the

walls,

or

aim

them

away

from

the

listener.

This

will

tend

to

soften

the

sound

and

create

a

more

natural

ambience.

If

you

listen

predominantly

to

contemporary

music

it

may

be

advan-

tageous

to

place

the

back

speakers

in

the

corners

and

beam

them

into

the

room.

CONNECTING

THE

SPEAKERS

Use

any

type

of

wire

to

connect

your

speakers

to

your

receiver.

However,

it

should

be

pointed

out

that

the

heavier

the

wire,

the

lower

the

loss

of

power.

Ordinary

lamp

cord,

or

zip

cord

as

it

is

sometimes

called,

is

excellent

for

this

application

since

it

can

be

dressed

easily

around

the

molding

and

it

is

usually

heavy

enough

to

extend

great

lengths

without

an

appreciable

loss

in

power.

Do

not

drive

tacks

or

staples

through

the

center

of

the

wire

since

this

can

result

in

a

short

circuit

which

would

either

cut

the

volume

level

down

considerably

or

short

out

the

sound

completely.

It

is

permissible

to

use

approximately

50-60

feet

of

heavy

gauge

speaker

connecting

wire

for

each

speaker

without

loss

of

volume.

CONNECT

YOUR

SPEAKERS

WITH

CARE,

AVOID

SHORTS.

DO

NOT

CON-

NECT

THE

SPEAKERS

WITH

THE

POWER

ON.

WORK

CAREFULLY

TRIMMING

ALL

LOOSE

WIRES

ON

THE

REAR

OF

THE

SPEAKERS

AND

RECEIVER.

THE

RE-

CEIVER

HAS

BEEN

DESIGNED

TO

PREVENT

DAMAGE

FROM

MOMENTARY

ACCIDENTAL

SHORTING.

HOWEVER,

REPETITIVE

SHORTING

CAN

DAMAGE

THE

OUTPUT

DEVICES.

The

75+

connects

two

pairs

of

speaker

systems

for

the

front

channels,

and

another

two

pairs

for

the

back.

Any

pair

may

be

driven

independently

or

a

combination

of

two

pairs

may

be

driven,

as

selected

by

the

MAIN

and

REMOTE

Speaker

Switches.

Connect

them

to

the

receiver

as

instructed

in

the

diagrams

(Fig.

2

and

Fig.

3),

taking

care

not

to

confuse

the

FRONT

and

BACK,

LEFT

and

RIGHT

channels,

and

the

plus

and

minus

polarities.

Sufficient

care

should

be

taken

not

to

short

circuit

the

plus

and

minus

leads.

SPEAKER

IMPEDANCE

Each

speaker

system

connected

to

your

75

+

must

possess

an

impedance

of

from

4

to

16

ohms.

Should

you

wish

to

drive

two

pairs

of

speaker

systems

simultaneously,

they

should

all

have

an

impedance

of

8

ohms

or

more.

2

Harman Kardon 75 Owners Manual - Page 3

Installation

Page 3 highlights