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RB-993

THREE-CHANNEL

POWER

AMPLIFIER

Owners

Manual

A

CAUTION

RISK

OF

ELECTRIC

SHOCK

DO

NOT

OPEN

IA

CAUTION:

TO

REDUCE

THE

RISK

OF

ELECTRIC

SHOCK,

DO

NOT

REMOVE

COVER.

NO

USER-SERVICEABLE

PARTS

INSIDE.

REFER

SERVICING

TO

QUALIFIED

SERVICE

PERSONNEL.

APPLICABLE

FOR

USA,

CANADA

OR

WHERE

APPROVED

FOR

TO

THE

USAGE

CAUTION:

TO

PREVENT

ELECTRIC

SHOCK.

MATCH

WIDE

BLADE

OF

PLUG

TO

WIDE

SLOT.

INSERT

FULLY.

ATTENTION:

POUR

EVITER

LES

CHOCS

ELECTRIQUES,

INTRODUCE

LA

LAME

LA

PLUS

LARGE

DE

LA

FICHE

DANS

LA

BORNE

CORRESPONDANTE

DE

LA

PRISE

ET

POUSSER

JUSQU

AU

FOND.

v___

y

A

...

->

WL

This

symbol

is

to

alert

the

user

to

the

presence

of

uninsulated

dangerous

voltages

inside

the

prouct’s

enclosure

that

may

constitute

a

risk

of

electric

shock.

A

l

..

This

symbol

is

to

alert

the

user

to

important

operating

and

maintenance

(service)

instructions

in

this

manual

and

literature

accompanying

the

product.

-j

WARNING:

There

are

no

user

serviceable

parts

inside.

Refer

all

servicing

to

qualified

service

personnel.

WARNING:

To

reduce

the

risk

of

fire

or

electric

shock,

do

not

expose

the

RB-993

to

moisture

or

water.

Do

not

allow

foreign

objects

to

get

into

the

enclosure.

If

the

unit

is

exposed

to

moisture,

or

a

foreign

object

gets

into

the

enclosure,

immediately

disconnect

the

power

cord

from

the

wall.

Take

the

unit

to

a

qualified

service

person

for

inspection

and

necessary

repairs.

Read

all

the

instructions

before

connecting

or

operating

the

RB-993

.

Keep

this

manual

so

you

can

refer

to

these

safety

instructions.

Heed

all

warnings

and

safety

information

in

these

instructions

and

on

the

product

itself.

Follow

all

operating

instructions.

Clean

the

RB-993

only

with

a

dry

cloth

or

a

vacuum

cleaner.

Keep

the

ventilation

inlets

on

the

unit

unobstructed.

For

example,

do

not

place

the

unit

on

a

bed,

sofa,

rug,

or

similar

surface

that

could

block

the

ventilation

slots.

If

the

RB-993

is

placed

in

a

bookcase

or

cabinet,

there

must

be

sufficient

clearance

around

the

unit

and

ventilation

of

the

cabinet

to

allow

proper

cooling.

Keep

the

RB-993

away

from

radiators,

heat

registers,

stoves,

or

any

other

appliance

that

produces

heat.

The

RB-993

must

be

connected

to

a

power

supply

only

of

the

type

and

voltage

specified

on

the

rear

panel

of

the

unit.

Connect

the

RB-993

to

the

power

outlet

only

with

the

supplied

2-pin

polarized

power

supply

cable

or

an

exact

equivalent.

Do

not

modify

the

supplied

cable

in

any

way.

Do

not

attempt

to

defeat

grounding

and/or

polarization

provisions.

The

cable

should

be

connected

to

a

2-pin

polarized

wall

outlet,

matching

the

wide

blade

of

the

plug

to

the

wide

slot

of

the

receptacle.

Do

not

use

extension

cords.

Do

not

route

the

power

cord

where

it

will

be

crushed,

pinched,

bent

at

severe

angles,

exposed

to

heat,

or

damaged

in

any

way.

Pay

particular

attention

to

the

power

cord

at

the

plug

and

where

it

exits

the

back

of

the

unit.

The

power

cord

should

be

unplugged

from

the

wall

outlet

if

the

unit

is

to

be

left

unused

for

a

long

period

of

time.

Immediately

stop

using

the

RB-993

and

have

it

inspected

and/or

serviced

by

a

qualified

service

agency

if:

•

The

power

supply

cord

or

plug

has

been

damaged.

•

Objects

have

fallen

into

or

liquid

has

been

spilled

into

the

unit.

•

The

unit

has

been

exposed

to

rain.

•

The

unit

shows

signs

of

improper

operation

•

The

unit

has

been

dropped

or

damaged

in

any

way

Place

the

RB-993

on

a

fixed,

level

surface

strong

enough

to

support

its

weight.

Do

not

place

the

RB-993

on

a

moveable

cart

that

could

tip

over.

Contents

(circled

numbers

refer

to

illustration)

Figure

1

-

Controls

and

Connections

_

1

Figure

2

-

Wiring

Connections

(RCA

inputs

/speakers)_2

Figure

3

-

Wiring

Connections

(balanced

Inputs)

_2

Getting

Started

_3

A

Few

Precautions

3

Placement

3

AC

Power

and

Control_3

AC

Power

Input

0

3

Power

Switch

0

and

Power

Indicator

0

3

Protection

Circuitry

0

4

Input

signal

connections_4

RCA

Input

Connections

(unbalanced)

0

4

XLR

Input

Connections

(balanced)

0

4

Speakers

_4

Speaker

Selection

4

Speaker

Wire

Selection

4

Polarity

and

Phasing

4

Connecting

the

Speakers

0

5

Troubleshooting_5

Front

Panel

Power

Indicator

Is

Not

Lit

5

Fuse

Replacement

0

5

No

Sound

5

Protection

Indicator

Is

Lit

5

Specifications_5

Figure

3

-

Wiring

Connections

(balanced

inputs)

SURROUND

PROCESSOR

©

©

©

ROTELRB-993

RB-993

Getting

Started

Thank

you

for

purchasing

the

Rotel

RB-993

power

amplifier

When

used

in

a

high-quality

music

or

home

theater

system,

your

Rotel

amplifier

will

provide

years

of

musical

enjoyment.

The

RB-993

is

a

powerful

three-channel

power

amplifier,

ideal

for

driving

the

front

and

center

speakers

in

an

audiophile

quality

home

theater

system.

The

RB-993

provides

the

highest

level

of

au¬

dio

performance.

Discrete

output

devices,

low

negative

feedback,

and

Rotel's

Balanced

Design

ensure

superb

sound

quality.

Its

high

current

capability

allows

the

RB-993

to

drive

the

most

demanding

loudspeakers.

Be

aware

that

the

RB-993

is

capable

of

high

power

levels,

in

ex¬

cess

of

200

watts

per

channel.

Make

sure

that

your

speakers

can

handle

the

power

of

the

RB-993.

If

in

doubt

about

your

speakers,

ask

your

local

Rotel

audio

specialist

for

advice.

The

RB-993

is

straightforward

in

its

installation

and

operation.

If

you

have

experience

with

other

power

amplifiers,

you

shouldn't

find

anything

terribly

perplexing.

Plug

in

three

sets

of

high-quality

RCA

cables

from

your

preamp

into

the

amplifier

inputs,

wire

up

your

speakers,

and

enjoy.

Alternatively,

the

RB-993

provides

an

optional

set

of

"balanced"

inputs

for

use

with

preamps

or

proces¬

sors

that

offer

these

low-noise

XLR-connections.

A

Few

Precautions

Please

read

this

manual

carefully.

In

addition

to

basic

installation

and

operating

instructions,

it

provides

valuable

information

on

various

RB-993

system

configurations

as

well

as

general

informa¬

tion

that

will

help

you

get

optimum

performance

from

your

system.

Please

contact

your

authorized

Rotel

specialty

retailer

for

an¬

swers

to

any

questions

you

might

have.

In

addition,

all

of

us

at

Rotel

welcome

your

questions

and

comments.

Save

the

RB-993

shipping

carton

and

all

enclosed

packing

mate¬

rial

for

future

use.

Shipping

or

moving

the

RB-993

in

anything

other

than

the

original

packing

material

may

result

in

severe

dam¬

age

to

your

amplifier.

Fill

out

and

send

in

the

owner's

registration

card

packed

with

the

RB-993.

Also

be

sure

to

keep

the

original

sales

receipt.

It

is

your

best

record

of

the

date

of

purchase,

which

you

will

need

in

the

event

warranty

service

is

ever

required.

Placement

Because

of

its

high

power

output,

the

RB-993

may

generate

con¬

siderable

heat.

The

heat

sinks

and

ventilation

openings

in

the

am¬

plifier

are

more

than

capable

of

dissipating

this

heat

under

normal

conditions,

but

don’t

smother

your

amplifier.

There

must

be

ad¬

equate

clearance

around

the

chassis.

The

ventilation

slots

in

the

top

cover

must

be

unblocked,

and

there

must

be

reasonable

air¬

flow

around

the

amplifier.

Use

common

sense

when

placing

the

amplifier

in

a

cabinet

or

when

stacking

other

equipment.

Likewise,

remember

the

weight

of

the

amplifier

when

you

select

an

installation

location.

Make

sure

that

the

shelf

or

cabinet

can

support

its

considerable

bulk.

Again,

use

common

sense.

AC

Power

and

Control

AC

Power

Input

Q

Because

of

its

high

power

rating,

the

RB-993

can

draw

consider¬

able

current.

Therefore,

it

should

be

plugged

directly

into

a

2-pin

polarized

wall

outlet.

Do

not

use

an

extension

cord.

A

heavy

duty

multi-tap

power

outlet

strip

may

be

used

if

it

(and

the

wall

outlet)

is

rated

to

handle

the

current

demanded

by

the

RB-993

and

all

the

other

components

connected

to

it.

Be

sure

the

power

switch

on

the

front

panel

of

the

RB-993

is

turned

off

(in

the

"out"

position).

Then,

connect

the

supplied

power

cord

to

the

AC

power

receptacle

on

the

rear

of

the

unit

and

the

AC

power

outlet.

NOTE:

You

may

find

it

convenient

to

use

a

remote

power

control

accessory,

such

as

Rotel's

RLC-900

Line

Conditioner,

to

turn

on

and

off

your

entire

system

automatically

Alternately,

some

pream¬

plifiers

have

a

switched

outlet

that

can

handle

the

current

de¬

mands

of

the

RB-993.

However,

again

be

sure

that

the

switched

outlet

is

up

to

the

task.

Your

RB-993

is

configured

at

the

factory

for

the

proper

AC

line

voltage

in

the

country

where

you

purchased

it

(either

115

volts

AC

or

230

volts

AC

with

a

line

frequency

of

either

50

Hz

or

60

Hz).

The

AC

line

configuration

is

noted

on

a

decal

on

the

back

panel.

NOTE:

Should

you

move

your

RB-993

amplifier

to

another

country,

it

is

possible

to

reconfigure

your

amplifier

for

use

on

a

different

line

voltage.

Do

not

attempt

to

perform

this

conversion

yourself.

Opening

the

enclosure

of

the

RB-993

exposes

you

to

dangerous

voltages.

Consult

a

qualified

service

person

or

the

Rotel

factory

service

department

for

information.

If

you

are

going

to

be

away

from

home

for

an

extended

period

of

time

such

as

a

month-long

vacation,

it

is

a

sensible

precaution

to

unplug

your

amplifier

(as

well

as

other

audio

and

video

compo¬

nents)

while

you

are

away.

Power

Switch

O

and

Power

Indicator

©

The

power

switch

is

located

in

the

center

of

the

front

panel

of

your

amplifier.

To

turn

the

amplifier

on,

push

the

switch

in.

The

LED

indicator

above

the

switch

will

light,

indicating

that

the

ampli¬

fier

is

turned

on.

To

turn

the

amplifier

off,

push

the

button

again

and

return

it

to

the

"out"

position.

NOTE:

If

you

are

using

the

Rotel

RLC-900

AC

Line

Conditioner

or

other

switched

outlet

to

turn

on

and

off

your

amplifier,

you

can

leave

the

power

switch

in

the

"on"position.

3

POWER

AMPLIFIER

RB-993

Protection

Circuitry

Q

The

RB-993

features

a

thermal

protection

circuit

that

protects

the

amplifier

against

potential

damage

in

the

event

of

extreme

or

faulty

operating

conditions.

Unlike

many

designs,

the

RB-993's

protection

circuit

is

independent

of

the

audio

signal

and

has

no

impact

on

sonic

performance.

Instead,

the

protection

circuit

monitors

the

temperature

of

the

output

devices

and

shuts

down

the

amplifier

if

temperatures

exceed

safe

limits.

Most

likely,

you

will

never

see

this

protection

circuitry

in

action.

However,

should

a

faulty

condition

arise,

the

amplifier

will

stop

playing

and

the

LED

indicator

on

the

front

panel

will

light

up.

If

this

happens,

turn

the

amplifier

off,

let

it

cool

down

for

several

minutes,

and

attempt

to

identify

and

correct

the

problem

that

caused

the

protection

circuitry

to

engage.

When

you

turn

the

am¬

plifier

back

on,

the

protection

circuit

will

automatically

reset

and

the

indicator

LED

should

go

out.

In

most

cases,

the

protection

activates

because

of

a

fault

condi¬

tion

such

as

shorted

speaker

wires,

or

inadequate

ventilation

leading

to

an

overheating

condition.

In

very

rare

cases,

highly

re¬

active

or

extremely

low

impedance

speaker

loads

could

cause

the

protection

circuit

to

engage.

If

the

protection

circuitry

triggers

repeatedly

and

you

are

unable

to

isolate

and

correct

the

faulty

condition,

contact

your

Rotel

au¬

dio

specialty

retailer

for

assistance

in

troubleshooting.

Input

Signal

Connections

The

RB-993

gives

you

a

choice

of

two

different

kinds

of

input

con¬

nections

—

conventional

"unbalanced"

RCA

type

connections

(such

as

found

on

nearly

all

audio

equipment)

or

"balanced"

XLR-

type

connections

for

use

with

some

high-end

preamps

or

digital

processors

featuring

this

lower

noise

connection.

NOTE:

You

must

choose

one

or

the

other

type

of

input

connection

—

not

both.

Do

not

connect

both

balanced

and

unbalanced

inputs

simultaneously.

RCA

Input

Connections

(unbalanced)

O

[See

Figure

2

for

wiring

illustration]

When

a

component

with

"RCA"

connectors

—

such

as

a

pream

plifier

or

surround

sound

processor

—

supplies

signals

to

the

RB-993,

the

RCA-type

phono

plug

inputs

should

be

used.

NOTE:

To

prevent

loud

noises

that

neither

you

nor

your

speakers

will

appreciate,

make

sure

the

amplifier

is

turned

off

when

you

make

any

signal

connections.

Select

high

quality

audio

interconnect

cables.

Connect

the

first

output

channel

of

your

preamp

or

surround

processor

to

the

Input

1

"unbalanced"

RCA-connector

on

the

RB-993.

Connect

the

second

output

channel

of

your

preamp

to

the

Input

2

"unbalanced"

connector.

Connect

the

third

output

channel

of

your

preamp

to

the

Input

3

"unbalanced"

connector

on

the

RB-993.

XLR

Input

Connections

(balanced)

O

[See

Figure

3

for

wiring

illustration]

If

you

are

using

one

of

the

few

high-end

preamplifiers

or

proces¬

sors

with

low-noise

"balanced"

signal

outputs

to

drive

your

RB-993,

you

may

choose

to

use

special

XLR-type

connections.

See

your

audio

specialist

for

the

appropriate

cables.

Connect

the

first

output

channel

of

your

preamp

to

the

Input

1

"balanced"

XLR-connector

on

the

RB-993.

When

properly

seated,

the

connector

should

"click"

into

the

connection.

Connect

the

sec¬

ond

output

channel

of

your

preamp

to

the

Input

2

"balanced"

con¬

nector.

Connect

the

third

output

channel

of

your

preamp

to

the

Input

3

"balanced"

connector

on

the

RB-993.

Speakers

Speaker

Selection

We

recommend

using

loudspeakers

with

a

nominal

impedance

of

4

ohms

or

higher

with

the

RB-993.

You

should

exercise

some

cau¬

tion

in

driving

multiple

pairs

of

speakers

in

parallel

configuration,

because

the

effective

impedance

the

amplifier

sees

is

cut

in

half.

For

example,

when

driving

two

pair

of

8

ohm

speakers,

the

ampli¬

fier

sees

a

4

ohm

load.

When

driving

multiple

speakers

in

parallel,

it

is

recommended

that

you

select

speakers

with

a

nominal

imped¬

ance

of

8

ohms

or

higher.

Speaker

impedance

ratings

are

less

than

precise.

In

practice,

very

few

loudspeakers

will

present

any

problems

for

the

RB-993.

See

your

Rotel

audio

specialist

if

you

have

any

questions.

Speaker

Wire

Selection

Use

insulated

two-conductor

stranded

wire

to

connect

the

RB-993

to

the

speakers.

The

size

and

quality

of

the

wire

can

have

an

au¬

dible

effect

on

the

performance

of

the

system.

Standard

18

gauge

"zip

cord"

will

work,

but

can

result

in

lower

output

or

erratic

fre¬

quency

response.

For

wire

runs

of

50

feet

or

less,

we

recommend

16

gauge

or

larger

wire.

For

longer

runs

and

for

optimum

perfor¬

mance,

12

gauge

wire

should

be

used.

For

best

performance,

you

may

want

to

consider

special

high-quality

audio

cables.

Your

local

audio

specialty

retailer

can

help

in

the

selection

of

speaker

cables.

Polarity

and

Phasing

The

polarity

—

the

positive/negative

orientation

of

the

connec¬

tions

—

for

every

speaker

and

amplifier

connection

must

be

con¬

sistent

so

all

the

speakers

will

be

in

phase.

If

the

polarity

of

one

connection

is

mistakenly

reversed,

bass

output

will

be

very

weak

and

stereo

imaging

degraded.

All

wire

is

marked

so

you

can

identify

the

two

conductors.

There

may

be

ribs

or

a

stripe

on

the

insulation

of

one

conductor.

The

wire

may

have

clear

insulation

with

different

color

conductors

4

RB-993

(copper

and

silver).

There

may

be

polarity

indications

printed

on

the

insulation,

Identify

the

positive

and

negative

conductors

and

be

consistent

with

every

speaker

and

amplifier

connection.

Connecting

the

Speakers

Q

[See

Figure

2

for

wiring

illustration]

The

RB-993

has

three

pairs

of

color

coded

binding

posts

on

the

back

panel.

These

connectors

accept

bare

wire,

connector

Jugs,

or

dual

banana

type

connectors

(except

in

the

European

Commu¬

nity

countries

where

their

use

is

not

permitted).

Be

sure

that

you

are

connecting

the

correct

speaker

to

the

de¬

sired

output

For

example,

if

you

have

connected

the

left

channel

signal

to

Input

3

on

the

RB-993,

make

sure

that

you

connect

the

left

speaker

to

the

Speaker

3

terminals,

etc.

Route

the

wire

from

the

RB-993

to

the

speakers.

Give

yourseff

enough

stack

so

you

can

move

the

components

enough

to

allow

access

to

the

speaker

connectors.

If

you

are

using

dual

banana

plugs,

connect

them

to

the

wires

and

then

plug

into

the

backs

of

the

binding

posts.

The

collars

of

the

binding

posts

should

be

screwed

in

all

the

way

(clockwise).

If

you

are

using

terminal

lugs,

connect

them

to

the

wires.

If

you

are

attaching

bare

wires

directly

to

the

binding

posts,

separate

the

first

few

inches

of

the

wire

conductors

and

strip

about

1/2"

of

insulation

from

the

end

of

each

conductor.

Be

careful

not

to

cut

into

the

wire

strands.

Twist

the

strands

of

each

conductor

to¬

gether

to

avoid

fraying.

Unscrew

(turn

counterclockwise)

the

binding

post

collars.

Place

the

connector

lug

around

the

binding

post

shaft,

or

insert

the

bundled

wire

into

the

hole

in

the

shaft.

Turn

the

collars

clockwise

to

clamp

the

connector

lug

or

wire

firmly

in

place.

NOTE:

Be

sure

there

are

no

loose

wire

strands

that

could

touch

adjacent

wires

or

connectors.

Short-circuits

caused

by

loose

strands

touching

will

trigger

the

amplifier

's

protection

circuity

,;

Troubleshooting

Most

difficulties

in

audio

systems

are

the

result

of

poor

or

wrong

connections,

or

Improper

control

settings.

If

you

encounter

prob¬

lems,

isolate

the

area

of

the

difficulty,

check

the

control

settings,

determine

the

cause

of

the

fault

and

make

the

necessary

changes.

If

you

are

unable

to

get

sound

from

the

RB-993,

refer

to

the

suggestions

for

the

following

conditions:

Front

Panel

Power

Indicator

Is

IMot

Lit

No

main

power

to

the

RB-993.

Check

the

front

panel

power

switch.

Make

sure

that

it

is

set

to

the

"on"

position.

Check

AC

power

connections

at

the

amplifier

and

the

AC

outlet.

Fuse

Replacement

Q

If

everything

checks

out

correctly

and

you

still

cannot

get

the

am¬

plifier

to

turn

on,

check

for

a

blown

fuse.

Disconnect

the

AC

from

the

wall

and

remove

the

fuse

holder

on

the

back

panel.

If

the

fuse

is

blown,

replace

with

a

new

fuse,

and

try

again.

NOTE:

Make

sure

that

the

power

cord

is

disconnected

from

the

wall

before

checking

or

replacing

the

fuse.

Replace

only

with

the

identical

size

and

type

fuse

(10

amp

AGCl

No

Sound

tf

the

amp

is

getting

AC

power,

but

Is

producing

no

sound,

check

the

Protection

indicator

on

the

front

panel.

If

it

is

lit,

see

below.

If

not,

check

alf

of

your

connections

and

control

settings

on

associ¬

ated

components.

Check

the

input

selector

switch

on

the

RB-993

back

panel

to

be

sure

that

its

setting

matches

the

type

of

input

you

are

using.

Protection

Indicator

Is

Lit

The

front

panel

indicator

lights

when

the

RB-993

protection

cir¬

cuits

have

shut

off

the

amplifier.

Typically,

this

occurs

only

when

the

ventilation

openings

are

blocked,

when

there

is

faulty

speaker

wiring,

or

after

a

period

of

extreme

use.

Turn

off

the

system

and

wait

for

the

amp

to

cool.

Then

push

the

front

panel

power

switch

in

and

out

to

reset

the

protection

devices.

If

the

problem

is

not

corrected

or

reoccurs,

there

Is

a

problem

with

the

system

or

the

amplifier

itself.

Specifications

Continuous

Power

Output

200

watts/ch

(20-20

kHz,

<

0.03%,

8

ohms)

Total

Harmonic

Distortion

(20

Kz-20

kHz,

8

ohms)

<

0.03%

Intermodulation

Distortion

(60

Hz:

7

kHz.

41)

<

0.03%

Frequency

Response

(+

0.5

dB,

-3

dB)

15-100k

Hz

Damping

Factor

(20-20,000

Hz,

8

ohms)

280

Speaker

Impedance

(Normal

mode)

4

ohms

minimum

Signal

to

Noise

Ratio

(IHF

A

network)

116

dB

Input

Impedance/Sensitivity

32

k

0hms/l

.5

volt

Power

Requirements

115

Volts,

60

Hz

or

230

Volts,

50

Hz

Power

Consumption

600

Watts

Dimensions

(W,

H,

D)

440

x

121

x

365

mm

17.38

x

4.75

x

114.38*

Weight

(net)

18.3

kg,

40.3

lb

All

specifications

are

accurate

at

the

time

of

printing.

Rote!

reserves

the

right

to

make

improvements

without

notice.

5