C-Audio ST400i, ST600i, ST1000i Owner's Manual

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STiSERIES

OWNERS

MANUAL

CONTENTS

l

INTRODUCTION

1.1

1.2

1.3

1.4

1.5

1.6

1.7

lntroduction
Serial

Number
Warning
Caution
Attention

Loudspeaker

Warn

ing

Smoke

Warning

On/Off

Power

lndication

B

ridge
Level
Peak

Indicators

Cooling

vent

4 .5

Pott'e

r

Recllt

i

retrle

nts

4.6

Voltage

Selectiorr

4.7

AC

tvirilrg

4.8

Balancing

Ollliotr

4.9

Balanced

Sigrral

-

A

DescriPtiort

4.10

Input

Connectiorrs

Balanced

4.1

1

lnput

Connections

U

nbalanced

4.12

Speaker

Wi

re

4.13

Output

Con

nections

4.1

4 Signal

Match

ing

4.15

Cable

Routi

ng

4.1 6

C

rou

nd

ing

3.3

3.4

3.5

3.6

3.7

Signal

Output

Cround

Switch

Cooling

Fan

Signal

Input

Bridge

Switch

Mono

Parallel

Mode

Mono

Bridged

Mode

Protection

Clean

ing

4INSTALLATION

4.1

U

npacking

4.2

Mounting

4.3

Cooling

Requ

irements

4.4

Cable

Looms

6

PERFORMANCE

&

SPECIFICATIONS

6

.1

Genera

I

SPec

if

icat

io

rr

s

6.2

Stereo

SPecifications

2

FRONT

PANEL

2.1

2.2

2.3

2.4

2.5

2.6

3

REAR

PANEL

3.1

AC

Input

3.2

Fuse

5

OPERATION

5.1

5.2

5.3

5.4

5.5

5.6

5.7

5.8

Powerup
Power

Down

Power

Loss

Stereo

Mode

6.3

Bridged

Mono

SPecifications

1.

INTRODUCTION

1.1

Introduction

The

STI Series

of amplifiers

from

C Audio

consists

of

three models,

ST400i

5T600l

and

ST1 000r;

incorporating

considerable

knowledge

and

expertise

accumulated

over many

years

involvement

in

the

art of

Amplifier

design

and manufacture.

Modern

power

amplifiers

are

sophisticated

pieces

of electronic

engineering

capable

of producing

extremely

high power

levels.

They

must

be handled

with respect

and

correctiy installéd

ii

they are

to provide

you

witÂ

many

years of

reliable

service.

They

are

potentially,

extremely

dangerous

if abuseâ,

misused

or inôorrectly

installed.
PIease

take

a little

time

to study

this STI

Series manual,

in

order

that you

can

get

the

best service

from

the

amplifier.

1.2

Serial

Number

Every

STi

Series amplifier

has

an individual

serial

number

which

is marked

on

the rear of

the unit.

Make

a

separate

note

of this number

somewhere

safe where

you

can

refer

to

it.

You may

need

to know

this number

on

an occasion

when

the amplifier

is

not

to hand,

e.g. if it

is

stolen or has

been

sent away

for repair

or

the

rear

is not

easily

accessible.

1.3

Warning

The

STi amplifier

must

be earthed

via

the

earth

connection

in

a three

core mains

cabte

supplied

(see

4.2).

To

prevent

the

danger

of

electric

shock

or fire hazard

do not

expose the

unit

to

rain

or môisture.

lf

the

unit

shoufd

come

into

contact with

moisture

for

any reason,

disconnect

it from

the mains

supply

and leave

it in

a suitable

place

to

dry out.

1.4

Caution

All

controls

needed

for

the

safe operation

of this

amplifier

are

accessible

from

the outside

of

the casine. There

are no

user serviceable

parts

inside

the

unit.

Never remove

the service

covers with

the unit

connectei

to the

mains

supply.

In

the event

of a failure

refer

to your

Dealer.

Unauthorised

servicing

or tampering

with

the

circuitry

may

be

dangerous

and

invalidates

your

warranty.

1.5

Attention

The

STi. Series

has

been

designed

to be rack-mounted

in

any

standard

lg"

equipment

rack

or

(in

fixed

installations)

"stack" mounted

on its

base.

lf this

amplifier

is

to be

used in

a mobile application

it must

be

properly

mounted

in

a suitable

equipment

rack

with front

and rear

support. C Audio

wili not

be responsible

for

any.damage

electronic

or mechanical

sustained

due

to a failure

to

rack mount

in a mobile

application,

or insufficient

support

in

the

rack.housing.

Failure

to

comply with

this will

invalidate

the warranty.

please

read

section

four

concerning

installation

which

details

the

correct procedures

for mounting

the

STI Series.

1.6 Loudspeaker

Warning

The

single most common

cause of loudspeaker

damage

is

due to amplifier clipping. This may

be due to

driving the power

amplifier itself into

clip,

or

by

sending a clipped signal

to

the

amplifier.

Never

operate the

amplifier with the red

S"peak" LEDt flashing

more than occasionally.

Also,

beware of sending

a clipped

signal to the

amplifier. Owing

to

the

amplifiers

wide

bandwidth and high

slew

rate,

such

signals will be reproduced

with

extreme accuracy and loudspeaker

damage will almost

certainly result.

lf

you

are

operating your

system with

the

mixer faders

near maximum and the

amplifier

level

controls below half

way you are in

danger of

clipping the mixer. Wherever possible

the amplifier level

controls should be near

maximum and

the level controlled

by the mixer master

faders.

Alrvavs keep

an eve

on the mixer meters

to ensure you

are not

overdriving the mixer.

Never operate the

amplifier with less

than the rated load

impedance. This

will

not result

in incre.rsecl

ltorrer,

but due to the amplifiers

output

protection

is likely

to

result

in

premature

clipping

ancl

clanrage

kr tlre

loudspeakers

1.7

Smoke Warning

Clycol based smoke machine fluids

(i.e

most of them) deposit

a residue which is a conductive solvent

and

attacks

some metals

(especially

copper).

In addition to

spoiling the paint

finish

of

your

amplifier,

such deposits,

if

allowed to accumulate, will

attack

component leads

and Printed

Circuit Board

traces.

The best course

of defence against

this

potential problem

is to

ensure that sources of smoke are located well

away

from

the fan intakes.

Damage

caused to amplifiers

by smoke residue

can

be costly to repair and

is

explicitly excluded from

the

normal

warranty

cover.

2.

FRONT

PANEL

CONTROLS

2.1On/Ofl

This

switch

powers

up

the

amplifier.

The

amplifier

is

oN

when

the

switch

is switched

to

the

riSht

(see

5

1)'

2.2

Power

Indication

ThegreenpowerLEDisavisualindicatorthatwi|||ightupwhentheunitisconnectedtothemainsand

switched

on.

2.3

Bridg.

The

yellow

bridge

LED

is a

mode

(see

section

5.5).

visual

indicator

that

will

light

up

when

the

amplifier

is

being

used

in

bridge

mono

2.4

Level

Thetwob|ackrotary|evelpotentiometersindividua||ycontroItheinputsigna|.o,"".1,:ftheamplifier,s

.n"nn"ir.

When

turned

fully

clockwise

they

allow

the

amplifiers

maximum

gain

to

be

utilised'

2.5

Peak

Indicators

The

two

red

peak

indicators

show

when

each

channel

is about

to

clip

(see

1'6)'

2.6

Cooling

Vent

All

high

power

amplifiers

produce

considerable

heat

as a

by

product

9{po::t^oltpu].lÎ:l'"t

an

amplifier

cool

is

essential

to

it,

p"rtorrun.e

and

long

life.

The cooling

iystem

of

the

STi

Series

emql,oVs

a

fan

mounted

on

the

rear

of the

amplifier

chassis

which

iraws

air

through

ti-re

amplifier

and

exhausts.through

the

vent

in

the

front

panel. lt is

important

to

ensure

that

this

vent

is

nèver

blocked

(see

3'5

and

4 3)'

3. REAR PANET

3.1

AC Input

On amplifiers

set to 22o/24jv

mains is

connected to

the amplifier via the IEC 10

amp

"Euro"

connector. A

mating mains

connector

also rated at 10

amps is

supplied with the amplifier.

The voltage 22O/24oV

is

set by removing

the fuse

cover and

re-inserting

it with

the appropriate voltage

uppermosr.
On

amplifiers set to

operate at lOO/11O/12OY

mains is

connected to

the amplifier

via a fixed

mains cable.

This cable is rated

at 20

amps with the voltage

internally

set at the factory.

3.2 Fuse

A mains fuse is

fitted to protect

the amplifier.

The fuse is

of the anti-surge

type.

The rating

of this fuse varies

depending

on

the

amplifier model

and what

voltage

the amplifier has been set to operate

on:

220/240V

100/

110/ 120V

ST400t T10

amp - 20mm

T20

amp 32mrn

ST600i

T10

amp - 20mm

T20

amp 32mrn

ST1000i T10

amp - 20mm

T20

amp

32mrn

It is

essential that if

the fuse should

need

to be replaced for

any

reason

only one of the correct

type and rating

are useo.

The correct fuse

allows

the STi Amplifier

to deliver its full

power

without danger. A

fuse of a lower value

than

specified will be likely

to blow

again when

the amplifier is required

to deliver its full rated

output, whilst

a fuse of a higher

value will

not protect

the unit. Never

attempt to bypass the fuse as

this can result in serious

damage

and will invalidate

your warranty.

3.3

SignalOutput

There

are two Speakon

connectors.

When connecting

speaker

cables it is most important that

correct phase

polarity

is observed

(4.13)

otherwise your

speaker

system's performance will

be

reduced.

3.4 Ground

Switch

This

switch is

used to lift

the audio ground from

the AC

ground.

For its

use see section 4.16

3.5

Cooling Fan

A cooling fan is

mounted inside

the

chassis behind

the chrome fanguard

to ensure the cool running

of the

amplifier

(2.6

and 4.3).

lt is important

that nothing

obstructs

the airflow to the fan at any time.

3.6 Signal Input

Input

to the

amplifier is via two

male or female

XLR connectors. Although

the

inputs

are balanced, provision

has

been made for

them to be

used unbalanced

if required without

the need for adapters.

(see

4.8,

4.9, 4.10,

4.11).

3.7 Bridge

Switch

The

STi series may

be

configured

to Bridge Mode,

enabling the total power

of both channels to

be summed

into

one load

(e.9..

1200 watts

in the

ST600i For normal

stereo operation the switch remains

in the left

position labelled

stereo,

moving

the switch to

the right selects

bridged mono operation.

Caution. Never

operate

this switch

when the

amplifier is switched

on.

Never

power

up the amplifier

after

moving

the switch without

resetting

the speaker

connections

(see

5.6). Never use in bridge mode with

a load

of less than

8Q nominal. Failure

to

observe these requirements

may result

in

permanent

damage to

the

amplifier or

speakers connected

to it,

and

will

invalidate

the warranty.