Universal audio 535 User manual

www.SteamPoweredRadio.Com

I

Murn

□

model

535

DUAL GRAPHIC EQUALIZER

model

533

GRAPHIC EQUALIZER

UNITED

RECORDING

ELECTRONICS

INDUSTRIES

8460

SAN

FERNANDO

RD

..

SUN

VALLEY

.

CALIFORNIA

91352

(818)

767

-

1000

.

M[re

~

www.SteamPoweredRadio.Com

I

BEFORE

PROCEEDING

WITH

COMPLETE UNPACKING AND

SETUP,

CONSULT UNPACKING AND INSPECTION INSTRUCTIONS

ON

PAGE

4

model

535

DUAL GRAPHIC EQUALIZER

model

533

GRAPHIC EQUALIZER

United

Recording

Electronics

Industries

8460

SAN

FERNANDO

ROAD,

SUN

VALLEY,

CALIFORNIA

91352

(818)

787-

.

1000

Printed

in U.S.A.

©

Copyright

1979,

UREI

www.SteamPoweredRadio.Com

I

TABLE

OF

CONTENTS

SECTION

I.

INTRODUCTION

1.1

.

DESCRIPTION

1.2

SPECIFICA~IONS

1.3

CONTROLS

SECTION

II.

INSPECTION

AND

INSTALLATION

2.1

UNPACKING

AND

INSPECTION

2.2

ENVIRONMENTAL CONSIDERATIONS

2.3

POWERING

2.4

LINE

VOLTAGE

SWITCH

2.5

EXTERNAL CONNECTIONS

2.5.1

MODEL

301

XLR/QG ADAPTER

2.6

IMPEDANCE

AND

TERMINATION

2.7

SIGNAL LEVEL

AND

OVERLOAD

DETECTOR

2.8

ACCESSORIES

2.9

RACK

MOUNTING

A

MODEL

533

2.10

RACK

MOUNTING

TWO

UNITS

(MODEL

533)

SECTION

Ill.

OPERATING INSTRUCTIONS

3.1

GENERAL

3.2

SYSTEM

CHECK

3.3

EXPERIMENTATIO~

3.4

DOCUMENTATION

3.5

APPLICATION

3.5.1

OBJECTIVE

MEASUREMENTS

VS

SUBJECTIVE

HEARING

3.5.2

ADDITIONAL

HINTS

3.5.3

SPECTRAL

DISTRIBUTION

IN

THE

AUDIO SIGNAL

3.5.4

EQ

SYSTEMS

AND

LIMITERS

3.6

DISCUSSION

OF

EQUALIZATION

3.6.1

BEFORE EQUALIZATION

3.6.2

MEASUREMENT

TECHNIQUES

3.6.3

ADJUSTMENT

OF

EQUALIZERS

3.6.4

SOME

PROBLEMS

WITH

CORRECTIVE

ROOM

EQ

3.6.5

FEEDBACK

~UPPRESSION

3.7

GAIN STRUCTURE

AHD

SIGNAL-TO-NOISE

3.8

INPUT LEVEL

3.9

OVERLOAD

INDICATOR

SECTION

IV.

THEORY

OF

OPERATION

4.1

GENERAL

4.2

INPUT

AMPLIFIER

4.3

GAIN

AMPLIFIER

4.4

GRAPHIC EQUALIZER

4.4.1

GENERAL

4.4.2

FILTERS

PAGE

1

2

3

4

5

6A

7

8

9

11

-

11

13

14

15

17

18

19

20

21

22

23

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I

TABLE

OF

CONTENTS

4.4.3

THE

ACTIVE INDUCTOR

4.5

OUTPUT

AMPLIFIER

4.6

OVERLOAD

INDICATOH

4.7

POWER

SUPPLY

SECTION V.

MAINTENANCE

5.1

GENERAL

5.2

REPAIRS

AND

WARRANTY

5.3

SERVICE ADJUSTMENTS

5.3.1

COMMON

MODE

BALANCE

5.3.2

OFFSET ADJUSTMENT

5.4

CLEANING

5.5

ON

OP

AMPS

SECTION

VI.

ILLUSTRATION

SCHEMATIC

DIAGRAM

OF

UREI

MODEL

SCHEMATIC

DIAGRAM

OF

UREI

MODEL

(Continued)

PAGE

25

26

27

28

29

533

535

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I

; .

SECTION I

INTRODUCTION

Bffll

FIGURE

1.

MODEL

535

FRONT

PANEL.

NOTE:

This

manual

contains

complete

instructions

for

the

operation

of

the

two-channel

"Dual

Graphic

Equalizer"

Model

535.

However,

this

manual

is

also

intended

for

the

single

channel

"Graphic

Equalizer"

Model

533.

If

used

with

a

Model

533,

all

references

to

the

two-channel

unit

should

be

disregarded.

1.1

DESCRIPTION

The

Model

535

Dual

Graphic

Equalizer

is

a

studio

quality

product

which

has

wide

application

in

recording,

sound

reinforcement,

radio

and

TV

production,

and

high

fidelity

music

systems.

The

system

is

designed

to

operate

at

any

nominal

level

from

as

low

as

-20

dB

(Ref.

0.775

V)

allowing

its

use

with

low

level

mixers,

high

or

low

impedances,

and

balanced

or

single-ended

circuits.

The

Model

535

provides

12

dB

of

boost

or

cut

at

each

of

its

10

frequencies

which

are

centered

at

ISO

!-octave

increments

from

31.5

Hz

to

16

kHz.

The

positions

of

the

control

arms

of

the

vertical,

stepless

controls

provide

a

graphic

representation

of

the

response

curve

selected.

The

filters

are

active,

minimum

phase,

2-pole

synthesized

LC

networks,

whose

skirts

properly

combine

for

minimum

ripple

and

phase

shift

when

used

in

combination.

A

front

panel

control

adjusts

the

gain

from

-10

dB

to

+20

dB.

Bypass

switches

permit

switching

the

equalization

out

for

A-B

tests.

An

optional

(SC-1)

security

cover

may

be

installed

to

protect

all

operating

controls

against

inadvertent

disturbance

or

tampering

in

fixed

installations.

-1-

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I

l.

✓•

SPECIFICATIONS

ELECTRICAL

(EACH

CHANNEL):

INPUT:

Balanced

bridging,

differential

amplifier.

INPUT IMPEDANCE: 40

kohms,

used

as

balanced

input.

20

kohms,

used

as

unbalanced

(single-ended)

input.

MAXIMUM

INPUT LEVEL:

+20

dB

(7.75

volts).

EQUIVALENT

INPUT NOISE:

Less

than

-90

dBm.

15.7

kHz

noise

bandwidth

with

all

controls

set

flat,

output

termina-

ted

with

600

ohm

load

(Model

535,

-88

dBm).

GAIN:

Variable,

-10

dB

to

+20

dB,

with

front

panel

control.

FREQUENCY

RESPONSE:

±1

dB,

20-20,000

Hz

(with

no

EQ).

OUTPUT:

Floating,

transformer

isolated.

OUTPUT

LOAD:

150

ohms

or

greater.

POWER

OUTPUT:

+24

dBm

into

600

ohm

load

(12.28

volts),

+20

dB

into

150

ohm

load

(7.75

volts).

DISTORTION:

Less

than

0.25%

THD, 30

Hz

to

15

kHz

at

maximum

rated

output.

FILTER TYPE:

2-pole

synthesized

L-C.

FILTER

BANDWIDTH:

1-octave

at

-3

dB

points

with

8 dB

boost

or

cut.

CENTER

FREQUENCIES:

Standard

ISO

(Hz)

31.5

63

125

250

500

lk

2k

4k

Bk

16k.

FREQUENCY

ACCURACY:

RANGE

OF

BOOST

AND

CUT:

CALIBRATION

OF

BOOST

AND

CUT:

CHANNEL

SEPARATION:

MISCELLANEOUS:

POWER

REQUIREMENTS:

±3%

of

center

frequency.

12

dB,

single

filter

section.

Within

1 dB

of

indicated

setting,

Oto

±6

dB,

within

1.5

dB

of

indicated

setting,

±6

to

±12

dB,

(single

filter

section).

60 dB

worst

case

at

high

frequencies,

typically

better

than

80

dB.

100-125

VAC

or

200-250

VAC,

50/60

Hz,

switch

selectable,

less

than

10

w.

-2-

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I

·1

I

ENVIRONMENT:

Operating

0°C

to

+50°C

(+32°F

to

+122°F);

storage

-20°C

to

+60°C

(-4°F

to

+140°F).

CONNECTIONS:

Input

and

output,

through

rear

chassis

barrier

strip,

or

XLR/QG

connectors

through

Model

301

accessory

adapter;

Power

through

3-wire

power

cable;

Model

533

utilizes

IEC

style

connector

and

power

cord.

(See

Installation

Instructions,

Section

2.5.)

PHYSICAL CHARACTERISTICS:

DIMENSIONS:

Model

535,

483

x

89

mm

rack

panel;

depth

behind

panel

203

mm.

(19"

x

3-1/2"

x

8");

Model

533,

216

x

89

mm

rack

panel;

depth

behind

panel

190

mm

(8-1/2"

x

3-1/2"

x

7-1/2").

FINISH:

Panel

is

3.18

mm

(1/8")

brushed

clear

anodized

aluminum,

in

two

shades.

Chassis

is

cadmium

plated

steel.

WEIGHT:

Model

535,

4.31

kg

(9.5

pounds);

Model

533,

2.95

kg

(6.5

pounds).

SHIPPING

WEIGHT:

Model

535,

6.35

kg

(14

pounds);

Model

533,

4.08

kg

(9

pounds).

ACCESSORIES:

Model

SC-1

Security

Cover,

smoke

gray

transparent

plastic;

covers

all

operating

controls

(Model

535

only).

1.3

CONTROLS:

Model

301

XLR/QG

adapter;

two

needed

for

Model

535.

One

adapter

provides

connec-

tions

for

signal

input

and

output.

EQUALIZATION:

Vertical

slide

controls,

continuously

variable

Oto

±12

dB.

GAIN:

Screwdriver

adjustable

from

-10

dB

to

+20

dB.

EQ

IN/OUT:

Front

panel

toggle

switch.

POWER:

Front

panel

toggle

switch.

INDICATORS: LED,

Power

ON;

LED,

Overload

Condition,

levels

monitored

at

3

circuit

points;

MAINS

VOLTAGE:

Rear

panel

slide

switch,

115/230

volts.

-3-

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I

SECTION

II

INSPECTION

AND

INSTALLATION

2.1

UNPACKING

AND

INSPECTION

Your

Model

535

was

carefully

packed

at

the

factory,

and

the

container

was

designed

to

protect

the

unit

from

rough

handling.

Nevertheless,

we

recommend

careful

examination

of

the

shipping

carton

and

its

contents

for

any

sign

of

physical

damage

which

could

have

occurred

in

transit.

If

damage

is

evident,

do

not

destroy

any

of

the

packing

mater-

ial

or

the

carton,

and

immediately

notify

the

carrier

of

a

possible

claim

for

damage.

Shipping

claims

must

be

made

by

the

consignee.

'

The

shipment

should

include:

Model

535

Dual

Graphic

Equalizer

UREI

Instruction

Manual

(this

book)

Two-part

Warranty

Card

bearing

the

same

serial

number

as

the

Model

535.

Mounting

screws

and

finish

washers

(for

rack

mounting

of

535

only).

2.2

ENVIRONMENTAL

CONSIDERATIONS

The

system

will

operate

satisfactorily

over

a

range

of

ambient

temperatures

from

0°C

to

+50°C

(+32°F

to

122°F),

and

up

to

80

%

relative

humidity.

If

the

system

is

installed

in

an

equipment

rack

together

with

high

heat

producing

equipment

(such

as

power

amplifiers),

adequate

ventilation

should

be

provided

to

prolong

the

life

of

components.

Also,

while

circuitry

susceptible

to

hum

pick-up

is

sufficiently

shielded

from

moderate

electromagnetic

fields,

installation

should

be

planned

to

avoid

mounting

the

system

immediately

adjacent

to

large

power

transformers,

motors,

etc.

2.3

POWERING

The

535

may

be

operated

from

either

100-125

VAC

or

200-250

VAC

mains

(50

or

60

Hz,

single

phase.)

As

indicated

in

Section

2.4,

the

nominal

line

voltage

may

be

selected

with

a

rear

panel

switch.

BE

SURE

TO

VERIFY

BOTH

THE

ACTUAL

LINE VOLTAGE,

AND

THE

SETTING

OF

THE

VOLTAGE

SELECTOR

SWITCH

BEFORE

CONNECTING

THE

535

TO

THE

MAINS.

-4-

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I

To

comply

with

most

Electrical

Codes,

the

535

is

supplied

with

a

three-wire

AC

cord,

the

grounding

of

which

is

connected

to

the

chassis.

In

some

installations

this

may

create

ground-loop

problems.

Ground

loops

can

become

very

evident

(as

hum

and

buzz)

if

a

significant

potential

difference

exists

between

the

AC

conduit

ground

and

the

~rounded

metal

enclosure

in

which

the

chassis

is

installed.

If

hum

is

experienced,

check

for

the

possibility

of

ground

loops

by

using

a

3-prong

to

2-prong

AC

adapter,

ungrounding

the

AC

plug

temporarily.

This

ungrounds

the

Model

535,

and

will

probably

cure

the

hum

or

buzz,

but

is

not

a

substitute

for

proper

system

grounding.

Be

aware

that

unless

the

Model

535

Dual

Graphic

Equalizer

is

AC

grounded,

a

safety

hazard

can

exist.

UREI

accepts

no

responsibility

for

legal

actions

or

for

direct,

incidental

or

consequential

damages

that

may

result

from

violation

of

any

electrical

codes.

2.4

LINE

VOLTAGE

SWITCH

Unless

a

tag

on

the

line

cord

specifies

otherwise,

the

Model

535

was

shipped

ready

for

operation

with

nominal

115

VAC

power

mains.

In

order

to

change

this

for

nominal

230

V

(50

or

60

Hz),

slide

the

VOLTAGE

SELECTOR

switch

on

the

rear

panel

to

the

230

position.

The

voltage

is

visible

in

a

window

the

switch

slot.

Be

sure

to

change

the

fuse

to

the

correct

value:

1/8-amp

slo-blo

when

changing

to

230

V

operation

or

1/4-amp

slo-blo

for

115

V

operation.

A

small

screwdriver

should

be

used

to

move

the

recessed

switch.

2.5

EXTERNAL

CONNECTIONS

Permanent

input

and

output

signal

wires

should

be

shielded

cable,

and

connected

in

accordance

with

standard

wiring

practice,

as

indicated

on

the

rear

panel

barrier

strip.

If

the

XLR/QG

connectors

are

to

be

used,

install

the

accessory

Model

301

according

to

the

instructions

suppplied

with

the

adapter.

(See

also

"Mounting

Instructions,"

page

6A.)

If

the

Model

535

output

is

connected

to

a

high

impedance

circuit,

we

recommend

shunting

the"±"

and

"COM"

output

terminals

with

a

620

ohm,

1/2

watt

resistor.

This

assures

optimum

loading

for

the

535.

(See

section

2.6

regarding

input

termination).

(See

Figures

2

and

3

on

the

following

page)

-5-

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I

OUTPUT

GRD

INPUT

±

COM

±

FIGURE

2.

CONNECTING

THE

MODEL

535

WITH

BALANCED

INPUT

AND

BALANCED

OUTPUT

CIRCUITS.*

OUTPUT

GRD

INPUT

±

COM

±

FIGURE

3.

CONNECTING

THE

MODEL

535

WITH

UNBALANCED

INPUT

AND

UNBALANCED

OUTPUT

CIRCUITS.*

*With

a

balanced

input

and

unbalanced

output,

or

vice-versa,

use

the

appropriate

connections

suggested

by

each

of

the

above

diagrams.

No

special

switching

or

transformers

are

needed.

-6-

Universal Audio 535 User manual

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