Dolby Laboratories SR 280 User Information

[](I

DolbY

SR

Cat.
Spectral

User

No. 280

Information

Recording

Module

USER

INFORMATION

FOR

SPECTRAL

RECORDING MODULE

CAT. NO. 280

Dolby

U.S.A. 100

Tel: [phone]; Telex: 34409;

U.K.

Tel: [phone]; Telex: 919109;

Laboratories

Potrero

346

Clapham

Avenue,

Road,

San

Incorporated

Francisco,

Fax:

London

[phone]

SW9

Fax:

01 720-4118

CA

9AP

94103

WARRANTY
defects

01'

warranty
defective,

distributor.

inadequate

Dolby

circumstances

All

ill1986

in

implied

Laboratories'

requests

Dolby

materials

warranties

period

provided

packing

INFORMATION:

and

workmanship

and

Dolby

Defects

shall

for

repairs

Laboratories

Laboratories

the

unit

caused

for

service

obligation
Dolby

or

information

Inc.

Equipment

no

warranty

is

shipped,

by

modifications,

return,

is

restricted

Laboratories

manufactured

for

one

year

of

merchantability

will

repair

prepaid,

are

not

covered

to

the

be

liable

should

include

from

or,

at

to

misuse

repair

for

any

its

the

or

by

other

the

the

accidents,

this

or

unit

by

Dolby

date

of

purchase.

or

fitness

option,

manufacturer

warranty.

replacement

damage,

serial

for a

replace

and any

number

Laboratories

There

particular

components
directly

further

of

defective

either

direct

to

ensure

is

warranted

are

no

other

purpose.

which

or

via

an

damage

parts

and

or

consequential.

rapid

service.

against
express

During

prove

authorized

caused

S871741717493

the

to

under

be

by

no

This
Cat.
basic
familiarity

information

No. 280

principles

spectral

of

with

Dolby

is

intended

recording

audio

A-type

to

serve

module.

recording,

noise

as

an

introductory

It

assumes

complementary

reduction

and

previous

signal

interface

user's

processing,

frames.

guide

knowledge

for

and

the

of

the

some

The
both
Cat.
Dolby
Cat.

Cat.

pin

No.

A-type

No.

No.
22
22

module
established
the

rear

of

appropriate

280

and

A-type

module

and

studio

the

frame

Important

spectral

level

module.

user

can

with

continue

procedures.

Cat.

No.

type.)

Note

recording

compatible

In

most

simply

the

recording

(A

280

must

module

with

cases,

replace

Cat.

switch

be

set

No.

using

to

is
the
the
the

280

on

the

Dolby®

Cat.

No.

280

Spectral

Recording

Module

Co",pare

DOlbY

••

Noise

Ref Tape

Auto

DD

DoibySR

The

Cat.

No.

280 module is the
first commercially available
embodiment
recording process developed
Dolby
has been designed for ease of instal­lation
M-Series frames from
Laboratories.

Dolby

new

audio recording technique
which provides audible signal
integrity superior to
other

recording
performance of
contemporary

tape recorders stands
tensive scrutiny.
module has been designed to allow
easy operational use of the
SR process, using existing frames,
with

no

changes

of the

new

Laboratories.

in

existing 360-Series

spectral recording

major

or

capital expenditure.

The

that
method
Dolby

analog professional

The

Cat. No. 280

studio equipment

spectral

module

Dolby

of

in use.

SR

up

to ex-

by

and

is

a

any

The

with

Dolby

The

Cat.

No.

280 spectral
recording
logic similar to
Cat. No. 22 A-type noise reduction
module; consequently the control
facilities of 360, 361
units operate normally, such as
IN/OUT, RECORD/PLAY
input

Dolby

a

new
verification tool called
Compare
generator in the module applies

bursts of noise (Dolby Noise) at a
calibrated level to the recorder.
The signal is used

tape to identify the use of

SRI

bration

recording process

of

input/output
Dolby
During playback, the
pare
nates the
the

module

/output

SR modules incorporate

recorder alignment

. A built-in

and

to assist in recorder cali-

(however, the spectral

A-type noise reduction).

circuitry automatically alter-

monitor

Dolby

Noise off-tape

utilizes function

that

of the

and

M-Series

gain controls.

Auto

pink

at

the

head

is

more tolerant

gain errors

Auto

output

between

and

Dolby

and

and

noise

Dolby

than

Com-

of a

the

internal noise generator. LED
indicators
indicate the current
dition.
recorder set-up alignment,
additionally provides a
method
track

Dolby
livered over 80,000 Cat. No. 22
noise reduction modules through­out
availability of interfaces accepting
the Cat. No. 280 modules will
facilitate
Dolby

are available, including
No.
and

two testers are available to as sist
process evaluation
performance verification.

about
process,

describing other Dolby

and
from Dolby Laboratories.

on

the module front

monitor

Auto

Compare

of checking a recorder

by

ear

during a session.

Laboratories

the

world, and

adoption

SR process.

Other

Dolby SR configurations

431

, a module for Dolby SP-

XP-Series units.

Full descriptive information

the

Dolby spectral recording

and

product

testers are available

assists in

but

rapid

has

de-

this widespread

of the

new

the

Cat.

In

addition,

and

module

leaflets

SR

modules

on

request

con-

Dolby®

Cat.

No. 280

Specifications

INTERFACES:

The

Cat. No. 280 module can be installed

in the following frames:

Models 360 and 365

All

module

functions available, including
simultaneous
if

two

Model

and

Record

Model

Auto

361

Compare

record/play

360s are used in dedicated

Play

modes.

functional

Auto

durin

Compare

g
tape-playback following recording,
not

during

simultaneous recording.

M-Series Units

Simultaneous
The

Cat. 280 requires a special top cover

No

(Cat.
18 of M-Series interface.

CAT.

record/play

Auto

. 359) to fit in Channels 2, 10,

NO.

280 MODULE

Compare

SPEGFICATIONS:

Layout:

A

pair

of printed circuit cards

togeth

er

output

form the module. Signal

and

control functions compatible

with Cat. No. 22 noise reduction

mounted

input/

modul

Input Circuit:

680 k

ohms

unbalanced, 300 mV rms for

reference leve

l.

Peak Encode Input Level:

3.0 V rms (20

Peak

3.0 V rms from

5.0 V

Decode

rms

from

dB

above

reference level).

Output Level:

Output

1,

Output

2.

Line Amplifier:

When

mounted

output

+ 22
into 600
(0

dB = 0.775 V rms).

in interface,

dB

into bridging load, +

ohms

maximum

(A 6 dB higher level is possible using

V line-amplifier supply voltage.)

+ 36

Overall Frequency Response:

± 1 dB, 20

Hz-20

kHz

(encode/decode).

but

21

and

e.

dB

Bandwidth Limitation:

Internal filters: 10

Hz-50

kHz.

Overall Harmonic Distortion:

2nd & 3rd
below
Negligible higher
ponents

Overall
SR

105
noise level.
93
weighted noise level.
105

A- weighted noise

.

95 dB - clipping level to unweighted noise
level, 20

peak

harmonic

level, 20

each 0.3%
Hz-20

order

at

any

level.

Dynamic

System (typical}:l

dB-clipping

dB-clipping

dB

- clipping level to NAB

Hz-20

level to

level to CCIR Rec. 468-2

leve

kHz.3

distortion com-

Range

CCIR/ARM

}2

Typical Obtainable Dynamic
Range,

90-95 dB.

15

ips:

Matching Between Units:

±1

dB

at

any

level

20

Hz-20 kHz.

and any

Signal Delay:

Approximately

J.l.S

overall, encode/decode, plus delay

14
of interfaces used.

7.0

J.l.s

per channel,

Calibration Facilities:

Dolby

Noise

generator

correct levels

and

built-in meter amplifier

Output

meter.

signal

external analysis facilities.

audible

Auto

comparison

with

internally generated reference

pink

noise.

Compare

of

for establishing

frequency response, via

and

can

also be fed to

Automatic

function, allowing

Dolby

Noise from tape

Status Indicators:

Yellow LED
Dolby
Auto
status indicated
on

front of module.
(LED control signal available for remotely
situated LEDs

on

front of module indicates

Noise mode,

Compare

or

Reference/Tape function

by

red

and

lamps.)

at

3 dB

kHz.

of

frequency,

interface

green LEDs

Control Inputs:

External + 18 to +
mode

(provided in interface).
External single pole switch for process
in/out

(provided in interface).

External single pole switch for

mode

Noise
Internal three position switch to adjust
operating logic to
Model 361,

30 V to actuate record

Dolby

(provided in interface).

Models

360

or

M-Series interfaces.

and

365,

Stability:

System

is

highly stable - does

not

require
routine alignment (no adjustable internal
controls).

Operating Temperature:

Up to 45 degrees

C.

Construction:

Fiberglass printed circuits, solid state
devices

throughout;

aluminum

covers, black characters.

clear anodized

Size:

192 x 155 x

20

mm

(7.6

x 6.1 x 0.8 inches).

Weight:

500 gm

(18

oz.).

Power Requirements:

SR

circuit:

+20

V to

+28

V,

Line amplifier:

+18

V to

100-140 mA.

+36

V,

13-17 mA.

D[] Dolby

Dolby

Laboratories

San

Francisco,

Teleph

one

346

Clapham

Teleph

one

"Dolby"

and

Dolby

Laboratories

5871741717493

Specifications

CA

94103-4813,

(415)

558-0200,

Road,

(01)

720

-1111, Telex 919109.

the

double

subject

Inc.,

100

London

-D

licensing

to change

Potrero

Telex

34409.

SW9

symbo

Corporation.

without

Avenue

9Ap,

l are

,

trademarks

notice.

of

1.

Processor alon

l

evels use

2.

Weighting

pass

filter

3.

Rms

or

d.

filter

to

ensure

average

e; in interfaces,

supplemented

that

only

audible

responding

may

by

meter,

depend

25

kHz 4-pole

nois

e is

4-pole

on

line

low
measured.
filters.

-

II

SECTION

SECTION

SECTION

1

INTRODUCTION

1.1 Dolby

1.2 Dolby

1.3 Dolby

Spectral
SR

SR

1.4 Dolby SR

Cat.

1.5

No. 280

360

M-Series .
SP/XP
Cinema

2 CAT. NO. 280

2.1

2.2

2.3

2.4

General
Configuration
Interface
Optional

3 CAT. NO. 280

3.1 Dolby

3.2

3.3

3.4

3.5

Auto
Auto
Auto
Auto

Noise.
Compare
Compare
Compare
Compare

3.6 Dolby Tone

Recording.

Packaging

. .
Compatibility
Calibration.

Applications.

Series

Series

Products

. . . . . . . .

(CP50,

INSTALLATION

Installation

Switch

Frame

Switch

External

. . . . .

and

Connections

CALIBRATION

. 3-1
Control
Metering
Synchronization.

and

the

Cat.

TABLE

OF

CONTENTS

Page

1-1

1-1
.
.

1-1

1-1

1-2

1-2

1-2

1-3

CP100,

CP200)

1-3

2-1

Indicators

Labeling

2-2
2-2
2-3

3-1
3-2

3-2
3-2

No. 280 3-3

SECTION

SECTION

APp(i~NnIX

APP(i~NUIX

4

5

A

B

SYSTEM

4.1

ALIGNM(i:N'I'

General

System

4.2 Recording

4.3

4.4

4.5

PRACTICAL

General
Using

VU

Aligning

Alignment

OP~:RA'I'ION

5.1 Model 360

5.2

Auto

Compare

5.3 Model 361

5.4

5.5

5.6

Auto
M-Series
Auto

Compare
Compare

Technical

Optional

Alignment

Levels

Meters

with

for Dolby

with

Peak

Operation

in

the

Operation.

in

the

Operation

in

the M Series

Aspects

Cat.

No. 280

SR

Using

VU

High

Level

Program

. . . .

Model

360

. . .

Model 361 .

.

Connections.

. 4-1

4-1

Meters

Reference

Meters

Tapes.

4-2
4-3
4-3

5-1

.

5-1
5-2
5-3
5-5

5.5

A-I

B-1

1-1

SECTION 1

INTRODUCTION

1.1

Dolby

modern
implementation
frames
widespread

1.2

To

facilitate
same
This

will

Series

unit

due

SR

module,
multi-track

While
is

one
(about
existing
cards
packaging
This

long
panel
used

in

Dolby

spectral

professional

manufactured

introduction

Dolby

easy

card

profile

allow

and

M-Series

to

incompatibilities

the
frames.

the

Cat.

major

.15

have

by

close-pitch

difference:

inch, 3 mm)

Cat.

No. 22

been

adaptation

but

thin

about 7 112

Spectral

recording,

recording.

of

this

new

by

SR

Packaging

interchange,

and

pin

the

process to be

interface

Cat.

No. 431,

No. 280

is

applications.

mounted

of

adaptation

inches,

situations.

Recording

or

Dolby SR,

recording

Dolby

ofthis

generally

the

than

the

out

as

frames.
with
will

standard

the

close

Cat.

extends

or

new

190

has

The

Laboratories

high-quality

the

the

conveniently

the

be

compatible

Cat.

To
together,
No. 280

mm,

Cat.

process.

Dolby
familiar

The

Cat.

available

Cat.
No. 22,

address

has

the

thereby

been

developed to

No. 280

It

can

recording

SR

circuit

Cat.

used

Cat.

No. 280

No.

230

for

with

No. 280

and

situations

such

Dolby

as

been

allowing

SR

module

be

used

and

the

SR

will,

format.

has

been

No. 22 noise

in

commonly

cannot

carrier

the

module

therefore

in

developed,

circuits

card.

existing

Cat.

is

where

the

Model

Dolby

answer

in

existing

therefore,

reduction

be

SP-

No. 22

physically

will

the

forward

the

is

packaged

available
used

A specific Dolby

and

XP-Series

module,

not

fit

the

Cat.

362, a special

Cat.

No. 280-L.

of

SR

modules

needs

the

first

interface

allow

in

the

module.

360-

in

the

SP

there

thicker

in

some

No. 22

the

front
to be

of

a

The

increased

in

a few

and

modules

18,

special

channels

used

1.3

Electrically,

Both
decoded
noise
or
compatible--Dolby
cards

Dolby

properly,

reduction

transmission

and

1.4

As

with
correctly
accomplished
new,

easily

DN,

is

always

thickness

module

in

these

Dolby

the

Dolby

A-type

systems

channel.

vice

versa.

Dolby

A-type

set

identifiable

noise

in

level

using

used

of

the

of

the

M-Series

covers

channels

SR

Compatibility

SR

process

NR

and

give

excellent

in

its

Dolby

SR

encoded

SR

Calibration

reduction,

with

Dolby Tone;

alignment

to

establish

Cat.

frame.

(Cat.

only.

Dolby

ability

A-type

tapes

respect

with

correct

No. 280

No. 359)

is

very

SR

are

results.

to

improve

should

Dolby

to

the

the

signal:

decode

will

not

allow

To

accommodate
must

different

complementary

Dolby

and

SR

encode

Dolby

Dolby

be

SR,

the

Dolby

not

be decoded

requires

module.

SR

Noise.

level.

process,

standard

M-series

installed

from

A-type

however,
overall
SR

are

the

Dolby

modules

channels

on

the

noise

processes

goes

quality

not

with

decode

With

it

of a recording

considered

Dolby

module

A-type,

is

achieved

Noise,

to fit

1,10

Cat.

No. 280

reduction.

that,

far

abbreviated

when

beyond

cross-

A-type

to be

this

using

is

a

In

addition

generator,

The

Auto

gain

and
Compare
signal
verify
noise

fully

and

the

with

in

Section 3 --

to

the

the

Cat.

No. 280

Compare

frequency

mode

the

performance

the

circuit,

response

allows

internally

Dolby Noise from

Calibration.

Dolby

an

automatic

of

the

spectral

contains

using

generated

Dolby Noise

information

recording

the

1-2

recording

an

important

about

aural

pink

system

tape.

comparison

The

circuits

as a signal,

the

noise.

by

Auto

and

new

feature--Auto

gives

recording

of

the

The

user

comparing

Compare

the

Dolby

Compare.

the

user

valuable

channel.

recorded Dolby

can

quickly,

the

feature

The

by

reference

is

discussed

Noise

Auto

Noise

ear,

pink

1.5

The

following
interface
covered

Cat.

No. 280

is a summary

frames.

in

Section 5 -­360

Series

Model

The
encode
two
simultaneous
Compare
record

Model 361
The

single
Cat.
playback
Auto
back

360

Model

Cat.

and

Model

No. 280

Compare

previously

Applications

A

full

Practical

360

or

decode

No.

280

feature

playback.

361

module

module

signal

of

how

discussion

Operation.

is

intended

operation.

modules

record

is

sequence

and

can

designed

for

both

is

paths

recorded

the

Cat.

of

Cat.

for

single-channel,

Two

are

required

playback

be

fully

switched

just

is

Dolby Noise.

operational

for

changeover

record

as

with

available

No. 280

No. 280

interface

for

operation.

and

playback.

into

the

the

Cat.

only

can

be

used

operation

dedicated

frames

one

channel

The

during

operation

record

No. 22.

when

playing

in

specific Dolby

in

these

and

of

Auto

both

of

a

The

and

The

units

is

Model

The
modules,
Due
modules
the
must
circuit
module,
results
length,

7t

M-Series

The
A-type
accommodate
Dolby

362

Model

to

height

cannot

Model

be

cards

with

in a module

therefore

inches

M-Series

modules.

SR

362

and

362, a special

used.

(190

in

is

designed

functions

restrictions,
be

installed.

The

that

make

one

mounted

that

extending

mm).

chassis

24

all

was

Two

or

32

channels,

to

hold

two

as a dual-channel

two

standard

To

incorporate

adaptation,

Cat.

No. 280-L

up

the

behind

is

of

single

forward

designed

chassis

channels.

provided

the

standard

thickness

of

to

can

It

that

Cat.

No. 22

Cat.

Cat.

contains

Cat.

the

other.

the

front

hold

16

be

is

possible

special

A-type

Model 360.

No. 280

Dolby

Cat.

SR

in

No. 280-L,

the

two

No. 280

This

but

double

panel

linked

by

No. 22
to

use

covers

to

are

installed
channels
Cat.

No. 280

in

all

other
referred
Dolby

product

1, 10

to

as

on

the

and,

modules

M-series

the

distributors.

with

Cat.

No. 359, will be

Cat.

No. 280

in

the

standard

channels.

M-24

modules

unit,

covers

The

special

available

used

channel

can

be

cover,

through

in

18.

used

SP/XP

The

use

electrical
card.
SP
plug-in
combination
Cat.

Cinema

The

within
however,
CP50,
Laboratories

Series

greater

in

the

incompatibilities

The

Cat.

and

XP

replacement

No. 331 A-type

Products

Cat.

No. 280

cinema

it

CP100

thickness

SP

Series.

No. 431,

multi-track

in

existing

module

(CP50,

requires

units.

may

be

necessary

or

a CP200.

for

more

of

the

Cat.

Additionally,

with

the

due

in

late

units.

for

the

SP

in

This

entire

the

CPI00,

minor

In

a few

to

use a Cat.

In

this

information.

No. 280

Cat.

1986,

module

units

newer

prohibits

there

No. 230

will

fit

Cat.

and

XP

frames.

CP200)

modification

special

No. 280

case,

contact

its

are

some

carrier

both

the

will be a

No. 230/22

for

the

for

use

situations,

in

Dolby

a

2-1

2.1

If

the

Cat.

No. 22 A-type module,
therefore,
interface
plugging

For

optimum
recording
and

is

installed
information

The

Cat.

Cat.

No. 22 A-type

is

important
particularly
and

below

General

Dolby

interface

simply a matter

frame,

in

the

module.

performance

system

covered

at

in

the

same

regarding

No. 280

that

the

the

chassis.

Installation

frame

setting

and

interface

Section 4.

time,

connections, etc.

module

module

adequate

M-Series

has

the

system

of

removing

the

configuration

of

the

Dolby SR circuits, however,

frame

If

the

interface

refer

to

consumes

and,

therefore,

free

air

be provided

unit,

which

CAT.

been

the

roughly

previously

is

basically

the

input

frame

appropriate

has

should

NO.

ready

existing

switch

and

output

(360

the

same

the

same

around

always

280

INSTALLATION

aligned

for use

for use.

Cat.

No. 22 from

on

the

Cat.

calibration

levels

Series

interface

or

M Series)

frame

amount
cooling

the

Dolby

requirements.

have a blank

SECTION

with

Installation

the

No. 280,

is

recommended

is

manual

of

power

interface

panel

as

frame,

2

the

is,

Dolby

and

of

the

being

for

the

It

above

2.2

Before
function

installing

of
indicators
set

for

the

Configuration

the

Cat.

the

switches

and

one

switch

appropriate

• • • Set

360 M 361

usage

usage

n 0 II-i

U 0

O

Switch

and

No. 280,

and

indicators

on

the

Cat.

condition.

s~itCh

to

mode

SR

1.17

DOLBY

Dolby

Indicators

the

user

mounted

No. 280.

SPECTRAL

laboratories

Inc.

should

The

RECORDING

San

francIsco

be

familiar

on

the

module.

configuration

Cat.

No.

280

and

London

with

There

switch

the

basic

are

three

should

be

~~--~~~---,--~------~~--------~--------~---------~---~~-~~~-

·

SR

DOLBY

SPECTRAL

D(]

o

D

GREEN

lb

ry

Cat. No.

RECORDING

280

Module

Cat.

No.

280

Configuration

2-2

Switch

Selects

This

usage

switch
module.
correct

operation
general,
frame
exists,
an
decode
this

"360"
Since

360,

should

If

this
may
the
The

containing

however,

M-Series

operation,

case,

position.

the

the

be

the

Cat.

switch

not

Dolby

tape

regardless

mode.

is

found

It

selects

of

it

should

be

the

when

unit)

as

the

configuration

Model

362

configuration

set

to

the

"360"

No.

280

module

incorrectly

operate

SR

will

of

correctly. No

circuits

always

the

position

(360,361, M Series)

on

the

rear

of

the

appropriate

the

Auto

set

to

Cat.

No. 280

Model 361

are

used

if

they

functions

swith

match

for

were

switch

as a dual-channel

internal

Compare

the

module.

frames

dedicated

Model

should

on

the

position.

is

set,

plugged

the

into a frame

Auto

damage

will

continue

be

properly

ofthe

to

operate

encoded

configuration

the

Cat.

circuits.

type

of

An

exception

(or

channels

encode

360

units.

be

set

Cat.

No. 280-L

Compare

will

occur,

correctly.
or
switch.

No. 280

logic for

In

interface

of

or

In

to

the

Model

with

circuit

and

decoded

Cat.

No.

YELLOW

RED

and

2.3

280

Indicators

indicator.

The
Tone/Cal
Dolby
of

Dolby

GREEN

These
audio.
noise.

played

Compare

Interface

yellow

indicator

button

Tone/CAL

Noise

Indicators.

two

LEDs

RED

ON

GREEN

off

the

is

inactive.

Frame

on

the

button

and

to

enable

indicate

indicates

ON

recorder.

Switch

is

ON

interface

is

used

the

the

the

indicates

Neither

and

whenever

frame

to

control

Auto

Reference

source

internal
the

Dolby

LED

Meter

the

is

pressed.

the

generation

Compare

(R~~n)

of

Auto

reference

Noise

is

ON

Labeling

Dolby

Dolby

The

mode.

ITape

Compare

pink

being

if

Auto

Noise

ON

(GREEN)

The

Cat.

originally
switches
installed,
the

switch

No. 280

designed

are

labeled

the

switch

labeled

card

has

for

the

inappropriately.

labeled

NR

ON/OFF

been

Cat.

Dolby

is

designed

No. 22

Tone/CAL

used

to

to be

A-type

For

is

switch

installed

NR

module;

example,

used

to

ON

or

OFF

in

with

select

the

interface

therefore,

the

Cat.

several

No. 280
Dolby Noise,
Dolby

SR

process.

frames

and

2.4

The

main

remote
available
provided
encouraged
Auto
these

edge

display

at

that

Compare
options.

Optional

connector
of

the

the

edge

will allow

to use

more

(i:xternal

on

Auto

these

convenient.

Compare

connector

Auto

optional

Connections

the

Cat.

No. 280

status

for

other

Compare

connections

Appendix B gives

has

indicators.

uses.

circuits

Additionally, a terminal

to

terminals

The

to

be

synchronized.

make

the

specific

which

reference

use

information

can

of

pink

Dolby

be

has

The

on

used

noise

been

user

SR

using

for

is
is

and