Orban 622B Operating Manual

622 Parametric

Equalizer

OPERATING

MANUAL

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Performance

Specifications apply to each

except as noted. All

when equalizer drives 600

impedances. All noise

assume

with 18 dB/octave

Operating

EQUALIZATION

WIDTH, and

bands.

IN/OUT,

Frequency

mechanically flat)

Available Gain:

by means of

Input: (RF

Output: (RF

Risetime:

20-20,000 Hz bandpass filter

a

MASTER

GAIN,

Impedance:

with lOOOpF,

Driving impedance

ohms

Absolute

greater than

Level:

ohms,

Impedance: 47 ohms

lOOOpF,

provides a

output for both

Equalizer is

will not ring

Butterworth

Controls:

IN/OUT, BAND

TUNING

EQUALIZATION

POWER ON/OFF.

Response: (EQ

±0.25 dB,

+

12 dB,

front-panel

suppressed)

(each leg)

electronically

or less.

Overload

suppressed)

20-20,000 Hz

unbalanced.

transformer-balanced

unconditionally

with any

less than

channel

specifications apply

ohm or higher

specifications

skirts.

EQUALIZATION,

each

for

controls

20-20,000 Hz.

adjustable

GAIN control.

100K

in

balanced.

should be

+

Point:

26dBm.

+

dBm into 600

19

in parallel

(Option 01

channels)

4

stable and

captive load.

microseconds.

Specifications

greater than 6 V/microsecond.

bandlimiting assures that slew

severe equalization and program

spurious ringing at any output

only ringing observable

associated with any given

curve.

active RC, utilizing FET-input

transistor current booster.

Harmonic Distortion (+

than

less than 0.002% at 1kHz,

using

dBm typical.

102 dB for any

BANDWIDTH

Crosstalk, 622B dual-

Hz.

of four

parallel

600

with

Slew Rate:

Internal

rate limiting will not occur

most

material.

Square Wave Response:

exhibits no

level. The

theoretically

equalization

Circuitry:

set

to

IC opamps. The

discrete

Total

-

oo

output): less

Typically

dBm.

SMPTE Intermodulation

Typically 0.008%

peak output,

Noise: At Output,

for unity gain, all EQ

controls FLAT: Less

-87

Overload-to-noise

Parametric Bandpass Filter:

than

TUNING and

Interchannel

channel equalizer: less

20-20,000

with even the

Square wave

that

is

output line driver utilizes a

18 dBm

20-20,000

0.025%,

Distortion:

+

at

18 dBm

Hz/7

60

GAIN control

kHz;

switches IN, all EQ

-84

than

Ratio of Single

Hz.

+

equivalent

4:1.

adjusted

dBm;

greater

18

combination of

settings.

-90

than

dB,

Equalization

shows

maximum and minimum

each band. DB equalization

of the individual bands add

action. BANDWIDTH,

EQUALIZATION

uously variable.

Range of
Range of

ization:

depth obtainable is

Tuning Range (per band):

68-1700 Hz,

Tuning dials are calibrated at ISO

frequencies.

Power Requirements: 115/230

Hz

AC,

watts (622B).

cord. Option 02

supply. Power

version

02

60 ma per

supplied on

recommended only for

install a large

given installation.

in a

Overload

mately 200 mS if the instantaneous peak
output of any amplifier in the

is driven within 1 dB of

Size:

high x

Shipping

Characteristics: Figure 1

curves corresponding to the

bandwidths

contributions

without inter-

TUNING, and

controls are all contin-

Adjustment

Adjustment of Peak Equal-

+

16 dB

240-5850

approximately

Captive “U-Ground” power

eliminates the AC power

requirements for the Option

18 to 28 volts DC at

are ±

equalizer channel. Option 02 is

special order only, and is

number of 622 channels

Lamp:

19"

(48.3 cm)

5.2"

(13.3 cm) deep.

Weight: 10 lbs.

“Q”:

of

-oo

Typical notch

to

.

40 dB.

Hz, 800-20,000 Hz.

4 watts (622A),

users planning to

will light for

its clipping point.

3.5"

wide

x

(4.5

0.29 to 3.2.

20-500

approxi-

equalizer

kg).

for

Hz,

preferred

50-60

volt

cm)

(8.9

7

Phone:

(1)

m

f-

<

'4* i

510/351-3500;

1525

if* -rn

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*

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.........

'C/.,

Ofbcifl

Alvarado Street. San

Fax:

510/351-0500;

(1)

Leandro, CA

E-Mail: [e-mail];

P/N: 95013.000.10

94577

ty

1

USA

Site: www.orban.com

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Table

of

Contents

Specifications

Registration Card

Warranty

A:

Part

I

I Introduction

Performance

1

Front Panel

2
2 Rear

AC Power

3

Mechanical

3

Installation

Panel Description

Balanced

4

Electrical

Input

Output

Wiring

Grounding

Typical

OPERATING

6

the

Using

Boost/Cut

Headroom

B: Specific

Part

8

Highlights

Description

Installation

Output

Installation

Two-Conductor

With

Diagram

Input/Output

INSTRUCTIONS

Section

EQ

Curve

Applications

Operation

and

Tranformer

Connection

Familes

Installation

Shielded

Rules

Cable

C:

Part

^

13

Introduction

I s

Performance

General

Power

Signal Processing

Maintenance and

'

Preventive

Control

Replacement

Troubleshooting

Factory

Shipping

Circuit

^

General

Input

Equalizer Sections

IN/OUT

EQ

Overload

Output

Power Supply

Appendix:

24

Maintenance

Evaluation

Supply

Service

Maintenance

Replacement

Components

of

1C

Service

Instructions

Description

Buffer

Switch

Indicator

Buffer

Interconnections

and

Circuitry

Opamps

Alignment

Printed

on

And Grounding

Circuit Boards

Stereo

8

Reinforcement

Sound

9

House

Notch

Stage Monitors

Individual

Dance

10

I Recording

I

Motion

I I

12

Broadcasting

12 Electronic

Bars

Tuning

Filtering

Driver

Studios

Picture

Music

Sound

Equalizer

Driving

24

Level Sources

24 Grounding

PARTS LIST

26

PARTS

30

SCHEMATIC

31

Input

the

LOCATOR

High-Impedance

From

And/Or

High-

REGISTRATION

CARD

The original purchaser

with this

manual.

should have

received

postpaid Registration

a

Card

packed

Registration is

benefit to you because

of

it

enables

applications, possible performance improvements, service

developed over the life of the product.

that we may more promptly respond to

future

purchase).

Please fill in the

If

please photocopy the image of

envelope. Use the

(without having to request

Registration Card and return it to

Registration

the

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address

become lost

the card reproduced below and

shown on the title page.

It

also provides

possible

a copy of your

or you

claims

Bill

us.

have

Model #

Name or Title

Organization

Street

City/State/Country

or Mail Code

Zip

us to

aids,

with the date of sale so

us

of

tell

etc., which may be

under

Sale

Warranty

other

or

you

of new

in

proof

purchased the unit used,

send it to us in an

Serial

#

.

the

of

WARRANTY

Purchased from

Nature of your application

How did you hear about

Comments:

The Warranty,

Warranty

future reference.

Details on

Certificate on

obtaining factory

which

it?

Fig.

I: REGISTRATION

applies only to the

separate sheet

a

service are provided

City

Date of

CARD

first end-user

packed with this manual.

in Part

of record,

C.

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is stated on the

Save

it for

Part

A:

Installation and

Operation

INTRODUCTION

The

Orban

622A

channel contains four parametric

Isolation of the

622A/B

is

single-channel equalizer;

a

two channels in the 622B is extremely high

20-20, 000Hz). Therefore,

audible crosstalk.

The 622 is equipped with rotary-type

and

better than

useful

notch filter.

variable to enable precise

Each

"constant-Q"

channel of the

The

40dB

center

parametric equalizers

are

the 622B

equalization

channel may

each

of cut.

characteristics, and permitting the equalizer to

622

The controls are non-reciprocal,

frequency and bandwidth of each band are continuously

control of the audio spectrum.

has an

electronically-balanced

bands.

be used independently without

EQ

controls providing

unbalanced output which can be balanced by the

transformer.

filtering. l2dB of gain is

are monitored

peak clipping can be detected

The

flexibility

all

areas

broadcasting, motion

Input,

of audio: sound

output,

an extremely fast "peak -stretching" overload detector, so that

by

offered by

picture sound, dance bars

and power line connections all contain

available.

and corrected before

the 622 makes itaparticularly powerful tool in nearly

Aj|

potential

reinforcement, public address, recording

(discos),

high

of

is

overload points

it

professional

dual-channel equalizer. Each

a

(greater than

lodB

providing musically

be used as a

in

addition

up to

bridging input and an

of an optional output

becomes audible.

theater...

quality. The

-90dB,

danger of

of boost

effective

the equalizer

RF

studio,

PERFORMANCE

HIGHLIGHTS

The 622 easily meets

the quality,

performance, and reliability

requirements

demanding professional, and is also well-suited for use in semi-pro or

applications.

The

controls and

familiarize

622

for

EQ

Four

True

you

your specific

Section

bands,

parametric operation: non-interacting

parameters

+

l6dB, -infinity equalization range

"Constant-Q" curves

Each

band tunes over

"Q"

is variable between 0.29 and 3.2

features

with the unit's

installation and application.

the 622 are fully described in this manual.

of

potential and enable

each with TUNING

25:

frequency range

1

BANDWIDTH

and

to imaginatively

you

control

control over all three equalization

the

of

audiophile

It will

the

use

Bands

are totally non-interacting

In/out switches

for each

equalizer

band

Circuitry highly resistant to

General

l2dB available gain

performance deterioration

caused by

control wear

FRONT

PANEL

DESCRIPTION

Very low

High

"Peak-stretching” overload lamp

distortion

Industrial-grade parts and construction

Extremely

RFI

Balanced

INPUT

The

OVERLOAD

The

amplitude due

equalization.

perceived. Overloads

noise and distortion

slew rate for minimum

is audible

service

easy

suppression on input, output,

output optional (order

control adjusts the drive level

indicator monitors all critical points to

excessive input amplitude or to large amounts of peak boost

to

It indicates peak clipping substantially before any audible effects are

access

are

eliminated

TIM (SID)

warns

and power leads

retrofit kit

to the equalizers.

by

of clipping

required)

as

turning

anywhere in equalizer before

warn

down the

of excessive

INPUT

signal

control.

The CHANNEL EQ IN/OUT

input buffer

associated with

OVERLOAD LAMP

Input/output polarity is constant regardless

and output amplifier so

large amounts of equalization) occur.

will still operate as

The BAND EQ IN/OUT

equalizer

summing

noise

The EQ

+!6dB, -infinity dB.

The TUNING

have

The BANDWIDTH

band by disconnecting

amplifier.

contribution

controls

controls adjust the center frequency of each

a typical calibration accuracy of +1/3 octave.

Putting

from the

adjust

controls adjust the

switch defeats the entire EQ section,

that

gain

no

if

full equalization were occurring.

the position

of

switches defeat the equalization action of a

the output

unused bands in

resonators and

the maximum peak

of the bandpass resonator from its

the OUT

will

assure accurate flat

or dip in each band over a

"Q"

(sharpness) of each band.

becomes broader when turned clockwise; sharper when

Calibration

tolerance is typically

+10%

of the nominal

"Q"

retains the

but

changes (other than

In

the OUT position, the

this switch.

of

position will eliminate any

the

of

turned counterclockwise.

value.

four bands,

those

given

response.

range

and

"Q"

The

of

REAR

PANEL

DESCRIPTION

The

230V

The INPUT

screw).

FUSE

operation. Replace with the same type only.

used in the 622

OUTPUT

and

connectors provided

is a

3AG slo-blo

allow

2

type:

1/8 amp for either I

connection via

barrier

1

strip

5V

or

(//5

AC

POWER

The

power transformer

operation.

the modification.

If

the

can be

unit was ordered for

strapped for I

230 volts,

15 volt

a tag

230 volt 50

or

on the power

or

cord

60Hz

warns

AC

of

The two primary windings of

115

volt operation, and

Diagram

To

at the

strap the

the 622. Strapping

power tranformer.

strapping

insulation.

back

of

power transformer for a

instructions are found on the insulating fishpaper around the

It

is

be performed

can

The power cord is terminated in a

green/yellow) wire (which is

(or

to the

loops, this should

than

622

by

chassis.

damaging

If

it becomes necessary to lift

done

be

the power plug.

the power

in series for 230 volt operation. (See the Schematic

this manual.)

not

necessary

with bare jumper wire. Take care not to burn the

transformer are connected in paral lei for

different

to rearrange the heavy

"U-Ground"

voltage,

plug

to

remove

USA

the top cover

insulated

standards.

wiring;

The

connected to the long prong) is connected directly

with

a three-prong to

It is not recommended

this ground

two-prong

to suppress ground

adapter plug, rather

that this ground be

all

green

defeated unless absolutely necessary because it eliminates the intrinsic safety

feature

of the three-wire system.

WARNING!

IF

THE GROUND

THE

UNIT OR THE SYSTEM TO

RESULT

IN APPEARANCE OF FULL LINE VOLTAGE BETWEEN

CHASSIS AND

CAUSING SEVERE

IS DEFEATED, CERTAIN FAULT CONDITIONS

EARTH GROUND. SUCH VOLTAGE

INJURY OR

DEATH!

WHICH IT

IS CONNECTED CAN

IS CAPABLE OF

IN

of

MECHANICAL

INSTALLATION

Vertical space of

two standard

Mounting the unit directly

power amplifier may

temperature should not

shorten component

exceed

powered.

Balanced

the factory,

retrofit kit, available directly

have been designed to

you

performance

at high output levels,

performance

standards should produce

amplifier) without

The

transformers

Output Transformer

refer to

the installation

have

wish to

use

some other

measurements

acceptable for your

significantly compromising

Electrical Installation

are used.

with special attention to

thus

approximately

rack units

over

large

1

Installation:

13 degrees

l/2"/8.9cm) is required.

(3

heat-producing devices like a

life and

F

(45

If

transformers were

instructions furnished with the transformer

not recommended. Ambient

is

degrees

C)

from Orban. The transformers supplied

negligible effect on

a

transformers, it would be wise to

determining the

application.

+20dBm (limited

published specifications. Should

LF

distortion and

output

A

level

transformer

clipping in the output

by

performance.

section describes grounding procedures

vacuum-tube

when equipment is

not

installed at

with this kit

make careful

HF

response

achievable with

meeting Orban

in the event

3

ELECTRICAL

INSTALLATION

Connecting

Relatively

recording

without

casual,

analyzed if

interfacing

The

instructions

discussion

Input

The

electronically-balanced

the 622

uncomplicated

studios,

serious

provided

you are

between

of

interconnections

compatible with

or unbalanced,

whose

some vacuum-tube

input

to accomodate

Equalizer

systems (such

electronic music

grounding problems

that high RF

familiar with

balanced

below will

and unbalanced

apply

input

most

professional and

source impedance

audiophile

the situation.

preamps),

to other

studios,

even if

fields are

the standard

to

and

grounding can

of each

semi-professional

a minor

Please refer

equipment is

as home

dance bars,

the wiring

not

present. Unusual

systems.

the

majority

channel

is 600 ohms

modification

to the Appendix

quite straightforward.

playback systems,

etc.) tend to

practices

situations

rules governing

of cases. A

be found in

of the 622

sound

equipment,

or less.

If

it

may be made

for further

"semi-pro"

together

come

are somewhat

can be

grounding and

comprehensive

the Appendix.

equalizer is

balanced

is greater

details.

(as in

to the

Nominal

input

level

+26dBm.

Output

The

two

outputs

optional transformers),

to the

Wiring

We

equivalent)

does

ground

majority

chassis

the 622 With

recommend

not carry

at one

of

of each channel

RFI

(for

wiring with

because signal current

signal,

end

installations.

is between

and the

suppression).

-10

and +4dBm. The

of the 622 are

source impedance

Two-Conductor Shielded

two-conductor

flows through

is

only.

The following

used

only

for shielding,

table

unbalanced

is 47 ohms in

Cable

shielded

the two

and is

and diagram

absolute overload

(unless fitted with

parallel

cable

(such as Belden

conductors

ordinarily

are applicable

with

only. The

connected

to

point is

the

lOOOpF

8451

or

shield

to

a great

4

INPUT

TYPICAL

TABLE

INPUT/OUTPUT

I:

CONNECTION

RULES

Always

When the 622

circuit ground

When the 622

chassis

to

use

"+"

and

is driven from

of source, and

driven

is

ground.

as the two input

an unbalanced

to chassis

from a

balanced

Do not connect shield

terminals

source, connect

ground

of

source, connect

622

at

end.

OUTPUT

On the

driving

When

(on rear panel). When driving an

622

cord

only

If optional output

ground

Because it is not always possible to determine if the

or being

chassis grounds (which are always connected

cord), and

because it

diagram

622 output,

balanced or unbalanced).

driving

a balanced

connect shield

load, jumper circuit

at

Do

622

unbalanced

chassis

or

as last resort.

driven by the

are

should always

through rack.) For maximum protection from

transformer(s) are installed on

to chassis ground on the

622

have their circuit grounds internally connected to their

because

the

can be noisy

not

universally

use

applicable.

of the

or

earth-grounded

be

622.

AC

power line ground often introduces problems

otherwise imperfect, the wiring

end to

not connect

ground

(i.e. through third wire in power

to

the ground prong of the

to the 622.

shield both

622.

shield

at source end

chassis

to chassis

load,

do

shock, float

622,

pieces of equipment driving

ground (whether

shield

at other end.

ground on 622

not

attach

this ground

jumper the circuit

jumper.

AC

techniques

in the

to

line

If

you follow the

diagram

experiment. If the noise

isn't

enough grounding.

terminal on the

strapping the

A

ground loop

buzz. If

jumper

either

principle: one and only one circuit ground path should exist between each piece of

between circuit and chassis grounds on the

case,

622's barrier strip and see if the buzz goes away. You can also try

622's chassis and circuit grounds together, and see if

usually

you have a ground loop, you can often break it by disconnecting

think

equipment! (Bear

are connected

together internally, and could conceivably introduce

you do not take this

Try

sounds like a

carefully about what is going on, and keep in mind the general

in mind that the circuit grounds

connection into account in planning

5

sounds

and hum

like

or noise appears, don't be afraid to

low-level

a

connecting the input

smooth,

crackling buzz, then probably

the 622 to

of

steady hum rather than

rear-panel barrier strip.

622's

the two channels of

of

chassis ground

a

this

a

ground

a

your wiring.)

there

helps.

crackly

the

622B

a

loop if

In

OPERATING

The

operating controls

adjustment.

protrudes further from the front

located below

The EQ

its associated

of the

and

622 have

BANDWIDTH

EQ

been configured

controls are

panel.

and BANDWIDTH

The TUNING

concentric;

controls.

to

permit easy,

control

the

for each

EQ

intuitive

control

band is

To provide

calibration

reference

the

with

stereophonic

alone

clockwise than,

Matching in

Using the

To use the

BAND EQ switch

the

For those

become familiar

best value,

accuracy.

guides. Accurately

BAND

IN/OUT switch. When

matching of

is impractical.

"5",

then no

Part B for

EQ Sections

EQ section, switch the

for

who have never used a

with the

BANDWIDTH controls to

console channel

experimenting

try

affect the sound.

When you

broadband peaking

clockwise of

BANDWIDTH

equalizer.

with the

boost the

"0").

Contrast this with the

control

(BANDWIDTH control close to full

toward

the 622 uses

Calibrations

defeating

several

However,

problems

matching

each band

622

is to

"6".

The 622 will now

Once

you

TUNING and

EQ, discover

narrow (ccw).

controls

approximate, and are

are

equalization in a given

the

operating

622 channels

if the

BANDWIDTH controls are set

will occur.

instructions.)

of high

with narrow

on the basis

(See the subsection

CHANNEL EQ section switch

you wish to use.

Parametric Equalizer before,

center the

TUNING controls, and adjust

behave like an

have gotten the "feel" of

BANDWIDTH controls to

the subtle shelving

"ringy", colored

reliability

intended primarily as

but

modest

band is best done

bandwidths, accurate

on panel calibrations

on,

or

on Stereo

IN,

and switch

the easiest way to

ordinary "four-knob"

the 622 in this

see how they

effects available

clockwise;

quality of setting

mode,

EQ control

more

IN

the

from

the

When

essentially inaudible,

typically better than

harmonics, use one

you cut

The EQ curves are

because

this curve family to be

curves.

of the "Constant-Q"

The "Constant-Q"

EQ

the

but permit

band per

not reciprocal:

observe

40dB

than 40dB) notches to be

other interference of

Specified

varying the

of the curve vary.

"Q"

BANDWIDTH control, the

fixed pitch.

for any setting of

range

Despite the non-reciprocal

EQ (in recording a

the track

original recording,

the

settings,

which is reciprocal to

cancelled, use a

the converse is true.

curve

through the

and

be precisely

will

with the

track, for example)

equalizer with

with all

BANDWIDTH controls

the one used

broader

When

reciprocal

the effects you

(If

sounds

the

suppressing

each band.

in

dominant harmonic.)

provides

boost

configuration of

musically useful than the more

more

family also

created

permits infinite-depth (in

which are highly useful for

peak

nature of

the "Constant-Q" curves, a

the equalizer. Experience

TUNING

the

gain remains

can be precisely

TUNING controls set

all

EQ controls set equal but

readjusted (by ear) to

make the recording.

to

"Q"

setting

the

(more clockwise); if a cut

BANDWIDTH

the original.

to

control is correctly

now achieve.

fixed frequency (like

of

sound

to be

wider bandwidth

a

control is

constant while the skirts

cancelled later by

opposite to

Narrowband

suppressed is

has shown

common

eliminating

0.29

as

If

is to be

"reciprocal"

practice, greater

3.2. When

to

given amount of

they were during

their

provide

boost is to be

a

cancelled,

adjusted,

are

dips

hum),

rich in

than cut

hum

passing

original

curve

a

such a

or

6

HZ

Fig. 3:

More boost or

frequency. Typically,

provided by a

overload

While

swept

Notes

and

in the narrowband boost

give a sound similar to

to

Headroom

On

The overload-to-noise

somewhat

power amplifiers, for

the overload

cut can be

-80dB of cut

single band), and

noise buildup

ratio available from the

on the settings of

example, the overload point of the 622 should

point of the

ATTENUATOR settings on

sinewave input to

OVERLOAD

622

oscilloscope,

amplifier used.

622/power amp

the 622 is adjusted

Clipping

lamp.

power

output

This

procedure

combination.

CONST

achieved

+32dB

ANT-Q CURVE

by tuning adjacent bands to the same

(which

is seldom more useful than the

of boost are then

FAMILY

available. But beware

when boosting!

mode, a band's

"phasing".

the controls. To minimize audible noise

power amplifier. This

the

power amp(s) to

in level such that it just

in

meters,

amplifier

the

other overload indicator,

or

assures minimum noise and

TUNING

622

control can be continuously

typically l05dB,

is

done

is

by

make the amp(s) barely clip

may be

detected by means of

-40dB

and

while

be matched to

adjusting the

barely lights the

depending on the

distortion

from

cut

of

depends

driving

INPUT

when

an

the

a

PRIOR

TESTING, BE SURE

TO

AS A LOUDSPEAKER) IS

IF

THINK THAT

YOU

SIGNAL WITH

NOISE LOWPASS

IT MIGHT BE, USE A DUMMY

A

HIGHER

FILTERED

TWEETERS.

WARNING!

THAT THE POWER

DAMAGED BY

NOT

PEAK-TO-AVERAGE

AT

KHZ) SO AS

I

7

AMP LOAD (SUCH

FULL-POWER

SINEWAVE.

LOAD OR A

RATIO (LIKE

NOT TO BURN OUT

TEST

PINK

Part

Specific

B:

Applications

This

to

Picture Sound, Broadcasting, Dance Bars, and provides comments on Electronic

Music.

involved in its more eclectic aspects, such as

applications information

I: STEREO For

difficulty

calibrations

however,

then

assuring precise

the

monitor

The

achieve the

reference

"reference",

achieve

the

are

adjustment

sensitive

It

part of

use

the manual provides very specific

the 622

the fields

in

We recommend that

broadband equalization

should result when

In

alone.

if any

test

instruments should

section on

tuning and reinforcement

following

to panel calibrations.

a precise

"differential

swept

because

is performed

BANDWIDTH

stereo imaging

Dance Bars below for

procedure assumes that both channels

desired equalization,

and the other

instrument-match

method": the

out-of-phase,

is tweaked

it automatically indicates both

follows:

as

Sound Reinforcement, Recording Studios, Motion

of

anyone involved in pro

in each

will undoubtedly provide much food for thought.

(BANDWIDTH

the channels are matched

applications other than

control is

be used to

and accurate mono

applications.)

One channel must

channel's controls

reference channel and the

and their outputs are

to minimize the amplitude

adjusted "narrowband"

assure matching between

a discussion of

and that both are adjusted

this

to

reference.

instructions

Theater)

controls

and suggestions on

audio

read all

at or clockwise of

on the basis

monitor

tuning or sound reinforcement,

summing of the channels. (See

matching requirements in

have been adjusted

be arbitrarily chosen

must then be slightly

This

is most readily done by

channel

summed. The channel

of the

phase and amplitude

sum.

how

(and certainly those

the

sections.

(i.e., 0 through

stereo channels,

The

"5"),

no

of panel

5),

by ear to

identically with

the

as

tweaked to

under adjustment

under

This method

very

is

mismatches.

1) Connect

the

channel's

Connect

2)

adjustment. Connect the

input.

Sum

3)

side

critical). Connect

oscilloscope.

Sweep

4)

easily

Switch

5)

on the channel

Switch

6)

out on the

Slightly

7)

a sinewave sweep generator

reference

channel such that the hot output

input, and its (-) input

(+)

another output from the sweep

hot

output

the outputs of the

of a 22K 5% 1/4 watt carbon resistor (the value is

the other side of both resistors to the vertical input

two

channels by connecting each

the channels from 20-20,000Hz,

see the swept component.

IN/OUT

aU

all

adjust

IN/OUT

reference

switches on

adjustment

under

switches

channel).

IN

the various controls on the channel under adjustment to

with logarithmic sweep

is connected

is grounded.

generator

to this channel's

and adjust the

both channels OUT. Adjust

null the

to

(unless

some

output observed on

these switches

of

minimize the amplitude of the differential component as observed

to the

the

to

input; ground

(-)

(+)

scope

the

to the input of

reference

channel

output to

not

sensitivity

under

its

(+)

one

particularly

an

of

to

GAIN control

the

scope.

normally

are

on

the

scope.

8

SOUND

2:

The

notch

622 is a

filter and

versatile

broadband

sound

equalizer.

reinforcement

equalizer which can

function as

a

reinforcement

Man/

results

eight bands

House

in series)

room

in their

out

limiter or

damage.

that

can be

are

Tuning:

can do a

without the use of a

narrowband

the major

compressor

Advance

the limiter is

frequency of

the

systems

obtained by

available for

then

economy

In an

surprisingly

notching

ring modes.

system

feedback, and

BANDWIDTH control to

to change

frequency.

tuned

are

as

the

control until

until

half-way

readjust

Finally, turn the

reappears.

not

will

out

appear.

they

"point

TUNING

the

TUNING control

TUNING control

observed

(narrowband), and

the ring

frequency

ring

frequency

ring

modes

frequencies

eliminated,

are mono.

connecting

third-octave

This

in the

circuit

gain until

gain reduction

in

broad

the

the feedback

between

frequency.

the

Back

reappear

This

later.

Usually

diminishing

of

notch

installation,

effective

(BANDWIDTH full

mode

most

is

before the

it feeds

choose

,

and

a

turn the

feedback

returns at

the two

Now reduce

TUNING

EQ control

off about

when the

procedure

after the

returns"

In these

both

filtering or

job of

filter set. Use

effectively and

installations,

622B channels in

622B (with

the

tuning a

power

back

at

protect the

to

band on the

EQ control

changes

as

4dB, This will

frequency.

settings

necessary

system

its

the

up

gain is

may be

first

reached.

is

particularly

four of

A

connected

system to a

the bands

series .

equalization.

both channels

reinforcement

three or

counterclockwise)

safely

amplifier to

a single

speakers.

which covers

622

down to

Continue

original

where the

done

frequency. Make

frequency.

there is a

if

prevent

Estimate the

it.

-infinity.

to adjust

feedback

BANDWIDTH to full CCW

notch centered

"0"

leave

increased

the

(or flat)

headroom so

when

the

with

frequencies

more ring

have been

to keep

toward

repeated

four ring

powerful

total of

notch

to

speaker

sure

Turn the

Adjust

the

Set the

was

the

until

the

that

new ring

on

remaining

The

equalization of

analyzer

octave

deal

Notch

the

eight ring

a

by

Stage

low cost

Tuning

Individual

substantial

system

to

equalization

for

analyzer,

—

with

Filtering:

622B

may be

modes.

third-octave

Monitors:

per

above.

advantages

with its

correct

not

Driver

for

affect

bands

the

most

use

whole

a

If

used

The notches

equalizer.

The

channel

own

individual

on the

system.

precise

your

third-octave

third-octave

a

solely as a

622 is an

and

Equalizer:

equalizing

to

parametric

drivers.

other

622B are

Use a

results.

Fortunately,

ears.

obtainable are

effective

notching

Some

equalizer.

driver

pink-noise

However,

set!

filter set

narrowband

capabilities.

practitioners

each

response

now

generator and

if your

you only

available

is

notch

somewhat

stage

driver

in a

claimed

It is

anomalies

available to

budget

have

for

filter

sharper

monitor

Follow

have

equalizer

the

discovered that

complex

that this

without

perform

third-octave

doesn't

four or

permit a

broadband

set to

eliminate

than those

because of

instructions

sound

is the

having

broadband

real-time

third-

bands to

five

equalization,

up to

created

House

in

there

reinforcement

best way

corrective

the

its

are

9

If the

622

between

appropriate

can

this

(exploiting

used

is

appropriate

the

power

accomplished

be

the 622's

in this

amplifier.

balanced

way, simply

output of

If

phase

either at

input

connect each channel of

the electronic crossover

reversal of an

the power amplifier

feature.)

individual

and the input of

driver is necessary,

output or at

622 equalization

the

the 622 input

DANCE

3:

BARS

in

The sound generally

out and boogie (or

get

in the

bands of

available for

region of

the 622 can

"house

midrange acoustic

The amount

available amplifier

by

of bass

maximum capability,

clipped occasionally

electronic crossover is necessary.

In

all cases, the setting of the 622 low frequency TUNING

controls

without

with

is quite

being "boomy" (like "jukebox bass"). Correct settings will

loudspeaker type and room acoustics.

desired

down and drink...).

sit

40-80Hz,

and a

employed for

be

tuning".

response of

boost is primarily limited not by subjective

power

bi-amping

without

critical in obtaining

be obtained with a horn-loaded

Trying to

distortion and also

We do not

course

contractor to the

provided with

boost bass below

has the

recommend

of

his normal activities.

manager's

equalization, sufficient

potential

that

specifications,

records can be supplied by

range.

dance bar is one

a

This usually

smaller amount of

this purpose, leaving

In this case, we

the loudspeakers

loudspeaker

and

recommended

is

causing

the

the D.J. be permitted to operate the 622

obvious harshness.

bass that is punchy, "tight", and sensual,

In

particular, satisfactory

system with a cutoff

bass

cutoff frequency of

damaging the

of

The 622 should

and

power

simple 5-band graphic

a

to correct the sound of inadequate

that will

treble boost.

mean

in the room

power-handling capacity. For

bass

because

drivers.

adjusted once

be

then locked

equalizer

make the customers

implies a large bass boost

LF

The

the remaining bands

smoothing out midbass and

.

considerations but

the bass

In

amplifier

this case, an

and

vary considerably

results cannot

frequency above 40Hz.

the

horn

will

by the

If the D.J.

up.

with

and

can

external

BANDWIDTH

severe

cause

the

in

installing

is to be

more limited

HF

be

If

the sound contractor has access

noise

for

flat

undesirable,

conversation. For

of its potential for subliminal irritation.

If

a

system,

frequency

different

the

room unless the room

good recording

are slight,

It is

below 200Hz

equalization is much more

in

correcting room acoustics.

equalizer

source, these can

acoustic

response

and can cause

the same reason,

third-octave

it is

range below

analyzer is available to monitor the

not necessary or

200Hz

substantial aid in adjusting the

be of

in the

customer edginess. It

desirable

according to Stereo

loudspeaker locations will ordinarily

been

has

studio control room). In

to say the least!

quite acceptable

to smooth

to adjust the two 622

standing

out

useful

in

If

the

channels should therefore

third-octave

to a

real-time analyzer

MLF

midbass and midrange. Coloration

can also interfere with

excessive

acoustically designed

waves, resonances,

correcting the

loudspeakers

be adjusted

treble boost should be avoided because

acoustic response

to exactly match the channels

Matching above. This

produce different

and is symmetrical (like

dance

a

bar, the

channels

chances

substantially differently

and the like.

response

are reasonably

to

of the loudspeaker than

also be well-matched above

10

pink-

and

MHF

and

bass

of fhis occuring

bands

here

of the

in the

is because

balances ]n

Above 200Hz,

well-matched, the

is

a

200Hz. If

system's

being

microphone

problems

exaggerated!

"A" and

the

well-equalized

was located)

"B"

channel

the

at

only

at

expense of

curves

one place

differ greatly,

in the

other locations

this

room

often

(where the

which

may

results

measuring

have their

the

in

RECORDING

4:

STUDIOS

The 622

conventional

Parametric

internal

If

a

used in

substantially

material.

The 622

wideband

different sound

Telephone,

generated

1.3kHz,

narrow

sound

the

overdriving

flashes.

The 622 can

particularly

can be

Equalization to

console

track is

narrowband

its

The

is

notches

by

for

bandwidths

of a ringy

distinctive

equalizer

equalizers can't

plagued

eliminate

notching of

capable of

gives

with a

transistor

adjusting

example).

sound

the input of

also be

when a

Reinforcement section

in the

used

is used.

hum or

by

notching mode

the sound

a

similar

radio,

the

The

and both

bandpass

desired.

effectively

third-octave

above.

recording

Most studios

invaluable

be

handle.

other

find at

in

interference of

(BANDWIDTH full CCW;

negligible effect

with

harmonic

each

producing a

"phasing" sound.

true

flavor.

and

MLF and

wide variety

"old-time" recording

MHF bands

BANDWIDTH controls

EQ controls

with

filter

Authentic-sounding

622 beyond the

the

are

approximately

employed

equalizer

studio

cleaning up

just about

least

requires

Sweeping

close

are adjusted

for

set

distortion

point

as a

is too

anywhere

channels of

two

pitch,

EQ

tracks that

the 622 can

at

"difficult"

fixed

upon desired

separate

effects.

of

use of a

special

narrowband

effects are

together in

l6dB boost.

frequency

to give

This produces

12dB/octave slopes

can be

where the

monitor

costly.

OVERLOAD lamp

system

See the

that a

patchable

the

-infinity) to

program

band.

Sweeping

peaks gives

most easily

(around

moderately

the

gives

and

generated by

equalizer,

Sound

be

a

5: MOTION

PICTURE The 622 can be

versatile

SOUND

many

Fine-tuning capability,

1)

difficult or

Instant notch

2)

Increase

3)

channel 8-band

The scoring

The 622

adjusting the "B" chain in the

response

adjusted.

Those interested in motion picture

Recording

in flexibility

mixer can

can be

standard.

Studios immediately above.

used to

features,

poorly-recorded

filtering

particular

such as:

which can reduce

when both

equalizer.

similarly benefit from the

used to equalize

The music scoring

advantage

allowing the

location

mixer

recordings;

hum and

622B channels are

the motion picture

re-recording theater to

stage monitoring system

applications should also

dialog

as a

to obtain

equalizer

best

the

because

possible

camera whine;

cascaded

adjustability of the

fine

monitoring

the studio's accepted

to make a

environment

can be similarly

review

the section on

its

of

sound for

single-

622.

by

acoustic

BROADCASTING

6:

AM,

in

greatly

particularly

Normal

622

FM,

facilitate installation

precautions regarding

is installed.

TV

and

broadcasting

recommended

of the 622.

for stations

grounding

applications, the

The

optional output

with studio

and transmitter

and shielding

integral

RF

suppression will

transformers

at the

should be followed

are

same site.

when

the

The 622

records,

If

sibilance

Sibi

lance Controller. If

BANDWIDTH

necessary will help control

Use

However, be

cartridges

Stereo

The

satellite

be used

and HF TUNING

can often be enhanced by boosts

The 622

equalizers,

In the main

is invaluable in the

and

equalize the

to

is a problem, the best

production

announce

microphone for

solution is

one is unavailable,

close to

of narrowband peaking,

approximately

sibilance

and sweeping

aware that excessive

usually

used.

This

can be avoided

Compressor/Limiter, which

622

can

also be used to enhance

feeds, shortwave

in their shelving mode (both BANDWIDTHs

at

most effective phone line equalizer.

is a

the

622's flexibility

studio,

20kHz)

the 622

broadcasts,

to remove

in

can

can be used

"5",

--

although

high frequency

assures clean

and network

out-of-band

4-5kHz region.

the

effectively deal

to notch

studio. It

tuning

and turning down

by

the

hum and ventilation system noise with minimal

band

for each

major 60Hz harmonic, with

BANDWIDTH

can

maximum punch.

the use

622

a

band to 6kHz,

at the expense

can

create

boost

can saturate

following

carts under

sound

of telephone

feeds. The LF

"10",

at

noise. Presence

Unlike

with

out cart

effect

on

be used to

an Orban

of

EQ

the

of vocal

some wild

the

622

the

all

and

with

EQ

calls,

HF

LF TUNING

and intelligibility

simpler phone

minor response

or tape

voice quality.

control

machine

adjusted to

"sweeten"

Dynamic

adjusting

control

presence.

gimmicks.

7.5ips tape

the Orban

conditions.

remotes,

bands

at 20Hz

company

"glitches".

motor

Use

the

as

may

one

"0".

ELECTRONIC

7:

MUSIC

The 622 may also be used in the

partially compensating

certain amount of high

rolled-off

with

material

essing). Therefore,

OPTIMOD-AM,

equalization.

The 622

particularly useful as a formant

certain instrument body sounds.

up to eight high

The

useful in approaching live instrument

typical

performance of such

conventional compressors

with

large

which is

highly valuable adjunct

is a

"Q"

synthesist will find

synthesizer

for

frequency boost is essential

amounts of high frequency energy, and

for ultimate

resonances

the

systems.

AM

the inadequacies of typical consumer

radios. However,

and limiters

performance,

complete signal

a

filter,

(If

both channels

can

be simulated.)

more extreme equalization

sound and getting away

As this whole area is highly specialized,

that the beginner familiarize himself

physics.

program line to equalize the

air

AM

to counteract the extremely

extreme boosts can cause problems

(such as severe pumping, "gulping" on

audibly obvious de-

we recommend using the Orban

processor including adjustable

any

to

and can be

we will

with

electronic music synthesizer. It is

used as a

622B

of a

resonator to

are connected in series,

settings to be particularly

from the raw sound of

not explore it further.

the literature on musical instrument

sound,

thus

radios.

simulate

We suggest

A

12

Part

Introduction: This part

how

622,

repair it

make

to

something goes wrong.

if

sure that it is working according

Maintenance

C:

the manual provides

of

instructions on how

to specifications, and how to

to maintain

the

PERFORMANCE

1:

EVALUATION

PERFORMANCE

HIGHLIGHTS

Factory service is available throughout the life

Factory Service subsection of

information.

General

This section provides

whether

not the 622

or

a

series

alignment controls which are adjusted

evaluation

procedure is executed.

MAINTENANCE AND

thorough, definitive

of

operating normally. Each

is

at the same time that the

Power Supply

Equipment Required:

VTVM

1)

Oscilloscope

2)

The

following tests will verify correct operation

Using the DC voltmeter, measure the voltage

1)

positive and negative unrequlated

the two

depending

DVM

or

large filter capacitors.

line voltage; it

on

of

supplies.

This

should measure between

This

voltage

the 622. Please

of

SERVICE below

bench tests which

for further

will

band of the 622

performance

the Power Supply:

from circuit ground

can be readily

measured across

may be expected to vary

+18

and +26

volts DC.

refer to

verify

has two

to both

widely

Measure the voltage between circuit ground and

2)

and negative voltage regulators, IC70I and IC702. The

between +14.25

implies that

than 14.25

for troubleshooting hints.

Using

3)

the oscilloscope, measure the ripple and noise

its associated 1C

VDC,

and negative power

+15.75 VDC.

and

refer to

the Power

busses. Ripple and noise should

If

regulator

either supply exceeds

is defective.

Supply

each bus.

Signal

Processing Circuitry

Equipment

1)

2)

3)

4)

5)

6)

Required:

Oscilloscope with

Audio sweep

Tektronix

Bistable

20-20,000Hz

VTVM

Storage mainframe may

DVM

or

Harmonic

Sound

THD

Technology

residual

Low-distortion oscillator with residual THD

(A

DC-coupled display

generator with

5L4N

distortion analyzer with

Low-Frequency

bandpass filter, !8dB/octave

below 0.0015%

I700A

or

sinewave

Spectrum Analyzer

be substituted

built-in

H-P

339

will

the outputs

supplies should

If

either

portion of Part 4

on the regulated positive

be less than 2mV

output and logarithmic sweep (A

for items (I) and

slopes

400Hz

and 80kHz

of the positive

15.75

VDC,

supply is lower

this

in

in a Tektronix

filters

below 0.0015%

satisfy

(5)

and

(6))

put out

section

peak

5111

(2).)

and

it

on

For

620 ohm

the following

1/2 watt 5% carbon resistors are suitable.

tests, a

600

ohm load must

13

be

provided

across each

622 output.

IN THE CASE OF THE DUAL-CHANNEL 622B, THE TEST

SHOULD BE FOLLOWED FROM

REPEATED

FOR CHANNEL "B".

BEGINNING

TO END FOR CHANNEL

PROCEDURE BELOW

"A", THEN

I) Signal Passage

a) Connect the high

harmonic

oscilloscope. Connect

b)

Ground the (-) input of the 622 and connect the output of the low-distortion

oscillator

c) Move

d)

e) Continue

f) Verify

DC Offset

2)

a)

b)

Distortion

3)

a)

b)

c)

d)

e) Measure the Total

f) Repeat at 20Hz; +l8dBm

a||

Adjust

appears at the

that

this clipping level exceeds +l9dBm

signals.

level

at

Disconnect the

Move the

appearing at the output

Ground

the

(-) input

Center all

IN

position.

Using the

the gain

Apply

622's

the distortion meter. The

a

GAIN

Test

side of the

(+)

distortion

to the

IN/OUT

GAIN

the

advance the

to

that the

IkHz.

output.

oscillator from the 622 input.

analyzer,

ground side

the

input of the

(+)

switches

control clockwise, and verify that an undistorted sinewave

OUT,

to

GAIN

OVERLOAD

lamp flashes

CHANNEL IN/OUT

the 622. The voltage

of

Inverting

and

the

(+)

the 622.

of

operating controls, and move

same

is the same

20kHz

control

Operation

input

of

the 622

Adjust the oscillator to IkHz.

procedure as in

previously measured +0.3dB.

as

signal and adjust the output level

until

Harmonic

+l8dBm

Distortion,

THD

output;

622 main

and

also to the vertical input of the

622.

of the

output to

622

and center all EQ controls.

control until clipping

20Hz, IkHz,

for

at, or slightly below, the clipping

switch

connect

and

the Signal Passage

is observed at the 622 main

should not exceed 0.025%.

400Hz

IN.

to

the low-distortion

BAND IN/OUT

al]

using the 400Hz

filter OUT. The THD

is

Measure the DC voltage

should not exceed 30mV DC.

Test above,

of

the

instrument ground.

to

barely visible. Verify

and

switches

the

oscillator and the

80kHz

and

exceed 0.025%.

input of the

20kHz

oscillator to

input

to

the

verify that

output.

on

filter

should not

Noise

4)

a) Adjust the

b)

Switch OUT

20-20,000Hz

c) Disconnect

inputs

d) Center all

IN/OUT

e)

Measure the

described, it

the

HF,

5)

The

bands. The

described

IN/OUT

flashes at

622 GAIN

the

bandpass filter

the oscillator

to circuit ground.

controls except

switches IN.

noise at the

should

analyzer

MHF,

following

is available,

MLF

and

procedure

alignment procedure

immediately

switches of the

any time, reduce the

control

400Hz and

not exceed -84dBm.

to produce

between the

from the

for

main output

the

noise will

80kHz

GAIN

unity

filters

622

and

622,

(adjusted in

of the 622.

If

measure

input/output gain.

in the analyzer.

output

connect

and the analyzer input.

both

step

With

only

the 80kHz

somewhat

Equalizer Swept Response and Alignment

should be performed in

for the

below. As

bands not

you perform the

under test are OUT. If

LF

turn on

band

the

is slightly

tests, be sure that the

GAIN.

14

Connect

and

(+)

(a)), and place

the

test setup

filter

internal to

higher.

HF,

MHF,

and

different and is

the OVERLOAD

the

(-) 622

all

as

MLF

BAND

lamp

The

procedure below

repeated

each band

Connect

a)

sweep

the 622

to

produce a

b) Switch

the MHF

for

as appropriate.

the sweep generator

generator

output

CHANNEL

the

OUT.

Adjust

c)

d)

Move the

e) Adjust the HF

swept

f)

Adjust the

and

throughout the

minimum

Adjust the

g)

is

entire

at all

the 622 INPUT

HF

response.

HF

note the change

change

HF

better than

range.

settings of the

It

may be

above.

specifically refers to

MLF

and

bands

the

by substituting the

output to the

ramp output

to the vertical input

20-20,

000Hz

log

IN/OUT

control

BAND IN/OUT

EQ

control

BANDWIDTH

in the depth

range.

If

in null depth as the BANDWIDTH

BANDWIDTH

-25dB

when the

If

the null

is less than

HF TUNING

the horizontal

to

of the

sweep.

switch

for full-scale deflection on

IN,

switch to the IN

to -infinity, and note

control throughout

the

of

null depth

control

null.

varies appreciably,

"10"

to

HF TUNING

-25dB,

control.

NOTE:

necessary

to fine-tune RI05

HF

band. The

analogous controls

input

(+)

input

of the scope. Connect

scope.

Adjust

and all

position.

The

(broad) and

control

adjust RI25

as described in

BAND

that

a

its range

null

should remain

is adjusted

procedure

the

of

the sweep

IN/OUT

the scope

notch

appears

(from

adjust RI05

control

verify that

throughout

for

maximum

a

step (f)

622,

"0"

should be

and

generator

switches

screen.

in the

"10")

to

constant

is

varied.

the null

null

for

the

for

its

h)

Repeat

LF

6)

a)

b)

c) Adjust the LF EQ

d) Adjust
e) Adjust

f) Adjust

steps

Band

Test

Connect

622,

frequency

Switch

in the depth of the

and

the

the

the

the

the output

adjust the

in

LF

LF

appreciably,

Adjust

g)

better than -25dB when

range. If

of the

It

the

LF

may

LF

the null

TUNING

be necessary

above.

Tuning

7)

Control Calibration

through

(d)

and

your

LF

BAND IN/OUT

(g)

Alignment

of the

oscillator's frequency

country).

control

BANDWIDTH

TUNING

LF BANDWIDTH

adjust

control

null.

R405

BANDWIDTH

is less than -25dB,

control.

Test

for the MHF

low-distortion

switch

-infinity.

to

control to

for

control throughout

The

null should remain

for a minimum change in

control

LF TUNING

the

and MLF

to

IN,

and all

10 (broad).

maximum

"0"

to

adjust R425

oscillator to

60Hz

null. (Be

its range

(sharp), and verify that

control is

NOTE:

to fine-tune R405

and Alignment

as described

bands.

the

(+)

(50Hz if

other

constant. If the

BAND

as

and

that is the

switches OUT.

precise

note

the depth

adjusted throughout its

for best null

at

in step

input of the

mains

as possible).

the change

null varies

of the null.

the null is

all

settings

(f)

a)

Connect

622.

b)

Switch

c) Adjust

d)

Adjust the TUNING

o'clock.

the output

all BAND IN/OUT

EQ

the

control on

of the low-distortion

control on the

switches OUT

the band being

15

oscillator to the

except

tested

band being

for the

to -infinity.

tested

input

(+)

band

being tested.

to

approximately

of the

I

Adjust

e)

TUNING dial

Adjust

f)

that

frequency set

on to

go

knob is

readjust

alternately

by

oscillator

the

calibration

TUNING control for a null

622

the

the position

in step

the next band

outside

it until it

frequency to the

close to

the

of

If the

(e).

repeat steps (b)

and

the +1/3

reads the

octave

tightening its

frequency appearing on

the I o'clock

in the

TUNING control

TUNING control

through (f)

tolerance, loosen

correct

frequency.

two Allen setscrews

position.

622 output

corresponds to

reads correctly,

above.

the

Retighten the

until both are

the 622

level, indicating

the oscillator

octave,

+1/3

TUNING

If the

TUNING knob

TUNING knob

and

tight.

MAINTENANCE

2:

AND

SERVICE

Preventive

The front panel may be

should

the plastic control

The

inside

short-circuits if

in a dusty or humid

interior of the chassis cleaned.

Maintenance

A

new parametric bandpass

Maintenance

cleaned with

avoided, as they may damage the paint,

be

knobs.

interior

the 622 should

of

the chassis can cause loss of cooling and

the

absorbs moisture from the air. It is particularly important

dirt

environment that the covers be

Operating Controls

of

resonator was designed for the 622 which

immune to the effects of ordinary

Wear on the

bandwidth

in

depth

is

on the BANDWIDTH

Wear

compromise notch depth.

TUNING

as the

not

compromised.

control is manifested almost

TUNING

control is

control

be

mild household detergent.

a

the silk-screened lettering,

kept

free

of dust and

can

wear

of

BANDWIDTH

the

completely as a

operated. However,

changes

calibration slightly,

its

Stronger

dirt, since dirt buildup

also cause high-resistance

periodically removed and

solvents

essentially

is

and TUNING controls.

slight

change

the available notch

but does not

or

the

Wear on the

will compromise the notch depth.

periodic alignment of

the EQ

(PERFORMANCE EVALUATION

Response and

The controls

EQUALIZATION control (such that its total resistance is changed)

RI25,

225, 325, 425,

controls are placed

in their

AND ALIGNMENT),

Alignment)

622

the

of

instructions.

for

not hermetically sealed, and can therefore readily be

are

cleaned with a commercial spray-type

replacement

(see section below on

equivalents.

Replacement of

important

It is

PC boards.

intermittent

The

circuit

variety.

through-holes

is needed,

Components on

to

Failure to do so

problems.

board used in the

This means

contain a

it should be

Factory Service), as the controls have no commercial

Printed Circuit

the correct

use

that there are traces on

metallic plating

technique for

will result in possible circuit

622 Equalizer

Therefore, with heavy

will

which

-

infinity positions. Refer to section

maximize

subsection

we recommend

use,

the

null depth

(Equalizer Swept

5

contact cleaner if they become noisy.

ordered

directly from

Orban Associates,

Boards

replacing components mounted

damage

is of

both

in

order to conduct

16

the double-sided

sides of

the board, and

plated-through

current through

when

If

Inc.

on

and/or

that the

the

I

a

board.

hole, requiring a sophisticated

damage

Because of the

the

to

board.

plated-through holes, solder often creeps

technique

1/16"

up

component removal to prevent serious

of

into the

If

the technician has no

technique of removing

damage, it

body while the

discarded,

pair of long

heating with

a spring-activated desoldering tool.

wiser to cut each of the

is

leads

and each lead

nose

pliers.

low-wattage soldering

a

practical experience with the elegant

components from double-sided

leads

of an

are still soldered into the board.

is heated independently and pulled out of the

Each hole may then be

iron and sucking

THIS METHOD

PC

boards without board

offending component from

The

component is then

cleared

out

THE ONLY SATISFACTORY

IS

solder

of

the remaining

METHOD OF CLEARING A PLATED-THROUGH HOLE OF SOLDER!

The

new component may

starting

with step

(4).

Use the following technique to replace a

Use a 30 watt

1)

side

of the

soldering iron to

PC board. Do not

soon as the solder is

desoldering

BOARD;

conductive

pliers to wiggle the

in the hole.

tool

overheating will almost surely damage the

foil to

now

be

installed

following the directions below

by

component:

melt

the solder

soldering gun or a high-wattage iron! As

use a

on the solder (underneath)

molten, vacuum it away with a spring-actuated

the Edsyn "Soldapullt".

like

AVOID OVERHEATING THE

board

separate from the board. Use a pair of

lead horizontally until it can be

observed

and

demanding

board with

by carefully

with

solder

causing the

by

fine needle-nose

move

to

freely

its

a

Repeat step

2)

freed.

Now

3)

Bend

4)

lift the component out.

the leads of the replacement component until it

until each lead to

(I)

appropriate PC board holes.

each lead fo the

Make

sure that the joint is smooth and shiny.

bottom

the plated-through

side

hole, soldering of the topside pad is not necessary.

be removed has been cleared of solder

will

a good brand

Using

the board with a 30 watt

of

of rosin-core solder, solder

If

no damage has been done to

fit easily into

soldering

However, if the removal procedure did not progress smoothly, it would be

prudent to solder each lead at the topside as well in order to avoid potential

intermittent

Cut each lead of the replacement component

5)

side of the PC board with

Remove

6)

trichloroethane, naptha, or 99% isopropyl alcohol. The

1,1,1

usually available

are

proof spot remover and regular spot remover, respectively. The

is less effective, is usually available in drug stores. Rubbing alcohol is highly

diluted with water

problems.

all residual

to the

close

a pair of diagonal cutters.

flux with

in supermarkets under the brand name "Energine"

and is

a cotton swab moistened with

ineffective.

solder

a solvent like

first

alcohol, which

(underneath)

two

and

the

iron.

solvents

fire-

It

removed the flux

most rosin fluxes are not corrosive, they

become sufficiently conductive to cause

performance.

is

policy to make sure that

good

and has not just smeared it

defluxing operation

this

that it

so

is less visible. While

can slowly absorb moisture

progressive deterioration

has actually

and

of

17

Troubleshooting

1C Opamps

1C opamps are usually operated such

circuits are

external feedback

terminal to be

if the technician

the

1C is probably bad.

Exceptions are

have

been saturated due to excessive

earlier stage. Also,

sensitive

more

positive than

this

almost

polarities

A

defective

sensitivity. If

diagnosing

intermittent

circuits

Factory

Please

Warranty

from the 622

a reasonable

the

factory

transportation

essentially independent of

components. The feedback

extremely close to the voltage

measures more than

IC's used without feedback

be sure that the voltmeter

points

affecting

and

its (-) input,

certainly indicates

are reversed.

opamp may appear

parameters appear

the

problem. Freeze-spray

problems. But,

due

to moisture

Service

refer

to the terms

which

,

extends

and is

charge

service facility. Repaired

charges (which

condensation on

not bound with

will

be made for parts,

the measured voltage.

yet the output

to work,

use

sparingly

of

your

to the first end-user.

are usually quite

customer.

that the

1C characteristics and

few

a

input voltage because

that it is bad.

to drift

cold

Orban

this manual.

units will

characteristics

forces the voltage

at the

millivolts between these two

(as comparators)

yet it may have

excessively,

is also

because

,

surfaces.

Associates

This

labor, and packing

input terminal.

(+)

and IC's

is not interacting

However, if an IC's

of the

1C is sitting

The

same holds if

extreme

freeze-spray

invaluable

can

it

cause

Limited

warranty

After

be returned

nominal)

was packed

expiration

if you

C.O.D.

shall

their

of

associated

dependent only on

at the (-) input

Therefore,

terminals,

whose outputs

of a defect in

with these

input is

(+)

-14

at

volts,

the above

temperature

may aid in

in tracking

resistive

One-Year

of the warranty,

choose to

In

be borne by

down

short

Standard

separately

use

all cases,

the

an

Ordering

require all of

—

—

—

--

Returning

obtained

address shown

YOUR

Shipping

If

the original

of

at least

Parts From

The

Orban

The

Reference

A

brief description

And,

from

-

the exact

-

the Serial

-

The

"M" number,

the 622

from the

RETURN

Instructions

employed.

the following

part number,

Designator

the serial

Model Number

Number

to the Factory: After

factory,

on the

front

AUTHORIZATION

OR

packing

pounds bursting

200

the Factory:

information:

if ascertainable from

R503)

(e.g.

the

of

if any

part

label on the

units

should be shipped

page of this manual.

NUMBER

THE

PACKAGE

PHONE

OR

TELEX

material is available,

test and

If

parts

rear of the

a formal

MUST

WILL NOT

957-1067

(415)

17-1480

it should

no smaller

are ordered

the

Parts List

unit

Return

to CUSTOMER

BE SHOWN

BE

ACCEPTED!

be

than

from

the

Authorization

SERVICE

ON THE

used. Otherwise,

22"

10"

x

10"

x

factory, we

number is

at the

LABEL,

a carton

should

be

18

I

I

622

The

material

finish.

blankets are acceptable. Folded

Equalizer

protecting every point. A

Cushioning material

should be packed

such as Air-Cap, Bubble-Pak,

that

so

plastic wrap around

newspaper is

there

not suitable.

should be tightly wrapped around the 622 Equalizer

the

unit from

The

carton should be packed evenly and fully with

voids such

sealing

use

the carton and shaking vigorously.

more packing.

shifting out

that the unit cannot shift in the carton.

of its

packing

and contacting

If

the unit

is at

the chassis will

foam "popcorn",

of

protect the

or fibre

1-1/2"

least

Blanket-type materials

and taped in

the walls

the packing material filling

Test for

can

be felt

place to prevent

of the carton.

this by closing but

heard

or

to move,

packing

all

not

CIRCUIT

3:

DESCRIPTION

The carton

should be well-sealed

top and bottom of the carton in an

tapes will

The package

red: DELICATE INSTRUMENT, FRAGILE!

the box

almost solely on the

General: Except

independent

described.

The

1)

2)

3)

4)

5)

6)

7)

not stand the stresses applied to commercial

should

be

marked

around as if it were

taken in packing!

care

the power supply, the

for

and identical.

circuitry is divisible into seven major blocks. These

input buffer and "active transformer"

high

frequency equalizer

mid-high

mid-low

low

overload indicator

power

frequency equalizer

frequency equalizer

frequency equalizer

supply

In

the

(HF)

3"

with

"H"

with

the name

filled with

following

(MHF)

(MLF)

(LF)

with

reinforced

Even

junk. The survival

discussion, the

sealing tape applied

pattern. Narrower

shipments.

of the shipper, and the words

so, the freight

left and right channels

are:

discrete current-booster

or parcel-post

people will

of the unit

LEFT

CHANNEL

across the

depends

of the 622

will

output stage

type

in

throw

are

be

will

These

Input Buffer

The signal enters

leads to

frequencies; therefore, ferrite beads have been placed around the input and output

leads to suppress such high

RF-proofing

installation next to a high-power transmitter

RF

suppression,

considerations familiar

conjunction with the

The

filtered signal

differential amplifier with

inputs are driven by

600 ohms

as
that appear equally on the non-inverting

described in

be

the

chassis.

the 622 in balanced form.

order.

These

capacitors

frequency

is moderate but adequate for

careful examination

the

622's

is applied

source impedance which

a

or less), the

to

built-in

a

amplifier

broadcast engineer may have to be used in

RF

to 1C

gain of 0.5. When both non-inverting and inverting

CIA,

CIB shunt

are

not effective at

RF.

It

should be noted

vast

a

majority of

may still cause problems.

the grounding

of

suppression.

I,

low-noise FET-input

a

small with respect to I00K (such

is

is essentially insensitive to signal components

RF

from

the input

VHF

and

that this

installations. However,

degree of

Additional

scheme, and

opamp

configured

and inverting inputs (such as hum),

19

higher

other

as

and

a

responds

inputs.

obtained

inverting input is

with full

Thus it serves as

for unbalanced

gain to

driven.

the difference

"active

an

signals

if the

between

transformer".

non-inverting

non-inverting

the

Ordinarily,

input

inverting

and

best results

grounded and the

is

are

GAIN control

The

differential

indicate

Frequency

High

The

first

ICI

in

and to make an

Equalization

adding it

either

HF

Bandpass Resonator:

(where "x"

Cx03

HF

band, for

will be

reference

the

The

resonator

input

this.

equalizer stage is

is

specifically

attenuated by

frequency,

IC502), is

of

amplifier

is padded

way

fast

measured from

101.

1C

down to

determining

of

is located

exceeds

Equalizer

additional

achieved by

or subtracting

to

Except for

denotes a

example),

designators are

has

voltage

+ l6.8dB in the

In

all resonators

discussed.

substantial

divider

other bands

the

-l.2dB. Measuring

if the

after 1C I

approximately

configured

!2dB gain

taking the

it from

the

corresponding

digit

However,

changed

gain. To

R

0

1

1 ,

wiper of

the

HF

section.

(which have

resonator is

. Therefore,

+26dBm.

1 8dB gain to

for

available.

output of a

its input

values of

are identical.

discussion

this

appropriately.

avoid

two-pole

signal.

the two

to the

The

overdriving the

RI03. The normal

R9 to the

This

resonator outputs

complements the

OdB gain), the

gain at the

the

faulty.

ICI will

OVERLOAD lamp

The

make up for the

bandpass

tuning

band in

applies to aj|

question:

resonator in the

resonator,

gain at

the peak

l8dB

peak

resonant

peak

6dB

if its

will

loss

overload

resonator and

capacitors CxOI,

"I" for the

HF band

of the

bands if

its input is

resonant

I and

(pins

gain in main

resonator

provides

gain

one

7

and

change

and

the details of

the resonator

frequency, but

the phase

360 degree

producing a

shifters

response

the bandpass

"Q"

the

are taken

is fixed by

user-adjustable

two cascaded phase

with

response.

of

around

R5IS. The

Because

general description will be

a

Basically,

phase shift of the

function of

frequencies.

If the input to

0

reinforce,

the phase

the bandpass

peak of

To

feedback

"Q"

introducing a

BANDWIDTH control

the resonance

(sharpness)

gains are

Ordinarily,

adjustment

of

correctly

RI05 need

resistor

if a

adjusted.

resonator

consists

shifters is

operation

provided.

the gain of

frequencies

bandpass

response as

dual-ganged

produced

the bandpass

can be

the phase

"Q"

amount

RI09. Adjusting

without

A

trimmer

adjusted

be

within the

are best

pair of

of

a

shifters varies from

the phase

subtracted

cancel

will

desired.

TUNING control

adjusted

response

shifters.

can be

of

resonator is

reduced (and the response

counteracting

the amount of

affecting the

control

only once,

explained

allpass phase

shifters is

from the

phase shifters'

and the 180

By adjusting the

Rill, the peak

without affecting

produced,

The

RI05

replaced.

both positive

positive

negative feedback

feedback

peak gain,

provided for

is

and should

mathematically,

networks.

shift

360 degrees as a

0 to

constant at

degree

frequency

phase

frequency

the

and

feedback

increases

broadened)

changes

provided

this purpose.

require

only

only

The

all

output,

gain at

through the

that circuit

the

will

shift of

the

negative

the

"Q"

the

field

of

by

Troubleshooting

loops, familiar

"cut-and-try"

the Resonator:

signal-tracing procedures

procedures

must usually be used.

Because the

are not

20

resonator uses

effective

when troubleshooting, and

multiple

feedback

First,

controls

the

replace

are

opamps

capacitors

(greater

resistors

than

must

understressed

the

suspect

are

defective,

C

1 0

1 ,

50

megohms)

be

and highly

opamps. if

because

CI03

tested

they

then

on

an

conductance.

one-by-one.

reliable,

this

does

are

subject

passive

impedance

Because

resistor

not

to

component

bridge

If

the

capacitors

failures

cure

wear. If

failure

for

these

are

the

problem,

neither

should

correct

are

metalfilm

most

improbable.

the

the

be

suspected.

value

and

good, then

resistors

adjustable

controls

negligible

the

are

nor

Test

fixed

very

Operation

is

pin 7

This

main

inverter.

feedback

which

either

The

is

boost

amount

determined

RII3,

signal

R

is

When R

the

input

The

taper

EQ

control

occurs

Achieving

amplifier

peak

the

RI25.

the

readjusted

and

symmetrically

gain

unequalized

Since

characteristics

maximum

of

the

of IC502B.

resonator

Not

only

within

used in

or cut

of in-

by EQ

1 1

RII9.

7,

added

I 1

5 is rotated

signal,

adjust

and

precise

ICIOI

of the

wear

from

nulls

HF

EQUALIZATION

This

does the

the

resonator,

conjunction

equalization.

or

control RII5

When R

to the

toward

and

peak

resistors

adjust

about

cancellation

when

the

resonator

input

on R

of the

time

to time

are

required.

output

output

output

with

out-of-phase

1 1

input

dip

set

the

control

the

EQ

control

be

signal.

1 1

(which

5

entire

is inverting

is

connected

of IC502A

but

also

provides

the

out-of-phase

in

association

5 is rotated

signal in

pin

7

of IC502A,

results.

the

point

operation

12

o'clock

of

fhe

is

precisely

This

gain

changes

taper-adjusting

if the

equalizer

Control:

with

to IC502A,

addition

toward

1C

101,

of

zero

so that

point.

resonator's

in

the

matched

match

its total

The

main

respect

provide

an

in-phase

output

(and

thus

with

pin I

and

peak

and

out-of-phase

equalization

the

peak

(-) infinity

(and

is

achieved

resistance)

network,

is

frequently

output

to the

operated

the

source

output

from

the

amount

its

taper-adjusting

of IC502A,

boost

equalization

signal

at

first

+4dB

frequency

position

out-of-phase)

by adjusting

will

RI25

used

of

the

resonator's

as

a

for

the

of the

IC502B

an

is

12

o'clock

of

equalizafion

in

requires

to the

slightly

may

have

as a

notch

resonator

input.

unity-gain

negative

resonator

to

provide

EQ)

of

network

in-phase

results.

added

on

summing

that

gain

trimmer

change

to

filter

is

to

the

the

of

be

The

equalization

EQ

control

Cl 07

controls

region

limited

equalizer's

Mid-High

These
C30I,

they

provide

values

voltage

Low

Frequency

The

LF

major

additions.

equalizer

amplifier

operation

constant

switch.

from

the

(starting

bandwidth

stability

and Mid-Low

two

equalizers

C303.

These

unity

R22I

of

dividers R20

Equalizer

equalizer

to

drive 600

IC40I

when

input/output

in

a given

ICIOI

by

means

high

frequency

1

at

75kHz).

above

and

the

immunity

Frequency

are

identical

stages

gain instead

and R32I

is

The first

are identical

are chosen

R203; R30

1 ,

similar

is

ohm

is

switched

the CHANNEL

polarity

band

is

defeated

BAND

of

response

The

entire

audio

to

equalizer

range,

RF

interference.

Equalizers

except for

to

of +l8dB

to the

a

discrete-transistor

loads.

from

to yield

R303,

1 ,

three

The

normal

gain

IN/OUT

regardless

of the

by

IN/OUT

of ICIOI

which

their

the high

under

unity

are

equalizers

current

second

inverting

switch

position

disconnecting

switch

by

is

purposely

S

1 0 1

rolling

contributes

tuning

capacitors

frequency

no-equalization

gain,

and the

chosen

to yield

preceding

booster

addition

assures

operation to

is switched

of the CHANNEL

the

it

off in the RF

designed

greatly

equalizer

conditions.

resonator

it

except

which

OUT.

output

C20I,

of

to have

to the

C203;

except that

-3l.3dB

for two

enables

that

summing

non-inverting

This

retains

IN/OUT

the

The

input

loss.

the

21

When the

operates

a) two capacitors C407, C4II are inserted in

isolate

b)

a

CHANNEL IN/OUT

exactly like the other equalizers,

IC40I

the switching

and

switch is

except that

from possible pop-producing DC

complementary-symmetry discrete-transistor

ICAO I'sfeedback loop.

in the

IN

position,

series with the summing junction

the

LF

offsets; and

output stage is included within

equalizer

to

Discrete Output Stage:

followers in a

stabilize the

class-AB configuration. R443, R445

quiescent

The

output transistors

bias current through the output stage. The

biased by diode-connected transistors

their associated output transistors to

output stage

against thermal

runaway.

Q40I,

provide

Q405,

thermal

Q407

Q403,

provide local DC feedback to

which

are thermally coupled

feedback which

Current limiting to short-circuit protect the output stage is

CR407

exceeds the

diode conducts, shunting the drive

thus protecting

IC40I,

boostrapped to

junction of

conjunction with

in

turn-on

Q403,

the driver, is loaded by

the

R439

and

Because the output stage has

see a load of 5.4K

voltage

across

R439

boostrap thus relieves IC40I

load, and reduces distortion.

The

output is connected to

R447,

C4I9A, C4I9B. This

parallel with lOOOpF.

is replaced with

a jumper to assure best performance from the transformer.)

R443, R445.

threshold of

Q407

from

output of the

R44I

to follow the

a

(R439+R44I),

(and therefore the current through it) does not vary. The

from the

the

makes the

(Note: When the optional output tranformer

When the

its associated diode (about

current

burnout.

R439, R44I. The

gain

but rather a constant current sink because

outside world through

away

emitter

almost

of

task

output impedance of the

voltage

from

followers by C4I5, which forces

AC

voltage excursions

+1,

of driving a relatively low-impedance

drop across

Q403,

junction of

this means that IC40I does

RF

are operated as emitter

output stage

stabilizes the

provided

R443

0.55

volts), then the

Q407

and into the load,

R439

of the output.

suppression network

equalizer

is installed,

and

by

47

CR405,

R445

or

R44

ohms

R447

1 is

the

not

the

is

to

in

Channel In/CXit Switch: R429

charge

which

could

cause a pop

assures that C407

upon switching.

and

Because

C4II

R429

do not build

connected between

is

true ground and the virtual ground produced by the summing junction

almost

has

When

the

connected

is ungrounded and connected

assures that C409 does not pick up

R435

assures that the

CHANNEL IN/OUT

Under these conditions, IC40I has

the fact that 1C 10

CHANNEL IN

The entire circuit

potential.

the switch

if program material is being passed through the equalizer

other

no

effect upon circuit operation.

CHANNEL IN/OUT

AC

to

ground

and CHANNEL OUT

However,

being operated,

is

through C4II, R43I.

switch

no longer

1 is

is carefully arranged to avoid

because the program is interrupted

switch

the wiper of the

to

input

(+)

is operating.

in

modes.

click due to waveform discontinuity

a

switched

is

Simultaneously, the

DC charge which

a

IC40I

of

non-inverting

a

the

circuit and assuring

OUT,

the (-) input

(+)

GAIN

control

is referenced to ground while the

gain of +l8dB,

due

pops

for a

through C409. R433

cause

could

equal gain in both

differences

to

few milliseconds

as the

switch

DC

a

up

IC40I,

of

IC40I

of

input

IC40I

of

a pop, and

making up for

in

DC

while

operated.

is

heard

may be

it

is

22

Overload

Indicator

The output of

pair of

R60I,

R6II).

appropriate

relatively

diodes. One

R603); the

If the

diode

high

main-signal-path

each

diode is

other

instantaneous

conduct

will

impedance.

connected

diode is

output of

and couple a

amplifier

to a

in the

+10 volt bus

connected to a

amplifier

any

pulse

622 is

(created by

-10

volt

exceeds

onto one of

connected to

voltage

(created

bus

+10.6 volts,

the busses,

its

divider

R609,

by

then the

which

own

are

Positive-going

Q60l's

going

collector

overload

appears at

IC60I and

to

Ordinarily,

higher voltage

a

going pulse

switching

R6I9,

R6I3,

C605,

R6I7, R6I9, which

output is

overloads are "time

Under

flash on and off.

Power

continuous

Supply

Unregulated

CR702

C702.

operation;

and CR703,

The power transformer

overload

amplified

pulses are

Q60

collector

1's

associated

IC60I

is

than voltage

transmitted

IC60l's output

latches

and

HIGH,

the

stretched"

overload

voltage

the two sections of

connected in series for

pulses are

inverted so

and

connected

negative-going

a

as

circuitry,

OFF

through

(pin

divider

C603 pulls

held

HIGH. This

IC60l's output

normally

OVERLOAD

lamp

and can be

conditions, it

supplied by

is

CR704 operating

Tl

the

230 volt

operation.

fed into

directly to

transistor

that they

Q60l's

pulse, and is

connected

6 LOW) because

R6I3, R6I7 holds its

IC60l's

pulls

turn

in

HIGH

until C605

takes about

illuminated

is

easily seen.

is normal for

pairs of

two

into a pair

strappable

is

primary

of energy

paralleled for

are

inverter

are

collector.

Q60I and

negative-going.

coupled

(-)

one-shot

holds

(+)

input

input

(+)

as a

R6I5

IC60l's

can discharge

milliseconds. While 1C

200

through

full

wave diode

R62I. Thus very fast

OVERLOAD

the

storage

for either 115

115 volt

appear

Negative

Thus any overload

through C603

multivibrator.

IC60l's

input.

down, thus

(-)

A

negative-

input at

briefly

HIGH through

through

60

lamp to

rectifiers

capacitors C70I,

volt or

CR70I,

230 volt

operation and

at

1

’s

The nominal unregulated

widely

vary

unregulated

Regulated

regulators

expected

to see

caused

current limiting or

into

If

it becomes

securely

to

included in

To prevent high

frequency-compensated by

PC board.

the

excessive

CR705,

protect the

and

cause a

with line voltage

voltage

voltages

IC70I,

to be

falls below

are supplied by a

IC702. Because

extremely

whether other

excessive

the original

current

necessary

insulate

frequency

These also

power-lead

CR706 are

reverse polarity

inductance.

connected

rest of

the heat

assembly.

voltage

about

reliable.

abnormalities

demand which

thermal

into

replace a

to

sinks from

oscillations,

ceramic

small

prevent

from

the circuitry

voltage

on either

+22 volts DC at rated

is

volts.

of

operated so

are

causing the

is

Regulator dropout

overrated

before

circuitry

variations.

+17.8

pair

they

Therefore,

in the

shutdown, their

other by

the

sure to

regulators

regulator, be

each

capacitors

signal-carrying IC's

power

each

fault

bus.

ground to

from a

23

line

500mA "three

conservatively,

replacing

(such as a

regulator

built-in

two

replace its

means of

C705-C7I4

from

power bus

condition

voltage.

will occur

regulators,

the

shorted

IC's

protective

the

IC70I and

distributed

oscillating

in reverse

might

that

This

if

terminal" 1C

can be

they

check

1C)

either

to go

modes.

sink and

heat

fish paper

IC702 are

around

due to

polarity,

otherwise

will

the

have

Appendix:

FROM

DRIVING

HIGH

IMPEDANCE/

LEVEiL.

THE 622

SOURCES

Interconnections

together

Small systems

interconnections

the

and

complex.

discussion on

Therefore,

most people

things don't

case

it in

"+"

Both

through

these

impedance

professional

The 622

outputs of

"+"

outputs.

unbalanced

If the

capacitors will

which

and

lOOOpF capacitors.

capacitors do

of the

can be

some vacuum

inputs, and

(See the section

connections.)

lOOOpF capacitors

rolls off at

usually

interconnections

will

and

cause a

come

between various

do

ever need

work

sides of

not be

to

right and you

the

intimidated

grounding below.

and

successfully

622 inputs

To assure

affect the

not

equipment

semi-professional sound

tube

these

unbalanced

preamps) by

driven by

driving

below

are left

high

frequency

driving

inputs from

on Grounding

in place

frequency

6dB/octave thereafter.

and

easily because

pieces of

by the seeming

install a

need to

are bypassed to

common

the

rolloff

mode rejection,

response of the

622 should be

equipment

sources up

removing the

the hot side of

for an

and the source

which

Grounding

cable runs

equipment are

This

is more

small system;

find out why.

600 ohms or less.

will satisfy

to 10,000

lOOOpF capacitors

explanation of

3dB down

is

are usually short

complexity

information

have included

we

chassis

ground for

and to assure

system,

fh is

ohms (such as

driving equipment's

the

impedance is

at

terribly

not

of

than

that

the output

Most

requirement.

from the

balanced

I0K,

6kHz, and

1

the

RF

the

and

the

GROUNDING

The

absolute

will cause

GAIN

control.

If levels greater

before

making such

Indianapolis,

Grounding

electronic

clipping

OVERLOAD lamp to

the

the 622 input.

pads.

Howard W.

serves

equipment, and

and hum).

(Interference caused

special

and

audio, such shielding

heads,

transformers.

this

sort

There

ground reference

shield in

conductors.

intentionally

are

magnetic shielding

magnetic

of interference.)

are

phono cartridges,

Line-level

two types

for the

the same

Whether the

joined

scheme.

level of the

+26dBm are

than

The Audio

(Tremaine,

Sams & Co.,

two purposes:

shields the

it

magnetic

by

is ordinarily

equalizers such as

ground: circuit

of

electronics.

way that

circuit and

depends

622

flash on

expected, an

Cyclopedia

H.M.:

Inc., 1969).

it joins

fields is not

materials

with low-level

used

and

Chassis

the shield

chassis

on the type

input

the

electronics

+26dBm.

is

and

off

Section

,

Audio Cyclopedia

The

ground

decreased by

must be used

dynamic

622 are not

the

chassis.

and

ground

shielded cable

on

grounds

equipment

of

If

such

regardless of

external loss pad

contains

5,

references

from

of

various electric

conventional

where hum is a

magnetic

microphones,

Circuit ground

permits use of

are identical,

transducers

and with

normally

and the

clipping

the setting of

occurs, it

must be used

instructions

Second

,

various

protects

are

pieces of

fields

shielding,

problem.

like tape

low-level

sensitive to

serves

the chassis

the

separate, or

interconnecting

the

for

Edition,

(RFI

as

as a

inner

In

a

24

In professional

these:

systems

correct

grounding

important.

is

The general principles

are

In

audio system,

1)

2)

It is when these

problems

more

A

60Hz

loop

the ground

to appear

this

an

to a good

earth)

the

Meanwhile,

piece of

than one ground

ground loop

AC

will have a hum

equipment.

develop. If there is a

magnetic fields

wire has

between different parts

voltage

hum

common ground

one and only

by

there must be

two requirements

can be viewed as

can intrude on

How grounding is

interconnected is balanced or

An unbalanced connection uses

connections are

phone plugs are often

ground loops,

mixed

be

typically single-conductor

hum voltage

a

the desired signal since the

into

the chassis of

point (ideally a

one wire.

one and only

connection

path exists, then a

exist at every

current induced

cppreciable

impedance, this

the audio

accomplished

unbalanced.

two terminals:

used

terminate

to

appears between "hot"

between the desired signal and hum.

each piece

become

"ground loop" may

a single

point served

in it by

of the

ground system.

signal.

depends on

such cables.)

equipment must

of

cold water

one circuit

confused,

missing,

turn of a

hum and

by mains

AC magnetic

stray

current will

whether the

"hot" and ground.

shielded.

(RCA

If, because

and ground,

unbalanced

connection cannot distinguish

be

pipe

ground

omitted, or

giant transformer.

a rod driven into

or

path between each

redundant that

noise will result.

develop.

power, the ground

fields. Because

cause a hum

If

great

care is not

equipment to be

Wires used in such

and two-conductor

plugs

stray fields or

of

then this hum will

connected

If

Because

voltage

taken,

In the case

the input

third terminal is connected to

the

shield of the

example). If

then

the

ba lanced

of

responds

a hum voltage is

balanced

connections,

the difference

to

two-conductor

input would

responds only to the difference

audio

between

chassis

ground and

shielded wire

developed

reject this

in voltage

reject hum and noise is the primary

Referring back

rules are

applied

to

in

For involved systems

recording studios, or large

"transmission

Section 24 of

(Interesting

ground system"

The Audio Cyclopedia for

digression:

telephone company, which has to run

and also to high

from other

with

popular

earth providing the

the

and power lines

voltage

circuits. Originally,

with the telephone

telephone company

line technique, and

optimum compromise

Today, the telephone

extremely tight,

entire system.)

as

ELECTRICAL

the

the table and diagram.

such as

arena-type

broadcasting

should be

The "balanced"

miles of unshielded

AC

lines without

telephone circuits

ground

were placed on

service

so

embarked on a

to the choice of

between rejection

company's

proper

common

return. As soon as electric

badly as to

research

specification for

mode rejection is vital to

applied to the

is

voltages at

the

available

is

that would be used

between

the

shield

"common mode" voltage,

between the audio wires.

advantage

INSTALLATION

facilities, a formal

worked out for the

details

(

technique was first

pickup of excessive

telephone

render conversation

program which

the familiar

of electrical

of a

section, notice

sound reinforcement,

op. cit.).

cables close to

were unbalanced

poles,

the power lines

led

600 ohm

and magnetic

maintenance

"+"

and

the two terminals.

the connection of

for

(Belden

terminals;

8451,

and both audio

since the input

This ability

balanced

configuration.

how these

professional

and systematic

entire system.

perfected by the

each other

hum

or

on single wires,

lighting became

interfered

impossible.

both the

to

impedance

interference.

balance

line

of

the success of

for

wires,

to

See

crosstalk

The

balanced

the

as

the

A

is

25

Parts

List

Parts

are listed

part class by assembly

by

parts such as:

Fixed Resistors,

which are described generally

3/8"

Trimmer Resistors, Signal Diodes

Square

under the

DIODES

ALL

DIODES

NOT LISTED BY REFERENCE DESIGNATORS

Diodes,

NOTE: This is a

Signal

silicon small-signal

with 1N914 or, in Europe, with

BV:

75V min.

NOTE: For Zener Diodes

(VR.

I

@

= sv

r

Miscellaneous

see

..)

RESISTORS

ALL

COMMON RESISTORS NOT SPECIFICALLY LISTED ARE

Replace resistors only with the same

or

stability

compromised. If the

be

style and with the

resistor is damaged, consult

the value.

Metal Film Resistors

Body:

Orban P/N:

Power Rating:

conformally-coated

I.D: five color band or printed value

20038-XXX

1/8

Watt

-

20045-XXX

70°C

@

Tolerance: 1%

Temperature Coefficient:

Military Spec.:

U.S.

Manufacturers: R-Ohm (CRB-1/4FX)

Dale,

100

PPM/°C

MIL-R-10509, Style RN55D

TRW/IRC,

,

Corning,

Matsushita

in Reference Designator

appropriate

heading and

ARE:

22101-000

diode, ultra

BAY-61.

I

25nA max.

:

r

fast recovery,

V

@

Section

GENERALLY SPECIFIED BELCW:

exact value as

Beyschlag,

order except

which

must

FSC 1N4148

high

20V

=

r

Vf

:

1.0V

marked on the

the factory or

Carbon Composition

Body: molded

four color bands

I.D. :

Orban P/N:

Power

Rating:

Tolerance

U.S.

: 5%

Military Spec.: MIL-R-11,

Manufacturers:

for

examined to

be

conductance.

max.

refer

Resistors

phenolic

2001X-XXX

(70°C)

Allen-Bradley,

Matsushita

certain

@

If

resistor

Watt

1/4

watt (Body

1/2

RC-20

widely used common

determine

MANY

It may

=

100mA t

body, lest

the Schematic to

to

0.090"

(Body

0.140"

Style RC-07

W)

(1/2

TRW/IRC,

the exact

replaced

be

4ns

:

rr

Stackpole,

value.

max.

performance

obtain

0.250")

x

0.375")

x

(1/4W) or

Carbon

Film Resistors

Body:

conformally-coated

I.D.: four color

bands

Orban P/N: 20001-XXX

Power Rating: 1/4
Tolerance:

Manufacturers:

OBTAINING

SPARE

Watt

5%

R-Ohm (R-25)

Phillips,

PARTS

Because special or subtle

design at a reasonable

notations in the Parts

cases,

the factory should

70°C

@

Piher,

,

Spectral, Matsushita

characteristics

cost, it is unwise to

Beyschlag, Dale,

certain

of

make

List indicating "Selected" or

be consulted if optimum

Orban normally maintains an inventory of tested,

future demand

When ordering

-

-

-

Orban can supply

the factory for the contents of

or

for this

Parts

maintenance.

extensive

quickly at

parts from the

The Orban

The Reference

A brief

description

standardized Spare Parts

unit have

The U.S.

distribution

nominal cost.

factory, we will need

Number, if

Part

Designator for a

of the part

been chosen

headquarter addresses

facilities

throughout the world and

ascertainable

defective component

Kits for

such kits

and

from the catalogs of

are listed at the end

Cermet

Trimmer

Body:

I.D.:

Orban P/N:

Power Rating:

Resistors

3/8"

square

printed

marking on

20510-XXX, 20511-XXX

1/2

Tolerance : 10%

Temperature

Manufacturers:

Coefficient:

Beckman (72P,

Matsushita

components are exploited in

substitutions for listed

"Realignment

Required" when replacing

performance is to be

replacement spare parts to supply any

exact

all of the

following

-From

parts. It is also

maintained.

information:

the Serial

-The exact Model Number

-The Serial

-The "M" number, if any

production life.

this

their

product

prices.

well-known

may often be

during

its

manufacturers

of the Parts List.

contacted through

(9mm)

side

order

70°C

@

100 PPM/°C

to

Watt

Label on the

Number

for

ease

Most manufacturers

68W- Series),

Spectral,

produce an elegant

unwise to

ignore

components. In

present or

rear

Consult

future

in

normal

your

have

local offices.

Rev. 01

such

dealer

1/86

26

Cl,

2 Ceramic Disc,

1KV,

10%; O.OOluF

21112-210

CRL

DD-102

C419,420 Ceramic

Disc,

1KV,

10%; O.OOluF

21112-210

CRL

DD-102

Diodes

CR601

LED,

Red

CR707

LED,

Green

Inductors

LI,

2 Inductor,

RF

Choke,

ImH,

160

mA 29502-000

MIL 4662

Miscellaneous

NONE

Fuse, 3AG,

Slo-Blo,

1/8A

28004-113

LFE 313.125 BUS

NONE

Line Cord,

AC,

3 Wire

28101-000

BEL

17534

NONE

Transformer,

Power,

38 VCT,

4.3 VA 29001-000

Resist

ors

ho

R9,10

R109,110

Rill,

112

R115,116

R209,210
R211,212

R215,216

R309,310

R311,312
R315,316
R409,410

R411,412
R415,416

Switches

S101,102

Swi tch

,

Toggle,

Min.

,

SPDT

26037-009

CK 7101SYA

S201,202

Switch,

Toggle, Min.

,

SPDT

26037-009

CK 7101SYA

S301,

302

Switch, Toggle,

Min.

,

SPDT

26037-009

CK 7101SYA

S401.402

Switch, Toggle,

Min.

,

SPDT

26037-009

CK 7101SYA

FOOTNOTES:

(1)

See last page for

abbreviations

(4)

Realignment

may

be required if

replaced,

see

(2)

No

Alternate Vendors known

at

publication

Circuit

Description

and/or

Alignment

(3)

Actual part is specially

selected from

Instructions

part listed, consult

Factory

Pot,

Single,

5K

20%,

CW Log

20717-000

CTS

Pot,

Concentric,

20K/100K

10%,

OCW Log 20718-000

CTS

Pot, Dual,

50K/50K

10%,

OCW

Log

20708-001

CTS

Pot,

Concentric,

20K/100K

10%,

OCW

Log 20718-000

CTS

Pot,

Concentric,

20K/100K

10%,

CCW Log 20718-000

CTS

Pot,

Dual,

50K/50K

10%,

OCW

Log

20708-001

CTS

Pot,

Concentric,

20K/100K

10%,

CCW Log 20718-000

CTS

Pot,

Concentric,

20K/100K

10%,

CCW Log 20718-000

CTS

Pot, Dual,

50K/50K

10%,

CCW Log

20708-001

CTS

Pot,

Concentric,

20K/100K

10%,

CCW Log 20718-000

CTS

Pot,

Concentric,

20K/100K

10%,

CCW

Log 20718-000

CTS

Pot, Dual,

50K/50K

10%, CCW Log 20708-001

CTS

Pot,

Concentric,

20K/100K

10%,

OCW Log 20718-000

CTS

25103-000

GI MV-5053

FSC

25104-000

GI MV-5253

FSC

fO

CO

REF

VEN

ALTERNATE

-

DES

DESCRIPTION

ORBAN P/N

(1)

VENDOR

P/N VENDORS

(1)

NOTES

PCB MAIN

ASSEMBLY

Capacitors

C3-6 Tantalum,

35V,

10%;

0.33uF

21307-433 SPR

196D334X9035HA1

MANY

C7,8

Mica, 500V,

+l/2pF

-l/2pF; lOpF

21017-010

CD

CD15-CD100D03

C101-104 Capacitor

Set, .0015uF and .015uF

28501-001 ORB

C107,108

Mica, 500V,

5%;

12pF

21020-012

CD CD15-CD120J03

C109,110

Tantalum, 35V,

10%;

6.8uF

21307-568 SPR

196D685X9035KA1

MANY

C201-204

Capacitor

Set,

.005uF and ,05uF

28501-002

ORB

C207,208

Mica, 500V,

+l/2pF -l/2pF; lOpF

21017-010

CD

CD15-CD100D03

C301-304

Capacitor Set,

.018uF and

,18uF

28501-003 ORB

0307,308

Mica, 500V, +l/2pF

-l/2pF; lOpF

21017-010

CD CD15-CD100D03

C401-404

Capacitor Set,

.062uF and .62uF

28501-004 ORB

C407-410

Tantalum, 35V,

10%;

6.8uF

21307-568

SPR

196D685X9035KA1

MANY

C411, 412

Tantalum,

15V,

10%;

15uF

21304-615

SPR

196D156X9015JA1

MANY

C413,414 Mica,

500V,

5%;

12pF

21020-012

CD

CD15-CD120J03

C415,416

Tantalum,

15V,

10%;

22uF

21304-622

SPR

196D226X9015KE3

MANY

C501

Mica,

500V,

5%;

22pF

21020-022

CD

CD15-ED220J03

C502

Mica,

500V,

5%;

180pF

21020-118

CD

CD15-FD181J03

C601-604

Ceramic

Disc, 50V,

+80% -20%; 0.005uF

21108-250

CRL CK-502

0605,606

Ceramic

Disc,

25V,

20%;

0.15uF

21106-415

CRL

UK25-154

0701,702

Alum.,

Axial, 40V,

-10%

+100%;

470uF

21224-747

SPR

TVA-1315-1000-40

SIE,PAN

0703,704

Alum.,

Radial, 25V,

-20%

+100%;

lOOuF

21206-710 PAN

ECE-A1EV1

01S

C705-714

Monolythic

Ceramic, 50V,

20%;

O.luF

21123-410

SPR

1C25Z5U104M050B

Diodes

CR701-706

Diode,

Rectifier, 400V, 1A

22201-400

MOT 1N4004

MANY

Integrated

Circuits

IC1,

2

Linear, Single

Opamp

24009-202

NAT LF356N

10101,102

Linear,

Single

Opamp

24010-202 NAT

LF357N

10201,202

Linear,

Single

Opamp

24013-202

TI TL071CP

10301,302

Linear,

Single

Opamp

24013-202 TI

TL071CP

10401,402

Linear

,

Single

Opamp

24013-202

TI

TL071CP

10501,502

Linear,

Dual

Opamp

24202-202 RAY

4558NB

MOT,

FSC

10601,602

Linear,

Single Opamp

24002-202 NAT LM741CN

TI

IC701

D.C.

Regulator, 15V

Positive

24304-901

FSC

F78M15UC

IC702

D.C.

Regulator, 15V Negative

24303-901

FSC

F79M15AUC

Transistors

Q401-404

Transistor,

Signal,

NPN

23202-101

MOT 2N4400

FSC

Q405-408

Transistor,

Signal,

PNP

23002-101

MOT 2N4402

FSC

Q601.602

Transistor, Signal,

NPN

23201-101

MOT 2N4123 FSC

P/L REVISIONS 06013-VER-09 CHASSIS

ASSEMBLY

30115-VER-Q9

PCB MAIN ASSEMBLY

FOOTNOTES:

SPECIFICATIONS

AND SOURCES FOR

(1)

See

last page

for abbreviations

(4)

Realignment may be required

if replaced, see

REPLACEMENT PARTS

(2)

No

Alternate Vendors

known

at publication

Circuit Description and/or Alignment

EQUALIZER MODEL 622A/B

PCB MAIN

ASSEMBLY

Capacitor s/Diode

s/ICs/Transistor s

(3)

Actual

part is

specially selected from

part listed,

consult Factory

Instructions

AB

AD

AM

BEK

BEL

BRN

BUS

CD

CH

CK

COR

Vendor

Codes

Allen-Bradley

Co.

CJRL

1201

South

Second

Street

Milwaukee,

WI

53204

Analog

Devices, Inc.

Route

1,

Industrial

Park

P.O.

Box

280

CTS

Norwood,

MA

02062

Amphenol

North

America

An Allied

Company

ECI

2122 York

Road

Oak Brook,

IL 60521

Beckman

Instruments,

Inc.

ERE

Helipot

Division

2500 Harbor

Blvd.

Fullerton,

CA 92634

EXR

Belden Corporation

Electronic

Division

Richmond, IN

47374

FDY

Bourns, Inc.

Trimpot Products Division

1200 Columbia Avenue

Riverside, CA

92507 ESC

Bussmann

Manufacturing

Div.

McGraw-Edison Company

P.O. Box 14460

GI

St.

Louis, MJ

63178

Gornell-Dubilier

Electronics

150 Avenue

"L"

Newark, NJ

07101

HP

Cutler-Hammer

Landmark

Office

Center

2081

Landings Drive

INS

Mountain

View, CA

94043

C

S

K Components,

Inc.

15 Riverdale

Avenue

IRC

Newton,

MA 02158

Centralab,

Inc.

A

North

American

Company

5757

North

Green Bay

Ave.

Milwaukee

,

WI

53201

CTS

Corporation

905

North

West Blvd.

Elkhart,

IN 46514

Electrocube

1710

South Del

Mar Avenue

San

Gabriel,

CA

91776

Erie

Tech.

Products,

Inc.

644

West Twelfth

Street

Erie,

PA

16512

Exar

Integrated

Systems, Inc.

P.O.

Box

62229

Sunnyvale

,

CA

94088

F-Dyne

Electronics

Company

449 Howard

Avenue

Bridgeport,

CT 06605

Fairchild

Camera

&

Instr. Corp.

464

Ellis Street

Mountain

View,

CA 94042

General

Instruments

Optoelectronics

Div.

3400

Hillview Avenue

Palo

Alto, CA 94304

Hewlett-Packard Corporation

1501 Page Mill Road

Palo Alto, CA 94304

Intersil, Inc.

10710 North Tantau

Avenue

Cupertino,

CA 95014

TRW/IRC

Resistors

401

North Broad Street

Philadelphia, PA

19108

MAL Mallory Timers

Company

RCA

Emhart ElectricalAlectronic

Gr.

3029 East Washington Street

Indianapolis,

IN 46206

SAE

ME

Mepco/Electra,

Inc.

Columbia Road

Morristown,

NJ

07960

SCH

MIL J.W. Miller Division

Bell Industries

19070 Reyes Avenue

P.O. Box

5825

SIE

Ccmpton, CA 90221

MOT

Motorola, Inc.

P.O.

Box 20912

Phoenix, AZ 85036

SIG

NAT

National Semiconductor

Corp.

2900 Semiconductor

Drive

Santa Clara, CA

95051

SPR

NCB Noble

Teikoku Tsushin Kogyo

Co.

Ltd.

335,

Kariyado, Nakahara-ku

Kawasaki

211,

JAPAN

STK

CUM Ohmite Manufacturing Company

A North

American

Philips Co.

3601

Howard

Street

SYL

Skokie,

IL 60076

ORB Qrban Associates, Inc.

645 Bryant Street

San

Francisco,

CA 94107

TI

PAK

Paktron

Div. of Illinois Tool Works

Inc

900

Follin Lane, S.E.

WES

Vienna,

VA

22180

PAN

Panasonic

Electronic

Components Div.

P.O. Box 1503

WIM

Seacaucus, NJ 07094

Corcom, Inc.

1600 Winchester

Road

Libertyville, IL

60048

LFE

Littelfuse

A Subsidiary of

Tracor

800 East

Northwest Highway

Des

Plaines,

IL

60016

RAY Raytheon Semi

conductor Division

350 Ellis Street

Mountain View, CA

94042

RCA

Solid

State Division

Route

202

Somerville,

NJ 08876

Stanford

Applied

Eng.

340 Martin

Avenue

Santa Clara,

CA 95050

ITT Schadow,

Inc.

8081 Wallace Road

Eden Prairie, MN

55343

Siemens

Components

Division

186 Wood

Avenue, South

Iselin,

NJ 08830

Signetics

Corporation

A

Sub.

of

US Philips

Corp.

P.O.

Box 9052

Sunnyvale,

CA

94086

Sprague

Electric Co

125

Marshall Street

North

Adams, MA

01247

Stackpole

Components Co

P.O. Box

14466

Raleigh,

NC

27620

Sylvania

Conn. Prod. Op.

GTE

Products Corp.

Box

29

Titusville, PA 16354

Texas Instruments

P.O. Box

225012

Dallas, TX

75265

Westlake

5334 Sterling

Ctr Drive

Westlake

Village, CA 91361

WIMA

P.O.

Box 2345

Augusta-Anlage

56

D-6800

Mannheim

1

GERMANY

H3

k

53

Orban

Associates

Inc.

TITLE:

ASSEMBLY

DRAWING

MODEL 622A/B

30

T

1

5-VER-08

Orban

Associates

Inc.

SCHEMATIC

MODEL

622A/B

600 )

3

-

000-09