Arp Omni User Manual

;

Scan by Manual Manor

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OMNI

Model

2480

SERVICE

MANUAL

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MAINTENANCE

O.SCLOSED

AS

TO

APPROPRIATE

OTHERS

ARP

INSTRUMENTS,

320

Needham

Newton,

(617)

Document

ARP

IT

IS

WITHOUT^

THE

NOT

'IxSSIJigSJKg&Sy

Number

©

February,

INSTRUMENTS,

TO

BE

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INC.

Street

MA

02164

965-9700

90020000

1977

INC.

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£PJRATI0N

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TO

ARP

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.NSTRUMENTS.

THE

EQUIPMENT

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,NC.

,T

IS

AND

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IT

T0

BE

OMNI

Scan by Manual Manor

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Model

2480

SERVICE

TABLE OF

1.

INTRODUCTION

1.1

1.2

1.3

2.

THEORY

3.

CIRCUIT

3.1

3.2

3.3

3.4

3.5

3.6

3.7

Product

Specifications

Function

Upper

Lower

String

Synthesizer

Phaser

Power

Description

OF

OPERATION

DESCRIPTIONS

Voicing

Control

Board

Supply

Board 5

Board

Control

Board

Board 9

MANUAL

CONTENTS

2

3

5

6

8

10

11

4.

ASSEMBLY/DISASSEMBLY

5.

GENERAL

6.

CALIBRATIONS

7.

SCHEMATICS & LAYOUTS

8.

PARTS

INFORMATION

LIST

12

13

14-33

34-36

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tiro

4—|

Swran r "*»■"

nnnnjnh

1.3

Function

1;

string

2

LFO

Frequency

3

Master

the

mixed

4

Waveform

produced

sound.

5

Chorus

through

reduces

pressed

string

Description

Control:

voices

and

Speed:

Varies

Oscillator.

Volume:

output.

Enhancement:

by

the

Phaser:

the

string

the

phase

the

synthesizer

output

as

[^

Determines

the

synthesizer

the

frequency

Determines

Omni

to a hollow

Routes

well.)

the

section's

shifters

output

volum

SUSTAIN

FOOT

SWITCH

the

balance

voices.

overall

Alters

>

synthesizer

phase

speed.

appears

of

the

of

the

Low

/

volume

of

waveforms

like

(square)

output

shifters

and

(When

on

de

the

18)

r

SYSTEM

INTERFACING

TRIG

OUT OUT ACCESSORY

11

VCF

synthesizer

12

VCF

13

VCF

range

14

Violin

ranges.

15

Bass,

(low note

only).

16

Attack:

17

Release:

string

(16)

•, r VCF

GATE

ADSR

section.

LFO

Slider:

Pedal

and

of

external

and

Cello:

priority,

Determines

section

(17)

CONTROL

INPUTS

PEDAL

Slider:

Viola:

Determines

Accessory

pedal

Slider:

or

accessory.

Selects

bass

string

lowest octave

attack

the

final

(also

effects

synthesizer

(15)

(14

-,

brightness

depth

of

tremelo.

Determines

the

string

pitch

ranges

and a half

of

string

section.

release

time

release).

of

6

Synthesizer

tion's

7

Synthesizer

sizer's

and

4'

half).

8

ADSR

attack

sizer

9

VCF

frequency

10

VCF

resonance

8\

pitch

ranges.

Bass

bass

voices

Envelope

and

decay

section.

Frequency

cutoff

Resonance

("wow"

4':

Selects

8',

and

in

bass

Generator:

characteristics

Slider:

point.

Slider:

effect).

the

synthesizer

16':

Selects

disables

range

synthesizer

(first

Determines

of

Sets

the

Sets

degree

the

octave

VCF's

sec

synthe

and

the

synthe

initial

of

VCF

8'

a

18

Bass

Volume:

synthesizer

19

Sustain

foot

switch

slider

settings).

20

Gate

and

connect

21

Accessory

input

so

ternal

sources

Sample

effects.

22

Pedal

Jack:

Determines

16',

8'

Foot

Switch:

is

depressed

Trigger

to

other

synthesizers.

Jack:

that

VCF

such

and

Hold

Used

bass

volume

and

bass

and

cello.

Sustains

Output

Connected

may

as

the

outputs,

to

connect

all

notes

(regardless

Jacks:

to

VCF

be

controlled

ARP

Sequencer

etc.

for

VCF

filter

for

when

of

release

Used

to

control

by

ex

or

special

pedal.

MASTER

Scan by Manual Manor

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OSCILLATOR

1

line

TOP

OCTAVE

DIVIDER

J-LTL

12

lines

FREQUENCY

DIVIDERS

SIMPLIFIED

OMNI

49

WAVE

SHAPERS

21

BLOCK

lines

GATE

CIRCUITS

lines

DIAGRAM

PHASER

STRING

VCA

BUS

RODS

BASS

AR

KEYING

CIRCUITS

21

lines

BASS

PRIORITY

CIRCUIT

STRING

AR

STRING

I

VCF

j

SYNTHESIZER

SECTION

chorus

switch

a

ADSR

1

VCA

envelope

generator

SECTION

j

OUTPUT

MIX

OUTPUT

O

SYNTHESIZER

OUTPUT

O

SECTION 2 THEORY

Scan by Manual Manor

http://www.markglinsky.com/ManualManor.html

The

OMNI's

master

scale

integrated

octave

the

instrument.

remaining

squarewave

a

sawtooth

the

waveshape

The

tones

transistor

string

section

tor

gating arrays

connected

(how

long

determined

input.

i

The

outputs

routed

section.

tone

generator

oscillator

divider

gating

to

at

500

circuit

produces

Frequency

pitches

to

from

outputs

form

from

the

by

the

of

each

(the

waveform

to a differentiated

the

waveform

arrays

which

and

the

synthesizer

are

'keyed'

each

key.

The

note

remains

the

release

of

all

the

gating

string

section

circuitry

kHz.,

top

octave

the

highest

the

top

divider

route

release

after a key

capacitor

arrays

OF

OPERATION

consists

which

drives a large

divider.

dividers

octave

are

enhancement

generator

the

section.

on

by

time

The

twelve

tones

derive

divider.

waveshaped

squarewave).

are

fed

signal

The

transis

an

RC

circuit

of

each

release)

on

each

are

summed

and

the

/synthesizer

of

a

top

in

the

The

to

alters

to

the

key

is

gating

and

The

string

section

shifters

from

processed

control

trolled

circuit).

The

the

Voltage

controlled

synthesizer

section

selected.

the

string

together

output

which

the

by

modulate

gating

through a Voltage

attack

the

"*

synthesizer

arrays

phasers

Chorus

section

of

is

section

through a Voltage

Controlled

by

an

output

when

The

speed

Phaser

and

in

the

instrument. A separate

provided

consists

circuits.

characteristics.

release

Amplifier,

ADSR

can

of

is

the

synthesizer

Mix

for

of

three

the

sawtooth

The

phaser

Controlled

(The

capacitor

processes

on

the

Controlled

both

Envelope

be

routed

through

the

Chorus

the

phasers

selected.

Circuitry

stereo

Phaser

is

The

section

and

effects.

parallel

waveforms

outputs

Amplifier

release

each

gate

outputs

Filter

of

which

Generator.

reduced

outputs

are

routed

synthesizer

phase

are

to

is

con

gating

of

and

are

The

the

string

Switch

is

when

of

the

summed

to

the

SECTION

3.1

Upper

GENERAL:

Master

Dividers,

Keying

ten

Gate

Keying

Lower

tics

for

3.1.1

(Refer

L1

and

approximately

tor

can

(externally

waveform

to

the

Scale

Integrated

highest

(C6-C7).

3

Voicing

The

Upper

Oscillator,

Wave

Circuits

Circuit

Circuits

Voicing

this

MASTER

DIVIDER

to

Q1

be

Top

octave

Top

Shaping

for

keys

I.C.'s.

and

Board. (Note:

board.)

OSCILLATOR

Upper

Voicing

produce a 0

500KHz.

varied

by

accessible).

from

the

Octave

Circuit)

(square

CIRCUIT

Board

Voicing

Octave

Gate

Master

Divider,

Divider

for

tones

21

through

The

remaining

I.C.'s

There

AND

Schematic,

to

—15

The

frequency

adjusting

Z1

the

buffers

Oscillator

Z2.

divider

waves)

which

DESCRIPTIONS

|

Board

contains

I.C.,

C7

through

49

and

Waveshaping,

are

located

are

two

TOP

sheet 1 of

volt

sine

of

the

core

of

and

squares

and

Z2

is a LSI

produces

of

the

instrument

the

Frequency

C4,

six

of

the

on

the

schema

OCTAVE

2.)

wave

at

oscilla

the

coil

the

supplies

it

(Large

the

3.1.2

(Refer

The

clock

which

wave

inverters

The

are

selected

the

resulting

DIVIDER

to

square

inputs

produce

outputs

AND

Upper

Voicing

wave

outputs

of

CD452OBE

square

of

the

Z9-Z16.

+v

Waveform

square

differentiated

negative

converter

waves

rrom

by

for

each

frequency).

portion

in

sawtooth

WAVE

SHAPING

Schematic,

from

Z2

are

divider

waves

for

each

key.

CD452OBE's

and

waveform

inverters

capacitors

of

the

differentiated

shaped

are

enhancement

Z9-Z13

C17-C49

CR1

through

waveforms.

CIRCUITS

sheet 1 of

supplied

chips

The

buffered

and

(values are

square

By

2.)

to

the

(Z3-Z7)

square

by

from

Z2

CR41

clip

wave

altering

the

Scan by Manual Manor

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DC

bias

(P6-7,

the

negative

permitted

Waveform

"hollow"

3.1.3

(Refer

Each

to a 22uf

resistor.

(The

When a key

to

—15

to 0 volts

be

varied

Control

key

(indicated

circuits;

portion

to

pass

Enhancement

type

sound.

KEYING

to

Upper

key

contact

electrolytic

The

capacitor

negative

side

is

depressed,

volts.

The

sets

the

by

the

Board.

one

The

by

for

8',

Waveform

of

the

through

Control

differentiated

diodes

is

selected

CIRCUITS

Voicing

(P7-5,

Schematic,

P7-4,

P7-3,

capacitor

is

normally

of

the

capacitor

the

capacitor

time

the

capacitor

release

time

release

letters

slider

key

voltages

KV)

one

for

are

4'.

Bus)

waveform

CR1-41

etc.)

through

charged

is

takes

of

each

(R31)

produced

supplied

when

resulting

sheet 2 of

is

connected

a

to 0 volts

at

—15

is

discharged

to

note

on

the

to

some

of

is

the

in

a

2.)

470ohm

volts.).

recharge

and

can

String

for

each

two

gate

as

the

inputs

used

for

4'

pitches

one

key

controls

The

Upper

arrays

the

Lower

base

forms

resistor

pack

Z30

voltages

also

through

as

the

tor

remains

voltage

sistor

the

collector

cuitry

3.2

Voicing

and

three

Voicing

(7)

grounded.

are

supplied

(e.g.

Tone G 4

pins 5 and 6 to

(denoted

150Kohm

keying

voltage

off.

drops

in

the

array

of

(e.g.

from

Lower

Voicing

to

the

devices.

and

five

two

gate

Board

8'

arrays;

Board.

Each

to

an

emitter

by

KV)

resistors

is

at

When a key

to

—15

volts,

and

permits

the

array

12

of

Board

Five

of

the

for

8'

pitches.

chips

at a time

contains

the

remaining

All

of

three

arrays

the

arrays

the

sawtooth

through a lOOKohm

is

supplied

are

supplied

or

near 0 volts,

is

which

and

Z31

through

12

of

Z31.).

to

the

(e.g.

KV21).

depressed,

turns

on

the

signal

out

to

the

to

14).

arrays

are

Therefore,

(4'

and

8').

4'

gate

are

on

have

the

wave

resistor

Keying

emitters

As

long

the

transis

the

keying

the

tran

to

pass

to

mixing

cir

KEY

CONTACT

BUS

ROD

J

-15V

Keying

3.1.4

(Refer

There

(TDA470)

tone

Gate

with

GATE

to

Upper

are a total

in

generator

has

ten

common

■15

470

ohm

3.3K

150K

22uf

t

-15V

100K

\

SAWTOOTH

WAVE

(TONE)

JL_

SUPPRESSION

TRIGGER

AND

STRING

RELEASE

CONTROL

and

Gating

CIRCUITS

Voicing

the

OMNI

sections

transistors

collectors

Schematic,

of

10

gate

which

to

the

(on a common

and

bases.

TDA470

TRANSISTOR

ARRAY

circuit

sheet 2 of

transistor

gate

signals

output

section.

substrate)

The

emitters

2.)

arrays

from

the

Each

serve

GENERAL:

Bass

Low

circuitry,

keys 1 through

G3#

and

3.2.1

The

Lower

Note

Priority

Gate

Sensing

8'

and

16'

20,

Gate

Waveshaping

WAVESHAPING,

CIRCUITS

(Refer

The

board

Voicing

detailed

3.2.2

(Refer

The

note,

lowest

through

fixed,

control

polyphonic

and

The

to

(only)

shaping

to

Lower

Voicing

Waveshaping,

are a

Board.

Gating

continuation

See

sections

descriptions.

BASS

to

8'

low

octave

the

generates

function

route the

in

LOW

Lower

Voicing

and

16'

Bass

note

priority.

and a half

20).

The

release

over

the

circuits

control

the

Bass

tones,

the

only

square

of

the

square

wave

Bass

section

(through

Voicing

Board

circuitry,

Bass

circuitry,

circuits

for

KEYING

Suppression

Keying

for

tones

AND

Schematic,

and Keying

of

the

circuits

3

1.2,

3.1.3

NOTE

section

Bass

PRIORITY

Schematic,

of

the

The

Bass

section

of

the

keyboard

time

of

the

on

the

front

section.

Bass

Unlike

Priority

waves.

Low

Note

of

the

lowest

to

the

8'

and

CR41-60)

contains the

4'

and

8'

Mixing

Trigger

circuits

tones

C2

through

C2

through

GATE

sheet 1 of

circuits

OMNI

Circuit

Priority

note

for

on

the

Upper

and

3.1.4

CIRCUIT

sheet 2 of

is

single

covers

(Keys

Bass

section

panel

has

the

4'

and

receives

circuit

depressed

16'

Bass

Wave-

processing.

for

G3.

3.)

this

for

3.)

the

1

is

no

8'

is

The

Scan by Manual Manor

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may

Bass

Waveshaping

only

accept

one

circuits

waveform

are

at a time.

monophonic;

they

(Z33-Z47)

keys

to

transmit

higher

than

the

one

serially

a

logic 1 state

depressed.

to

all

Square

Voicing

three input

outputs

only

Z33B

are

NOTE:

section

Metal

particular

ground

voltage

KEYING

The

only

and

The

Z33B,

provided

circuit

wave

tones

Board

frequency

nor

of these

when

the

other

pin 6 is a square

at

logic

0.).

All

logic

are

COSMOS

Oxide

Semiconductor)

application,

and — 15

between

(B)

VOLTAGE

output

when

"enable"

under

ground

—7.5

(A)

ENABLE

(C)

of

the

Enable

the

Keying

input

3)

will

no

keys

examination.

C2-G3

are

dividers

gate

for

each

nor

gates

two

wave

gates

in

the

(Complimentary

they

volts.

Therefore,

and

volts

and

<—H

the

NOR

gate

(A)

voltage

of

the

three

always

are

be a logic 0 (—15

depressed

routed

are

inputs

only

Bass

from

the

to

one

input

key

(Z33-Z39).

inverted

square

are a logic 0 (e.g.

if

pin 4 and

Low

Note

Symmetry

devices.

are

operated

a

logic 1 is

—7.5

volts,

logic 0 is

-15

volts.

will

be a square

input

is a ibgic 0 (-15V)

is

less

than

-7.5V.

input

nor

gates

to

the

left

Upper

of

a

The

waves

3

Priority

For

this

between

any

wave

(e.g.

volts)

of

the

(C)o

The

ENABLE

|B)o

Enable

Keying

is

charge

not

keys

of

keying

3.2.3

(Refer

The T point

supplies a voltage

Low

diode

to

drops

insures

bus

depressed.

3.2.4

(Refer

(A)

is a logic 0 oniy

voltage

release

fixed

path

depressed

are

Q1-20

(bus

BASS

to

is

time

at

about

is

provided

to

depressed,

is

always

rod)

KEYING

Lower

of the

Note

Priority

drops

higher

the

Lower

are

that

voltage

GATE

keyboard

created

Q1-20

which

DETECTOR

to

Lower

less

than

(decay

2.5

seconds,

shorten

Q1-20

held a full

voltage

Voicing

Bass

to

Circuit

than

using

will

Voicing

when

Enable

-7.5V

(logic

time

after

keys

however,

through

Q1-20

the

release

are

off.

The

diode

in

the

reference.generator.

VOLTAGE

Schematic,

Keying

the

bus rod

CR114,

be

decreases

Reference

bass

of

Q1-20

which

the

keying

(P1-14).

Q30

biased

ON

as

is

and

more

CIRCUITS

Schematic,

ENABLE

o{A)

(C)

and

the

0).

are

released)

an

additional

for

those

keys

time.

When

no

base

voltage

drop

above

the

sheet 3 of

3.)

Generator

of

the

Bass

at

least

three

voltage

regardless

supplied

The

diode

CR113.

This

of

the

keys

are

sheet 3 of

3.)

When a key

discharges

transistors

C42

through

depression.)

the

capacitor

through a 3.3Mohm

voltage

gates

permits

input

provided

volts

no

lower

The

keying

COSMOS

is

depressed,

a

1uf

(Q1-Q20).

R7r

When a key

is

routed

(e.g.

Z33B,

the

square

of

the

three

that

A)

and

B)

the

keys

are

voltage

inverter

sustain

Q2

allowed

to

the

enable

being

—15

volts

capacitor

'{e.g.

Key

and

CR63

is

released,

to

charge

resistor

an

wave

input

keying

(e.g.

input

of

4).

Thus

to

be

transmitted

nor

voltage

input

is a logic 0 (indicating

played).

is

also

processed

(Z45-Z47)

from

the

bus

through

2,

P1-12

discharges

to

-15

volts

the

voltage

back

to 0 volts

R5).

This

the

three

input

the

keying

from

gate

to

the

is

less

than

through

and a nor

rod

keying

on

key

on

keying

nor

voltage

the

output

-7.5

a

gate

There

are

two

bus

rods

lowest

the

(Bass

20

keys,

bus rod

AR)

in

to

one

for

this

manner

be

developed

keys.

CR107

source

through

is

volts

R130

across

differentiated

comparator

volts

duration,

(Upper

for

CR107

depressed,

to

ground

on

R130.

to

Bass

the

upper

and

comparator

(Gate).

key

depression

The

by

Z52A

-15

volts

longer

Gate

bus

R130to

voltage

C86

momentarily

and

for

in

the

OMNI,

the

upper

29

keys.

permits a bass

separately

Detector)

rod.

the

Z52B

The

current

results

change

so

back

multi-key

from

is

—15

volts

bus

rod.

switches

drawn

in a voltage

across

that

the

switches

again

(10ms.

depressions).

one

for

the

Splitting

envelope

the

higher

the

voltage

is

supplied

When a key

from

—15

through

drop

R130

is

output

from

of

+15

typical

This

pulse

Scan by Manual Manor

http://www.markglinsky.com/ManualManor.html

is

used

for

triggering

(ADSR)

not

3.2.5

(Refer

The

Priority

gated

and C77.

when

when a key

CR105

Z51A.

amplitude

couples

and

Q22).

samej(+7V).

rising

clipping

sawtooth

down

synthesizer

and

signal.

8'

in

for

provided

3.2.6

(Refer

The

clipping

key.

waveforms

+15

ground

off,

a

little

+15

about

NOTE:

output

more

input,

by

This

specialized

and

to

discharge

being

played.

8'

AND

16'

to

Lower

single

square

Circuit

through a "VCA"

no

to

As

the

8'

The

edge

off

(U2)

The

Bass

keys

are

is

depressed.

clip

the

AR

of

the

square

Bass

Waveshaping

base

and

This

of

the

falling

waveform

by

R114

Bass

signal.

resonated

The

square

half

(Z49).

the

by

16'

Bass

wave

from

CR106,

16'

Bass

as

with

the

WAVEFORM

to

Lower

Waveform

diodes

When

volts,

when

+15

volts

extra

volts

+13.5

Control

in

the

output

are

produced.

the

"hollow"

the

when

voltage

since

the

volts

by

The

CA339E

comparator.

negative

the

external

device

in

output

"pull

is

not a standard

comparator

BASS

Voicing

wave

is

AR

depressed

square

voltage

square

wave

emitter

means

squarewave

on

the

and

Q22

Waveshaping

Z51A

R119

circuit.

8'

Bass

CONTROL

Voicing

the

Waveshaping

Waveform

the

to

op

amp

itself.

When

voltage

is

open;

up"

resistor

(no

the

Envelope

sustain

capacitors

WAVESHAPING

Schematic,

from

buffered

made

voltage

and

This

voltage

wave

drops

wave

to

an

emitter

(R116,

of

that

only

will

edge

of

emitter

R174

The

sawtooth

and

used

and

Buffer

(Q23

Schematic,

sets

the

of

Z53

When

sound

Enhancement

switch

is

the

output

cannot

(Z52)

is

the

inverting

than

the

voltage

circuits

sheet 3 of

the

Bass

through

up

of

CR105,

(J11-8)

drops

to

sets

on

the

from

ground,

increases.

follower

C78,

Q21

are

the

differentiated

bias

Q21

the

squarewa've.

of

Q21

and

used/for

is

for

the

accepts

divides

the

C80

are

and

filtering

and

Q24)l

sheet 3 of

bias

point

circuits

is 0 volts,

the

output

is

produced.

on.

CR107

when

supply

an

open

input

the

noninverting

is

or

op

amp;

feedback).

Generator

on

keys

3.)

Low

Note

Z51A

and

R112

is 0 volts

—15

volts

the

bias

of

output

R117,

biased

of

the

C77

AC

(Q21)

C79,

the

on,

thus

The

is

divided

the

also

altered

string

bass

buffered

frequency

the

"VCA"

are

3.)

of

the

for

each

sawtooth

of

Z53

is

J11-9

is

switch

the

more

collector

determined

networks.

is

provides

input

is

than

(—)

is

(+)

it

is

a

The

Lower

Bus

Trigger

Bus

Gate

Detector

Bus

circuitry.

R150

creates

trigger

The

Upper

the

base

drive

circuit

common

each

key.

keying

from

running

maximum.

3.2.7

4'AND

(Refer

The

outputs

arrays

circuits.

instrument.

blocking

section

Bass

switches

Bass

controls

diodes.

The

4'

are

routed

theOMNI.

3.3

String

GENERAL:

String

AR

Squelch

Suppression

key

depressions,

times.

The

AR

to

capacitors

Voice

Selection.

3.3.1

(Refer

to

Z1

is a COSMOS

pitch

ranges:

bass.

Z3A

to

the

Phaser

Synthesizer

signals

Pins

1, 2 and

voices

are

CR112

the

voltage

on

key

depression.

and

Lower

of

Q27

and

sustain

discharge

The

trigger

capacitor

not

together

8'SUM

to

Lower

Voicing

of

the

(TDA470)

Formant

are

filtering

CR101,

diodes

which

(first

20

notes)

are

on.

are

on

Poly

Sum

(J11-16)

to

the

Control

The

String

Envelope

and

String

forces

yielding

AR

Squelch

be

the

same

by

tracking

STRING

and

VOICE

String

Control

Quad

4'

and

sums

the

Board.

section

for

processing

13

disable

selected.

Detector

circuit

are

is

the

difference

Bus

supplied

bus.

path

for

pulse

being

when

Schematic,

five

4'

summed

CR102,

disable

when

Z48

supplies

which

reverse

String

and

circuit

equivalent to

lower

bus

Triggers

via

The

the

keying

rapidly

played

the

and

8'

in

the

is

provided

CR103

the

outputs

the

8'

+15

biases

and

8'

Synthesizer

Board

Control

Generator,

Voice

Selection

the

AR

forces

as

the

release

the

audio

SELECTION

Board

Switch

8r

polyphonic

four

pitch

Z2

(pins

to

be

through

the

Board

AR

to

release

the

proper

the

release

time

level

Schematic.)

which

ranges

3,

4 and

summed

String

AR

and

Lower

the

Upper

voltage

source,

for

the

lower

bus

are

combined

Q26

to

sustain

capacitors

discharges

to

prevent

release

slider

sheet 3 of

gating

4'

and

to

and

CR104

of the

or

16'

Synthesizer

volts

the

Poly

Sum

sections

contains

Suppression,

circuits.

fully

string

time

of

all

from

the

selects

and

8'

and

routes

5)

permits

with

the

Phaser

when

on

the

pulse

bus

is

the

for

any

notes

is

at

3.)

transistor

8'

Sum

voice

the

are

bass

when

the

blocking

(J11-2)

of

the

AR

The

AR

between

attack

of

the

key

String

the

four

and

16'

them

the

String

Board.

no

string

3.3.2

Scan by Manual Manor

http://www.markglinsky.com/ManualManor.html

STRING

(Refer

to

String

Control

The

String

control

VCA

on

integrating

no

keys

gate

signal

0

volts.

volts

which

rate

determined

released,

through

When a key

partially

remains

3.3.3

(Refer

Z4B

monitors

Voice

Z4B

and

(—15V)

reverse

charging

AR

voltage

which

the

Synthesizer

capacitor

are

depressed.

on

Z4A

Comparator

charges

by

the

—15

R37,

38, 39.

is

depressed,

discharge

from

SQUELCH

to

String

Control

the

audio

Selection

as

biases

circuit.

supplies

it

long

as

CR11

faster

than

AR

AND

Board

Envelope

controls

and

When a key

pin 6 changes

Z4A's

C15

the

volts

C15

key

Board

signal

C10

to

Z4C.

an

audio

and

the

AR

Schematic)

Generator

the

Control

is

Board.

normally

from

output

down

toward

attack

slider.

is

allowed

Q3

momentarily

to 0 volts

depressions.

Schematic.)

from

integrates

The

output

signal

prevents

decay

of

SUPPRESSION

produces

gain

of

the

String

C15

is

the

at 0 volts

is

depressed,

changes

—15

When a key

to

if

Z3A

the

of

is

present

the

AR

the*

audio

when

the

—15

volts

to

—15

volts

at a

discharge

turns

on

any

voltage

jn

the

String

output

Z4C

is

low

which

from

dis

signal.

a

to

is

to

of

volts

to

+15

volts

when

the

volts.

This

then

reverses

through

the

When

of

repeats.

3.4.2

(Refer

The

attenuates

gain

current

ADSR

(pin

trimmer

voltage

balancing the current

CR8

external voltages

through

3.4.3

(Refer

R45

and

the

direction

the

Z4A

SYNTHESIZER

AMPLIFIER

of

integration

output

switches

to

of

back

Synthesizer

signals

of

the

supplied

output

3,

Z2)

(R14)

changes

and

R17

the

STRING

AMPLIFIER

to

from

VCA

is

to

the

is

connected

via

P12

minimizes

on

provide

from

output

jack.

VOLTAGE

Synthesizer

rate

Z4B

reaches

to

VOLTAGE

Control

Voltage

the

determined

differential

the

through

output

entering

Control

output

of

Z4B

the

direction

control

—15

(R44)

at

the

output

—5

volts,

volts

and

CONTROLLED

Board

Schematic)

Controlled

output

10.

output

CONTROLLED

of

the

by

the

amount

pair

Z2A,

to

the

control

The

control

the

effect

Z2A

protection

the

Board

of

the

and

Z2B.

OMNI

Schematic.)

reaches

of

the

+5

current

and

thus

of

Z4B.

output

the

cycle

Amplifier

VCF. The

of

B.

The

input

rejection

control

VCA

by

CR7,

to

prevent

circuits

3.3.4

ADSR

BLANKING

The

ADSR

circuit

prevents

pedal

3.4

GENERAL:

the

Synthesizer

Oscillator,

String

Mix

and

3.4.1

(Refer

The

output

20Hz.

from

hysteretic

blanking

on

the

Synthesizer

the

ADSR

is

released.

Synthesizer

The

Synthesizer

Voice

Synthesizer

Voltage

Bass

LOW

to

LFO

in a frequency

Z4B

current

Controlled

AR

Envelope

FREQUENCY

Synthesizer

produces a triangle

and

C11

passing

switch

whose

provides a pulse

Control

from

triggering

Control

Board

when

Control

Selection,

Voltage

Amplifier,

Generator.

OSCILLATOR

Control

range

are

an

integrator

through

output

Low

Controlled

Board

and a square

from

R45.

switches

to

the

ADSR

board

which

the

foot

Board

contains

Frequency

Amplifier,

final

Output

Schematic.)

wave

about

.1Hz

to

which

charges

Z4A

is

a

from

—15

The

String

Voltage

circuit as

controlled

instead

3.4.4

(Refer

The

are

mixed

volume

3.4.5

(Refer

The

Polyphonic

audio

sizer

output

gates

selected.

the

Synthesizer

by

the

of

the

ADSR.

OUTPUT

to

output

of

MIX

Synthesizer

of

the

by

Z5A.

the

two

SYNTHESIZER

to

Synthesizer

four

pitch

range

and

8',

through

Control

of

(TDA470s)

Z1

Board.

the

first

when

Controlled

String

Synthesizer

R23,

signals.

VOICE

push

16'

to

the

CR5

20

notes

the

Amplifier

VCA

except

AR

Envelope

Control

the

Board

VCA

Mix

slider,

SELECTION

Control

Board

buttons,

4',

Synthesizer

VCF

input

and

CR6

disable

of

the

polyphonic

8'

and

16'

is

the

same

that

it

is

Generator

Schematic.)

and

String

VCA

controls

Schematic.)

8'

Synthesizer

Bass

on

the

route the

Synthe

the

audio

tone

pitch

ranges

are

3.5

Scan by Manual Manor

http://www.markglinsky.com/ManualManor.html

Synthesizer

GENERAL:

Voltage

Generator,

Output

3.5.1

(Refer

to

The

four

and

16'

input

of

Voltage

Octave

The

filter

octave)

Z1B

sums

the

VCF.

trimmer,

audio

output

routed

to

3.5.2

(Refer

to

To

"start"

of

Z3A

(Logic

ADSR

Pulse

Drive.

with

no

keys

depressed.

input

(Z4D

and

Z4D.

will

cause

(logic

0)

volts

for

The

Pulse

and

pulses to

is

depressed.

but

drops

released

The

output

(0

volts)

Pulse

The

Controlled

ADSR

Processing

VOLTAGE

Synthesizer

pitch

ranges,

Bass,

are

the

VCF

Controlled

and

has a manually

accepts

on

pin 4 to

and

inverts

R22,

prevents

(pin

the

Synthesizer

ADSR

GATING

Synthesizer

the

ADSR

must

change

1

to

Logic

Gating

to

The

keys

depressed,

The

pin 13)

The

first

Z4C

to 0 volts

as

long

Drive

is

logic 1 (about

The

to

logic 0 when

to

prevent

of

Z4A

but

drops

Drive

pulse

Board

Synthesizer

Filter,

Gating

circuits.

CONTROLLED

Board

4'

summed

(pin

1,

M1).

Filter.

Board

ADSR

and

the

Schematic.)

and

8'

and

voiced

M1

It

has a cutoff of

variable

negative

the

control

external

CVR

the

voltages

(Control

voltages

10).

The

output

VCA

via

Board

Schematic.)

Envelope

Generator,

filter

from 0 volts

0).

Two

signals

set

up

this

condition:

Gate

(J12-7)

is

-15

and 0 volts

Gate

is

supplied

of

R-S

flip

flop

negative

(logic

as

the

normally

ADSR

the

to

or

transition

10

to

change

1).

10

Gate

on

logic 0 (about

-1

volt)

blanking

the

sustain

ADSR

from

is,

therefore,

logic 0 (—15

the

ADSR

contains

the

Envelope

Gate

and

Trigger

FILTER

Polyphonic

is a 4075

Q

voltages

which

Voltage

from

of

J12,

to

must

volts

with

made

from

will

J12-7

every

is

normally

triggering.

normally

volts)

blanking

and

8'

on

the

audio

Low

Pass

24

dB/

(resonance).

(—1

volts/

cutoff

point.

control

Reset)

affecting

the;

the

bejsent

the

one

to

on

remain

is

footswitch

the

VCF

is

output

—15

volts

to

the

Gate

and

(Logic

0)

or

more

the

Reset

up

of

Z4C

8

—15

volts

at

at 0 volts.

-13

volts)

time a key

logic

1,

logic

during

the

pulse.

0

is

1

second

output

3.5.3

The

negative

and

ATTACK:

high

R46

the attack

from

3 and

integrating

DECAY

following

of

turn

Z3D.

falls

—7.5

low

CR4,

turns

and

reverse

R51

RELEASE:

goes

on

Q6

input

the

release

setting

sustain

disabled

occurs

3.6

GENERAL:

identical

Low

responsible

OMNI.

Pulse

Drive

to

logic 0 to

ADSR

the

to

ADSR

off

below

applying

R46

and

low

capacitor

to

sustain

Phaser

Envelope

going

DC

VCA.

When

low,

—15

the

noninverting

mode,

ground.

applies

Z2

—15

capacitor

AND

SUSTAIN:

the

voltage

and

R35

Z3C

and

Z3D

the

threshold

volts)

the

output

—15

R38

and

CR3

on

and

the

establishes

biased

and

CR5

to

the

When

which

turns

C13

ground.

of follower

time.

on

footswitch

whenever

The

and

decay

Q5

the

front panel

by

ADSR

the

Board

The

parallel

Frequency

for

the

directly

approaches

Z2

Oscillators.

will

momentarily

restart

the

ADSR.

Generator

voltage

the

volts

Q4

to

output

is

applied

input

is

off

follows

volts

through

C13

down.

on

capacitor

lowers

volts

the

is a bistable

of

Z3C

from

thus

voltage

capacitor

discharges

divider

the

Sustain

level

at

the

gate

on

Q6.

output

through

charge

and

Q7

to

is

depressed.

Release

footswitch

Phaser

Phase

Shifters

orchestral

circuit

control

of

Z3A

of

follower

and

R45

the

CR6,

Z1A

is a buffer

—10

volts,

voltage

latch.

the

changes

holding

consisting

Level.

C13

discharges

Z2

voltage

The

through

of

Z1A

R59

thereby

paths

from

permit

be

overridden

Pulse

Control

is

released.

Board

each

The

Phasers

string

force

Z3A's

provides

the

VCF

cutoff

changes

through

is

disconnected

voltage

R52

C13.

Q2

on

When

nand

from

10

of

Q2

off.

3.

is

removed,

remaining

R53,

is

applied

affecting

the

release

Drive

pulse

contains

from

CR2

and

Z2.

During

on

to

charge

amplifier

The

output

begins

13

gate

(about

high

Z3

through

Q4

now

of

R45

CR6

is

now

through

Z3B

voltage

R50

and

to

the

preventing

the

slider

when

the

input

which

three

modulated

are chiefly

effects

of

the

a

to

of

13

to

is

by

Z3A

will

change

Z4C

has

changed

logic 1 as well.

until

after

10

Thus

the

from

to

logic 1 and

Z4A

Pulse

logic 1 to

after

delays

the

Drive

pulse

logic 0 then

Z4A

ADSR

has occurred.

when

changes

"starting"

to

A

3.6.1

(See

Oscillator

LFO

Section

3.4.1

circuit.)

for

details

of

the

Low

Frequency

The

Scan by Manual Manor

http://www.markglinsky.com/ManualManor.html

three

Low

Frequency

modulate

to

Pin 1 of

clipped

R128

depressed,

3.6.2

(Refer

Voltage

used

Z104B

inherent

5

is

to

0

which

Z104A

should

oscillate

discharges

The Q output

oscillates.

Q102

current

the

of

Q101,

placed

modulation

varying

Q102-Q101.

3.6.3

(Refer

Z102

controlled

pins 2 and

be

out

the

Phase

.8msec.

Z105A

to

approximate

in

parallel

which

HIGH

FREQUENCY

to

Phaser

controlled

to

control

is a COSMOS

capacitance

pf)

as

the

timing

charged

maximum,

by

Q101.

the Q output

resets

the

is

used

Z104B

after

Z104B

and

Q101

converter

H.F.O.

the

square

of

R116

H.F.O.

102

to

in

parallel

when

the

depth

DELAY

to

Phaser

is

an

analog

by

12

waves

phase.

The

with

slows

Board

delay

one

to

cease

power

of

Z104A

are a linear

which

(calibrate)

The

vary

with

CIRCUITS

Board

the

(typically

Oscillators are

Shifters

is a triangle

capacitor

varying

the

waveform

a

sinewave.

R127

when

the

down

the

LFO.

OSCILLATOR

Schematic)

High

Frequency

time

of

each

one

shot

which

of

COSMOS

on

T2.

Once

the

"capacitor"

(pin

10)

shot.

maintain

oscillation,

14

oscillation

or

up,

the Q output

to

start

Z104B

is a logic 1 as

voltage

determines

sets

the

sinewave

the

of

frequency

delay

frequency

of

the

audio

from

the

H.F.O.

R118

Schematic.)

exponentially.

to

increase

chorus

switch

change

line

whose

of

the square

50KHz.).

same

input

exact

of

the

used

to

delay

time

up

which

is

Z106B

The

the

connects

chorus

switch

is

Oscillators

phase

gates

are

shifter.

uses

the

(typically

capacitor"

is

charged

changes

initial

frequency,

to

logic

i

in

Z104B:

i^ot

begin

to

of

Z104

oscillating.

long

as

Z104B

to

exponential

frequency

of

frequency

LFO

controls

R119

is

the

depth

of

is

selected

produced

delay

2 and

device

by

time

wave

on

12

must

180

is

3,

SUMMMING

the

outputs

Z103

frequency

are

13

is a latching

pulses

flip

from

CO.

3.6.4

FINAL

(Refer

The

outputs

by

Z1

Synthesizer

3.7

Power

3.7.1

Z1

contains a voltage

approximately

connected

an

op

amp.

an

emitter

controls

of

the

tion

of

the

op

amp

emitter

the

power

3.7.2

-15

The

—15

+15

volt

—

15

volt

of

R14

through

increase,

then

forces

lowering

3.7.3

SHORT

R7

and

limit

the

milliamps.

to a maximum

MIX

to

Phaser

Board

of

the

and

supplied

Board.

Supply

+15

VOLT

SUPPLY

+7

volts

through

The

output

follower,

the

pass

transistor

power

supply

R11

and

R12

op

amp

in

Z1

will

then

follower

volt

supply

and

R2.

the

and

supply's

VOLT

SUPPLY

supply

through

is

R15

is 0 volts.

Should

voltage

Q2

to

output

CIRCUIT

the

transistor

+15

supply's

Q3

and

of

1000

three

pin 5

supply a correction

voltage

at

to

R5

AMP

OUTPUT

and

14.

flop

which

converts

Z104B

change,

will

with

pass

derives

the

on

supply

to

square

Schematic.)

Phase

Shifters

to

the

string

reference

to

pin 6 of

to

the

of

the

also

located

(Q1).

the

supply

the

transistor

to

normal.

R14.

When

correct

Z2

output

pin 2 of

more

—15

volts.

which

Z1.

noninverting

op

amp

Should

voltage

the

voltage

difference.

(Q1)

its

regulation

the

voltage,

is

referenced

of

the

Z2

also

current,

PRODUCTION

in

Z1

connected

current

limit

to a maximum

the

—15

supply's

milliamps.

the

high

waves

(Q

and

are

summed

VCA

on

the

supplies

This

voltage

is

connected

in

Z1,

the

at

the

inverting

voltage

and

from

output

the

to 0 volts

minus

increase.

is

input

of

to

which

output

junc

input

The

to

the

bring

the

of

the

junction

supply

Z2

thereby

to

pins 2 and 3

of

800

current

11

SECTION 4 ASSEMBLY/DISASSEMBLY

Scan by Manual Manor

http://www.markglinsky.com/ManualManor.html

TUNE

CONTROL

A.

Remove

all

10

screws

as

indicated,

B.

Lift

to

clear

rear

of

Tune

Control).

instrument

3-4

inches

(high

enough

C.

Pull

forward

SECTION

5.1

LM339

The

LM339

voltage

the

comparators.

LM339

OUTPUT

OUTPUT 4 INPUT

14

OUTPUT

2-3

inches.

5

GENERAL

Comparator

contains

is

3

2

four

With

compatible

INPUT

1

INFORMATION

independent

an

open

collector

with

TTL

and

INPUT

4+

INPUT 4-I

11

10

1-

3+

INPUT

|9

INPUT2-

precision

output,

CMOS.

3-

B

D.

Lift

chassis

In

the

OMNI,

-15V.

Thus

(voltage

+INPUT

-INPUT

determined

Q3.5uA

straight

12

the

ouput

by

(J)100uA

up.

of

LM339s

states

of

the

external

9V+

circuitry)

(J)3.5uA

are

connected

device

are

or

(J)100uA

to

open

-15V.

12

SECTION

Scan by Manual Manor

http://www.markglinsky.com/ManualManor.html

6.1

Synthesizer

6

Board

Trim

CALIBRATIONS

Procedure

REF.

R22

R16

6.2

Synthesizer

R14

TRIMMER

VCFCVR

VCFCAL

SYNTH

VCACVR

Control

Board

1.

Monitor

2.

Put

the

3.

Put

the

4.

Set

the

DOWN,

5.

Adjust

1.

Monitor

2.

Clip a 33K

3.

Put

the

UP;

put

4.

Adjust

Trim

1.

Monitor

2.

Set

3.

Put

4.

Put

5.

Set

R16

Procedure

all

VOICE

the

ADSR

DOWN,

6.

Put

all

other

7.

Adjust

depressing

R14

10

of

filter

VCF

FREQ

slider

VCF

"ADSR"

ADSR

sliders

as

RELEASE

R22

for

ohm

VCF

all

other

for a 16Hz

the

MIX

MASTER

sliders

RELEASE

for

keys.

DOWN.

minimum

10

of

filter

resistor

FREQ

slider

sliders

high

level

SELECTION

slider

fully

VOLUME

as

follows:

DOWN.

sliders

at

minimum

TRIM

PROCEDURE

module

slider

follows:

module

from

M1

with

and

VCF

RESONANCE

fully

UP.

ATTACK

amplitude

fully

M1

10

DOWN

when

with

of

DOWN.

sinewave.

output

of

the

Omni

switches

LEFT

fully

OFF

(synthesizer).

RIGHT

ATTACK

i

minimum.

deflection

of

an

oscilloscope.

slider

fully

DOWN,

keys

an

oscilloscope.

M1

to

and

the

with

(out).

(maximum).

DOWN,

the

oscilloscope

DECAY

are

depressed.

2.

VCF

RESONANCE

an

oscilloscope.

DECAY

trace

DOWN.

3/4

UP,

while

UP,

SUSTAIN

slider

fully

SUSTAIN

repeatedly

R33

6.3

Phaser

R116

R216

R316

6.4

Power

R19

STRING

VCA

CVR

Board

supply

Trim

HFOCAL

Trim

+

15

VOLT

1.

Perform

2.

Move

3.

Depress

4.

Adjust

depressing

Procedure

1

2

3

Procedure

SET

1.

Monitor

2.

Attach a 100K

3.

Adjust

1.

Monitor

2.

Attach a 100K

3.

Adjust

1.

Monitor

2.

Attach a 100K

3.

Adjust

1.

Monitor

2.

Adjust

the

synth.

VCA

the

MIX

slider

to

(turn

on)

the

R33

for

minimum

keys

in

the highest

TP7

(Z102)

R116

for

TP9

with a frequency

R216

for a 20.4

TP11

R316

for a 11.3

the

power

R19

for

with a frequency

ohm

resistor

an

11

ohm

resistor

with a frequency

ohm

resistor

supply's

exactly

CVR

trim

procedure.

fully

RIGHT

STRING;

deflection

from

microsecond

from

microsecond

(string).

BASS

voice

of

the

octave.

counter.

+15V

supply

period

counter.

the

+15V

period

counter.

from

the

+15V

microsecond

+15

+15.00

period

volt

output

volts.

selection

oscilloscope

square

supply

squarewave

supply

squarewave

with

switch

(only).

trace

while

to

TP6.

wave

(+0.1

to

TP8.

(+0.1

microseconds).

to

TP10.

(+0.1

microseconds).

a digital

voltmeter.

microseconds).

repeatedly

R20

-15

VOLT

SET

1.

Set

2.

Put

and

3.

Adjust

R5

(+15

volts)

the

digital

put

the

meter's

R20

for

first.

voltmeter's

exactly

ground

plus

lead

+15.00

lead

on

the

volts

on

the

power

supply's

(reversed

ground

polarity).

supply's

-15

volt

output.

output

13

Arp Omni User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual