ARP 3301 User manual

ARPPIANO

16

VOICE

ELECTRONIC

PIANO

SERVICE

MANUAL

Models

3301,

3302,

&

3303

MUSIC

DEALER

SERVICE

A

Div.

of

T.E.A.M.S.

Inc.

4700

West

Fullerton

/

Chicago,

Illinois

60639

(312)282-8171

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SECTION

1

GENERAL

DESCRIPTION

The

ARP

16-voice

Electronic

piano

is

the

first

;/iano

to

offer

a

wide

variety

of

touch

responsive

percussive

sounds

in

one

instrument.

Among

the

sixteen

sounds

are

acoustic

piano,

vibes,

bells,

harpsichord,

harp,

tunings,

envelope

follower

effects

and

other

voices

which

are

ideal

for

both

solo

and

group

performance

applications.

The

instrument

has

a

73-note

keyboard

with

sta.

.dard

wood

piano

keys

and

a

specially

designed

and

weight

ed

maple

action

which

faithfully

reproduces

tho

feel

and

response

of

traditional

grand

pianos.

In

addition,

a

pedal

assembly

is

included

with

two

pedals,

one

for

sustain

and

the

other

may

be

used

as

a

soft

pedal or

may

be

reassigned

to

become

a

vibrato

on/off

pedal.

Also

a

stereo

phase

shifter

is

included

which

can

be

switched

on

or

off

with

any

of

the

voices.

Other

features

include

vibrato,

master

tune

controls

and

detune

controls

for

effects

such

as

honky-tonk

piano

or to

"warm-up"

the

sound.

A

stereo

headphone

jack

is

provided

on

the

control

panel

along

with

the

volume

and

tone

controls.

The

instrument

comes

with

four

detachable

legs,

a

keyboard

cover

and

the

pedal

assembly.

SECTION

2

SPECIFICATIONS

& CONTROLS

■■55-

CONTROLS

1.

STEREO

HEADPHONE

JACK:

Accepts

I

ohm

stereo

headphones.

2.

VOLUME

&

TONE:

Affects

all

16

Voices.

3.

PHASOR:

Stereo

phasor

may

be

used

on

.II

16

voices.

Speed

&

Resonance

controls

adjust

the

effect

to

taste.

4.

MASTER TUNE

&

DETUNE:

Master

Tune

con

trol

is

used

to

tune

the

entire

instrument,

and

the

Detune

control

is

used

to

produce

a

"slightly

out

of

tune"

character

or

flavor.

5.

LEFT

PEDAL

SELECT

SWITCH:

Determines

whether

the

left

pedal

is

to

be

used

for

the

"soft"

effect,

or

for

vibrato.

6.

VIBRATO

SWITCH:

Used

to

provide

continuous

vibrato

on

all

16

voices.

7.

VIBRATO

SPEED

&

DEPTH:

Sets

vibrato

speed

&

depth,

and

the

Speed

control

is

also

used

to

set

the

trill

rate

for

voice

5.

8.

VOICE

SELECT

SWITCHES:

Used

to

select

any

one

of

the

16

voices

provided.

AUDIO

OUTPUTS

LEFT:

8V

PP,

low

impedance

RIGHT:

8V

PP,

low

impedance

MONO:

High,

8V

PP;

Low,

0.8V

PP;

low

impedance

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SECTION

3

THEORY

OF

OPERATION

3.1

Tone

Generation

The

tone

generation

system

in

the

ARP

16-voice

Electronic

piano

consists

of

a

master

high

frequency

oscillator,

a

clock

frequency

shifter

circuit,

top

octave

generator

chips

and

8

divider/keyer

ICs.

In

order

to

produce

pitches

for

each

key

on

the

key

board,

there

are

two

divider

chains

in

parallel.

This

dual

tone

generation

system

is

used

for

two

main

reasons;

1)

it

permits

the

two

pitches

generated

for

each

key

to

be

detuned

relative

to

each

other

and,

2)

a

dual

keying

system

permits

a

more

complex

envelope

decay

characteristic.

To

permit

accurate

detuning,

a

high

frequency

clock

which

is

derived

from

the

high-frequency

oscillator

drives

one

of

the

divider

chains.

The

other

divider

chain

is

driven

from

the

same

clock

signal

after

it

has

been

processed,

by

a

unique

pulse

chopping

circuit

which

effectively

increases

its

fre

quency.

This

scheme,

which

is.

described

in

more

detail

in

the

power

supply

circuit

description,

permits

accurate

detuning

of

the

two

divider

chains

and

there

fore

establishes

accurate

detuning

of

the

pitches

on

each

key.

The

final

divisions

in

the

divider

chain

are

made

in

special

purpose

MOS

integrated

circuits.

These

devices

contain

all

of

the

frequency

dividers

for

each

note

and

the

keying

circuits.

There

are

three

audio

outputs

on

each

chip

(8',

4'

and

2')

which

are

buffered

and

then

sent

to

the

voicing

circuits.

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3.2

Keying

Circuit

3.3

Voicing

Since

the

ARP

Electronic

Piano

is

touch-responsive,

envelopes

must

be

generated

which

are

proportional

to

the

speed

of

keys

which

are

depressed.

This

is

accomplished

by

an

RC

Time-of-Flight

muasure-

ment

scheme.

When

a

key

is

depressed,

a

capacitor

begins

to

discharge

until

the

key

reaches

iu

final

position,

then

the

remaining

charge

on

the capacitor

is

used

to

charge

two

other

capacitors

(one

for

each

of

the

two

tones

per

key)

which

decay

at a

much

slower

rate.

These

two

capacitors

are

directly

con

nected

to

the

divider/keyer

chips,

to

gate

out

the

audio

signals.

Thus

the

harder

(faster)

a

key

is

de

pressed,

the

larger

the

initial

envelope

voltage

on

the

two

decay

capacitors.

The

architecture

of

the

voicing

circuit

is

defined

by

the

audio

signals

which

are

sent

over

from

the

divider/keyer

circuitry.

In

total,

there

are

four

groups

of

three

audio

signals

(all

square

waves)

arranged

as

follows:

8',

4',

2'

Upper

keyboard

half,

Short

8',

4',

2'

Upper

keyboard

half,

Long

8',

4',

2'

Lower

half

keyboard,

Short

8',

4',

2'

Lower

half

keyboard.

Long

VOICE

BOARD

SIGNAL

FLOW

1.

Key

at

rest.

2.

Key

being

depressed.

(Capacitor begins

to

discharge.)

1

T

I

3.

Key

stops.

(Regaining

voltage

discharges

through

decay

circuit.)

Fast,

hard

strike.

Medium

strike.

Soft,

slow

strike.

The

decay

characteristics

of

the

struck

and

plucked

string

share

a

common

form.

The

initial

decay

is

more

rapid

(and

frequently

brighter)

than

the

final

decay

rate.

It

is

for

this

reason

there

are

two

differ

ent

decay

rates

on

each

key,

one

rapid

and

one

relatively

long.

These

two

decays

are

referred

to

as

the

"Short"

envelope

(or

signal)

and

the

"Long"

envelope.

The

Short

envelope

decay

rate

can

be

altered

by

a

PMD

(pulse

modulated

decay)

line

to

shorten

its

decay

rate

even

further

for

piucked

sounds.

These

two

audio

signals

keyed

on

each

note

are

combined

in

the

voicing

circuit,

producing

com

posite

envelope

on

the

output.

;

t

j ;

The

first

voicing

step

is

to

mix

and

pref

ilter

the

three

footages

in

each

voice,

according

to

the

voice

select

ed.

Some

voices

use

all

three

footages,

others

may

use

only

one

or

two.

The

outputs

of

the

first

mix

stages

yield

four

pre-mixed

signals:

Upper

Short,

Upper

Long,

Lower

Short

and

Lower

Long.

These

signals

are

then

processed

through

select

fixed

filters

which

can

be

low-pass,

band-pass,

or

high-pass,

depending

upon

the

voice

which

is

selected.

The

outputs

of

the

fixed

filters

are

then

combined

from

four

signals

(US,

UL,

LS,

LL)

to

two

signals

in

a

4-to-2

mix

circuit.

Depending

again

on

the

voice

which

is

selected,

two

mixdown

outputs

are

either

Upper

Keyboard/Lower

Keyboard

or

Short

Signal/

Long

Signal.

In

the

final

voicing

step,

the

two

signals

from

the

4-

to-2

mix

circuit

are

sent

to

a

six-band

resonator

bank

which

is

similar

to

a

graphic

equalizer.

Each

voice

has

its

own

frequency

response

established

by

a

resistor

matrix

before

the

resonator

bank.

The

resonator

bank

has

one

output

which

is

sent

to

the

phase

shifter

circuit

which

harmonically

derives

a

left

and

right

output

signal.

All

of

the

signal

paths

and

many

of

the

circuit

values

are

different

for

each

voice.

When

a

voice

is

selected,

the

control

panel

circuitry

sends

out

a

digital

code

which

addresses

a

ROM

(read

only

memory)

which

in

turn

sets

up

the

voicing

circuit

for

the

appropriate

signal

paths

and

filter

values.

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DISSASSEMBLY

Bezel/Top

Cover

i

Ol

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SECTION

4

CIRCUIT

DESCRIPTIONS

4.1

Power

Supply

The

power

supply

is

in

a

central

location

from

an

interconnection

standpoint

therefore

all

of

the

support

circuitry for

the

keyer

boards

is

on

this

circuit

board.

The

support

circuits

are

the

High

Frequency

VCO,

the

Interval

Logic

and

Frequency

Shifter

which

determines

the

tuning

or

interval,

Beat

Frequency

VCO

which

sets

the

amount

of

de

tuning,

Pulse

Generator

Circuit

which

is

used

to

modulate

the

decay

rate

of

the

Short

envelopes

on

the

keyer

boards,

Line

Drivers

which

drive

the

top

octave

synthesizer

on

the

keyer

boards,

and

the

Keyer

Bias

Supply

Circuit,

which

supplies

the

keyer/

divider

chips

on

the

keyer

boards

with

the

correct

reference

voltages.

TROUBLE

SHOOTING

HINTS

The

Interval

Logic

and

Frequency

Shifter

Circuit

is

running

at

a

high

frequency

and

it is

difficult

to

determine

whether

the

circuit

is

functioning

properly

or

not

To

quickly

check

out

the

circuit,

connect

the

trigger

input

of

an

oscilloscope

to

the

D

output

of

Z8B

(Pin

14,TP1).

This

will

permit

a

com

plete

cycle

to

be

displayed

exactly

like

the

timing

diagram

on

page

7

(except

that

the

waveforms

are

somewhat

rounded).

Then

simply

probe

each

gate

output

illustrated

on

the

timing

diagram.

4.1.1

POWER

Almost

all

of

the

instrument

is

run

+12

volts,

which

is

provided

by

two

3-terminal

regulators

(Z1

and

Z2).

Z3,

Q1

and

Q2

provide

+15

volts

for

the

keyer/

divider

ICs

on

the

upper

and

lower

keyer

boards.

A

power

sense

line

is

sent

through

P9-6

to

the

voice

board

to

activate

a

mute

circuit

when

the

instrument

is

turned

on

or

off.

4.1.2

HIGH

FREQUENCY

VCO

The

High

Frequency

Oscillator

(Z6

and

Q5)

oscillates

at

about

3.4MHz.

The

'M'

tune

line

comes

from

the

Master

Tune

control

on

the

control

panel

and

also

has

the

vibrato

signal

from

the

control

panel

when

it

is

selected.

4.1.3

INTERVAL

LOGIC

AND

FREQUENCY

SHIFTER

In

total,

there

are

three

different

pitch

relationships

used

in

the

instrument:

Unison

tuning

(voices

P,

3,

4,

and

7

through

16),

musical

fifth

tunings

(voices

2,

5

and

6),

and

a

high-pitched

eleven

to

eight

ratio

which

is

used

to

create

a metallic

"ting"

(voices

7

and

8).

(In

the

case

of

the

fifth

tuning

relationship,

the

clock

signal

for

the

short

chain

is

actually

lowered

by

a

musical

fourth

and

the

8'

signal

is

unused.)

In

all

cases,

the

clock

which

drives

the

Short

channel

is

the

one

which

is

altered.

The

Long

divider

chain

is

not

alterable

(except,

of

course,

by

the

master

tune).

The

different

tuning

relationships,

including

the

unison

detuning,

are

created

by

chopping

pulses

to

create

a

derived

signal.

The

High

Frequency

VCO

oscillates

at

approximately

3.4

MHz,

which

is

the

frequency

required

to

produce

the

metallic

"ting"

(voices

7

and

8).

The

remaining

pitch

relationships

are

derived

from

this

clock

signal

in

the

Interval

Logic

Frequency

Shifter

Circuit.

Long

Clock:

Z13B,

Z14A

and

B,

Z15B

and

C,

and

Z16A

chop

three

pulses

for

every

eleven

of

the

High

Fre

quency

VCO

(see

timing

diagram,

TP

Z13-11),

which

then

becomes

the

clock

signal

for

the

Long

divider

chain

(called

the

Upper

Long

clock

or

UL

clock).

Short

Clock:

When

the

Flat

control

line

is

high

(Z15A,

1)

then

another

two

pulses

are

added

to

the

same

derived

clock

signal

via

Z14C.

This

lowers

the

pitch

of

the

short

clock

signal,

which

will

be

supplied

to

the

Short

chain

by

a

musical

fourth.

Since

the

8'

audio

will

not

be

used,

it

will

come

out

sounding

like

a

musical

fifth

above

the

Long

chain.

The

Beat

Frequency

VCO

periodically

sends

a

pulse

over

to

Z16B

and Z17,

to

add

in

pulses

occasionally

which

slightly

raises

the

frequency

of

the

clock

signal

which

is

supplied

to

the

Short

divider

chain.

If

the

frequency

of

the

Beat

Frequency

VCO

is

increased,

the

rate

of

pulse

adding

also

increases,

which

in

turn

raises

the

effective

frequency

of the

clock.

The

Beat

Frequency

VCO

ranges

from

about

450Hz

to

60KHz.

At

maximum

frequency

the

Beat

Frequency

VCO

raises

the

Sharp

clock

approximately

%

of

a

semitone.

Z13,

10

is

the

"Upper

Short

Clock."

The

"Lower

Long

Clock"

is

picked

off

of

counter

Z8B,

14

and

is

three

octaves

lower

than

the

"Upper

Long

Clock."

This

clock

is

for

the

Lower

Keyer

boards.

The

"Lower

Short"

is

provided

by

Z8A,

which

also

divides

the

Upper

Short

clock

in

half,

three

times,

for

the

Lower

keyer

boards.

4.1.4

BEAT

FREQUENCY

VCO

The

Beat

Frequency

VCO

determines

the

exact

amount

of

detuning

between

the

Short

and

Long

clock

signals

by

supplying

a

pulse

of

constant

width

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TIMING

DIAGRAM

Z13A1MASTIR

CLOCK

Z1«A2<FEEOBACKI

213

•

U

UL

CLOCK.

COUNTER

INPUT

2»

•

II

COUNTER

OUTPUT

A

ZB

•

12

COUNTER

OUTPUT

B

28

•

13

COUNTER

OUTPUT

C

Z8

■

14

COUNTER

OUTPUT

O

TEST

POINT

1

(Tf>Mtf

ICOfM

•(

ttttl

pOMtll

BEAT

FREO

VCO

ZI7B

O

Z17B

0

Z13C

NORMAL

TUNING

£«>

,

<

FLATUNEH.GH

UPPER

SHORT

CLOCK

...

^

SHARP

LINE

HIGH

ru~L_n

L

_n

n

ri

L

1

I

J~L_TL

n

nn

n

"in

n

nn

n

TTLJ~U~U

LJ

L.i

ICLOCKS

,

|CLOCKS

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(4.5

microseconds)

to

the

Interval

Logic

ai

J

Fre

quency

Shifter

Circuit.

Its

frequency

ranges

between

450Hz

(minimum

detune)

and

60KHz

(maximum

detune),

depending

upon

the

setting

of

the

Detune

control

on

the

front

panel.

The

more

often

pulses

are

supplied

to

the

Frequency

Shifter

Circi

it,

the

more

often

are

pulses

added

to

the

clock

signa

which

raises

the

frequency

of

the

Short

Clock.

However,

these

pulses

are

ignored

on

voices

7

and

8.

4.1.5

PULSE

GENERATOR

The

Pulse

Generator

derives

from

available

clock

signals,

one

of

four

signals

which

are

supplied to

the

keyer

board

to

set

the

decay

rate

of

the

Short

envelopes

on

the

PMD

(Pulse

Modulated

Decay)

line.

A

two-bit

code

supplied

from

the

voice

board

deter

mines

which

decay

rate

is

set

by

this

circuit

(P9,

pins

5

and

12).

The

four

signals

are

as

follows:

Notice

that

Z10B,

which

drives

the

PMD

line,

is

powered from

a

voltage

which

is

derived

(and

is

always

less

than)

the

keying

bias

voltage.

This

is

to

insure

that

the

modulating

signal

does

not

affect

the

envelope

voltage

levels

when

the

Short

envelopes

decay

near

the

keying

bias

voltage

level.

4.1.6

KEYER

BIAS

SUPPLY

This

circuit

supplies

the

Keyer

board

with

the

follow

ing

reference

voltages:

Pedal

Control

(PED),

Keyer

Bias

(KB),

Timing

Bias

(TB),

+7

Volts

for

the

Keyer/

Divider

chips,

and

the

decay

chopping

power

line

(PMD

line).

Z4A

sets

the

Keyer

Bias

level

to

approximately

+

10.5

volts.

This

voltage

is

set

to

coincide

exactly

with

the

pinch-off

voltage

of

the

keyers

in

the

Keyer/

Divider

chip.

This

voltage

is

typically

two

diode

drops

(about

1.6

volts)

below

the

Keyer/Divider

chip's

supply

voltage

(+12

volts). In

practice,

the

best

envelope

decay

characteristic

is

achieved

by

set

ting

the

Keyer

Bias

such

that

the

Keyer/Divider

chip

does

not

quite

pinch-off.

This

prevents

the

decaying

sound

from

abruptly

stopping

when

the

envelope

reaches

the pinch-off

value.

To

prevent

this

truncation,

a

trimmer

(R37)

is

set

to

allow

a

very

small

signal

through

when

the

envelope

has

fully

decayed.

The

damper

circuit

on

each

key

supplies

a

voltage

to

pinch-off

the

signal

when

keys

are

not

being

depressed,

thus

preventing

unwanted

bleed-

through.

Q4

supplies

the

damper

buffers

on

the

Keyer

board

with

a

supply

voltage

of

+12

volts

when

the

pedal

is

not

depressed.

When

the

Sustain

Pedal

is

depres

sed,

the

PED

line

goes

low,

which

removes

the

damp

ing

function

from

all

of

the

keys.

When

this

happens,

the

Keyer

Bias

voltage

level

is

shifted

up

slightly

via

R9

and

R10

so

that

the

keyers

in

the

Keyer/Divider

chips pinch-off

during

the

time

the

dampers

are

removed.

Z4B

and

Q3

generate

the

Timing

Bias

reference

for

the

Keyer

boards.

The

capacitors

which

establish

the

time

of

flight

are

discharged

to

this

reference

level.

It

is

set

to

be

about

a

half-volt

lower

than

the

Keyer

Bias

level.

Z5A

supplies

about

9.8

volts

to

the

pulse

modulated

decay

drive

(Z10).

It

is

also

de

rived

from

the

Keyer

Bias

voltage

so

that

the

decay

rate

of

the

Short envelope

only

affects

the

first

part

of

the

decay.

4.2

Upper

and

Lower

Keyer

Boards

(Refer

to

the

Upper

Keyer

Board

schematic.)

The

Upper

and

Lower

Keyer

Boards

are

almost

identical

in

design.

They

both

use

the

same

printed

circuit

layout

but

are

assembled

with

slightly

differ

ent

component

values.

The

Upper

Keyer

Board

is

assembled

to

key

only

36

notes

and

the

envelope

decay

resistors

are

scaled

to

produce

short

decay

times

for

the

higher

pitches.

The

Lower

Keyer

Board

is

wired

for

37

notes

and

has

a

longer

decay

time

for

the

bass

notes.

In

all

other

respects,

the

two

boards

are

the

same.

TROUBLE

SHOOTING

HINTS

Envelope

Generators:

Often

problems

assumed

to

be

associated

with

the

keyswitches

are

actu

ally

on

the

Keyer

Board

in

the

Envelope

Gener

ator

Circuits.

These

circuits

cannot

be

probed

easily

since

they

are

very

high

impedance

circuits.

Just

touching

a

probe

to

most

of

the

envelope

circuit

nodes

is

usually

enough

to

key

the

pitch

on.

When

a

problem

occurs,

use

a

small

scribe

or

screwdriver

as

a

probe.

Touch

the

damper

bar

(ground)

with

one

hand

and

probe

with

the

other

(Stay

away

from

the

Power

Supply!).

-(CONTINUED)-

Scan by Manual Manor

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Just

touching

the

various

nodes

in

the

envelope

circuit

will

be

enough

to

key

on

the

note

and,

by

comparing

to

adjacent

keys,

problems

can

be

quickly

traced,

CAUTION:

Avoid

touching

the

board

with

your

fingers

as

this

will

leave

salts

which

can

contaminate

the

surface.

Then,

in

high

humid

ity,

notes

may

bleed

through.

NOTE:

The

73

keys

are

numbered

8

through

80

to

correspond

with

the

key

numbers

found

on

a

standard

88-note

piano

keyboard.

Since

the

keys

on

the

keyboard

are

numbered

this

way,

the

schematic

references

are

to

the

key

numbers

on

the

key.

Note

that

"L"

denotes

Long,

and

"S"

denotes

Short.

Therefore,

the

symbol

L37

denotes

Long

envelope,

key

num

ber

37

as

stamped

on

the

key,

not

the

number

from

the

lowest

key.

4.2.1

ENVELOPE

GENERATORS

For

each

key

there

is

an

Envelope

Generator

Circuit

which

produces

two

envelopes.

All

of

the

Envelope

Generators

are

identical

except

for

the

value

of

the

decay

resistors.

The

envelopes

are

all

negative

going;

that

is,

they

are

initially

at

a

high

voltage

(about

+11

volts)

and

they

drop

to

a

negative

voltage

when

a

key

is

struck

and

then they

decay

back

up

to

the

Keyer

Bias

voltage

of

approximately

+10.5

volts.

4.2.2

TIME

OF

FLIGHT

MEASUREMENT

1)

When

the

key

is

at

rest,

the

key

switch

holds

the

timing

capacitor

T110

at

-12

volts

through

R112.

2)

When

a

key

is

pressed

down,

the

keyswitch

breaks

contact

with

the

-12

volts,

and

the

timing

capacitor

quickly

begins

to

discharge

through

R111

and

R110

to the

timiag

bias

bus

(about

+10

volts).

3)

When

the

key

nears

the

end

of

its

travel,

the

key

switch

makes

contact

with

the

B

contact

and

the

rest

of

the

charge

on

the

timing

capacitor,

which

is

propor

tional

to

the

time

elapsed

since

it

left

the

-12

volt

contact,

is

then

deposited

on

the

envelope

capaci

tors

C111

and

C112,

through

diodes

CR112

and

CR113.

Rapidly

struck

keys

will

deposit

a

more

negative

peak

voltage

on

the

two

envelope

capaci

tors

and

thus

produce

louder

notes.

Softly

played

keys

will

produce

a

small negative

peak

voltage

on

the

envelope

capacitors.

The

envelopes

which

are

generated

by

C111

and

C112

are

directly

connected

to

the

envelope

inputs

of

the

Keyer/Divider

chips

(Z1,

2,

3

and

4).

These

inputs

are

very

high

impedance

and

have

no

effect

upon

the

discharge

rate

of

the

envelope

capacitors.

The

more

negative

the

voltage

on

these

inputs,

the

larger

the

audio

signal

on

the

output

of

the

Keyer/

Divider

chips.

C111

is

the

Long

envelope

generator

capacitor

and

its

decay

path

is

through

R114.

In

the

bass

region

of

the

Lower

Keyer

Board

where

very

long

decay

times

are

required,

the

value

of

this

resistor

is

33

megohms.

On

the

treble

end

of

the

Upper

Keyer

Board

the

value

is

3.9

megohms.

C112

is

the

Short

envelope

capacitor

and

its

decay

path

is

through

R115.

The

pulse

modulated

decay

line

(PMD)

provides

an

additional

discharge

path

for

C112

through

diode

CR114

and

R46.

This

line

provides

a

high

frequency

pulse

to

discharge

the

Short

envelope

capacitor

more

quickly

for

some

of

the

voices.

The

PMD

line

has

one

of

four

values;

0

volts,

25%

duty

cycle

pulse,

75%

duty

cycle pulse

or

+10

volts.

These

signals

are

generated

on

the

Power

Supply

PC

Board.

1.

KEY

AT

REST

2.

KEY

IN

MOTION

3.

KEY

DOWN

("STRIKE")

Scan by Manual Manor

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ARP 3301 User manual

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