Multimoog Musical Instrument Manual de servicio descargar pdf (Pagina 43)

5.

Set

SOURCE

and

ROUTING

controlsasshown

on

preceding

page.

Set

MOD

AMOUNT

wheel

as

shown.

6.

Depress

and

hold

any

key.

You

should

hear

a

contoured-pitch

"siren"

effect.

7.

Place

the

ROUTING

selector

to

the

OSC A&B

FILTER

position.

Play

the

same

key.

Note

that

tone

color

is

contoured

as

well

as pitch.

(The

FILTER

is

also

being

contoured.)

8.

Control

amount

of

contour

using

MOD

AMOUNT

wheel.

9.

Place

the

ROUTING

selector

to

the

FILTER

position.

Note

that

only

the

filter

(tone

color)

is

contoured

now.

j—i

10.

Place

the

ROUTING

switch

to

the

^

'

B

position.

Play.

Now

the

WAVESHAPE

of

OSCIL

LATOR

B

(only)

is

being

contoured.

11.

Repeat

steps

5-10

and

experiment

with

the

FILTER

CONTOUR

ATTACK

and

RELEASE

controls.

Try

both

settings

of

the

FILTER

SUSTAIN

switch.

When

the

FILTER

CONTOUR

is

the

selected

SOURCE,

any

section(s)

named

by

the

ROUTING

selector

may

be

contoured.

The

speed

of

this

contour

is

controlled

using

FILTER

CONTOUR

controls.

The

amount

of

this

contour

is

controlled

by

the

MOD

AMOUNT

wheel.

(Note

that

the

CONTOUR

AMOUNT

control

in

the

FILTER

section

doesn't

affect

the

amount

of

the

FILTER

CONTOUR

as

used

in

the

MODULATION

SECTION.

In

the

following

exercise

steps,

it

will

become

apparent

that

much

of

the

MODULATION

section

deals

with

repeating

patterns:

"*rt

source

..---.

routTSc

MOOUUATIOIM

12.

Select

the

_]"!_

SOURCE

setting.

13.

Explore

all

possible

ROUTING

settings

and

MOD

AMOUNT

wheel

positions.

14.

Vary

the

RATE

control

to

control

the

speed

of

the

modulation.

15.

Select

alternately

the

s^\/

,S&HAUTO,

and

S&H

KBD

settings

with

the

SOURCE

selector.

Repeat

steps

13

and

14

for

each

SOURCE

setting.

(END

EXERCISE)

Modulation

is

usually

defined

as a

change,

often

a

repeating

change.

On

the

Multimoog,

the

rate

of

any

repeating

modulation

is

controlled

by

the

RATE

control.

RATE

controls

the

frequency,

or

speed

of

the

"modulation

oscillator"

that

is

the

heart

of

the

MODULATION

section.

Also

included

is

sample-and-

hold

circuitry

whose

sampling

rate

is

controlled

by the

modulation

oscillator.

A

modulation

oscillator

is

one

which

is

used

as

a

controller.

It

is

a

source

of

repeating

voltage

pat

terns—waveshapes

like

any

oscillator—which

are

often

restricted

to

low

frequency.

That's

because

the

control

signals

are

generally

used

to

make

slow-

moving

modulations

like

vibrato,

trills,

"wah-wah,"

and

the

like.

Vibrato

rate,

for

example

is

around

six

to

eight

Hz,

or

beats

per

second.

On

the

Multimoog,

the

modulation

oscillator

has

a

frequency

span

of

.3

to

30

Hz.

Its

output

is

represented

by

the

symbols

_f~[_

,and

S*\/

,

(square

and

triangle

wave,

respectively)

in

the

MODULATION

section.

If

you

recall

exercise

1,

you

began

by

listening

to

the

sound

of

the

voltage

controlled

OSCILLATOR

B

section

at

a

very

low

frequency.

So

low,

that

only

a

series

of

clicks

was

perceived

instead

of

a

sound

in

normal

hearing

range.

That

sound

was

below

the

frequency

of

normal

hearing,

or

it

was

sub-audio.

The

modulation

oscillator

produces

waveshapes

in

the

subaudio

range

for

control

purposes.

We

can't

use

the

modulation

oscillator

as

a

sound

source,

but

its

effect

will

be

dramatic

indeed

when

connected

to

a

control

input

of

a

VCO

or

VCF.

You

have

heard

some

of

the

effects

from

preceding

exercise

steps.

The

sample-and-hold

creates

a

series

of

control

voltage

steps

in

a

metronomic

fashion

with

a

rate

determined

by

the

RATE

control,

(frequency

of

the

modulation

oscillator).

To

understand

how

the

sample-and-hold

works,

let's

make

an

analogy

to

a

camera.

A

camera

"samples"

(photographs)

motion

and

"holds"

a

fixed

instant

in

time

(the

print).

The

sample-and-hold

"photographs"

(samples)

a

moving

r

48

1 2 ... 38 39 40 41 42 43 44 45 46 47 48 ... 76 77

Comentarios a estos manuales

Sin comentarios