Roland Vocoder SVC-350 Service Notes

SVC-350

SERVICE

NOTES

SPECIFICATIONS

ROLAND

VOCODER

Modal

SVC-360

INPUTS

MIC

INPUT:

1/4

inch

STANDARD

snone

Jack

or

EIA-RS297

Connector

iciOOonm.

-54dBm

mm.)

INSTRUMENT

INPUT:

1/4

men

STANDARD

Phone

Jack

HOOkonm,

OdB

max.)

QUrTAR

INPUT:

1-4

inch

STANDARD

D*.one

Jack

dOOkonm.

GUITAR

flaw

level.)-lOdBmi75OmV)

INSTRUMENT

LEVEL

SELECTOR

Switch

(OdBm.

-i5dBm,

-30dBm)

Jack

HLJ-OI9-01-030

(O09-046)

Jack

HLJ-O2

46-01-030

(O09-030)

INPUT

LEVEL

INDICATORS:

.ED

DISPLAY

5

MIC

LEVEL.

Green.

Red/over

INSTRUMENT

LEVEL.

Green

Red'

over

GUITAR

LEVEL.

Green

Red/over

OUTPUTS

For

GUITAR

AMPLIFIER:

1/4

inch

STANDARD

Phone

Jack ( lOkohia)

MONO

or

STEREO

OUTPUTS:

1/4

inch

STANDARD

Phone

Jack

Knot

no.44

(016-044)

Pot.

3VH6PA361C14

(026-161)

CONTROLS

MIC

LEVEL

CONTROL

(,-5413111

to

-14dBm)

POWER

CONSUMPTION:

13W

DIMENSIONS:

482(W) x 92(H) x 350(0)

mm

WEIGHT: 5 •

3kg

Knob

no.77

(016-077)

Pot.

3WJEJA320B14

(026-155)

Pot.

EVH8MA361A14

(026-163)

Jack

HLJ-024-01-030

(009-030)

Switch

SSM-02308

(001-196

Knob

no.77

(016-077)

rot.

EVEEQA361314

(O26-158)

Knob

no.48

(016-048)

Pot.

EVHHPS20B14

(029-589)

c

MACHINE

SCREW

t—->

6-M4X10

BLK

Power

3w.tch

SDG5P001

(01-156)

100V

3DG5P0C1-2

('01-216)

117V

SDG5P5O2

(01-217)

220/240V

Button

no.

9

(016-009)

Panel

H58

(072H058)

HANDLE

108 H 00

3

RUBBER

FOOT

K-15U11-C3'

CCVER

O65HO6O

MACHINE

SCREW

6-M4X12

BLK

Haxa^a

socket

head

bolt 4 x

czim

blk

Recectacle

—(

NC-3PP

or

I-3M

(010-264)

MIC AMP

Beard

AP-127

(141-127/

CONTROL

Board

Switch

SSM-02308

(001-196)

Jack

HLJ-C264-1-030

(009-OP)

LED

TLR-124

(019-028)

red

TLG-124

(019-029)

green

Jack

HLJ-O261-O1-O3C

(009-037)

'

Jack

HLJ-O264-O1-C2C

(009-040)

1—Knob

no.44

(016-044)

Pot.

3Wo"EJA320B14

(026-155)

OP-142

(149-142)

FILTER

Board

FL-19

(145-019)

100.

ll'V

FL-19D

(14--C1C)D)

22C

240V

i—

LED

Board

OP-150

(149-15C)

r-Fuse

Board

OP-143

100V

OP-144

117V

OP-145

220/24CV

Power

transformer

C22-028N

100V

022-028C

117V

022-028D

220/240V

Terminal

TT501D-1

(042-032)

Ground

terminal

TT-9-4

(042-041)

Printed

in

Japan

A3

1

Dec.

8,1979

HOLD

MIC

HOLD

IC53

ANALYZER

BPF

IC5O.55

FL-19

FILTERS

SYNTHESIZER

FILTERS

OJ7

PEAK

METEC7&R

■LPF

5OHs

1

A

Kit

f

r-

SPF

/CA

BPF

:C2-7

EXPANDER

-CONT

INSTR'

OT4

'red

IC45

PEAK

PETCCBR

K

2?

(»B0)

I

AIIIMO

k—J

AUDIO

DELAY

J

Q3C

LPF

031

TC2K9

8BJ

AU&IO

DELAY

J

LPF

Oil

038

DIRECT

3IG.

CLOCK

OSC

AA

Q32-O36

CLACK

LPD-I

IC25

LFO'2

IC26.Q44

Q26

LNV-

icHz

DC

IC44

TRIAN6UU*

OSC

M

ilL

33

IC39

IC38

VCA

IC37

A

8f«-3

Circuit

♦

DIRECT

"ON"

fSi/3

i—■

AMP

IC12a

AMP

IC12b

l '

wt.

re

i*

f

air

L.rt.M

ATT

I

L.W.H

n

A

(A-»B)

1

-B.

AMP

LEVCL

ENSEMBLE

ON,

OFF

'0

PHONES

SVC-350

BLOCK

DIAGRAM

MOUII

IIUIM

-Deiail-

uec.

8,1979

CCMPR3USCR

After

ampi—

fled

by

14-54d3

through

Mic

Head

Amp

or.

Ar-127,

Mic

3ignal

ijoea

to

id

i,pin3

5-7)

whoje

gain

i3

reversely

proportional

to

she

control

current

from

Q5

emitter.

The

aic

3i,sr.ai

coming

from

IC2

pin 7 La

full-wave

rectified

by

IC3

(pir.3

5-7),

Dl

and

D2,

peak-voltage

detected

by

IC3

Ipins

1-3;,D*,

jncothed

to

DC

voltage

by

IC5

(pir.3

1-3),

ani

7-1

converted

by

IC4

(.pins

1-3),Q5 • Connected

acros3

IC4'3

pins 6 and

7 in

parailed

with feedback

resistors

is

IC1

3A6CJ.

As

the

mic

si-gnai

increases,

Q5

output

current

increases,that

causes

3A662

conductance

to

increase,

lowering

the

gain

of

IC4

(pins

5-7;

to

retain

either

half

peak

output

from

$oing

above

10V

(2OVpp).

In

thi3

7oc

oder,

there

are

two

other

compressors

similar

to

the

Mic

compressor

ir.

configuration:

in

Guitar

preamp

ohain

and

synthesizer

filler

output

channe-.

SXPAIJDSR

Ihe

output

-voltage

at

pin 1 of

IC5

io

al30

received

oy

3x?ander3

IC17-20,

322

and

32;.

The

current

from

322

^323)

varies

in

the

same

direction

a3

in

the

Compressor,

but

with

thi3

fashion,

3igr.al

flew

rate

through

IC13

(IC2G/

is

ii-

reciy

proportional

to

the

control

current;

the

more current

flows,

the

moire

signal

flows

through

IC13.

ANALYZER

FILTSR

Ten

3?Fs

witri a nign Q consisting

of

ICs

(s.

g.

IC<?G

and

IC55;

covers

most

of

the

audio

spectrum -3peech

signal.

The

3ignal

from

the

compressor

is

pre-emphasized

through

IC5l?in3

5-7)

and

fed

to

the

filter

bank

which

slices

up

the

3pectrum.

Each.

3lice

goes

to a iiode(e.g.

D37)

where

its

peak

is

letected,

3moothed

and

is

fed

to

the

7CA

in

the

filter

-Synthesiser

filter.

This

i3 a control

voltage

that

is

proportional

to

*.he

jtrer-ght

of

that

slice.

J

"/:.rTHE

JIZEli ? IL

:2h

Trie

Jyr.th^ji»'.«r

f-itor u a

jet

^f

oar.'i?-^

filr-jr,

.ier.-

ticai

to

tnose

of

the

Analyzer

3ection,iJfed

by

tne

o.^n-

■ii

•-•oming

througn

either

IllSTRUMENT

or

joJAR

preaap

and

IlAiuMCIIICS

circuit,

i'he

filter

bank

3lice3

Jp

instrument

3ound

jpectrua

into

banas

:n

the

3aoe

way

Analyser

filter

ioea

on

the

jpeech

3pectrua.

Each

3lice

tr?n

connects

to

•/oit'dge—

:ontroiied

amp

-7CA.

7CA

During

an

absence

of

signal

in

Analyser

'ilterie.g.IC5O

IC55.-C63),

negative

peaks of

trian^alar

*ve

jn

1J

of

IC33

is

kept

positive

-determined

by

7?.3 • with

respect

to

the

11,

disnabling

3witcnir.g

gata

-iC;2.

When

the

voltage

from

ICc3

increases

to . scae

extent,

it

exceeds

lower

portion

of

trianiguiar

wave,au3ing

IC33

13

turns

to

"H"

wnich

in

turn

gates

1C32

:.

When

pc3itive

going

triangular

wave

reaches

above

the

/ctage

on

11,

1;

tum3

to

"L"

and

IC32

turns

off.

Ths

signal

flow

rate

througn

IC32

aepend3

sn

the

width

of

lulse

:*r:a

1C33

and

pulse

width

is

proportional

to

-Co;

;;trcl

ventage.

pul3e3ating

rectified

3ignal3

are

smoothedwhile

tr.ey

are

passing

through

the

-IC39.

TOCCDiiR

I1CLD

IC33

10

IC33

11

IC63

7

IC33

1

-rj

n

HUH

CCNSCIIA3T

FILTER

This

H?F

allows

only

high-frequency

cccc'-.ent

-n

signal

from

tne

Mic

imp

:o

pass

30

aa

to

coaper.sa;

f^r

r.igh-

"requer.cy

range

.r.oapub^e

.:'

reprcciuc-.ior. : t.ie • :c

:aer

rhu

'jirrj;;

.j

•:

i.-npoj.jd

;f

QC.Q3

'lnd

Q.X.

*hen

the

KCLD

jacit

circuit

:pen3,

and

5Cm3

later,

the

Q2

output

mcrea3*3

in

-.r;-*

positive-going

to

turn

on tne

gate

Ql

and

to

jnunt

175 0 input

to

the

ground.

On

the

other

hand,

a

3ignal

supplied

through

D7

turns

FST

3witch

IC53

(pins

10-12)

on,

turning

1C53

(pins 3 and

9)

off,

disconnecting

H3O7

from

iiscr.argir.g

path,

increased

discharging

time

constant

can

r.old

previously

charged

C135

for

7-10sec.

7CICS

JHARACTCR

CONTROL

Because

resi3*or3,

-R726,728,

730

connected

to

wiper

terminals

of

CHARACTCR

CONTROL

pots,

are

different

in

value;

the

higher

the

frequency,

the

^arger

the

value:

overall

frequency

response

offer3

de-emphasized

charac

teristics

.

SOUNU

DETECTOR

During

an

absence

of

musical

instrument's

signal,7cccder

3hut3

inadvertent

3ignal3

in

under

the

coordination

of

a

system.

The

sound

detector

i3

the

first

3tage

of the

3y3tem.

IC45

(?in3

~-~},

D51

and D52

make

up a full-wave

recti

fier,

the

average

output

voltage

is

peak

of the

3ignal

ielivered

by

IC21

pir.

1,

then

IC45

(pins

1-3)

provides

adequately

smcctn

^C

output

from

1.

•hen

this

vc.tage -at

pin 4 of IC37 -exceeas

voltage

at

5,

pin I goe.s

to

negative,

cutting

Q29

off,

removing

the

ground

rrea

pin 2 of

1C17(IC19J.

Expanders

are

now

ready

to

function.

IC37

pin 7 al3o 3ees

Sound

Detector's

output

and

deter

mines

1's

output

pulse

rfidth

which

in

turn

regulates

H?F

sigriHl

flaw

rare.

While

Synthesizer

filter

7CA

re

sponds

to

s^e-izr. 3 peer

rum,

H?F

.'CA

to

tne

instrument'

3.

CIRCUIT

DESCRIPTION

—General-

Sound

from

Musical

Instrument

Voice

from

XIC

High

Sound

3yr:as3

Filter

Com

pressor

1st

Filter

Amplitude Detector

Sound

Detector

2nd

Filter

-*•

VCA

•*

Sxcander

Holi

In

the

Vocoder,

the

voice

signal

from a Mic

is

frequency-analysed

through a group

of

filters

to

slice

up a voice

signal

frequency

3pectruna

featuring

huaar.

voice.

Then

the

spectrum

is

duplicated

to

another

group

of

musical

sound

signal

filters

to

obtain

func

tions

equivalent

to

human

acuth

and

throat

and

thus

to

simulate

human

voice

with

musical

sound

signals.

Fundamental

Vocoder

functions

are

discribed

below

according

to

t.ie

Blocsk

Diagram

shown

above.

1.

Analyzing

(first)

Filter

and

Amplitude

Detectors

A

Mic

iixput

signal

is

resolved

by a group

of

filters

into

freqen-

cy

band

components

which

are

amplitude-detected

and

supplied

tc

the

VCAs

of

the

Synthesiser Filter

(second

filter).

Signals

passing

through

second

filters

are.

controlled

in

volume

at

VCA

b.y

the

control

signal

coming

from

corresponding

frequency

band of

tne

first

filter.

Z.

Synthesiser

,'3e;or.a;

liter

and

"CAs

Like

the

first

filter,

aausicai

3cund

signal

being

supplied

is

resolvd

into

frequency

spectrum

components.

Sise a musical

3ound

passing

through

the

3ecori

group

of

filters

is

proportional

to

the

f*st

filter

output

amplitude,

the

spectrum £ the

second

filter

output

is

analogous

to

trit

of

the

vcice

signal.

In

ether

words,

:he

second

filter

output

is

mixture

of

trie

input

musical

3cund

signal

and

the

firs:

signal

output.

Thus,

uniform

3ound

signa.

spectrum

would

be

ideal

for

reproduction

of

human

voice,

but

it

is

no

longer

of a musi:al

instrument.

3•

Compander

The

compander

is a combination

3f

a

compressor

and

an

excajier.

The

compressor

reduces a a

ic

input

signals

range

in

amplitude

and

su:

plies

smaller out-

cut

signals

range

than

inj

ut

signals'

to

the

first

filter.

On

the

contrary,

the

expan

der,

for a given

range

of

amplitude

input v oltages,

produces

a

larger

amplitude

range o f

output

voltage.

Thus

restores

the

ordinal

volume

range.

i.

Kigir.

Frequency

Voice

Signjil

Bypass

Filter

\Reiionant

Filter)

3mce

musical

sounds rarely

include

high

frequency

r.oise

components

such

as

"fricative"

may

be

in

V.ioe,

the

second

filter

has

no

spectrum

to

respen:

to.

Furthermore,

such a sound,

hardly

relating

t:

musical

intervals,

is

separated

from a mic

inpu"

signal,

passes

through

this

circuit

and

is

re-

ccmbined

with

the

second filter

outputs.

5.

Musical

Sound

Signal

Detector

This

circuit

-obstructs

tne

second

filter

output

a;

long

as a musical

sound

is

not

supplied

to

the

Vocoder

and

tells

the

circuits 3 and i whether

a

musical

scur.d

signal

is

being

fed

cr

net.

Thi3

circ

.it

enables

Vocoder

to

hold

its

output

luring

an

interruption

in

mic

signal,e.g.

when

a

singer

inspires,

-he

function

can

also

be

used

for

some

special

effect

applications.

During

holding,

this

circuit

retains

spec

trams

and

volume

by

holding

amplitude

ietectors

output

volt

ages

and

expander

control

voltage.

Tne

compressor

gain

is

minimised

and

the

vcice

gate

is

turned

off

so

as

to

1-ceep

vcice

unchanged

ever.

though

,Xic

input

singal

is

changing.

Roland Vocoder SVC-350 Service Notes

Specifications and Main Features

Frequently Asked Questions

User Manual