Nakamichi 630 User manual

Nakamichi

630

FM

Tuner

Preamplifier

Operating

Instructions

AS

WARNING

TO

PREVENT

FIRE

OR

SHOCK

HAZARD,

DO

NOT

EXPOSE

THIS

APPLIANCE

TO

RAIN

OR

MOISTURE

Please

record

the

Model

Number

and

Serial

Number

in

the

space

provided

below

and

retain

these

numbers.

Model

Number

and

Serial

Number

are

located

on

the

rear

panel

of

the

unit.

Model

Number

:

Nakamichi

630.

Serial

Number

CONTENTS:

Physical

Layout

............000-

1.2

PreGautions

wuc5:3

ha

eS

See

eet

2

Connections.)

since

Uae

alee

jabs

3

PM

LANtGNAa

cscs

cee

ced

wb

ate

bared

tie

4

Dipole

Antenna

............00-

4

Other

Indoor

Antennas

..........

4

Qutdoor

Antennas

.............

4

Installation

of

Coaxial

Connector

.

5

Outdoor

Antenna

Installation

Hints

..

5

OPEALION:

os

seek

eng

Swe,

oF

Sled

6

Preamplifier

Section

............

6

FM

Tuner

Section.

...........0-

7

Dolby

EM.

sci

cae

tec

Ba

BR

8

Block

Diagram

........-

eee

ee

eee

ee

9

Performance

Data

.........-..--00005

10

Troubleshooting

Chart

..............

11

Service

Information

...............0.

11

Specifications

...

0.6...

0.002

12

a

askin

tine

tesenerettec

trees

tee

cate

Congratulations!

You

have

purchased

one

of

the

finest

electronic

components

available

today.

The

Nakamichi

630

FM

Tuner

Preamplifier

combines

a

virtually

flawless

stereo

preamplifier

with

one

of

the

most

advanced

FM

tuners

ever

developed.

World

famous

Nakamichi

engineering

and

quality

assurance

further

guarantee

long-term.

enjoyment

and

investment

protection.

Although

many

of

the

630’s

features

are

self-explanatory,

we

strongly

suggest

you

take

the

time

to

read

this

manual

in

its

entirety

before

attempting

operation.

Thank

you.

NAKAMICHI

RESEARCH,

INC.

Physical

Layout

FUNCTION

SELECTOR

SWITCHES

Permits

selection

of

phono,

auxiliary

or

FM

as

source.

Additional

selector

buttons

for

FM

provide

Dolby

FM*,

interstation

muting,

and

choice

of

narrow

or

wide

IF

filter

response

(see

page

6).

POWER

SWITCH

ins

aun),

Fal

Dany

PaN

wate.

amvew

By

Ml

wy)

MODE

SWITCH

Provides

a

summed

signal

(L+R)

for

monaural

ie

tape

moniter

fode

operation

(see

page

7).

TAPE

MONITOR/DUBBING

SWITCHES

Selects

source,

tape

1,

tape

2

and

tape

copy

functions

(see

page

6).

«

CONTOUR

CONTROL

Provides

low

and

high

frequency

loss

compensation

for

low

listening

levels.

TONE

CONTROLS

Bass

—

permits

adjustment

of

low

frequencies.

Treble

—

permits

adjustment

of

high

froquencies.

STEREO

HEADPHONE

JACK

Accepts

stereo

headphones

in

the

impedance

range

of

8

to

200

ohms.

The

630’s

preamplifier

output

is

automatically

deactivated

when

headphones

are

inserted

into

this

jack.

300-OHM

FM.

ANTENNA

TERMINALS

For the

connection

of

all

antennas

utilizing

300-

ohm

twin

lead

cable

(balanced),

including

the

provided

dipole

(T-shaped

ribbon)

antenna

(see

page

4).

75-OHM

FM

ANTENNA

CONNECTOR

For

the

connection

of

an

external

antenna

via

a

75-ohm

unbalanced

coaxial

cable.

A

mating

con-

nector

is

provided

for

custom

installation

(see

page

4).

AC

VOLTAGE

SELECTOR

SWITCH

A

2-position

switch

for

AC

voltage

selection

(100—120

V

or

220—

240

V).

AUXILIARY

AC

OUTLETS

Switched

power

outlets

rated

at

350

VA

total.

PREAMPLIFIER

OUTPUT

JACKS

For

connection

to

power

amplifier.

AC

LINE

CORD

1

front

panel

STEREO

INDICATOR

LAMP

“SIGNAL

STRENGTH

INDICATOR

LAMP

TUNING

INDICATOR

LAMPS

es

ae

INDICATOR

LAMP

——

BALANCE

CONTROL

VOLUME

CONTROL

rear

panel

TUNER.

OUTPUT

JACKS

For

connection

of

only

the

tuner

section

to

another

preamplifier.

TAPE

RECORD

OUTPUT

JACKS

TAPE

MONITOR

(PLAYBACK)

INPUT

JACKS

AUXILIARY

INPUT

JACKS

PHONO

INPUT

JACKS

PHONO

INPUT

SENSITIVITY

SELECTOR

SWITCH

Three-position

switch

selects

1

mV,

2

mV,

or

5mV

phono

input

sensitivity.

GROUND

TERMINAL

Precautions

Wait

10—15

seconds

after

turning

the

power

to

the

630

and

the

rest

of

your

components

on

before

turning

the

volume

up.

This

will

permit

all

circuits

to

stabilize,

thus

reducing

the

risk

of

damage.

Always

make

sure

that

the

power

to

the

630

and

your

power

amplifier

is

off

before

performing

interconnec-

tions,

especially

loudspeaker

and

phono

cartridge

connections.

You

may

otherwise

cause

serious

damage

to

your

amplifier

and/or

!oudspeak-

ers.

It

is

highly

recommended

that

you

reduce

the

volume

to

a_

low

level

before

switching

sources

or

changing

stations,

even

with

the

interstation

muting

on.

Sudden

introduction

of

a

loud

signal

source

may

damage

your

loudspeakers.

Never

connect

components,

the

total

power

consumption

of

which

exce-

eds

350

VA,

to

the

auxiliary

AC

outlets

on

the

rear

panel

of

the

630.

Shorting

plugs

are

supplied

on

the

Phono

and

AUX

input

jacks.

Leave

them

inserted

unless

the

input

is

to

be

used.

Connections

Preamplifier

Output

Connect

the

preamp

output

jacks

of

the

630

to

the

inputs

of

your

power

amplifier

using

a

standard

stereo

shielded

audio

cable.

Observe

left

and

right

indications.

If

you

are

using

the

630

as

a

tuner

only,

the

preamplifier

outputs

may

be

connect-

ed

to

the

‘tuner’

or

‘aux’

inputs

of

your

separate

preamplifier,

although

you

may

prefer

to

use

the

630’s

Tuner

Output

for

this

purpose.

ow

Tuner

Output

The

tuner

section

of

the

630

may

be

directly

and

constantly

accessed

via

the

tuner

output

jacks.

The

tuner

output

is

not

affected

by

the

function

switches

(phono,

aux

and

FM),

the

tape

monitor

switches

(source,

tape

1,

tape

2,

and

dubbing)

nor

the

contour,

tone,

volume

and

balance

controls.

The

tuner

output

is

subject,

however,

to

the

effects

of

the

Dolby

FM*,

mute,

narrow

and

mode

switches.

When

using

the

630

in

combina-

tion

with

a

separate

preamplifier,

such

as

the

Nakamichi

610

Control

Preampli-

fier,

the

tuner

output

can

be

utilized

to

connect

the

630

to

the

“aux”

or

“‘tuner’’

input

of

the

preamplifier.

The

tuner

output

can

also

be

connected

directly

to

the

inputs

of

a

tape

deck;

since

this

output

is

constant

and

unaffected

by

the

630’s

preamp

controls,

it

enables

in-

dependent

taping

of

FM

broadcasts

(you

can,

for

example,

listen

to

your

record

player

while

taping

off

the

tuner

section).

Output

level

is

290

mV

at

50%

modula-

tion.

Auxiliary

Input

An

extra

set

of

high

level

inputs

permits

the

use

of

one

additional

source,

such

as

a

tape

player.

The

auxiliary

input

sensitivi-

ty

is

100

mV,

and

the

impedance

is

100K

Ohms.

Tape

Deck

The

630

provides

two

sets

of

tape

deck

record

and

playback

jacks.

Connect

the

“rec

out”

jacks

to

the

inputs

of

your

tape

deck(s).

The

“play

in”

jacks

should

be

connected

to

the

tape

deck

outputs.

Use

shielded

audio

cable

for

all

connections,

and

observe

left

and

right

indications

throughout.

It

is

not

necessary

to

re-

(com

g90g00

Power

Amplifier

Extra

Tape

Deck

Tape

Deck

1

connect

the

decks

for

tape

copying

as

this

can

be

accomplished

by

front

panel

switches.

Phono

Input

Connect

the

turntable

(record

player)

cables

to

the

phono

input

jacks

on

the

630.

Make

sure

that

the

channels

are

not

reversed.

Do

not

extend

the

turntable

cables

—

keep

them

short

to

avoid

hum

and

signal

degradation.

Also

connect

the

ground

wire

from

the

turntable,

if

one

is

provided,

to

the

ground

terminal

of

the

630.

The

phono.

sensitivity

selector

switch

located

above

the

ground

terminal

should

be

set

for

the

cartridge

in

use.

High

output

magnetic

cartridges

should

be

used

with

the

phono

sensitivity

at

5

mV.

Less

sensitive

cartridges

will

require

a2

mV

or

1

mV

setting.

Consult

instruc-

tions

provided

with

your

cartridge.

If

you

are

unsure,

start

with

the

5

mV

position;

switch

to

2

mV

or

1

mV

if

youdo

not

get

sufficient

volume

when

playing

a

record.

Moving

coil

pickups

amplified

by

a

boost-

er

(transformer

or

head

amp)

will

general-

ly

require

the

2

mV

or

1

mV

setting.

Ca

Calley

Meee

U

Tape

Deck

2

Record

Payer

The

quality

of

FM

reception

will

only

be

as

good

as

the

signal

entering

the

tuner

at

the

antenna

terminals.

Although

there

is

little

you

can

do

if

the

FM

station’s

broadcast

quality

is

poor,

you

can

ensure

that

the

630’s

FM

section

is

performing

at

its

best

by

selecting

the

proper

FM

antenna

and

installing

it

correctly.

The

following

is

intended

as

a

guide.

Your

high

fidelity

dealer

or

local

antenna

spe-

cialist

will

be

able

to

provide

further

information,

if

necessary.

Dipole

Antenna

If

you

are

located

in

a

metropolitan

area

or

otherwise

close

to

the

FM

broadcasting

stations

to

which

you

will

be

listening

(i.e.,

within

several

miles),

and

if

your

immediate

area

is

free

of

tall,

obstructing

structures,

the

dipole

(T-shaped

ribbon)

antenna

provided

with

the

630

will

most

likely

be

more

than

adequate

for

quality

FM

reception.

Connect

the

dipole

to

the

300-ohm

balanced

terminals

on

the

rear

Matching

Transformer

FM

Antenna

panel

of-the

630.

Stretch

the

dipole

into

a

“T’

shape,

and

position

it

for

best

reception

while

listening

to

the

broadcast.

if

the

signal

sounds

weak

and

distorted,

or

if

the

630’s

‘’signal’’

lamp

fails

to

light

with

most

stations,

the

use

of

a

direction-

al

outdoor

FM

antenna

will

yield

signifi-

cant

improvements.

If

you

are

receiving

stations

strongly,

but

the

sound

is

distort-

ed,

this

may

be

an

indication

of

strong

multipath

reception

(distortion

caused

by

multiple

arrivals

of

the

same

signal

at

the

antenna

terminals

—

tall

structures

nearby

will

cause

multipath

reception).

In

this

case

as

well,

the

use

of

a

directional

outdoor

antenna

will

improve

reception

quality.

Other

Indoor

Antennas

In

some

cases,

a

slight

improvement

in

reception

can

be

gained

by

using

“‘rabbit

ears’’

or

other

indoor

FM/television

an-

tennas

instead

of

the

dipole.

If

you

are

in

a

weak

signal

area,

however,

any

improve-

Dipole

Antenna

Coaxial

Cable

—==5

F

Type

Plug

FM

Antenna

ment

with

these

indoor-type

antennas

is

likely

to

be

marginal

at

best.

Outdoor

Antennas

Outdoor

antennas

vary

in

gain

and

direc-

tionality.

Generally,

antennas

with

the

greater

number

of

elements

will

have

higher

gain.

For

FM,

choose

an

antenna

with

3

to

8

elements,

depending

on

your

distance

from

the

broadcasting

stations

and

other

area

conditions.

Most

outdoor

FM

antennas

can

be

connected

to

the

630’s

300-ohm

balanced

terminals

using

300-ohm

twin-lead

antenna

cable.

Al-

though

this

is

preferable,

some

installa-

tions

will

require

the

use

of

coaxial

cable

because

of

noise

sources,

such

as

automo-

bile

engine

ignition

or

high

voltage

power

lines.

For

coaxial

lines,

utilize

the

75-ohm

unbalanced

connector

on

the

630.

Some

antennas

will

require

a

matching

transfor-

mer

for

75-ohm

operation.

Consult

an

antenna

specialist

for

specific

recommen-

dations.

i

|

if

Installation

of

75-Ohm

Coaxial

Connector

The

F-type

connector

supplied

with

the

630

mates

with

the

75-ohm

unbalanced

antenna

connector

on

the

rear

panel.

If

your

antenna

connection

is

via

75-ohm

coaxial

cable,

you

can

install

the

provided

connector

onto

the

cable

yourself

with

just

a

knife

and

pliers.

1.

Cut

and

remove

about

15mm

of

the

outer

insulation

(cover).

outer

insulation

mesh-type

braid

coaxial

cable

15mm

2.

Cut

and

remove

the

mesh-type

braid

with

the

knife,

but

leave

about

2mm

at

the

base,

right

the

edge

of

the

outer

insulation.

inner

insulation

2mm

3.

Cut

and

remove

the

inner

insulation

(cover),

leaving

about

5

mm

from

the

edge

of

the

outer

insulation.

a

-—

t+]

mm

4,

Pass

the

clamp

ring

over

the

cable,

and

spread

the

mesh-type

braid

with

your

fingers.

clamp

ring

5.

Push

the

pointed

end

of

the

connec-

tor

into

the

cable,

making

sure

it

goes

in

between

the

braid

and

the

inner

insulation.

a

<

7

|

laa

6.

Press

and

crimp

the

clamp

ring

with

the

pliers

to

secure

the

connector.

clamp

cing

\\

ZILA

+

The

coaxial

cable

is

now

ready

to

be

connected

to

the

75-ohm

terminal

on

the

rear

panel

of

the

630.

Outdoor

Antenna

Installation

Hints

te

lf

you

are

fairly

close

to

FM

broad-

casting

stations

but

find

you

have

to

use

a

directional

outdoor

antenna

to

reduce

multipath,

the

signa!

strength

may

be

sufficiently

high

to

cause

overloading

of

the

630’s

FM

front

end

(heard

as

a

severely

distorted

signal).

In’such

instances,

an

antenna

attenuator

must

be

installed.

Consult

your

local

antenna

specialist.

Since

most

outdoor

FM

antennas

are

highly

directional,

they

must

be

“aimed”

toward

the

desirecl

station's

broadcast

antenna.

If

you

live

in

an

area

where

FM

stations

exist

in

sever-

al

different

directions,

you

may

have

to

install

a

rotor

system

in

order

that

you

can

remotely

alter

the

direction

of

the

antenna.

Always

place

outdoor

antennas

as

far

from

highways

and

high

power

lines

as

possible.

Follow

your

antenna

dealer’s

recommendations

for

proper

placement.

300-ohm

twin

lead

cable

is

superior

to

coaxial

types

in

that

there

is

very

little

transmission

loss,

even

with

relatively

long

lengths

(thel

oss

factor

is

approx.

0.04

dB/meter).

The

draw-

back

of

300-ohm

twin

lead,

however,

is

that

it

easily

picks

up

noise.

A

75-ohm

coaxial

cable

systerm

is

much

less

susceptible

to

noise

pick-up,

but

cable

loss

is

not

negligible

(typically

0.12

dB/meter).

If

noise

problems

exist

in

a

weak

signal

situati

on,

speci-

al

low-loss

coaxial

cables

are

available

from

most

antenna

dealers.

Preamplifier

Section

Operation

of

the

630’s

preamplifier

sec-

tion

is

quite

straightforward.

Playing

any

source

other

than

tape

is

a

simple

matter

of

selecting

the

appropriate

function

(phono,

aux

or

FM),

making

sure

the

“source”

button

is

depressed,

and

turning

up

the

volume

control.

Tape

playback

or

copying

merely

requires

selection

of

the

appropriate

tape

monitor/dubbing

switch.

Bass,

treble

and

contour

can

be

adjusted

as

desired.

Each

of

the

preamplifier

con-

trols

are

described

in

detail

below.

1.

Function

Selector

Buttons

Phono

-

Selects

disc

source.

If,

upon

turning

up

the

volume,

the

phono

level

is

too

loud

or

soft,

relative

to

other

sources

(such

as

FM),

a

different

phono”

input

—

sensitivity

should

be

selected

with

the

rear

panel

switch

(see

Connections

—

Phono

In-

put).

Selects

high

level

source

plug-

ged

into

the

630’s

auxiliary

input.

FM

-

Switches

in

FM

Tuner

section

of

the

630.

Dolby

FM

Mute

Narrow

Aux

-

see

FM

Tuner

Section

operat-

ing

instructions

os

sfuinction

a

phono

aux

FM

OolbyNR

mute

narrow

t_

&y—__—_1

fa

tape

monitor

————-—]

source

tape}

“tape

2

1

b2

142

fA

ETE

Ch

Ldubbingd

J

Operation

2.

Tape

Monitor

Selector

Buttons

Dubbing-

Permits

tape

copying

from

Source

-

Must

be

depressed

to

listen

to

tape

deck

1

to

tape

deck

2

phono,

aux

or

FM.

and

vice

versa.

1

»

2

switch

Tape

1-

Selects

tape

deck

1

for

play-

programs

deck

1

for

playback

back

or

for

monitoring

during

and

deck

2

for

record,

1

4

2

record.

switch

programs

deck

2

for

Tape

2-

Selects

tape

deck

2

for

play-

playback

and

deck

1

for

re-

back

or

for

monitoring

during

cord.

record.

Tape

Copying

Th2

142

1hm2

142

ST

eo

wb

109000

|

ox

CREE:

Tape

Deck

1

Tape

Deck

2

Notes

on

Tape

Recording:

(i)

The

source

selected

by

the

function

{iii}

When

either

of

the

dubbing

switch-

(ii)

es

are

depressed,

the

“rec

out”

signal

to

the

deck

prograrnmed

for

switch

(phono,

aux

or

FM)

is

al-

ways

present

at

the

tape

“rec

out”

jacks.

The

signal

at

the

“rec

out”’

playback

is

blocked

to

prevent

jacks

is

unaffected

by

the

volume,

feedback

oscillation.

Make

sure,

balance

or

contour

controls.

Tape

1

therefore,

that

both

dubbing

switches

are

off

(up)

before

at-

tempting

to

record

one

of

the

sources

(phono,

aux

or

Fi}.

Since

the

dubbing

switches

operate

independently,

tape

copying

can

be

performed

while

you

listen

to

one

of

the

sources

(phono,

ay

x

or

FM}.

or

Tape

2

may

be

monitored

during

record

by

depressing

the

appropri-

ate

tape

monitor

button.

\f

more

than

one

of

the

first

three

(iv)

tape

monitor

buttons

(source,

tape

1,

tape

2)

are

depressed

at

the

same

time,

only

the

left-most

one

will

be

functional.

Care

should

be

taken

to

ensure

that

only

one

of

these

three

are

depressed

at

one

time.

3.

Mode

Switch

For

normal

stereo

operation,

leave

this

switch

in

the

“off”

position,

i.e.

out.

When

the

switch

is

depressed,

the

“‘pre-

amp

out”

jacks

will

deliver

the

identical

signal

to

both

channels

of

the

power

amplifier.

This

signal

will

be

the

sum

of

the

left

and

right

channels

(mixed)

of

the

source

(phono,

aux,

FM

or

tape

play-

back),

This

same

monaural

signal

wil!

be

present

at

the

“rec

out”

jacks

if

the

mode

switch

is

depressed

while

“source”

button

is

down.

There

are

several

applications

of

the

mode

switch:

(a)

To

play

a

monaural

signal

source,

such

as

television

sound,

over

both

stereo

loudspeakers,

or

to

record

the

same

on

both

channels

of

a

stereo

tape

deck;

(b)

To

blend

both

channels

of

a

stereo

signal

source

for

recording

on

a

monaural

tape

deck;

(c)

To

improve

the

listenability

of

a

weak

FM

stereo

station

or

a

scratchy

monaural

disc;

in

both

cases,

switch-

ing

to

monaural

with

the

mode

switch

will

cause

cancellation

of

some

of

the

background

noise.

Note:

The

“‘rec

out”

jacks

are

affected

by

the

mode

switch

only

if

the

“source’’

switch

is

depressed.

4.

Controls

Contour

-

The

normal

position

for

this

control

is

fully

clockwise.

The

contour

control

provides

automatic

compensation

for

the

human

ears’

dispropor-

tionate

decrease

in

sensitivity

to

the

extreme

low

and

high

frequencies

at

low

listening

levels.

To

use

the

contour

control,

first

turn

it

fully

clockwise.

Turn

up

the

vol-

ume

contro!

to

normal

maxi-

mum

listening

levels.

Then

turn

the

listening

level

down

with

the

contour

control

in-

stead

of

the

volume

control.

Loudness

compensation

will

take

place

automatically.

Bass

-

Permits

boosting

and

at-

tenuating

of

lower

frequen-

cies

within

+

9

dB

at

20

Hz.

Permits

boosting

and

at-

tenuating

of

higher

frequen-

cies

within

+

9

dB

at

20

kHz.

Volume

-

Controls

overall

listening

lev-

el.

Balance

-

Permits

correction

of

channel

imbalance.

Treble

-

Contour

characteristics

5.

Headphone

Plugging

a

headphone

into

the

front

panel

jack

provided

automatically

cuts

off

the

signal

from

the

preamplifier

output

to

the

power

amplifier.

Always

turn

the

volume

control

down

before

plugging

in

or

un-

plugging

headphones.

Note:

The

contour

control

has

no

ef-

fect

on

headphone

listening.

FM

Tuner

Section

The

highly

unconventional

tuning

dial

of

the

Nakamichi

630

was

designed

to

great-

ly

simplify

FM

station

selection.

instead

of

the

usual

tuning

meters,

the

630

utilizes

a

series

of

indicator

larmps

for

precise

tuning

indication.

stereo

ew

tuning

<=

signal

.

e

Mya

wwii

finy,

a

98

Mi,

\y

We,

Wr

09

yy

1.

Indicator

Lamps

Stereo

-

lights

to

indicate

FIA

multi-

plex

stereo

reception

Tuning-

the

three

lamps

in

the

center

of

the

group

are

fa

station

selection;

if

one

of

the

green

lamps

are

on,

the

tuner

is

slightly

off-station,

ined

you

should

turn

the

dig

in

the

direction

indicated

by

the

ar-

row

above

the

lamp

the

red

lamp

lights

to

indiate

that

the

tuner

is

centeecd

and

“locked

in’’

to

the

clesired

station.

indicates

the

strength

of

the

signal

from

the

antenna;

when

the

signal

lamp

is

glow-

ing

brightly,

there

is

suffi-

cient

signal

strength

for

opti-

mum

tuner

performance,

The

antenna

should

be

adjusted

for

maximum

brightness.

Note:Some

stations

will

be

too

far

away

(or

too

weak

simply

because

of

low

transmitter

power)

to

activate

the

signal

lamp.

Many

such

sta-

Signal

-

tions

nevertheless,

will

be

sufficiently

strong

for

normal

listening

purposes,

CAUTION:

Avoid

spinning

the

tuning

dial

so

that

it

“hits’’

either

end

of

the

scale.

Rough

treatment

of

this

nature

may

cause

damage.

2.

FM

Function

Switches

function

FM

DolbyFM

mute

narrow

_

Dolby

switches

in

the

25

microsec-

FM™*.

ond

de-emphasis

required

for

proper

Dolby

FM

reception

and

activates

the

built-in

B-type

Dolby

Noise

Reduc-

tion

decoding

circuitry.

See

full

explanation

of

Dolby

FM

below.

normally

left

on

(in)

to

elimi-

nate

interstation

noise;

should

be

turned

off

when

tuning

in

a

very

weak

station

because

the

muting

circuit

cuts

out

such

stations

with

Mute

-

the

noise.

Note:

It

is

recommended

that

you

turn

down

the

volume

when

changing

sta-

tions,

whether

the

mute

switch

is

on

or

off.

the

630’s

IF

stage

provides

two

selectivities,

narrow

and

wide

(80

dB

and

40

dB)

this

switch

is

normally

left

in

the

“wide'’

position

(out)

since

this

yields

the

best

distortion

and

separation

performance.

The

“narrow”

position

should

be

used

when

the

pre-

sence

of

many

_

stations,

crowded

close

together

on

the

dial,

makes

precise

tuning

difficult

or

impossible.

Note:

The

FM

Function

Switches

are

always

effective

at

the

630’s

tuner

output.

They

affect

the

preamplifier

output,

only

if

FM

is

selected

as

the

source.

Narrow

-

A

Brief

Explanation

of

Dolby

FM*

The

Nakamichi

630

incorporates

B-type

Dolby

Noise

Reduction

decoding

circuit-

ry

to

take

advantage

of

the

fact

that

there

are

now

many

stations

(in

the

United

States)

broadcasting

Dolby

FM.

FM

ste-

reo

has

always

been

a

relatively

noisy

medium,

requiring

a

rather

sharp

pre-

emphasis

(boosting

of

high

frequencies)

at

the

transmitter

and

a

complementary

de-emphasis

(restoration

of

pre-boosted

highs)

at

the

tuner

or

receiver

to

achieve

a

reasonable

semblance

of

noise-free

perfor-

mance.

The

75

microsecond

time

con-

stant

(50

microseconds

in

most

European

countries)

defines

the

standard

pre-

emphasis

curves

currently

being

used

by

non-Dolbyized

FM

stations.

The

draw-

back

of

so

much

pre-emphasis

is

that

stations

must

utilize

large

amounts

of

high

frequency

limiting

to

prevent

over-

modulation,

or

else

modulate

at

an

over-

all

lower

level

and

end

up

with

what

the

pre-emphasis

was

supposed

to

counter

in.

the

first

place:

poor

signal-to-noise

ratio.

This

is

why

even

the

best

of

FM

broad-

casts

have

lacked

the

dynamic

range

of

today's

better

quality

LP

discs,

especially

at

the

higher

frequencies.

Dolby

FM

improves

the

quality

of

reception

in

two

basic

ways

(assuming

the

station

is

broad-

casting

Dolby

FM):

a)

better

signal-to-noise

ratio,

especially

in

weak

signal

areas;

b)

full

recovery

of

high

frequency

dy-

namic

range

in

any

reception

area.

The

increase

in

signal-to-noise

is

the

result

of

the

well-known

properties

of

the

Dolby

Noise

Reduction

Systern.

Dolby

FM

utilizes

the

same

B-type

Dolby

cir-

cuitry

found

today

on

numerous

cassette

tape

recorders.

The

increase

in

high

fre-

quency

dynamic

range

can

be

attributed

to

a

new

FM

time

constant,

25

micro-

seconds.

FM

stations

broadcasting

Dolby

FM

utilize

this

new

time

constant

which

reduces

pre-emphasis

to

an

optimum

level.

High

frequency

over-modulation

and

the

need

for

drastic

limiting

are

eliminated.

Depressing

the

Dolby

FM

switch

on

the

Nakamichi

630

ch

anges

the

de-emphasis

time

constant

from

75

microseconds

as

well

as

actiyating

the

built-in

Dolby

Noise

Reductiow

System.

If

stations

in

your

area

are

broi:cicasting

a

high

quality

Dolby

FM

signal,

you

will

notice

a

distinct

improvement

in

recep-

tion

quality

when

you

switch

to

Dolby

FM

on

your

630.

Note:

When

recording

a

Dolby

FM

broadcast

on

your

tape

deck,

depress

the

Dolby

FM

switch

on

the

630.

Set

levels

asd

record

the

broadcast

as

you

would

any

other

program

source

4with

the

deck’s

Dolby

System

9.n,

if

pro-

vided).

;

Block

Diagram

=

-

3002

bal.

o—

2

output

is

front

end

IF.

discri.

PLL

MPX

Dolby

NR

2Apho

eae

752

unbal.

o

;

l

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f

as)

i

é

aa”

Hea

tuning

logic

vol.

bal.

phono

5

mV

5

(2)

>

output

3

—

TC

€

=

:

head

Level

(d8)

Cit

tt

Lt

0

10

20°

30

40

50

60

70

80

100

Antenna

input

(dB)

Input

vs.

Noise

Level

50

100

200

S00

tk

2k

Sk

10k

=

20k

*

Frequency

{Hz}

Stereo

Separation

Antenna

Input:

98MHz,

65dBf,

1mV,

3000hm

IF:

Normal

Total

Harmonic

Distortion

{%}

50

100

«200

Hi

ik

2k Sk

10k

Frequency

(Hz)

'

Frequency

vs.

Total

Harmonic

Distortion

(Stereo)

I

Antenna

Input:

S8MHz,

65dBF,

mV,

3000hm

|

Modutation:

main

45.5%

i

sub-carrier

45.5%

{

pilot

9%

i

Total

Harmonic

Distortion

(%)

Total

Harmonic

Distortion

(%)

Modulation

{%)

Modulation

vs.

Total

Harmonic

Distortion

45.5%

sub-carrier

45.5%

Modulation:

=

main

pilot

Frequency:

IkHz

Antenna

Input:

S8MHz,

65dBf,

ImV,

3000hm

Totat

Harmonic

Distortion

(%}

Antenna

Input

(d8f}

9%

Input

vs.

Total

Harmonic

Distortion

(Stereo)

Modulation:

main

sub-carrier

pilot

45.5%

9%

0.002

oom

UH

il

+H

finial

Goes

Siiiiimenniiiiale

ll

200300

S007001K

=

2K

3K

«SK

7K

10K

«620K

Frequency

{Hz}

Frequency

vs

Total

Harmonic

Distortion

Phono

Input

Output:

2V

constant

Input:

2mV

Performance

Data

100

t

+

f

i

\

[Narrow

a

1

+

90

—

as

|

[

if

_,

80

a

zB

—

t+

3

Normat

&

70

aT

=

|

L

§

T

ao

60

T

:

aaa:

3

£

a

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s

7

&

50

s

1.

t

7

|

x

3

~400

-200

O

+200

+400

Frequency

Separation

(kHz)

Selectivity

Impedance:

3000hm

Interfering

Signal:

1kHz,

100%

Modulation

Interference

Output

Level:

—30dB

Desired

Signal:

unmodulated

ik

10k

aoe

Frequency

(Hz}

MPX

Filter

Characteristics

Totst

Harmonic

Distortion

{%)}

700

200300

5007001K

=

2K

3K

5K

7K

10K

‘OK

Frequency

(Ha)

Frequency

vs

Total

Harmonic

Distortie7

Aux

Input

Output:

2V

constes

t

Troubleshooting

Chart

Trouble

Probable

Cause

Remedy

i

No

sound

1.

No

function

switches

depressed.

1.

One

function

must

be

selected

(phono,

aux

or

FM)

2.

Source

switch

not

depressed.

2.

Depress

source

switch

(tape

switch

for

tape

playback).

3.

Incorrect

or

loose

cable

3.

Check

all

cable

connections.

a

Distortion,

hum,

noise.

1.

Faulty

cables

or

cable

connections,

1.

Check

cables

and

replace

if

necessary.

2.

Poor

ground

connection.

2.

Check

ground

wire

from

record

player.

3.

Improper

or

loose

phono

3.

Check

cartridge

and

tonearm

cartridge

installation.

connections.

Un

nNDNUINN

SO

aoe

One

channel!

dead,

channels

1.

Input/output

connections

1.

Check

all

cable

connections.

reversed

or

no

stereo

separation.

loose

or

reversed.

2.

Balance

control

not

centered.

2.

Adjust

balance

control.

3.

Mode

switch

on.

3.

Release

mode

switch.

IS

No

record

output.

Dubbing

switches

depressed.

Check

both

dubbing

switches

{both

must

be

up).

a

eS

SS

No

FM.

Antenna

disconnected.

Check

al!

antenna

wiring

and

connections

(turn

off

mute

switch).

eee

ST

SERVICE

INFORMATION

Although

it is

unlikely

that

your

Naka-

michi

630

will

require

repair,

should

servicing

ever

become

necessary,

please

consult

your

Nakamichi

deaer

or

the

Nakamichi

dealer

closest

to

you.

As

there

are

no

user

serviceable

parts

imside

the

unit,

please

do

not

attempt

your

own

repairs.

Please

read

all

accompanying

Warranty

Cards

and/or

notices

very

carefSly.

1

Thank

you

for

your

confidence

in

Naka-

michi

products.

Nakamichi

630

Specifications

Power

Requirements---

100—120/220—240

VAC,

50/60

Hz

Power

Consumption---

20

VA

Preamplifier

Section

Input

Sensitivity

/Impedance

phono.

1TmV,2mV,5mV/100k

ohms

aux

++

100

mV/50k

ohms

tape

monitor

1,2.

100

mV/50k

ohms

Maximum

Input

Levels

PHONO

wreeeceeersereeeee

250

mV

(1

kHz,

5

mV

position)

Output

Levels/Output

Impedance/Load

Impedance

Preamplifier

output

1V/600

ohms/10k

ohms

-

TEC

OUT

vrveereeeees

100

mV/1k

ohms/50k

ohms

headphone

«+

40

mW/4.5

ohms/8

ohms

Maximum

Output

at

Clipping

preamplifier

output

5

V

into

50k

ohms

rec

out

4V

into

50k

ohms

headphone

---

300

mW

into

8

ohms

Frequency

Response

phono

RIAA

deviation

within

+0.3

dB

AUX

srrseeeesees

»

20-50,000

Hz

+0,

-1.5

dB

tape

manitor

20—50,000

Hz

+0,

-1.5

dB

Signal-to-Noise

Ratio

QHF-A)/Equivalent

Input

Noise

PHONO

wre

seeeseeereeeees

Better

than

80

dB

(ref.

1

mV)/-140

dB

aux,

tape

monitor

Better

than

100

dB/-120

dB

Residual

Noise

Level

(IHF-A)

headphone

«+

8

microvolts

or

less

(8

ohms)

preamplifier

output

4

microvolts

or

less

(VR

@

min.)

Distortion

PHONO

verrerrreerceestees

Less

than

0.003%

(al!

freq.

up

to

10

kHz)

aux,

tape

monitor

Less

than

0.004%

Tone

Control

bass

en.

vee

#9

dB

at

20

Hz

treble

+

£9

dB

at

20

kHz

Contour

(control

@

8")

-30

dB

@

3

kHz

-15

dB

@

20

Hz

~24

dB

@

20

kHz

specifications

Tuner

Section

Frequency

Band

«:.---

88

MHz

—

108

MHz

Usable

Sensitivity

(for

30

dB

quieting)

mono

».

2.5

uV

(300

ohms},

13

dB

stereo

«..

25

nV

(300

ohms),

33

dBf

Sensitivity

for

50

dB

quieting

mono

»

5

pV

(300

ohms),

19

dBf

stereo

---

50

uV

(300

ohms),

39

dBf

Sensitivity

for

3%

Tota!

Noise

and

Distortion

(Stereo)

sacdadusyhonsedlses

bet

vaseveets

35

dBt

Signal-to-Noise

Ratio

(@

65

dBf)

Dolby

NR

out

mono...

better

than

75

dB

stereo---

better

than

70

dB

Doiby

NR

in

mono...

better

than

80

dB

stereo...

better

than

75

dB

Muting

Threshold

.«-...-

15

nV

(300

ohms),

29

dBt

(tuning

lamp

“on’’)

Frequency

Response.»

30—15,000

Hz

+0.3

dB,

-1.5

dB

Distortion

(@

65

dBf,

100%

modulation)

100

Hz

and

1

kHz

wide

mono

less

than

0.05%

stereo

less

than

0.08%

narrow

mono

less

than

0.15%

stereo

less

than

0.5%

6

kHz

‘

wide

mono

less

than

0.1%

stereo

less

than

0.15%

narrow

mono

less

than0.3%

stereo

less

than

0.8%

Capture

Ratio

w+.

1

dB

(wide)

Alternate

Channel

Selectivity

wide

better

than

40

dB

narrow

»

better

than

80

dB

Stereo

Separation

wide

100

Hz

»

better

than

40

dB

T

KHZ

eee

better

than

50

dB

10

kHz

...

better

than

35

dB

narrow

100

Hz

«.

better

than

30

dB

T

KHZ

ee

better

than

30

dB

10

kHz

-.

better

than

30

dB

Spurious

Response

Rejection

errr

better

than

100

dB

Image

Rejection

- -

better

than

100

dB

@

98

Miz

IF

Rejection

«..-.

-

better

than

100

dB

AM

Suppression

- -

better

than

60

dB

SCA

Rejection

----

:

better

than

75

dB

Frequency

Drift

«less

than

30

kHz,

-10°

to

60°C

MPX

Filter

---

»

~70

dB

@

19

kHz

Antenna

-

300

ohms

balanced

75

ohms

unbalanced

290

mV

(50%

modulation)

16(W)

x

6-11/16(H)

x

9-5/16(

D)

inches

400(W)

x

170(H)

x

237(D)m/m

WEIGHT

vesseserseseersereereees

15-1/2

Ib.

(approx.)

7

kg.

Tuner

Output

Dimensions

e

Specifications

and

appearance

design

are

subject

t)

change

for

further

improvement

without

notice.

:

®

Dolby

NR

under

license

from

Dolby

Laboratories

@

The

word

“Dolby”

is

a

trademark

of

Dolby

Laboratories:

12

NAKAMICHI

RESEARCH

INC.

NAKAMICHI

RESEARCH

(U.S.A.),

INC.

1-153

Suzukicho,

Kodaira,

Tokyo

220

Westbury

Avenue

Phone:

(0423)

42-1111

Carle

Place,

N.Y.

11514

Telex:

2832610

(NAKRE!

J)

Phone:

(516)

333-5440

Cable:

NAKAMICH!

KOKUBUNJI

Telex:

144513

(NAKREI!

CAPL)

900

3419C

NAKAMICHI

RESEARCH

(U.S.m.),

INC.

1101

Colorado

Avenue

Santa

Monica,

Calif.

90401

Phone:

(213)

451-5901

Telex:

652429

(NAKREI

SNM)

Pointed

in

gapan

S-802

106

Der

NAKAMICHI

630

FM

Tuner-Vorverstarker

vereinigt

einen

makellosen

Stereo-

Vorverstarker

mit

einem

der

fortschrittlichsten

FM-Tuner,

die

jemals

ent-

wickelt

wurden.

Mit

diesem

Gerit

garantiert

Ihnen

die

Firma

NAKAMICHI

gro-

Be

Freude

durch

ihre

technische

und

qualitative

Sicherheit.

Obgleich

viele

Einrichtungen

des

"630"

keiner

Erklarung

bediirfen,

Sie

sich

doch

die

Zeit

nehmen,

diese

Betriebsanleitung

sorgfdltig

bevor

Sie

Ihr

Gerdt

in

Betrieb

nehmen.

Benutzen

Sie

bitte

diese

deutschsprachige

Fassung

im

Zusammenhang

Abbildungen

der

Original-NAKAMICHI-Bedienungsanleitung.

Die

Texte

Sie

unter

den

angegebenen

Seitenzahlen.

BEDIENUNGSANLEITUNG

sollten

zu

lesen,

mit

den

finden

Nakamichi

630

FM-Tuner/

Vorverstarker

Inhalt

Bedienungsfunktionen

Vorsichtsmainahmen

Anschliisse

UKW-Antenne

Betrieb

und

Gebrauch

Blockschaltbild

MeBdiagramme

Fehlersuchtabelle

Technische

Daten

Seite

1/2

4/5

6/8

10

11

12

AY

Bedienungsfunktionen

(s.

Abb.

der

Original-Bedienungsanleitung

S.

1/2)

FRONTSEITE

Funktionswahlschalter

(Function

Selector

Switches)

Zur

Wahl

der

Programmquellen

Phono,

Zusatzeingang

oder

UKW.

Zusatzliche

Wahlschalter

bei

UKW-Betrieb

fiir

"Dolby

FM",

Stummabstimmung

und

schmal-

oder

breitbandiges

ZF-Filter

(s.

S.

6).

Netzschalter

(Power

Switch)

honoschalter

(Mode

Switch)

Addiert

Signale

(L

+

R)

fiir

Monobetrieb

(s.

S.

7).

T3-Monitor-/Kopierschalter

(Tape

Monitor/Dubbing

Switches)

Wahit

Programmquelle,

Tonband

1,

Tonband

2

und

Tonband-Kopierfunktionen

ea:

S&

teks

Konturregler

(Contour

Control)

Kompensiert

bei

geringen

Lautstarken

Verluste

der

tiefen

und

hohen

Fre-

quenzen

entsprechend

der

Ohrcharakteristik.

Klangrerler

(Tone

Controls)

Bisse

(bass)

-~Einstellung

der

tiefen

Frequenzen

HGhen

(treble)

-Einstellung

der

hohen

Frequenzen

Stereo-Kopfhorerbuchse

(Stereo

Headphone

Jack)

Fur

Stereo-hopfhorer

mit

8

Ohm

Impedanz

oder

gréfer.

Der

"630"

Vorverstar-

ker-Ausgang

wird

automatisch

abgetrennt,

wenn

der

Kopfhorer

angeschlossen

wird.

Stereo-Kontrollampe

(Stereo

Indicator

Lamp)

Sirpnalstirke-Anzeigelampe

(Signal

Strength

Indicator

Lamp

)

Sendereinstell-Anzeigelampen

(Tuning

Indicator

Lamps)

Netzkontrollampe

(Power

Indicator

Lamp)

Sender-Skalenscheibe

(Tuning

Dial)

Balanceregler

(Balance

Control)

Lautstirkeregler

(Volume

Control)

RtUCKSEITE

300/240

Ohm-UKW-Antennenbuchsen

(300

Ohm

FM

Antenna

Terminals)

Fiir

alle

300/240

Ohm-Doppelleitungen

(symmetrisch)

einschlieBlich

der

mitgelieferten

Dipolantenne

in

T-Form

(s.

S.

4),

75/60

Ohm-UKW-Antennenanschlu&

(75

Ohm

FM-Antenna

Connector)

fofoV

eee

Fur

externe

Antennen

mit

unsymmetrischem

75/60

Ohm-Koaxkabel.

Ein

pas-

sender

Stecker

fiir

diesen

Anschlu&

liegt

bei

(s.

S.

4).

Netzsrannungswahlschalter

(AC

Voltage

Selector

Switch)

2-stufiger

Schalter

zur

Netzspannungswahl

(100-120

V

oder

220-240

V).

hetzspannungshilfsausgange

(Auxiliary

AC

Outlets)

nur

US-Ausfiihrung

Schaltbare

Hetzausgange

ftir

zusammen

350

VA.

Vorverstirkerausgang

(Preamplifier

Output

Jacks)

Zum

AnschluR

an

den

Leistungsverstdrker.

Netzkabel

(AC

Line

Cord)

Tunerausgang

(Tuner

Output

Jacks)

Zum

Anschlu&

des

LTunerteils

an

andere

Vorverstirker.

Ausgang

fiir

TB-Aufnahme

(Tape

Record

Output

Jacks)

Eingang

fiir

TB-Wiedergabe

(Tape

Monitor

Input

Jacks)

Zusatzeingang

(Auxiliary

Input

Jacks)

Phonoeingang

(Phono

Input

Jacks)

Phono-Eingangsempfindlichkeit-Wahlschalter

Phono

Input

Sensitivity

Selector

Switch

3-stufiger

Schiebeschalter

zur

Wahl

von

1

mV,

2

mV

oder

5

mV

Phono-

Enofindlichkeit.

Hassebuchse

(iround

Terriinal

)

VorsichtsmaBnahmen

(so)

1.

Nach

Einschalten

der

Netzsparnung

des

"630"'

und

der

anderen

Gerate

warten

Sie

10-15

Sekunden

bevor

Sie die

Lautstdrke

hochregeln.

Da-~

nach

sind alle

Schaltkreise

stabil,

und

Sie

vermeiden

damit

Bescha-

digungen.

2.

Stellen

Sie

immer

sicher,

daR

die

Netzspannung

des

"630"

und

Ihres

Leistungsverstarkers

ausgeschaltet

ist

bevor

Sie

Verbindungen,

spe-

ziell

Lautsprecher-

und

Abtastsystem-Verbindungen,

herstellen.

An-

derenfalls

kénnten

Sch&den

an

Ihrem

Verstadrker

und/oder

Lautspre-

cher

auftreten.

3.

Sie

sollten

die

Lautstarke

vermindern,

bevor

Sie

die

Programmquel-

len

oder

Sender

wechseln,

auch

wenn

die

Stummabstimmung

eingeschal-

tet

ist.

Ein

plotzlicher,

groker

Signalempfang

kénnte

Ihre

Laut-

sprecher

beschadigen.

4,

Nur

fiir

US~Ausfiihrung

Verbinden

Sie

keine

Gerate

mit

tiber

350

VA

Leistungsaufnahme

mit

den

Netzspannungshilfsausgangen

an

der

Riickseite

des

"630".

Anschlusse

(s.

3)

Vorverstarkerausgang

(Preamplifier

Output)

Verbinden

Sie den

Ausgang

des

"630"-Vorverstaérkers

und

den

Eingang

des

Leistungsverstarkers

mit

handelsiiblichem

Stereo-Uberspielkabel.

Beach-

ten

Sie die

Kanaltrennung

links

und

rechts.

Wenn

Sie den

"630"

nur

als

Tuner

betreiben,

kénnen

Sie

den

Ausgang

des

Vorverstarkers

mit

den

Ein-

gingen

"Tuner"

oder

"Aux"

des

separaten

Vorverstarkers

verbinden;

eben-

so

kénnen

Sie

zu

diesem

Zweck

den

Tunerausgang

des

"630"

benutzen.

Tunerausgang

Tuner

Output)

Der

Tuner

des

"630"'

kann

tiber

den

besonderen

Tunerausgang

direkt

mit

einem

anderen

Vorverstadrker

stdndig

verbunden

werden.

Dieser

Ausgang

wird

weder

von

den

Funktionsschaltern

(Phono,

Aux,

FM),

den

Tonband-

Monitor-Schaltern

(Programmquelle,

TB

1,

TB

2

und

Kopiereinrichtung)

noch

von

den

Kontur-,

Klang~,

Lautstarke-

und

Balancereglern

beein-

fluBt.

Dagegen

wirken

der

Dolby

FM-,

Dampfungs-,

Schmalband-

und

Mono-

schalter

auf

den

Tunerausgang.

Wenn

Sie den

"630"

mit

einem

getrenn-

ten

Vorverstirker

betreiben,

wie

zB.

NAKAMICHI

610

Kontroll-Vorver-

stdrker,

kann

der

Tunerausgang

"630"

mit

den

Eingingen

"Aux"

oder

"Tu-

ner"

dieses

Vorverstarkers

verbunden

werden.

Der

Tunerausgang

kann

ebenfalls

an

die

Eingd&nge

eines

Tonbandgerdtes

angeschlossen

werden.

Da

dieser

Ausgang

konstant

und

von

den

Vorverstarkerreglern

unbeeinfluft

ist,

k6énnen

Sie

unabhangig

UKW-Sendungen

mit

Tonband

aufnehmen

(z.B.

Schallplatte

abspielen

und

gleichzeitig

TB-Aufnahme

mit

dem

Tuner).

Ausgangspegel

bei

50

%

Modulation:

100

mV.

Zusatzeingang

(Auxiliary

Input)

Ein

hochpegeliger

Eingang

fiir

eine

zusatzliche

Programmquelle,

z.B.

Ton-

bandgerat.

Die

Eingangsspannung

ist

100

mV

bei

einer

Impedanz

von

100

k0hm.

Tonband

(Tape

Deck)

Der

"630"'

besitzt

je

zwei

Eingadnge

fiir

TB-Aufnahme

und

TB-Wiedergabe.

Vexr-

binden

Sie die

Buchsen

"rec

out"

mit

den

Eing&éngen

Ihrer

Tonbandgerate.

Die

Buchsen

"play

in'

sollten

mit

den

TB-Ausgéngen

verbunden

werden.

Be-

nutzen

Sie

fiir

alle

Verbindungen

Uberspielkabel

und

beachten

Sie

iiberall

die

Bezeichnungen

links/rechts.

Zum

Kopieren

brauchen

Sie

die

Verbindun-

gen

mit

den

Tonbandgeriiten

nicht

zu

verdndern,

dies

geschieht

durch

Schal-

ter

an

der

Frontseite.

Phonoeingang

(Phono

Input)

Verbinden

Sie

den

Plattenspielerausgang

mit

den

Eingangsbuchsen

''Phono"

des

"630".

Beachten

Sie die

Seitenrichtigkeit.

Diese

Kabel

sollten

so

kurz

wie

méglich

sein,

um

Brummen

und

Signalverluste

zu

vermeiden.

Ver-

binden

Sie,

falls

dies

vorgesehen

ist,

auch

die

Masseleitung

des

Plat-

tenspielers

mit der

Massebuchse

des

"630".

Der

Phono-Empfindlichkeits-

Schalter,

der

sich

iiber

der

Massebuchse

befindet,

sollte

auf

Ihr

Abtast-

system

eingestellt

sein.

Magnetabtastsysteme

mit

grofier

Ausgangsspannung

sollten

Sie

in

der

5

mV-Stellung

gebrauchen.

Weniger

empfindliche

Abtast—

systeme

bendtigen

die

2

mV-

oder

1

mV~Stellung.

Beachten

Sie

die

Angaben

des

Abtastsystem-Herstellers.

Wenn

Sie

nicht

sicher

sind,

beginnen

Sie

mit

der

5

mV-Stellung

und

schalten

auf

2

mV

oder

1

mV,

falls

Sie

nicht

geniigend

Lautstarke

beim

Abspielen

einer

Schallplatte

erhalten.

"Moving

coil"

Tonabnehmer

mit

Zusatzverstadrker

(Transformator

oder

Vorverstar-

ker)

benOtigen

grunds&tzlich

2

mV

oder

1

mV.

Nakamichi 630 User manual

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