NAD 5120 Manual de usuario

Otros manuales para 5120

5

Tabla de contenidos

Otros manuales de Placa giratoria de NAD

NAD

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NAD

NAD 5120 Manual de usuario

NAD

NAD TURNTABLE C 552 Manual de usuario

NAD

NAD 5080 Manual de usuario

NAD

NAD 5120 Manual de usuario

NAD

NAD 5120 Guía del usuario

NAD

NAD 533 Manual de usuario

NAD

NAD 5120 Manual de usuario

NAD

NAD C 588 Manual de usuario

NAD

NAD TURNTABLE C 552 Manual de usuario

NAD

NAD 5120 Manual de usuario

NAD

NAD TURNTABLE C 552 Manual de usuario

NAD

NAD C 556 Manual de usuario

NAD

NAD C 558 Manual de usuario

NAD

NAD C555 Manual de usuario

NAD

NAD C 558 Manual de usuario

NAD

NAD C 556 Manual de usuario

NAD

NAD C 556 Manual de usuario

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Gemini CDT-05 MKII Manual de usuario

Rotel

Rotel RP-820 Manual de usuario

Shuman

Shuman MC-250BT Manual de usuario

Stanton

Stanton STR8-150 Manual de usuario

Audio Technica

Audio Technica AT-LPW40WN Manual de usuario

Crosley

Crosley McQueen CR7011-GY Manual de usuario

Reloop

Reloop SMP-1 Manual de usuario

auna

auna TT-Classic Plus Manual de usuario

COMO AUDIO

COMO AUDIO Turntable Analog Manual de usuario

Dual

Dual 1009 F Manual de usuario

REED

REED Muse3C Manual de usuario

AXIOMTEK

AXIOMTEK OPS883-H Series Manual de usuario

Pioneer

Pioneer PL-71 Manual de usuario

Vestax

Vestax PDX-a1 Manual de usuario

Denon

Denon DP-400 Manual de usuario

Dual

Dual 504 Manual de usuario

Audio-Techica

Audio-Techica AT-LP60XBT Manual de usuario

Goldring

Goldring G99 Manual de usuario

SEMI-AUTOMATIC

BELT-DRIVE

|

TURNTABLE

INSaasielourle)ts

FOR

INSTALLATION

NN

[DO]

=1=7-VEle)\

OOnN

Qn

—

.

Transit

screw

.

Dust

cover

Hinges

.

Speed

change

knob

.

Drive

belt

.

Motor

pulley

.

Sub-platter

10.

11.

12.

13.

.

Pilot

light

15.

Main

platter

disc

Rubber

platter

mat

Center

hole

adapter

Stop/Play

control

Tonearm

15

13

14

1.

Transit

screw

5.

Signal

cables

2.

Dust

cover

11.

Rubber

platter

mat

3.

Hinges

15.

Tonearm

4.

AC

power

cord

WISE

OF

REEL,

or

DO

yet

KE.

CAUTION

TO

REOUCE

THE

AISK

OF

ELECTRIC

SHOCK.

00

NOT

REMOVE

COVER

{OR

BACK)

NO

USEA-SEAVICEABLE

PARTS

INSIOE

REFER

SERVICING

TO

QUALIFIED

SEAVICE

PERSONNEL

.

Tonearm

.

Pivot

assembly

.

Tonearm

socket

.

DVA

damping

rod

.

DVA

damping

fluid

.

Damping

fluid

chamber

21.

22.

23.

24.

25.

26.

Damping

scale

Tracking

force

wheel

Tracking

force

dial

Spring

washer

DVA

frequency

setting

screw

DVA

spring

27

28

30

31

32

.

Counterweight

.

DVA

frequency

scale

.

Tonearm

rest

post

.

Cueing

height

screw

.

Cueing

post

.

Antiskating

control

NOTE:

In

the

following

instructions,

numbers

in

square

brackets

identify

the

various

parts

of

the

turntable,

as

shown

in

the

illustrations.

UNPACKING

1.

Lift

the

entire

turntable

system

out

of

the

carton,

together

with

the

protective

styrofoam

blocks.

2.

Slide

the

styrofoam

blocks

off

the

front

and

rear

of

the

turntable

system.

3.

Remove

the

turntable

system

from

the

protective

plastic

wrapper

that

it

is

enclosed

in.

.

4.

Place

the

turntable

on

a

clean,

level

working

surface

such

as

a

large

table.

5.

Lift

off

the

plastic

dust

cover

[2]

and

set

it

aside.

6.

The

turntable

contains

a

large

sculptured

styrofoam

insert

containing

the

platter

and

tonearm.

Carefully

lift

this

insert

straight

up

away

from

the

turntable

and

place

it

on

your

working

surface

beside

the

turntable

base.

7.

Then

remove

the

platter

assembly

from

its

plastic

wrapper.

Note

that

it

consists

of

three

parts:

the

rubber

mat

[11],

metal

platter

disc

[10],

and

center-hole

adapter

[12].

8.

Remove

the

turntable/counterweight

assembly

from

its

place

in

the

styrofoam

insert.

9.

Find

the

small

accessories

bag

containing

a

small

screwdriver

shaft;

this

wiil

be

used

for

adjusting

the

damp-

ing

screw

in

the

tonearm.

10.

Proceed

to

the

ASSEMBLY

instructions

below.

11.

Do

not

discard

any

packing

materials

until

after

you

have

completed

setting

up

the

turntable

and

all

parts

are

accounted

for.

Then

we

suggest

that

you

reinstall

the

styrofoam

moldings

in

the

carton,

tape

the

carton

closed,

and

store

it

in

a

safe

place

so

that

it

can

be

re-used

in

case

the

turntable

must

be

shipped

in

the

future.

12.

RE-PACKING

NOTE:

If

it

becomes

necessary

to

ship

the

turntable

at

some

future

date

the

following

requirements

are

essential,

regardless

of

whether

you

use

the

supplied

'

packing

materials

or

not.

(1)

Lift

off

the

platter

assembly.

It

must

be

packed

separately

in

order

to

avoid

damaging

the

platter

bearings.

(2)

In

the

tonearm,

turn

the

damping

rod

[18]

counterclockwise

until

the

lower

end

of

the

screw

is

above

the

“0”

mark

on

the

damping

scale

[21];

this

is

necessary

in

order

to

seal

the

damping

chamber

and

pre-

vent

leakage

of

the

damping

oil.

(3)

If

you

are

re-using

the

original

carton

provided

with

the

5120,

unplug

the

tonearm

and

place

it

in

the

space

provided

in

the

styrofoam

insert.

If

you

are

using

another

carton,

you

may

leave

the

tonearm

in

its

socket,

taped

securely

to

its

rest

post

so

that

it

cannot

move

during

shipment.

(4)

Turn

the

nut

on

the

transit

screw

fully

clockwise

as

viewed

from

below,

drawing

down

the

floating

chassis

until

it

rests

firmly

on

the

bottom

of

the

base.

,

The

lightning

flash

with

arrowhead,

within

an

equilateral

triangle,

is

intended

to

alert

the

user

of

the

presence

of

sure;

that

may

be

of

sufficient

magnitude

to

constitute

a

risk

of

electric

shock

to

persons.

uninsulated

“dangerous

voltage”

within

the

product's

enclo-

ASSEMBLY

1.

Check

the

transit

screw

[1],

located

beneath

the

turntable

in

a

central

recess.

The

large

circular

nut

on

the

transit

screw

should

have

been

fully

tightened

(clockwise

as

viewed

from

below)

when

the

turntable

was

packed.

If

it

is

tight,

the

turntable’s

floating

chassis

assembly

will

be

rest-

ing

firmly

on

the

bottom

of

the

turntable

base

and

the

sub-platter

[9]

will

be

approximately

level

with

the

upper

surface

of

the

turntabie’s

base

(plinth).

NOTE:

WHEN

CHECKING

OR

ADJUSTING

TRANSIT

SCREW,

CAREFULLY

TILT

TURNTABLE

TO

A

MAXIMUM

OF

45

DEGREES.

DO

NOT

INVERT

TURNTABLE,

AS

SUB-PLATTER

MAY

FALL

OFF.

2.

Set

the

speed

change

knob

[6]

at

45

rom.

DO

NOT

plug

in

the

AC

power

cord

until

instructed

to.

3.

The

rubber

drive

belt

[7]

was

pre-installed

at

the

factory.

Check

to

see

whether

it

may

have

slipped

out

of

place

during

shipment.

The

belt

runs

around

the

rim

of

the

sub-platter

[9]

and

around

the

large

upper

portion

of

the

motor

pulley

[8].

Make

sure

that

the

beit

is

not

twisted

at

any

point

along

its

length.

4.

Rotate

the

sub-piatter

[9]

by

hand

in

a

clockwise

direction

(as

viewed

from

above),

and

check

to

see

that

the

belt

is

running

smoothly.

While

continuing

to

turn

the

sub-

platter,

re-set

the

speed

change

'..10b

[6]

to

33

rpm.

Check

to

see

that

the

beit

shifts

down

to

the

lower

(smaller)

portion

of

the

motor

pulley

[8]

without

twisting,

and

runs

near

the

lower

edge

of

the

rim

of

the

sub-platter

[9].

5.

Check

the

label

on

the

bottom

of

the

turntable

to

be

sure

that

your

AC

power

line

voltage

and

frequency

meet

the

turntable’s

requirements.

Plug

the

AC

power

cord

[4]

into

a

household

AC

mains

outlet,

or

into

an

accessory

outlet

socket

on

your

amplifier.

NOTE

TO

U.K.

USERS:

The

wires

in

the

power

cord

are

colour-coded

as

follows:

Brown

=

live,

Blue

=

neutral.

As

this

may

not

correspond

to

the

identifying

colours

in

your

power

plug,

you

should

connect

the

wires

to

the

plug

as

follows:

connect

the

Brown

wire

to

the

terminal

marked

L

or

coloured

Red,

and

connect

the

Blue

wire

to

the

terminal

marked

N

or

coloured

Black.

6.

To

check

the

operation

of

the

turntable,

turn

the

front-panel

STOP/PLAY

knob

[13]

to

the

right

(clockwise),

to

the

horizontal

PLAY

setting.

Note

that

the

adjacent

pilot

light

[14]

illuminates,

the

motor

starts,

and

the

sub-platter

turns.

Re-set

the

speed-change

knob

[6]

to

45

rpm

and

check

to

see

that

the

belt

[7]

moves

up

to

the

large

upper

portion

of

the

motor

pulley

[8],

causing

the

sub-platter

to

rotate

faster.

Re-set

the

speed-change

knob

to

33

rpm

and

note

that

the

belt

drops

down

to

the

lower

pulley

without

twisting.

Turn

the

PLAY

knob

back

to

STOP,

and

unplug

the

AC

power

cord.

7.

Rotate

the

large

nut

on

the

transit

screw

[1]

to

the

left

(counterclockwise)

as

viewed

from

below.

Continue

unscrewing

the

nut

until

it

reaches

the

lower

end

of

the

transit

screw.

The

turntable’s

internal

chassis

will

rise

up

above

its

normal

operating

position,

suspended

on

three

pressure

springs,

and

so

that

the

top

surface

of

the

sub-

platter

[9]

is

several

millimeters

above

the

top

surface

of.

the

turntable’s

base

(plinth).

CAUTION:

Do

not

turn

on

the

motor,

nor

rotate

the

sub-platter

by

hand,

while

it

is

floating

in

a

raised

position

The

exclamation

point

within

an

equilateral

triangle

is

intended

to

alert

the

user

of

the

presence

of

important

operating

and

-

maintenance

(servicing)

instructions

in

the

literature

accompanying

the

appliance.

on

the

springs

without

the

weight

of

the

platter

assembly

to

pull

it

down

to

the

correct

operating

height.

If

you

turn

it,

the

belt

may

slip

off

the

lower

edge

of

the

sub-platter’s

rim

and

—

will

have

to

be

re-installed.

8.

Locate

the

main

platter

assembly.

it

consists

of

three

parts:

a

metal

platter

disc

[10],

a

heavy

rubber

platter

mat

[11],

and

a

center-hole

adapter

[12]

with

two

finger-size

holes.

The

rim

of

the

metal

platter

disc

is

turned

up

and

fits

into

a

groove

in

the

lower

surface

of

the

rubber

platter

mat.

9.

Temporarily

remove

the

center-hole

adapter

(12]

_

and

set

it

aside.

Install

the

platter

assembly

[10,

11]

on

the

sub-platter

[9].

(The

metal

platter

disc

[10]

fits

on

the

center

spindie

and

rests

on

the

sub-platter,

while

the

rubber

platter

mat

[11]

rests

on

top

and

provides

the

supporting

surface

for

gramophone

records.)

Note

that

the

weight

of

the

platter

assembly

is

precisely

offset

by

the

pressure

of

the

chassis

springs

so

that

the

chassis

“floats”,

free

to

move

in

any

direction

(either

vertical

or

horizontal)

at

least

“th

of

an

inch

(+

3mm)

without

obstruction

or

friction.

7

10.

Re-install

the

center-hole

adapter

[12],

sliding

it

down

the

central

spindle

until-it

is

fitted

into

the

recess

in

the

center

of

the

rubber

mat.

Note

that

the

adapter

can

be

inverted.

In

the

normal

orientation

its

flat

upper

surface

is

flush

with

the

surface

of

the

platter

mat,

so

that

an

LP

disc

will

be

in

uniform

contact

with

the

vibration-absorbing

rubber

platter

mat

over

most

of

its

surface

area.

When

the

adapter

is

inverted

(with

its

smooth

side

down),

the

protruding

14-inch

(37

mm)

ring

in

its

top

surface

provides

correct

centering

for

45

rom

records

having

a

large

center

hole.

The

two

finger

holes

provide

a

convenient

means

of

grasping

the

adapter

in

order

to

install

and

remove

it.

11.

Unpack

the

plastic

dust

cover

[2].

Note

that

ithas

two

bends:

a

45-degree

bend

(at

the

FRONT)

and

a

90-

degree

bend

(at

the

REAR).

The

cover

fits

into

two

spring-

loaded

hinges

[3]

that

are

mounted

in

slots

at

the

rear

of

the

turntable.

Each

hinge

has

an

open

slot

to

receive

the

dust

cover,

tilted

about

45

degrees

up

to

the

rear.

Simply

hold

the

dust

cover

up

at

an

angle

and

slip

its

rear

lip

into

the

hinges

(it

may

be

a

tight

friction

fit).

The

spring-loaded

hinges

will

hold

the

dust

cover

in

its

fully

raised

position.

When

closed,

the

cover

sits

on

two

small

rubber

bumpers

mounted

in

the

side

panels

near

the

front.

Temporarily

remove

the

dust

cover

and

set

it

aside

while

installing

and

adjusting

the

tonearm.

TONEARM

INSTALLATION

|

_

Instead

of

a

conventional

piug-in

headshell,

the

NAD

5120

turntable

employs

a

plug-in

tonearm

assembly.

The.

four

connecting

pins

on

the

lower

surface

of

the

tonearm

are

designed

to

plug

into

the

four-pin

socket

[17]

that

is

sus-

pended

within

the

tonearm

pivot

assembly

[16].

We

suggest

that

you

familiarize

yourself

with

this

piug-in

arrangement

by

installing

and

removing

the

arm

a

few

times

before

mounting

a

pickup

cartridge.

lf

a

pickup

cartridge

has

already

been

pre-mounted

on

the

tonearm,

you

can

proceed

directly

to

the

section

on

adjustment

of

the

Dynamic

Vibration

Absorber.

In

order

to

plug

the

tonearm

into

its

socket,

the

four

pins

on

the

arm

must

be

aligned

with

the

corresponding

holes

in

the

socket.

To

align

the

tonearm

socket,

rotate

the

pivot

assembly

[16]

counter-clockwise

as

far

as

it

will

go.

Press

the

pivot

assembly

down

until

it

strikes

the

bottom

of

the

turntable

base,

and

hold

it

securely

in

place

with

one

hand.

With

the

other

hand,

grasp

the

flat

tonearm

near

the

con-

necting

pins,

hold

it

parallel

to

the

edge

of

the

turntable,

and

insert

the

pins

into

the

connecting

socket.

Press

firmly

down

on

the

tonearm

to

push

the

four

pins

all

the

way

into

the

socket,

until

the

tonearm

is

nearly

flush

with

the

top

of

the

pivot

assembly.

The

fifth

pin

on

the

lower

surface

of

the

flat

tonearm

fits

_

into

a

slot

in

the

top

of

the

rest

post

[29],

securing

the

arm

when

it

is

not

in

use.

To

remove

the

tonearm,

first

raise

the

front

of

the

arm

to

extract

the

securing

pin

from

the

slot

in

the

rest

post.

Grasp

the

pivot

assembly

[16]

with

one

hand

and

push

down

to

brace

it

against

the

bottom

of

the

turntable

base,

holding

it

securely.

With

the

other

hand,

grasp

the

tonearm

on

either

side

of

the

connecting

pins,

and

pull

straight

up.

PHONO

CARTRIDGE

MOUNTING

When

you

are

installing

a

phono

cartridge

you

prob-

ably

will

want

to

turn

the

tonearm

over.

Before

doing

so,

unscrew

the

DVA

damping

rod

[18]

until

it

projects

at

least

2mm

above

the

tracking

force

wheel,

so

as

to

seal

the

oil

chamber

and

prevent

leakage.

lt

also

is

wise

to

remove

the

stylus

assembly

from

the

cartridge

and

set

it

aside

temporarily.

If

the

stylus

is

not

removable,

keep

the

plastic

stylus

guard

in

place

whenever

possible

in

order

to

prevent

accidental

damage

to

the

delicate

stylus

assembly.

Refer

to

the

instructions

supplied

with

your

pickup

cartridge

for

any

specific

advice

on

installation.

Unplug

the

tonearm

from

the

turntable.

Locate

the

cartridge

between

the

two

elongated

slots

at

the

front

end

of

the

tonearm.

Most

cartridges

have

a

flat

upper

surface

which

should

be

in

uniform

contact

with

the

lower

surface

of

the

tonearm.

Select

mounting

screws

long

enough

to

pass

through

the

tonearm

and

through

the

mounting

holes

or

slots

in

the

cartridge

body.

(Caution:

if

the

screws

are

too

long

they

may

interfere

with

the

proper

seating

of

the

stylus

assem-

bly

on

the

cartridge

body.)

Select

screws

with

wide

heads,

or

install

flat

washers

beneath

the

screw

heads,

in

order

to

provide

a

large

bearing

surface

that

will

securely

grip

the

—

tonearm

when

the

screws

are

tightened.

(If

you

choose

to

run

the

screws

upward

from

the

cartridge

through

the

arm,

rather

than

downward

from

the

tonearm

through

the

car-

~

tridge,

place

the

washers

under

the

nuts.

See

Figure

1.)

Do

not

completely

tighten

the

mounting

screws

at

first.

Tighten

them

just

enough

to

hold

the

cartridge

in

place

while

still

allowing

its

position

to

be

adjusted.

Before

proceeding

with

the

alignment,

connect

the

tonearm

wires

to

the

terminals

on

the

rear

of

the

cartridge

and

set

the

vertical

tracking

force,

as

described

in

the

instruction

manual

for

the

NAD

5120.

Figure

1.

Mounting

PHONO

CARTRIDGE

WIRING

if

the

turntable

was

supplied

with

a

pickup

cartridge

pre-installed

in

the

tonearm,

you

can

skip

over

this

section

and

proceed

directly

to

the

adjustment

of

the

Dynamic

Vibration

Absorber.

The

four

cartridge

connecting

leads

on

the

tonearm

are

wired

in

accordance

with

the

standard

colour

code,

as

follows.

White—

L

Left

channel

signal

(hot)

Blue

—

LG

Left

channel

ground

Red—

R

Right

channel

signal

(hot)

Green—

RG

Right

channel

ground

The

connecting

leads

terminate

in

small

clips

that

fit

onto

the

terminals

on

the

rear

of

the

phono

cartridge.

Using

tweezers

or

small-nose

pliers,

slide

each

clip

fully

onto

the

cartridge

terminal

that

corresponds

to

its

colour

code.

The

clips

should

have

a

snug

friction-fit

on

the

terminals.

If

they

fit

loosely,

use

small-nose

pliers

to

squeeze

the

clips

very

carefully.

CAUTION:

Never

solder

connecting

leads

directly

to

the

terminal

pins

on

the

cartridge;

doing

so

can

severely

dam-

age

the

cartridge.

Similarly,

never

solder

terminal

clips

onto

the

connecting

leads

while

the

clips

are

installed

on

the

cartridge

pins.

If

you

accidentally

break

off

one

of

the

clips,

have

an

experienced

technician

install

a

new

clip

on

the

connecting

lead.

Examine

the

connecting

leads

to

be

sure

that

each

clip

—

is

securely

in

place

on

the

corresponding

cartridge

terminal,

and

check

to

see

that

the

clips

are

not

touching

each

other.

BALANCING

THE

TONEARM

lf

your

phono

cartridge

was

supplied

with

a

stylus

guard,

install

the

guard

to

protect

the

stylus

while

handling

the

arm.

Plug

the

tonearm

into

its

socket.

Then,

if

the

stylus

guard

is

not

a

permanent

part

of

the

cartridge,

remove

it

before

balancing

the

arm.

Unplug

the

AC

power

cord

so

that

the

Stop/Play

control

can

be

set

to

PLAY

without

causing

the

platter

to

rotate.

-

Disengage

the

tonearm

from

its

rest

post,

and

hold

it

just

to

the

left

of

the

rest

post.

Turn

the

contro!

knob

to

PLAY

and

wait

while

the

cueing

post

[31]

gradually

descends,

until

the

tonearm

is

completely

free

to

move

up

and

down.

Ro-

tate

the

tracking

force

wheel

[22]

until

the

arm

is

precisely

balanced,

floating

in

a

level

position.

When

it

is

accurately

balanced,

you

can

push

the

front

of

the

arm

slightly

up

or

down

and

it

will

return

to

the

level

position.

|

lf

the

phono

cartridge

is

a

low-mass

model

weighing

less

than

4

grams

(e.g.

the

Ortofon

Concorde

series),

it

may

be

impossible

to

balance

the

arm—or,

having

balanced

the

arm,

you

may

find

that

there

is

insufficient

range

of

counter-

weight

adjustment

remaining

to

allow

you

to

set

the

correct

vertical

tracking

force.

In

this

case,

it

is

possible

to

rotate

the

entire

counterweight

assembly

so

as

to

place

the

weight

closer

to

the

arm

pivot.

First,

turn

down

the

DVA

frequency.

setting

screw

[25]

until

the

top

of

the

screw

is

flush

with

the

top

of

the

counterweight,

and

turn

the

tracking

force

wheel

until

it

is

located

approximately

midway

along

the

slot

in

the

tonearm.

The

assembly

is

held

in

place

by

a

powerful

spring

washer

[24]

bearing

against

the

under

surface

of

the

track-

ing

force

wheel

[22].

Press

down

hard

on

the

tracking

force

wheel

to

flatten

the

spring

washer,

and

rotate

the

entire

assembly

180

degrees

(a

half-circle)

so

that

the

counter-

weight

is

facing

forward.

Release

the

pressure

on

the

tracking

force

wheel,

and

the

assembly

will

re-engage

the

slot

in

the

arm

and

lock,

as

before.

(If

you

have

any

difficulty

with

this

procedure,

your

NAD

dealer

can

show

you

how

it

is

done.)

Re-set

the

DVA

frequency

screw

[25]

to

the

desired

setting,

and

proceed

to

balance

the

arm.

When

the

counterweight

is

in

the

reversed

position,

the’

effectiveness

of

the

Dynamic

Vibration

Absorber

is

reduced.

So

it

is

preferable

to

keep

the

counterweight

in

the

normal

orientation

whenever

possible.

If

you

can

balance

the

arm

with

the

weight

in

the

normal

position

but

can’t

move

the

counterweight

forward

enough

to

set

the

tracking

force,

it

may

prove

preferable

to

add

a

gram

of

extra

mass

(in

the

form

of

a

shim

between

the

cartridge

and

the

arm)

instead

of

rotating

the

counterweight

assembly,

in

order

to

retain

optimum

damping

of

the

infrasonic

arm/cartridge

resonance.

SETTING

THE

VERTICAL

TRACKING

FORCE

(VTF)

_

After

balancing

the

tonearm,

secure

the

arm

in

its

rest.

post.

Use

one

hand

to

grasp

the

periphery

of

the

tracking

force

wheel

[22]

so

that

it

cannot

turn.

With

the

other

hand,

rotate

the

VTF

dial

[23]

until

the

zero

(0)

is

aligned

with

the

white

index

mark

in

the

middle

of

the

arm.

(The

VTF

dial

normally

rotates

with

the

tracking

force

wheel,

but

it

can

be

turned

separately

by

placing

the

tip

of

a

screwdriver,

ball-

point

pen,

or

a

fingernail

in

the

small

slot

provided.)

After

thus

calibrating

the

VTF

dial

to

indicate

0

when

the

arm

is

balanced

and

level,

set

the

vertical

tracking

force

(VTF)

by

turning

the

entire

tracking

force

wheel

clockwise,

until

the

desired

VTF

is

aligned

with

thewhite

index

mark.

The

dial

is

calibrated

from

0

to

3

grams

(30

milliNewtons),

with

dots

at

the

0.5

gram

points.

Refer

to

the

instructions

sup...

2d

with

your

pickup

cartridge

to

learn

the

optimum

setting

of

vertical

tracking

force.

If

a

range

of

permissible

VTF

values

is

given,

the

best

sound

(and

lowest

record

wear)

usually

will

be

obtained

with

a

VTF

setting

in

the

upper

half

of

the

suggested

range.

One

recommended

approach

is

to

begin

by

setting

the

VTF

to

the

middle

of

the

recommended

range,

and

complete

the

adjustments

below

(for

anti-skating

and

cueing

height).

Then

play

an

assortment

of

well-made

recordings,

listen-

ing

particularly

for

harsh

distortion

in

the

loudest

passages.

Listen

at

a

moderate

volume

level

in

order

to

be

certain

that

you

do

not

induce

distortion

by

overdriving

your

amplifier

into

clipping

on

the

loudest

peaks.

If

you

hear

dis-

tortion

due

to

mistracking,

increase

the

vertical

tracking

force

and

note

whether

the

sound

is

cleaner

(but

do

not

exceed

the

maximum

force

recommended

by

the

maker

of

the

cartridge).

ANTI-SKATING

BIAS

The

anti-skating

control

provides

side-thrust

compen-

sation

to

ensure

equal

stylus

pressure

on

both

walls

of

the

record

groove.

The

anti-skating

control

is

a

knurled

shaft

[32]

surrounding

the

lower

half

of

the

tonearm

rest

post

[29],

with

a

calibrated

dial

ai

the

bottom

of

the

shaft

displaying

values

from

0.5

to

3.0

grams.

An

index

marker

is

molded

into

the

turntable

base

(plinth)

in

front

of

the

control.

Turn

the

anti-skating

control

until

the

marker

indicates

a

value

equal

to

the

vertical

tracking

force

that

you

have

set

on

the

tonearm.

In

theory,

the

optimum

anti-skating

compensation

will

depend

on

the

shape

and

polish

of

the

stylus

tip,

and

is

best

determined

by

using

a

test

record.

The

calibrated

scale

will

provide

approximately

correct

settings

for

normal

pickup

cartridges

with

elliptical

styli.

For

Shibata,

hyperelliptical,

and

other

line-contact

styli,

set

the

anti-skating

dial

to

a

value

about

30

percent

higher

than

the

VTF

setting

(e.g.

if

the

VTF

is

1.2

grams,

set

the

anti-skating

to

about

1.5).

For

spherical-tipped

styli,

set

the

anti-skating

value

about

25%

lower

than

the

VTF

(e.g.

if

the

VTF

is

2

grams,

set

the

anti-skating

to

about

1.5).

It

is

not

necessary

to

make

the

adjustment

exact,

since

all

anti-skating

compensation

is

only

approximate

anyway.

rv

CUEING

HEIGHT

The

Stop/Play

knob

controls

an

arm-lift

cueing

mechanism

[31]

that

lifts

the

cartridge

off

the

record

at

the

beginning

and

end

of

play,

and

lowers

the

stylus

gently

into

the

groove

to

begin

play.

The

height

of

the

arm-lift

is

adjustable

to

compensate

for

the

varying

depth

of

car-

tridge

bodies.

To

adjust

it,

first

check

to

see

that

the

removable

tonearm

has

been

pushed

fully

downward

into

its

socket

[17].

Place

a

record

on

the

platter,

turn

the

Stop/Play

control

to

the

STOP-LIFT

position,

and

move

the

tonearm

over

the

record.

With

the

arm

cued

“up”

the

stylus

should

be

approximately

5

to

7

mm

(¥/

inch)

above

the

record.

If

the

distance

is

different,

correct

it

by

turning

the

threaded

shaft

[30]

in

the

top

of

the

cueing

post.

To

check

the

adjustment,

turn

the

Stop/Play

knob

to

PLAY.

The

stylus

will

drop

into

the

groove,

and

the

cueing

post

[31]

will

lower

a

little

further

until

it

is

no

longer

in

contact

with

the

tonearm.

PHONO

CARTRIDGE

ALIGNMENT

In

order

to

minimize

distortion

the

pickup

cartridge

must

be

precisely

aligned

in

three

angles

and

one

linear

dimension.

The

front/back

tilt

of

the

cartridge

affects

its

vertical

tracking

angle

(VTA).

Normally

the

VTA

will

be

correct

when

the

upper

surface

of

the

cartridge

body

is

parallel

to

the

record

surface.

With

cartridges

of

typical

height

this

requirement

is

satisfied

by

fastening

the

cartridge

directly

to

the

under-surface

of

the

tonearm.

If

this

is

unsatisfactory

because

of

a

non-standard

cartridge

height

or

because

you

are

using

a

line-contact

stylus

whose

vertical

angle

is

especially

critical,

the

VTA

can

be

adjusted

in

either

of

two

ways.

(1)

Place

a

shim

between

the

tonearm

and

the

front

or

rear

of

the

cartridge

body.

(2)

Take

advantage

of

a

unique

property

of

the

flexible

arm:

when

bent

beyond

its

elastic

limit

it

tends

to

retain

the

bend.

Thus,

to

decrease

the

VTA,

simply

grasp

the

tonearm

firmly

in

both

hands

and

bend

the

front

half

of

the

arm

upward.

The

rotational

tilt

affects

the

stereo

separation.

To

test

it,

place

a

small

flat

mirror

on

the

platter

mat.

Unplug

the

AC

power

cord

so

that

the

arm

can

be

cued

down

with-

out

causing

the

platter

to

rotate.

Lower

the

stylus

tip

onto

the

mirror,

look

at

it

from

directly

in

front,

and

compare

the

cartridge

with

its

reflection

in

the

mirror.

Ideaily,

the

stylus

cantilever

and

its

reflection

should

forma

siraight

line,

while

the

cartridge

body

and

its

reflection

are

parallel,

as

shown

in

Figure

2(b).

If

you

see

a

tilt,

as

in

Figure

2(a),

A.

Bad

B.

Good

Cartridge

LT

Reflection

In

Mirror

Figure

2.

Alignment

it

can

be

corrected

in

either

of

two

ways.

(1)

Place

a

shim

under

one

side

of

the

cartridge

body.

(2)

Grasp

the

tonearm

and

twist

it.

The

stylus

overhang

is

adjusted

by

moving

the

car-

tridge

and

its

mounting

screws

forward

or

backward

along

the

slots

provided.

For

optimum

performance

the

stylus

tip

should

be

located

precisely

Ye

inch

(3mm)

back

from

the

end

of

the

tonearm,

as

viewed

from

the

side;

see

Figure

3.

|

|

|

|

|

|

|

lq

|

3mm

Figure

3.

Stylus

overhang

If

the

cartridge

conforms

to

the

proposed

international

standard,

in

which

the

axial

distance

from

the

styius

tip

to

the

mounting

screws

is

¥%

inch

(9.5mm),

then

the

mount-

ing

screws

will

be

precisely

2

inch

(12.5mm)

from

the

end

of

the

arm.

This

position

is

marked

on

the

upper

surface

of

the

tonearm

by

dots

opposite

the

middie

line

in

the

group

of

five

lines

adjacent

to

each

slot.

This

location

of

the

mounting

screws

will

be

approximately

correct

for

all

phono

cartridges;

but

if

you

want

to

obtain

the

lowest

possible

distortion,

slide

the

cartridge

forward

or

backward

until

the

stylus

tip

is

precisely

3mm

from

the

end

of

the

tonearm,

and

tighten

the

mounting

screws.

The

cartridge

must

be

mounted

at

an

offset

angle

of

26

degrees

relative

to

the

longitudinal

axis

of

the

tone-

arm,

in

order

to

minimize

lateral

tracking

distortion.

To

help

you

make

this

adjustment,

an

“Alignment

Protractor”

is

provided.

Place

the

protractor

on

the

platter

mat,

with

the

turntable

spindle

passing

through

the

hole

in

the

protractor.

The

protractor

has

two

“alignment

points”

located

at

2.5

and

4.7

inches

(63.6

and

119

mm)

from

the

center

spindle,

each

marked

by

a

cross

within

a

circle.

If

the

cartridge

is

optimally

aligned

at

these

two

points,

minimum

distortion

will

be

obtained

over

the

entire

LP

record.

Unplug

the

AC

power

cord

so

that

the

tonearm

can

be

lowered

without

causing

the

platter

to

rotate.

Then

turn

the

platter

by

hand

so

that

the

stylus

can

be

placed

precisely

on

each

alignment

point,

and

compare

the

outline

of

the

cartridge

body

with

the

rectangular

grid

around

each

alignment

point.

(Do

not

be

confused

by

the

edge

of

the

tonearm,

which

should

not

be

parallel

to

the

grid;

what

matters

is

the

outline

of

cartridge

body.)

NOTE:

In

order

for

this

test

to

be

valid,

the

stylus

must

be

placed

exactly

at

the

center

of

the

circle

at

each

of

the

two

alignment

points.

It

may

be

helpful

to

use

adhesive

tape

to

stop

the

platter

from

rotating,

so

that

the

position

of

the

protractor

will

be

stable.

If

the

cartridge

body

is

precisely

parallel

to

the

grid

at

both

alignment

points,

the

geometrical

alignment

is

correct.

if

necessary,

twist

the

cartridge

body

to

make

it

parallel

to

the

grid,

and

then

tighten

the

mounting

screws.

If

the

stylus

overhang

distance

is

correct,

then

twisting

the

cartridge

to

obtain

the

correct

offset

angle

at

one

align-

ment

point

will

automatically

ensure

that

the

alignment

is

also

correct

at

the

second

alignment

point.

If

you

find

that

the

alignment

is

different

at

the

two

alignment

points,

then

the

overhang

is

incorrect

and

should

be

re-adjusted

as

follows.

First

place

the

stylus

tip

on

the

“inner”

alignment

point

(the

one

closer

to

the

center

spindle),

and

twist

the

cartridge

body

to

align

it

perfectly

with

the

grid.

Then

move

the

stylus

tip

to

the

“outer”

alignment

point

(the

one

closer

to

the

edge

of

the

platter),

observe

the

orientation

of

the

cartridge

body

relative

to

the

grid,

and

refer

to

Figure

4

to

see

whether

the

cartridge

body

should

be

moved

forward

or

backward

along

the

slots.

(The

angular

misalignments

in

Figure

4

are

exag-

gerated

for

clarity.)

If

the

angular

misalignment

at

the

outer

alignment

point

is

barely

visible

to

the

eye,

then

the

car-

tridge

should

be

moved

forward

or

back

a

distance

equal

to

the

separation

of

the

calibration

marks

on

the

tonearm

(0.8mm).

The

adjustments

for

overhang

and

offset

tend

to

affect

each

other,

so

you

will

then

have

to

readjust

the

lateral

twist

of

the

cartridge

to

achieve

correct

paral-

lelism

at

the

inner

alignment

point,

and

finally

re-check

the

alignment

at

the

outer

alignment

point.

MOVE

CARTRIDGE

FORWARD

(CLOSER

TO

END

OF

ARM)

MOVE

CARTRIDGE

BACK

(AWAY

FROM

END

OF

ARM}

-

Note:

Align

cartridge

exactly

at

inner

alignment

point

before

testing

at

outer

alignment

point.

Figure

4.

Cartridge

Alignment

At

Outer

Alignment

Point.

THE

DYNAMIC

VIBRATION

ABSORBER

The

counterweight

is

not

mounted

rigidly

to

the

tonearm

but

rather'is

Suspended

on

a

spring,

forming

a

compliant

assembly

that

is

free

to

vibrate.

When

correctly

tuned

its

vibration

matches

and

cancels

(i.e.

absorbs)

the

fundamen-

tal

arm/cartridge

resonance.

(This

resonant

vibration

occurs

in

all

tonearms

as

a

result

of

the

interaction

of

the

com-

pliance

of

the

phono

stylus

assembly

and

the

effective

mass

of

the

tonearm.)

Two

adjustments

on

the

counterweight

assembly

control

the

performance

of

the

Dynamic

Vibration

Absorber

(DVA).

its

frequency

is

set

by

means

of

the

white

plastic

screw

[25]

that

is

mounted

on

the

top

of

the

counterweight

[27]

near

the

rear,

protruding

through

a

slot

at

the

rear

of

the

arm.

This

screw

sets

the

tension

of

the

spring

[26]

and

therefore

the

frequency

of

the

counterweight’s

vibration.

Turn

it

until

the

ower

end

of

the

white

screw

is

aligned

with

the

desired

resonance

frequency

on

the

scale

[28]

that

is

provided

on

the

counterweight

itself.

The

counterweight

vibration

is

“damped”

by

means

of

a

small

threaded

rod

[18]

that

is

mounted

in

a

hole

in

the

center

of

the

tracking-force

wheel

[22]

and

extends

down

into

a

chamber

partly

filled

with

viscous

oil

[19].

When

shipped

from

the

factory

the

rod

is

withdrawn

from

the

oil

and

protrudes

several

millimeters

above

the

top

surface

of

the

tracking-force

wheel

[22];

this

is

done

to

seal

the

damping

chamber

so

that

the

oil

will

not

leak

out

in

transit.

The

top

end

of

the

damping

rod

is

slotted

so

that

it

can

be

adjusted

with

the

aid

of

a

small

jeweler’s

screwdriver.

A

Suitable

screwdriver

is

included

in

the

small

bag

of

acces-

sories

packed

with

the

turntable.

Screw

the

damping

rod

[18]

down

into

the

oil

chamber

[19]

until

the

/ower

end

of

the rod

is

aligned

with

the

desired

damping

ratio

(“Q”)

on

the

scale

[21]

that

is

provided

oh

the

front

of

the

counterweight.

When

the

tip

of

the

rod

is

above

the

“0”

mark,

there

is

no

damping

and

the

counterweight

will

vibrate

up

and

down

quite

freely.

When

the

tip

of

the

rod

is

immersed

in

the

oil

to

the

Q

=

3

level

(maximum

damping),

counterweight

vibra-

tion

is

rapidly

absorbed.

Recommended

settings

of

DVA

frequency

and

damp-

ing

for

many

phono

cartridges

are

provided

in

the

enclosed

leaflet.

If

there

is

no

listing

for

your

specific

model,

set

lower

tip

of

the

frequency

screw

at

10

Hz

and

the

lower

tip

of

the

damping

rod

at

2

(medium

damping)

for

now.

Even

if

these

values

are

not

exactly

optimum

for

your

cartridge,

the

result

will

be

better

than

a

conventional

rigid

tonearm

with

a

fixed

counterweight.

Refer

to

Appendix

B

for

further

infor-

mation

on

the

effect

of

these

adjustments

and

how

to

discover

optimum

values

for

cartridges

not

listed

in

the

enclosed

leaflet.

USING

MULTIPLE

ARMS

If

you

wish

to

use

more

than

one

phono

pickup

car-

tridge,

you

can

purchase

extra

plug-in

tonearms

for

the

5120

turntable.

On

each

arm

you

can

set

the

balance,

VTF,

and

DVA

frequency

and

damping.

Then

you

may

quickly

swap

cartridges

by

unplugging

one

arm

and

plugging

another,

with

no

readjustment

needed

(except,

perhaps,

for

anti-

skating

and

cueing

height).

When

removing

and

re-installing

tonearms,

it

is

always

wise

to

place

a

stylus

guard

on

the

cartridge

body

to

protect

.the

stylus

from

accidents.

When

you

unplug

the

arm

it

may

seem

natural

to

turn

it

over

and

set

it

down

on

its

back,

with

the

cartridge

facing

upward,

in

order

to

avoid

resting

the

weight

of

the

arm

on

the

delicafe

stylus.

This

is

NOT

recommended.

if

the

arm

is

inverted

for

more

than

a

few

minutes,

the

DVA

damping

fluid

may

leak

out

of

its

chamber.

(This

leakage

can

be

prevented

by

unscrewing

the

damping

rod

until

it

protrudes

several

millimeters

above

the

tracking

force

wheel.)

The

tonearm

should

be

stored

in

norma!

operating

position

with

a

stylus

guard

protecting

the

cartridge,

perhaps

in

a

tray

that

has

a

large

cut-out

to

accommodate

the

cartridge.

SIGNAL

CABLES

The

signal

cable

[5]

carries

the

audio

signals

for

the

left

and

right

channels

pius

a

“ground”

wire.

Connect

the

audio

signal

cable

to

the

PHONO

sockets

on

your

amplifier.

(The

red

plug

is

for

the

right

channel.

The

white,

gray,

or

black

plug

is

for

the

left

channel.)

Connect

the

ground

wire

to

the

Ground

terminal

on

your

amplifier.

In

most

cases

this

connection

will

minimize

_.

hum.

However,

if

you

experience

a

persistent

low-frequency

hum

in

the

audio

signal

when

using

this

turntable,

try

dis-

connecting

the

grounding

wire

and

see

whether

that

lessens

the

hum.

AC

PLUG

POLARITY

lf

the

AC

plug

supplied

with

your

player

is

of

the

kind

that

is

reversible

in

the

socket,

you

should

experiment

to

find

the

plug

polarity

that

yields

the

least

hum

in

the

reproduced

sound.

After

the

cartridge

installation

has

been

completed,

switch

on

the

turntable

by

rotating

the

control

knob

to

PLAY.

Set

your

amplifier’s

input

selector

to

PHONO,

turn

up

the

Volume

and

Bass

controls

to

higher

than

normal

settings,

and

note

the

level

of

low-frequency

hum

in

the

sound.

Turn

down

the

Volume

control,

reverse

the

turntable’s

AC

plug

in

the

socket,

restore

the

Volume

control

to

exactly

its

previous

setting,

and

note

whether

the

low-frequency

hum

is

louder

or

softer

than

before.

Leave

the

AC

plug

in

the

orientation

that

produces

the

least

hum.

PLAYING

RECORDS:

THE

OPERATING

CONTROLS

Before

playing

a

record,

set

the

Speed

Change

control

{6]

to

33

or

45

rpm,

as

appropriate.

When

playing

45

rom

records

having

a

large

center

hole,

invert

the

center

hole

adapter

[12].

Place

the

thumb

and

middle

finger

in

the

finger

holes

provided

in

the

adapter,

lift

the

adapter

off

the

spindie,

turn

it

over,

and

re-install

it.

Don't

forget

to

re-invert

it,

with

the

flat

side

up,

before

playing

LP

records.

To

play

a

record,

first

be

sure

that

the

Stop/Play

control

knob

is

in

the

STOP

position

and

the

tonearm

is

securely

held

in

its

rest

post.

Place

the

record

on

the

platter.

Push

the

tonearm

to

the

left,

freeing

it

from

the

rest

post.

Note

that

it

is

not

necessary

to

actually

grasp

or

lift

the

tonearm,

since

it

is

held

in

the

raised

position

by

the

cueing

mechanism.

The

tonearm

can

easily

be

moved

to

the

left

or

right

by

lightly

pressing

the

ball

of

the

thumb

against

the

front

end

of

the

arm.

Move

the

arm

to

place

the

stylus

above

the

lead-in

groove

of

the

record.

Lower

the

dust

cover.

Turn

the

Stop/Pliay

control

knob

to

PLAY.

The

pilot

light

will

ituminate,

the

motor

will

start

and

the

platter

will

come

up

to

speed,

and

the

cueing

mechanism

will

gently

lower

the

stylus

into

the

groove.

lf

you

want

to

start

the

platter

rotating

in

order

to

use

a

cleaning

brush

on

the

record,

simply

lock

the

tonearm

in

its

rest

before

turning

the

control

knob

to

PLAY.

If

you

have

already

cued

the

stylus

over

the

lead-in

groove,

turn

the

Stop/Play

control

knob

just

one-eighth

of

a

turn

clockwise

(and

hoid

it

there,

against

the

pressure

of

its

return

spring)

while

cleaning

the

record.

The

cueing

mechanism

will

not

lower

the

stylus

until

the

control

knob

is

turned

ail

the

way

to

PLAY.

At

the

end

of

the

record,

the

wide

spacing

of

the

lead-out

grooves

will

activate

the

automatic

stop

sensor.

The

Stop/Play

knob

wili

automatically

turn

to

the

STOP-LIFT

position,

the

arm

will

lift

up

off

the

record,

and

the

motor

will

stop.

Raise

the

dust

cover

and

move

the

tonearm

to

its

rest

post

before

removing

the

record.

if

you

want

to

interrupt

play

in

the

middle

of

a

record,

simply

turn

the

Stop/Play

control

knob

to

STOP-LIFT,

and

the

cueing

mechanism

will

lift

the

stylus

out

of

the

groove.

Move

the

stylus

above

the

point

where

you

wish

to

resume

play,

and

turn

the

control

knob

to

PLAY.

The

platter

will

come

up

to

speed

by

the

time

the

cueing

mechanism

lowers

the

stylus

into

the

groove.

IMPORTANT:

Whenever

you

are

not

playing

a

record,

the

tonearm

should

be

securely

fixed

in

its

rest

post.

As

you

move

the

arm

to

the

right

after

playing

a

record,

the

pin

on

the

arm

slides

into

the

slot

on

the

arm

rest

and

is

held

there

by

friction.

MAINTENANCE

Remove

accumulated

dust

from

the

plastic

dust

cover

by

wiping

with

a

damp

cloth.

Do

not

use

a

dry

cloth;

that

will

tend

to

create

a

charge

of

static

electricity

on

the

cover

which

will

attract

dust

quickly.

¢

APPENDIX

A:

SELECTING

A

LOCATION

FOR

THE

TURNTABLE

if

you

wish

to

obtain

the

finest

record-playing

perfor-

mance,

the

location

of

the

turntable

should

be

selected

carefully.

Several

factors

may

influence

this

choice:

Hum.

If

a

magnetic

phono

cartridge

(especially

a

moving-coil

pickup)

is

located

close

to

an

amplifier’s

power

transformer

or

to

a

powerful

electric

motor,

it

will

produce

a

low-frequency

hum.

Normally

it

is

sufficient

to

place

the

turntable

at

ieast

one

meter

(three

feet)

away

from

your

amplifier.

If

you

place

the

turntable

against

a

wall

and

hum

is

found

to

be

a

persistent

problem,

check

to

see

whether

a

large

electrical

appliance

(such

as

a

refrigerator

or

air

conditioner)

is

operating

just

behind

the

turntable

on

the

opposite

side

of

the

wail.

Heat.

Viny!

records

may

be

damaged

by

elevated

temperatures

and

by

prolonged

exposure

to

direct

sunlight,

so

the

turntable

should

not

be

located

adjacent

to

a

room

heater

nor

in

front

of

a

south-facing

window.

Convenience.

Of

course

the

turntable

should

be

placed

at

a

height

that

makes

it

convenient

to

use,

with

sufficient

lighting

to

allow

accurate

cueing

of

desired

selections

and

to

permit

inspection

of

the

stylus

when

cleaning

it.

Reserve

enough

space

above

the

turntabie

for

its

hinged

dust

cover.

Ordinarily,

of

course,

the

length

of

the

signal

cables

limits

how

far

the

turntable

may

be

from

the

pre-amplifier.

(This

limitation

applies

mainly

with

moving-magnet

cartridges,

because

their

relatively

high

coil

inductance

interacts

with

the

capacitance

of

the

connecting

cable.

If

you

are

using

a

low-inductance

cartridge,

such

as

a

moving-coil,

then

in

most

cases

you

can

install

the

turntable

wherever

you

like

and

use

long

signal

cables

to

connect

to

your

amplifier.)

Vibration.

This

is

particularly

important,

since

the

phono

pickup

cartridge

is

sensitive

to

sub-microscopic

vibrations,

and

so

we

will

discuss

the

problem

in

detail.

isolating

the

record

and

stylus

from

external

vibrations

is

a

primary

requirement

of

every

turntable,

and

the

unusually

compliant

floating-chassis

suspension

of

the

NAD

5120

provides

excellent

isolation

over

a

broad

range

of

frequen-

cies.

However,

complete

isolation

is

not

possible,

for

the

following

reason.

Any

compliant

suspension

has

a

natural

resonant

fre-

quency.

Above

its

resonant

frequency

the

suspension

is

an

efficient

mechanical

filter,

preventing

the

transmission

of

vibration

up

from

the

base

to

the

record

or

tonearm.

Below

the

resonant

frequency,

vibrations

will

pass

through

the

suspension

and

cause

the

floating

chassis

to

move;

but

since

the

platter

and

the

tonearm

are

both

mounted

on

the

floating

chassis

they

tend

to

move

together,

producing

little

or

no

relative

motion

between

the

stylus

and

the

record.

The

principal

difficulty,

therefore,

occurs

with

vibrations

whose

frequency

is

at

or

near

the

resonant

frequecy

of

the

suspension:

the

resonance

tends

to

amplify

the

severity

of

these

vibrations.

This

is

true

of

all

turntable

suspensions.

Therefore

the

influence

of

vibration

on

a

record

player's

performance

depends

both

on

the

resonant

frequency

of

its

suspension

and

on

the

spectrum

of

the

vibrations

that

reach

the

turntable

from

its

environment.

Many

turntables

employ

a

relatively

stiff

suspension

whose

resonant

frequency

is

10

Hz

or

higher.

The

advantage

of

this

approach

is

that

vibration

amplitudes

at

this

fre-

quency

are

seldom

large

enough

to

cause

groove-jumping

or

other

obvious

misbehavior

of

the

record

player.

The

disadvantage

is

that

in

many

buildings

there

is

an

inaudible