NAD 5120 User manual

SEMI-AUTOMATIC
BELT-DRIVE
| TURNTABLE
INSaasielourle)ts
FOR INSTALLATION
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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

but virtually permanent spectrum of structural vibrations
caused by motors, furnace blowers, the compressors of
refrigerators and air conditioners, etc. When these vibra-
tions reach the phono stylus they tend to colour the sound,
especially if they are further amplified by the resonance of
the arm/cartridge system. (This resonance, due to the effec-
tive mass of the tonearm interacting with the compliance of
the stylus assembly, is usually found between 7 and 12 Hz
with modern high-compliance pickup cartridges.)
The suspension frequency of the NAD 5120 is much
lower: less than 4 Hz. Since the suspension filters out
vibrations above its resonance, this design provides the
most effective isolation of the record and stylus fromthe
commonest kinds of environmental vibration, and therefore
it offers the purest sound quality. The low suspension
frequency has a disadvantage, however. If large-amplitude
low-frequency vibrations reach the turntable they are more
likely to cause obvious and perhaps annoying misbehavior,
such as “wow” (wobbly pitch) or even skipping of the stylus
between grooves. (Of course, unlike persistent colouration
of the sound, this obvious misbehavior is relatively easy to
identify and correct.)
If your listening room has a concrete floor, or if the
turntable is on a shelf that is fastened to a wall, such
vibration is unlikely to be a problem. But wooden floors often
have a springy low-frequency resonance of their own; danc-
ing or even walking on such a floor may produce large-am-
plitude vibrations that coincide with the turntabie’s suspen-
sion resonance. If this occurs, the best solution is to place
the turntable on a massive object (such as a polished stone
slab or a cabinet filled with records), or to isolate the
turntable from the floor by placing it on a shelf that is
fastened to the wall.
APPENDIX B: TUNING
THE DYNAMIC VIBRATION ABSORBER
Recommended settings for the DVA frequency and
damping are listed in the enclosed leaflet for many popular
pickup cartridges. If no recommendation is available for
your phono cartridge, excellent results will usually be ob-
tained by setting the DVA frequency screw [25] to 10 Hz and
the DVA damping rod [18] to an intermediate value (Q=1 or
2). Precise settings of the DVA adjustments are not neces-
sary
in
order
to
obtain
the
benefits
of
the
Dynamic
Vibration
Absorber.
However, if you want to conduct your own experiments
to determine the optimum DVA settings for your particular
cartridge, you will need a test record that has a frequency
sweep or a series of test tones recorded at a high level of
vertical modulation, spanning the range from about 15 Hz
down to about 5 Hz. A special NAD test record has been
created for this purpose, and it includes detailed instructions
for tuning and damping the DVA with any pickup cartridge.
The record contains a series of high-level “warble” tones
ranging in frequency from 5 Hz to 15 Hz. (Each warble tone
varies rapidly up and down in frequency over a 1 Hz range
centered at the nominal frequency, in order to be certain of
picking up any very narrow resonances in the playback
system. E.g. the 5 Hz tone varies between 4.5 and 5.5 Hz.)
Superimposed on each infrasonic warble tone is a
steady 440 Hz tone recorded at a relatively low level. When
you play the record, ideally you should hear only a steady
440 Hz tone since the infrasonic warble tones are below the
normal low-frequency limit of human hearing. But when the
infrasonic tone excites the arm/cartridge resonance, the _
stylus (and, to some extent, the cartridge body and tonearm
as well) will shake. This vibration may be large enough to be
visible to the unaided eye, if you look closely. In any case
the vibration of the stylus in the groove will produce an
audible warbling or “flutter” of the 440 Hz tone, due to
frequency intermodulation distortion (F.I.M.).
The first step in DVA tuning is to measure the natural
frequency of the arm/cartridge resonance, which requires
that the counterweight be immobilized. This can be done by
wedging some cardboard or styrofoam into the space above
and below the counterweight, so that the counterweight is
no longer free to vibrate on its spring. Another approach is
to screw the damping rod [18] down into the fluid to obtain
maximum damping (Q greater than 3); while this does not
completely immobilize the counterweight, it provides a suffi-
ciently stiff mechanical coupling between the arm and the
counterweight to allow an accurate measurement of reso-
nance frequency. |
Then play the test record, listening for the “flutter,”
pitch wobble, or warbling quality of the 440 Hz tone that is
caused by the arm/cartridge resonance. Play each band of
the record, and identify the band in which the worst flutter
~ occurs; or watch the cartridge closely'and note which band
causes the greatest visible vibration of the stylus assembly
and cartridge body. Use the voice announcement on each
band of the record to identify the frequency at which the
peak resonance occurs. (With some phono cartridges, the
440 Hz tone will be quite steady on some bands, in obvious
contrast to the pronounced flutter that is heard on the bands
where the peak resonance occurs. With other cartridges,
flutter will be heard over the entire 5 Hz to 15 Hz range
of the test record, and your task is to identify the band
or bands on which the greatest amount of audible
flutter occurs.)
Unscrew the damping rod [18], or remove the shims
that you installed to immobilize the counterweight, and
check to see that the counterweight is free to vibrate on its
spring. Turn the DVA frequency screw [25] until the lower tip
of the screw is aligned with the resonance frequency that
you have just determined from the test record.
Depending on the amount of internal stylus damping
in the cartridge, the resonance peak is likely to span a range
of frequencies rather than being sharply tuned to one
frequency. When in doubt, set the DVA frequency slightly
lower than the median resonance frequency. (For example,
if the peak resonance appeared to span the range from 8 to
12 Hz, set the DVA to 9 Hz.) This is for two reasons. (1) If
the arm/cartridge resonance is not completely cancelled by
the DVA, it is better to cancel the lower-frequency portion
of the resonance, leaving the relatively innocuous higher-
frequency portion of the resonance uncompensated.
(2) As damping is added, the added stiffness will tend to
raise the DVA frequency slightly above its nominal value.
The final step is to set the DVA damping rod [18]. With
most pickup cartridges the damping is uncritical, and the rod
should be set for a moderate amount of damping (Q =1 or
2). If you are using a cartridge that has an unusually small
amount of internal stylus damping (e.g. a Grado), you may
determine the optimum damping by trial and error: play the
test record several times, using different damping values,
to find the setting that yields the least audible flutter of the
440 Hz tone.

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