THORENS TD 125 User manual

INSTRUCTION
MANUAL
THORENS
TD 125

Contents
Page
1,
INTRODUCTION
3
2,
OPERATION
SUMMARY
4
3,
UNPACKING
6
4,
MOUNTING
7
TONE
ARM
AND
PICK
UP
"1
.
OPERATION
18
oa
.
THE
SOLID
STATE
CONTROL
SYSTEM
AND
HOW
IT
WORKS
18
|.
MAINTENANCE
19

1. INTRODUCTION
The turntable TD 125 is an electronic precision instru-
ment
which
will
guarantee
the
best
results
in
record
reproduction when handled carefully. In order to protect
the instrument and your precious records, the ope-
ration
should
not
be
learned
by
experimenting
but
by
careful reading of this instruction manual.
The Hi-Fi enthusi
and the expert will find in the
following chapters all the necessary information for
the
application
of
the
transcription
turntable
as
@
pro-
gramme
source
in
high
quality
Hi-Fi
equipment
and
for
its use in the professional field.

2. OPERATION SUMMARY
21. Connect the turntable to the AC mains power
supply. Check for the correct voltage.
2.2. The slide button in the centre of the contro! pan-
el Q is the AC mains on/off switch.
Position left: "OFF"
Position right: “ON™
2.3. The left hand slide ber @ is the speed selector
which controls the 3 speeds available. In the left hand
Position it is 16 */s RPM. Centre position 33 "/s RPM and
right hand position 45 RPM,
24. In front of the lighted stroboscope window @ is
the knurled wheel @ for the pitch control.
Moved to the left: turntable runs faster
Moved to the right: turntable runs slower
For the exact turntable speed it has to be adjusted so
that the stroboscope pattern © seems to stand still
2.5 The adaptor in the centre of the turntable platter ©
may be turned over for adjustment in order to play
records with either large or small centre hole.
26. Tone
Position le
Position
right:
play

3. UNPACKING
Place the carton top side up and open. Remove the
outer 12° turntable platter and its rubber mat. After
installing the unit carefully centre the outer turntable
platter
on
the
inner
turntable
platter
with
the
rubber
mat on top.
After removing the upper part of the foam plastic, the
turntable may be removed from the carton
The accessories are stored beneath the turntable.
Take the complete unit out of the foam plastic bottom
part
and
put
it
down
on
a
fiat
surface.
Remove the spacer between the suspended chassis
and control panel.
Attention: Save the complete packing. Shipping the
turntable without this could cause serious damage.

4, MOUNTING
4.1. Mounting the turntable
on a base
For the TD 1258 and TD 125 AB version, this chapter
is not applicable,
Remove the outer turntable platter before proceeding
to mount the unit,
If
the
turntable
is
to
be
operated
free
standing
outside
of
furniture
it
has
to
be
mounted
into
a
base
No
ST
509
or
equivalent.
The
chassis
must
be
fastened
from
underneath
with
the
4
screws
which
ere
supplied
with
the
turntable.
8 of the base do not fit to the turntable-
icken
screws
@.
Then
the
thread-bars
can
be moved according to the holes in the base.
4.2. Mounting the turntable
Into furniture
The TD 125 turntable should be mounted on a ply-wood
mounting board of not less than #/s inch thickne:
‘cut out according to the template X 830-2. This .
rectangular hole with the dimensions 451 x 341 mm
(17.75 x 13.42"). In this hole the mounting frame CE 509
fits without further fastening. The turntable chassis
TD 125 is fastened into the mounting frame as de-
scribed under 4.1
In order to ensure efficient operation of the floating
‘suspension it is essential when fitting the unit to allow
it clearance between the die cast chassis and
inting board.
3. Levelling of Unit
The turntable should be levelled after mounting the
tone arm by adjusting the three knurled levelling
knobs ®.
Turning clockwise raises and counterclockwise lowers.
Check to make sure that after adjustment Unit is
floating freely.
7

4.4.
Assembling
of
longer
length
tone
arms
The TD 125 is supplied
ting board to accommodate 9° (Brit
(American Standard) tone arms.
The turntable TD 125 may be equipped with a longer
tone arm. For the purpose a conversion kit JP 512 Is
ailable. It consists of @ larger tone arm mounting
board and a longer control panel. For this conversion,
follows: — after unscrewing the 3 sock
1d screws remove the standard tone arm mour
ting board. — Remove outer and inner turntable plat-
ters. — Loosen earth connection (cable) between upper
id lower chi Unscrew the 3 knurled nuts @
and remove the washers below. — Remove the upper
die cast chassis, taking care not to lose any part of
the spring suspension of this chassis. — Unscrew the
fastening screws of the slide buttons ® and remove
the buttons. — Unscrew the 3 screws maintaining the
control panel which become accessible after removal
of the die cast chassis. — Remove the standard control
panel.
For assembling the longer control panel and the larger
tonearm mounting board, proceed accordingly in re
erse sequence.
The conversion enlarges the turntable by 75 mm (2.957),
This also requires the longer base No ST 512.
ish Standard) 12

4.5. TD 125 with stiff suspension
A
In some special cases, for example for discotheque use,
it can be of advantage to suppress the resilient sus-
pension of the die cast chassis of the TD 125, although
this operation results in a slightly higher rumble level.
For this conversion, proceed as follows: — Unscrew
each one of the 3 knurled knobs ® of the die cast
10
chassis
suspension,
one
at a
time,
and
remove
the
spring
below.
—
In
place
of
the
spring
introduce
the
special
rubber
grommet
(please
order
separately
No.
CB
908)
and
insert
the
knurled
knob
upside-down.
— Beware
to unscrew
only
one
knurled
knob
at a
time!

5. TONE ARM AND PICK UP
The tone arm mounting board has to be removed by
unscrewing the 3 socket headed screws with the
Allen key supplied. The tone arm should be mounted
on
the
board
in
accordance
with
the
manufacturers
re-
commended
procedure
and
the
template
supplied.
Connect
earth
of
the
tone
arm
to
the
chassis
screw
@.
The
Thorens
TP
25
tone
arm
has
been
designed
to
per-
fectly
match
the
standards
of
the
TD
125
turntable
and
it
will
therefore
give
you
optimum
performances.
Moreover
the
lowering
device,
operated
from
the
rigid
front
panel
by
means
of
an
additional
slide
bar,
greatly
facilitates
its
use.
5.1. Cartridge installation
The TP 50 plug-in shell offers enough s
necessary mounting hardware to suit any standard
pick-up cartridge ('/2" hole distance). Making use of
the hardware supplied — washers, spacers ond
screws — mount the cartridge in a way to bring the
stylus tip at a distance of 1/1" to 7/«" (19—21 mm) from
the bottom of the shell. Fig. 3.
Attention!
It
is
essential
that
only
the
metrical
M2
screws
supplied
with
the
TP
50
shell
be
used.
The
screws
delivered
with
several
cartridges
have
a
Whitworth
thread
and
they
will
not
fit
the
metric
threads
used
on Thorens units.
"1

5.2. Cartridge alignment
The TP 50 plug-in shell allows to adjust first the vertical
tracking angle and then the stylus overhang for opti-
mum tracking.
4 15/16" Fig.3
49mm
5.2.1 Vertical tracking angle
Loosen slightly the two screws A on both sides of the
shell and small screws 8 (see fig. 3)
Insert the shell plug in the arm socket, allowing the
location pin to enter the slot. Press inward and tighten
the locking nut firmly but not more than necessary.
This operation is best performed when the arm is
clamped in the arm rest. Bring the tone arm over a
record (caution: take a worn record) and adjust the
vertical tracking angle according to the instructions
of the cartridge manufacturer, in turning the shell on
tt termined by the two screws A. Do not force
the
shell
into
position,
due
to
the
extra-light
design
this could lead to serious damages.
12
For 15° cartridges, the proper vertical tracking angle
is obtained when the upper surface of the plug-in shell
's horizontal
Make sure that the rear of the shell or of the cartridge
cannot contact a warped record. If necessary, increase
the vertical distance between the stylus tip and the
bottom of the shell with the help of spacers (see fig. 3).
At last tighten smail set screws B.
Due to this special adjustment it is possible to obtain
a
15*
vertical
tracking
angle
also
for
a
number
of
older
cartridges
which
were
not
manufactured
ac-
cording to the present international standards.
5.2.2 Stylus overhang
The optimum distance of 230 mm between stylus tip
and vertical tone arm bearing is obtained when the
stylus tip is at a distence of 49 mm from the rear
vertical surface of the plug-in shell (see fig. 3)
Tighten the two screws A.
5.3. Cartridge connection
Four separate colour coded leads are already soldered
to the terminal pins in the shell:

Red —— Right channel positive (hot)
Green — Right channel negative (shield)
These two leads constitute also the mono channel.
White — Left channel positive (not)
Blue — Left channel negative (shield)
4. Assembling
the counterweight
As a precaution against damage in transit, the counter-
weight
is
packed
separately,
already
threaded
on
the
removable
back
tubular
part
of
the
arm
with
the
set
screw.
Slide the back tubular part with the counterweight
‘onto the pick-up arm extension and lock it in position
with set screw.
For balancing the arm move the stylus force adjustment
lever back as far as possible to the abutment of the
lower end of the scale. Move the lowering device
slide bar to the “play” position. Position the arm
80 that the stylus tip is between the arm rest and the
turntable platter.
Turn the counterweight with the right hand, while main-
taining the lateral position of the arm with the left hand
to avoid damaging the stylus, until the arm assumes a
horizontal position, i.e. the stylus is at record surface
level.
5.5. Stylus force adjustment
After balance of the tone arm has been achieved, slide
the stylus force lever to the prescribed weight on the
stylus force scale as recommended by the cartridge
manufacturer. Fig. 4.
Stylus force
adjustment \
Anti-skating
adjustment", Fig. 4
5.6. Anti-skating adjustment
The setting of the anti-skating force depends mainly on
the applied stylus pressure. At the TP 25 tone arm it
can be adjusted by fixing the nylon thread which is led
through a hole in the tone arm mounting board in one
of the three different notches. The highest anti-skating
force is applied when the nylon thread hangs in the
outer notch.
Furthermore, the force can be decreased by un-
screwing the lower part of the antiskating weight.
13

The correct anti-skating force necessary for a particular
cartridge can be determined by means of a test record
which incorporates a tracking test, for instance CBS
no. STR. 111. Whilst playing this part of the record,
at first without anti-skating force, reduce the stylus
force until distortion becomes audible. Normally it is
first audible in the right channel and upon a further
reduction of the stylus force, in the left channel. Adjust
the anti-skating devi
the stylus force back to
@ distortion free reproduc- @ value which guerante
tion
kating fore
means of the groov
records.
When
piaying
this
part
of
the
record
the
nylon
thread
should
be
adjusted
in
such
a
way
that
the
tone
arm
does
neither
move
to the center
nor the outer
edge
of
the test
record.
olso be determined by
8 part of some other test
If such test records are not available the adjustment
can be do
Stylus force
1_—1.5 grams inside
15—2
grams
middle
2
—4
grams
outside
4
5.7. Pick-up output connections
The
tone
arm
is
wired
in
the
factory
according
to
Fig. 5.
Right
channel:
stendard
male
phonoconnector
plug,
black
colour.
Left channe!
white colour.
standard male phonoconnector plug,
[)
. left channe!
right ehanne: Al |
c+--—4
Fig. 5
Ground connection:
—
The
unit
plate
ond
the
metal
part
of
the
arm
are
connected
at
A
to
the
shield
of
the
right
channel
cable
acting as @ ground lead.
—
The
shield
of
the
left
channel
cable
is
insulated
from
the
base
plate
of
tho
turntable
and
from
the
metal
parts
of the arm.

The spring mounted parts of the turntable are connect
ed to the fixed unit plate by ground lead D. Lug E
should be fastened on the metal frame by the corre-
sponding set screw of the pick-up wooden board.
lf necessary for particular cartridges or amplifiers, two
different wiring systems may be easily realized:
3 wire system
Connect lugs 3 and 4 on the terminal strip with a wire
B; the shields of both channels are thus connected
together and to the unit plate
5 wire system.
When the ground for the turntable cannot be returned
to
the
amplifier
ground
through
the
signal
carrying
shieldings,
the
wire
connecting
lugs
t
and
3
should
be cut at A and a separate insulated wire C connected
from
lug
1
to
the
common
grounding
point
for
the
amplifiers.
6. OPERATION
6.1. AC Mains power
supply
connection
The
turntable
TD
125
may
be
operated
at
any
AC
mains
power
supply.
For voltages
between
210 and 240 V the
small
fuse
5x20
mm,
100
mA,
slow-blow
has
to
be
attached
to the fitting
fuse
holders.
For voltages between 110 and 130 the large fuse
6 x 32 mm, 200 mA, slow-blow has to be attached to the
respective fuse holder,
The fuse holders are easily accessible after removal
of the protective cap @.
Before changing the fuse don't forget to disconnect
the unit from the mains!
(ai Fig.
Due
to
the
electronic
speed
control
of
the
TD
125
turn-
table
an electrical
adjustment
to different
AC
mains
power
supply
frequencies
(50 or 60 Hz) is not neces-
sary.
For the adjustment
of the stroboscope
illumina-
tion
see
paragraph
64.
15

6.2. AC Mains power
supply switch
The slide bar © on the control panel has two positions:
Left position: OFF
Right position: ON
The synchronous motor is controlled by the solid state
control system. There is a built in automatic overload
protective
circuit.
Therefore
no
damage
will
occur
if
the
turntable
platter
is
stopped
by
hand
when
the
power
is on,
16
6.3. Speed selector
The slide bar on the left hand side of the contro!
panel @ is the speed selector for the three speeds
16 #/s, 33 '/s and 45 RPM.
It-can be operated at any time whether power is on or
off. The fine speed adjustment is made by the red
knurled whee! @ in front of the illuminated stroboscope
window @, The turntable speed is increased when the
knurled wheel is moved to the left and decres
moved to the right
When the appropriate stroboscope pattern
the following record speeds will be obt
following mains frequen!
At 50 Hz 45.11 RPM and 33.33 RPM
‘At 60 Hz 45.00 RPM and 33.33 RPM
When using the 162/ RPM speed, correct speed will
be indicated by the 33 '/s stroboscope pattern.

6.4. Stroboscope adjustment
for different AC mains
power supply frequencies
The TD 125 turntable can be operated without fre-
quency adjustment at 50 and 60 Hz (USA, Canada)
AC mains power supply. (Make sure that the correct
fuse, corresponding to the AC mains power supply
voltage is installed, see paragraph 6.1.)
The stroboscope illumination has to be changed when
‘operating the turntable at another AC mains power
supply frequency. This illumination has no influence
to the other function of the turntable. For the adjust-
ment, tho outer turntable, the drive belt and the inner
turntable have to be removed.
The two screws (@ in figure No. 7) should be loosened
‘one or two turns. The neon lamp carrier may now be
moved as indicated in figure No.7 corresponding to
the AC mains power supply frequency. After tightening
the screws, fit the inner turntable platter into its bearing
well and replace the drive belt.
The outer turntable platter is then centred on the inner
one. The drive belt should be kept entirely free from
any
trace
of
oil
or
grease
during
this
operation
Fig. 7
7

THE SOLID STATE CONTROL
SYSTEM AND HOW IT WORKS.
The TD 125 turntable is fitted with a Solid State Control
System. This replaces the mechanical linkage which is
normally necessary to maintain different record speed:
The Solid State Control Circuit consists of a transi
The necessary power for the synchronous motor is
produced by a push-pull amplification stage. To main-
tain
the
optimum
torque
from
the
motor
at
any
fre-
quency, a pair of frequency stepped switches are linked
torized Wien bridge oscillator, normally used in meas-
turing instruments, and the frequency of this oscillator
can be varied in definite steps so that the speed of the
16 pole synchronous motor can be changed. An additio-
nal fine frequency adjustment may be effected by
means of a potentiometer, thus providing an electronic
speed control within the range of + 2%.
13
Fig. 8
together thus providing different phase shift motor con-
densers.
The speed of the synchronous motor is therefore con-
trolled by the generated frequency. The desired record
‘speed will be provided by the precise frequency varia-
tion of the control generator.

8. MAINTENANCE
8.1. Turntable
The turntable bearing shaft revolves in self-lubricating
bearings. Under normal conditions lubrication is not
necessary before several 1000 hours of running. When
lubrication of the turntable bearing @ is necessary use
exclusively Caltex Regal oil B (ROB) as supplied with
our Lubrication Kit available as an accessory at your
dealer.
2. Motor
Due to the slow operating speed of the synchronous
iy under normal opera- motor no lubrication is ne
ting conditions.
8.3. Drive System
The belt, the motor pulley
of
oll
or
grease.
If
necessary,
clean
them
with
a
lint
free
cloth
dampened
with
denatured
alcohol
or
methy-
lated
spirits
8.4. Replacing the neon
stroboscope bulb
Before doing this, DISCONNECT THE UNIT FROM
THE MAINS. Remove the inner and outer turntable as
described in paragraph 6.4.
The neon bulb is then accessible, located under a cylin-
dricai lens at the upper edge of the black stroboscope
plate. Fig. 7. After unscrewing both screws left and
right
beneath
the
lens
@,
the
lens
can
be
removed
and
the neon buib replaced.
To reassemble the turntable proceed accordingly in
reverse sequence.
19

THORENS WARRANTY
1. We warrant that we shail replace free of charge every
defective part of this unit or repair it free of charge in our
works or in one of our authorized service stations; in case
a defect should set in within the period of warranty.
The warranty period is of one year from the date of the
original purchase.
2. Above warranty is valid only if the enclosed warranty card,
duly filled, is returned within 10 éays after purchase to the
Thorens General Representative in your country; his address
will be given by your dealer.
3. Should a defect set in within the warranty poriod, please
contact the Thorens General Representative and describe
completely the defective operation and quote Model and
Serial Number of your unit. In simple cases the General
Representative will send you the replacement part. Otherwise
he will give you the address of the nearest service station or
ask you to return the complete unit.
4, In the latter case, please pack the unit in the original packing
‘according to the instructions of the manual. Shipment must
be made shipping charges prepaid.
5. Any damage caused by failure to observe the instructions
contained in the manual, as well as by accident in transit or
elsewhere, will not be covered by this warranty.
6. The warranty expires if the unit is being repaired or altered
by anyone other than a Thorens authorized service station.
THORENS — FRANZ AG