|
 Compared
to the high priced, quality (and large) turntables of the sixties,
the launch of the all new TD 150 turntable in 1965 with the distinguished
name of Thorens at just over £20.00 was destined to be a winner.
Not only did it look different to its predecessors with its slim,
compact, modern look, it was also made in a completely different way.
Gone was the idler wheel mechanism, replaced by a simple belt drive
system that was driven by a minute multi-pole synchronous induction
motor, with a diameter of just 40 mm! It was this small motor
and drive system that enabled the designers to make the 150 so slim
and compact.
Fitted
on the motor spindle as shown here on the left, is the belt pulley,
machined to accommodate two belt positions, 33 rpm and 45 rpm, which
works on the derailleur principle, directed by a claw operated by the
33/45 control knob. The
speed control knob is directly linked to the speed control mechanism
which is situated directly below. The speed control mechanism has a
twofold existence, as it also operates the on/off micro switch
located next to it.
 When
the control indicator knob is at position '0' the supply is
cut and the spindle stops rotating.
 The
platter is in two sections, the inner has a diameter of 162 mm
around which the belt fits, it also has on its underside a short 50
mm x 10 mm spindle with a captive ball bearing on its tip.
 On
the top surface of its outer edge, there is a small 12 mm x 3 mm
step machined out of it, on which the 300 mm outer platter fits onto
a less shallow corresponding shelf to its underside. Both sections
have three finger lift holes. Other than the weight of the
outer platter resting onto the smaller inner section, no other means
of securing the two section together exists. That said, no more
is required.
 The
main chassis of the unit is also in two steel parts, separated by
three rubber damped coil springs. The top section of these two
parts carry the motor, cable connectors, belt claw and arm lift
mechanism. Suspended on its underside, is the second section which is
made-up of two steel members spot welded together forming a 'T'
shape. The longer of the two sections runs from  left
to right with the turntable bearing fitted at the centre and the
shorter cross member runs from front to back on the right hand side
to which the arm board is fitted. When in place, the top section is
screwed to the wooden plinth and the bottom section is suspended on
the underside, hence the term 'floating chassis'. When the
platter and pickup arm are in place, the weight imposed by them,
pushes down onto the bottom section, effectively separating the two
so that the arm board and platter/bearing are completely isolated
from the top fixed plate. The three coil springs can then be
adjusted to level-up the bottom section in relation to the fixed top.
 The
success of the TD 150, paved the way for the now classic Thorens
TD125, with a similar belt drive system to the 150 but more robustly
built, with added style. It has an electronic rather than
mechanical motor control and a strobe speed adjustment system.
I
have a number of quality turntables, including the TD 150 mk
II, which are all in varying degrees of renovation but I have to
admit that I do have a liking for the Thorens TD 150, though simple
in design, it does exactly what it is intended to do; very well.
|
Detail
of phono connection to the SME 3009 viewed from the  underside.
It
has been pointed out by a visitor to this page, that the point
at which the cables are fixed could restrict the arm. A point to
consider if you are thinking of this type of installation.
|
|
Specification |
. |
|
Model: TD 150 |
Drive System: Belt |
Platter: In two parts (8lbs) |
|
Speeds: 33 and 45 rpm |
Power Supply: 120 and 240 volts AC, (4watts) |
Size: 375 mm x 305 mm |
Page top |
