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 Like
its predecessor the Thorens 150, the 125 is based on its same
design principles; being driven by a very small motor and a belt
drive system. It also has the two tier arrangement where the
panel that carries the arm board and bearing is isolated from the
second panel that carries the motor and other components below. That
said, these principles are implemented into the 125 design in a
completely different way.
The
motor of the 125 derives its alternating current not from the AC
mains direct, but from an electronic oscillator/ amplifier, so that
the three speed selector  is
not a totally mechanical process as
in the 150 . The sliding speed
control block when moved to the three marked positions, operates a
series of small mechanical devices which in turn moves a slider which
is situated on the circuit board. This switching produces
frequency changes to drive the 16 pole synchronous motor for each of
the three; 20, 40 and 55 Hz giving 16, 33 and 45 rpm.
The
main bearing for the two section platter is fitted into a strong,
one-piece aluminium panel, the right hand  side
of which is stepped to the thickness of the arm board, where two
short lugs protrude top and bottom with a longer section extending at
the centre. These side extensions, each of which have threaded fixing
holes are designed to carry the arm board.
 The
stroboscope is fixed to the underside of the inner section of the
revolving platter. When the platter is located into the
bearing, it revolves over one of two cut-outs within the aluminium
plate, with the purpose of
this being that it reveals a portion of the revolving stroboscope for
the neon lamp which is fixed to the pressed steel panel below
it. This larger cut-out, also provides access to the  adjustments
screws that allow the neon unit to be moved to either the 50 or 60
Hz positions.
It
goes without saying that the strobe action would not be visible in
this location was it not
for the presence of a small mirror positioned about an inch below a
small window on the front panel of the turntable. By peering down at
the mirror (which is set at forty five degrees), the reflection of
the revolving stroboscope is clearly visible off a second deflector
lens, creating a periscope effect. Any adjustments to speed
that may be required can be done by means of a red thumb-wheel
situated directly in front of the viewing  window.
The
two tier panel arrangement is made up of; the top aluminium section
that carries the arm board, main bearing and platter, and the lower
pressed steel panel on which the motor, neon lamp, circuit board and
other components are fixed to. This lower steel panel is the
chassis and is firmly fixed to the wooden plinth as a rigid fixture,
to which the front aluminium fascia panel that houses the controls is
also bolted to. The two panels are  connected
together by three small diameter rods which are threaded at both
ends and firmly fixed in position to the underside of the top panel
and loosely fixed to the bottom panel with nuts and
washers. The contact points of the rods  are
isolated by rubber washers so there is no metal to metal contact
between them. The rods are of such length that they allow a gap
to exist between the two sections, which is the required space for
three quite large springs to fit. Each of the springs sits
inside plastic adjustable cups that fit into three threaded holes in
the bottom steel panel so that the two panels are in fact pushed
apart by the springs. The top panel is therefore 'sprung' and
can quite easily be pushed down by the fingers at any point.
When
everything is in place, the plastic cups are used to adjust the
level of the top panel so that its position corresponds to the top
edges of the level plinth.
The
Thorens TD125 mk11 is without doubt a turntable to be reckoned with,
(especially when you try and pick it up!) incorporating all the
qualities of the 150; it runs very quiet indeed, has excellent
specifications, fine speed adjustment and is simple to operate.
The thing that stands out about this turntable is its build quality,
a great deal of thought has gone into its design. Visually too,
this turntable looks good with the great 1970's styling.
I
use this table with the SME 3009
series II pick-up arm
and the Audio Technica cartridge. A combination I'm sure most
would be more than happy with. |
