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::
Turntable Terminology ::
Thanks to backspin for doing
most of the hard work compiling these terms :)
Aluminium
diecast :
Made by pouring molten aluminium into a mold. Designed to offer greater
precision
and vibration resistance than parts made of stamped sheet metal. Used
for
quality turntable platters.
Anti skating device :
A carefully calibrated, adjustable device acting on the tonearm near
its
rotational center to counteract the natural tendency of the tonearm to
move
toward the center of the record, thereby holding the stylus centered in
the
record groove. Spring-mounted or suspended weight systems are typically
used.
Armature :
The moving portion of a magnetic circuit. In a motor, the rotating
center
as opposed to the stationary stator. The coils in a MC cartridge; the
magnet
in a MM cartridge.
Audio Insulator :
An insulator or shock absorber intended to prevent outside vibrations
from
exciting the turntable. Turntable cabinet feet are often constructed to
act
as insulators.
Balance weight :
A weight to balance the tonearm and adjust the tracking force. Also
called "counterbalance".
Boron :
An element nearly as hard as diamond and having a high modulus of
elasticity.
Therefore, ideal as a phonocartridge cantilever material.
Boron nickel :
Nickel with a crystalline boron surface layer. Used for the contruction
of
the tubular portion of tonearms, this material maintains light weight
(low
mass) while raising rigidity and strenght.
Boron titanium :
Titianium with a layer of crystalline boron on the surface for
increased
rigidity. Because of its light weight (low mass), high strenght, and
corrosion
resistance, titanium is often used for aircraft parts.
Brushless motor :
A motor eliminating sliding contact conductive material or carbon
blocks
and using instead an electronic switching circuit to change the
polarity
of the stator. There is no direct contact between rotor and stator.
Cantilever :
The part of a cartridge that transmits vibrations, first picked up by
the
stylus tip from a record, to the electro-magnetic generating unit.
Cartridge :
A transducer that converts the mechanical vibrations caused by the
record groove undulations into an electric signal.
Direct Drive system :
A turntable system using a low speed motor (that turns at 33.3 or 45
rpm)
directly coupled to the platter so that the motor shaft is one with the
spindle.
Elliptical stylus :
A stylus tip having an elliptical cross section, as opposed to a
conical shaped stylus.
FG Servo motor :
A frequency generator in the motor produces a signal dependent on motor
rotation.
This is compared to a reference signal and the motor is controlled so
that
the two signals are the same. Compared to an electronic governor motor,
the
FG motor has less speed deviation or drift and is less affected by
temperature.
Friction :
Pivot friction occuring at the tonearm support. The less the friction,
the
more freely the tonearm moves to accurately trace the record grooves.
Full automatic
turntable :
A turntable that, hwen turned on by the operator has all the necessary
functions
to lift the tonearm from rest post and place it on the lead-in groove
and
return it to the rest post when it reaches the record's end. For
example;
the SL-Q310/SL-1300/SL-1350 are automatics.
Headshell :
A device for attaching the cartridge to the tonearm.
Manual turntable :
A turntable which does not automatically return the tonearm to rest
when it reaches the lead-out groove on the record.
For example; The SL-1200MK2
Moving Coil cartridge (MC) :
System in a cartridge in which a coil moves to generate an
electro-magnetic
force. Features low impedance and special characteristics.
Moving Magnet cartridge
(MM) :
System in a cartridge in which a magnet moves to generate an
electro-magnetic force. Easy-to-use and most common type.
Pitch control :
A control allowing speed changes of the record within a certain range,
usually 6% or 8%.
Quartz-phase-locked
control turntable :
A turntable with motor rotations controlled by very precise quarz
oscillations. Like the SL-Q310 or SL1200Mk2.
RPM :
Number of times a turntable rotates in one minute.
Semi-Automatic
turntable :
A turntable designed to automatically return the tonearm to the rest
when it reaches the lead-out groove on the record.
For example; The SL-1400/1410 D.D. turntable.
Servo motor :
A motor with a built-in automatic speed control device to stabilize
motor rotation.
Skating force :
Force drawing the tonearm toward the center when playing a record; this
action
is caused by and therefore also known as "Centripedial Force"
S-shaped tonearm :
A tonearm shaped in a S-shape as opposed to a straight tonearm. This
type
of design is the best compromise between fidelidy and tracking error.
Starting torque :
Force that makes a stopped turntable platter start rotating. Listed in
kg-cm
as well in lb-in, larger values mean that platter rotation will be less
affected
by stylus or record cleaner friction.
Stylus :
Needle-like object that follows the record groove and picks up
vibrations.
Sub Weight :
An
additional weight which can
be screwed on to the threaded end of a Technics 1200 turntable.
This weight is used to offset an unusually heavy cartridge / headshell
and allow proper tonearm balancing.
Tonearm :
Device that holds the phono-cartridge, applies the necessary tracking
force for tracing the grooves of the record.
Tracking force :
Weight or force pushing the stylus down into the record groove.
Wow and flutter :
Instantaneous variations in the rotaional speed of the turntable
platter.
WRMS :
Stands for the weighted root mean square, a method of using filters to
give
more "weight" to 4~6Hz modulations in the 3~4kHz region when making
wow&flutter
measurements since the ear is most sensitive to such speed fluctations.
Root
mean square is a formula for deriving a virtual value from a
fluctuating
waveform. In contrast, sometimes wow & flutter is listed as a
weighted
peak (W peak value).
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