Turntable Terminology

All laminated core :
A special permalloy laminated core production process is used to reduce eddy current loss and improve the linear response range of the cartridge's magnetic circuit.
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 :
Th 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.
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 :
(See the picture above)
A device for attaching the cartridge to the tonearm.
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.
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.
S-shaped tonearm :
A tonearm shaped in a S-shape as opposed to a straight tonearm.
Starting torque :
Force that makes a stopped turntable platter start rotating. Listed in KG*cm, 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.
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 turntableplatter.
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).