Audio Database

The

ONKYO PX-100M
500,000yen(1981 release)

Description
 
The high-class linear motor system which aimed at the radical modification of a rotation nakedness property aiming at the ideal of a phone motor.

PX-100M has adopted the guided type linear motor which carries out the perimeter direct drive of the turntable, and has realized the rotation precision which was very excellent. Moreover, a rotor is a non-magnetic pole, there is no cocking event in accordance with a magnetic pole pushing and pulling in a motion of a rotor, and the smooth rotation property is ideally secured also from the principle of operation as a guided type motor with the continuous thrust given from a stator.
Although a nakedness property is wonderful and a servo circuitry is originally needlessness in PX-100M, since it has few transition members partially, the temperature characteristic of the lubricating oil between a shaft/bearing etc. has applied the necessary minimum servo.

If an electric current is first sent through a coil, a magnetic field will occur, and an eddy current generates the rotation principle of a linear motor in the conductor in a magnetic field. Since the magnetic flux which cuts an overcurrent will change if this magnetic field is moved to the hand of cut, a disc is guided in the orientation which a magnetic field moves. In order for what is necessary to be just to add the sine wave which had the 90-degree phase difference for moving this magnetic field and to improve efficiency in fact, the 90-degree phase difference was given and what pole is also piled up. Furthermore, in order to raise the torque of a linear motor, it is made to counter focusing on a stator and a rotor, and magnetic flux is made to act effectively.
In the case of PX-100M, by arranging symmetrically 4 blocks of stators made to counter focusing on a rotor focusing on a shaft, torque unevenness was canceled completely and the smooth rotation is realized.

10kg of self-weights, inertial-mass 2000kg-cm2, and a deer have also adopted the heavy weight class turntable of pure-copper shaving appearance, and 20mm of diameters of a shaft, and 94mm in length a very thick and a high-rigidity stainless steel shaft as a turntable.
Conductivity begins to shave a good pure copper ideal as a rotor of a linear motor, comes out, and molds,With specific gravity 8.9, since it was large, it was made to the compact, it began to delete from a Naked, and for the の reason, the turntable and the rotor were finished by one and the merit with a securable precision of the rotor moreover pinched by the coil has been obtained. Moreover, deadning material is stuck on a turntable rear view, and the resonance of the turntable is pressed down.
Moreover, the ethylene system resin is used for the Tungalloy ball which has a hardness higher than any metals in the lower end of a shaft, and a thrust seat, it fills with Takani promotion-to-a-responsible-post special oil between a shaft and a ball, and it is aiming at the improvement in wear resistance and S/N.

In order to obtain a constant-speed rotation quickly, the high torque DC motor and driving circuit which operate only to a ramp-up period are carried.

After molding the aluminum casting of one into it in order to obtain a high rigidity in a cabinet, the precision manipulation by milling cutter manipulation has been performed further.
Furthermore, about an arm base portion, the damping alloys of an aluminum-Zn system are used on material, and consideration of putting this between a cabinet and binding it tight is carried out.

Transparent amorphous polyolefin was finished by center injection molding, it is uniform and the turntable sheet excellent in the thickness precision is adopted. The unnecessary vibration which originates in a failure of the physical properties of a turntable side or adhesion by this is eliminated.

The book jacket made from acrylics is attached.

The arm base corresponding to a long arm was an option.



Rating of a mode
Form Linear motor system
Motor The main motor: Outer rotor DD scheme guided type linear motor
Auxiliary motor: High torque DC motor
Turntable Tough pitch pure-copper block shaving appearance, 33cm of diameters of a maxima
10kg of self-weights, inertial-mass 2000kg-cm2
Control system Quartz PLL control
Wow and flutter 0.005%
Rotational frequency 33 1/3, 45 or 78rpm
S/N 78dB or more (DIN-B, limit of measurement)
Startup property It is a convention rotation (startup booster using) at 1/2 round.
Braking method Plunger drive mechanical type
Conformity arm effective length Main-unit arm base: 229-283mm
At the time of an option arm base using: 235-312mm
Power consumption 55W
Dimensions Width 560x height 206x depth of 374mm (book-jacket included)
Weight 40kg
Option The arm base for long arms AB-100 (\62,000)