|80,000yen(around the 1973 time)
The arm-less player which adopted the brushless DC
servo direct-drive hall motor.
The direct-drive phone motor adapting a
hall device is adopted as a motor.
Instead of the brush which was
indispensable to the conventional DC motor, Pioneer has applied the hole
blocking which developed the process to the magnetic-field detection of a
switching organization. The oscillation decreased compared with the DC motor
which has a mechanical switching organization by this, and S/N and the endurance are improved.
33 [ and ] as the rotational frequency of a record with the
same rotation of a motor itself the direct-drive which drives a turntable
directly at 1/3.45rpm -- since a scheme, the middle deceleration mechanism
leading to rotation unevenness did not exist at all, but has acquired the
A hall device is a kind of a semiconductor, is the crossbar thin film metals
made from the N type Insb composition, and if it sends an electric current
through two terminations and an attraction of magnet is applied to a quadrature,
it will have changed the magnetism into the electricity using the "hall
effect" which a voltage produces among other two terminations.
In Pioneer, the new process of a vacuum
deposition method was developed, and till then, 30-50micro have improved the
thinness which was a threshold to the thinness of 0.8micro, and has realized the
cheap and small hall device.
In order to always control a rotation
correctly, DC servo mechanism is carried.
The rotation is automatically
controlled by the capacitor type oscillator which does not receive the influence
by a transition of ambient temperature, and the attraction of magnet of a rotor
magnet, and this control circuit maintains the stable rotational frequency.
The brake mechanism who stops a turntable at the moment is carried at
the same time it turns OFF a power switch.
The pure electronic formula
is adopted as a switching of a rotational frequency. Moreover, a fine tune of a
velocity is possible, looking at the stroboscope minced by the perimeter of the
turntable by ±4% of within the limits.
The blinking switchpoint is provided
in the lamp which illuminates a stroboscope so that it can erase, when
The cabinet of the double structure which combined plywood
with thickness of 30mm and the metal base is adopted as a cabinet. Kibe is
rosewood native wood finish.
The large-sized thing is adopted as an
insulator and the howling and the extraneous vibration are reduced.
Moreover, while a height can adjust freely and looks at the level of a
panel, a coordination of the degree of level is possible.
It can be used
being able to attach a favorite tone arm to an attached panel. Moreover, if a
book jacket is removed, it can be used to 16 type arm.
This board serves as
a desorption type which can be removed simply on six screws, and if an optional
sub panel is used, it can exchange many kinds of arms easily.
||Brushless DC servo hall motor (18 very 36
||The product made from diameter aluminum
alloy die-casting of 31cm (1.4kg)
||33 1 / 3 or 45rpm
|Rotational frequency adjustable range
||±4%, an each rotational frequency
|Rotational frequency switching
||0.04% or less
||60dB or more
|The arm which can be attached
||14 types, 16 type (a hood mounting is
|An attached organization
||Rotational frequency fine-tune thumb
|The semiconductor used
||Transistor: 23 pieces
Diode: 15 pieces
IC: One piece
Hall device: Two pieces
||Width 570x height 187x depth of 434mm
||Sub panel PP-307 (1,500yen)