Audio Database

The

Pioneer PL-61 54,500yen(around the 1972 time)
58,000yen(around the 1973 time)

Description
 
It is the belt drive player which realized the more exact rotation by the brushless DC servo hall motor which carries the number control unit of rotational frequency control units.

The brushless motor of a hall device application by which Pioneer developed the process is adopted as a motor.
The drive magnetic field of this motor is made by the electric current from the transistor circuit committed by switching of a hall device. The attraction-of-magnet transition to a hall device is regularly performed one by one by the magnet rotor magnetized beforehand, and the exact rotation is obtained.
Moreover, since [ which is rotated by a 10 times as much speed as a turntable ] a low speed motor, there is little oscillation and S/N and the endurance are improving. furthermore, the powering by a voltage stabilizer -- since a scheme, it is not influenced by variation of supply voltage, either.

DC servo mechanism of the motor consists of a rotational frequency detecting element and a control circuit.
Since a capacitor type detector oscillates an alternating-current signal by rotation, a transition of a rotational frequency changes to a transition of an oscillation signal as it is. Since this detector is formed of the substrate attached to the rotor and stator of a motor, it also changes very small rotation deflection to a frequency of oscillation, controls a drive electric current, and is keeping the motor rotation constant.

33 1 / 3 or 45rpm speed switchover has adopted the electronic formula by switchover of a circuit constant. For this reason, since it is not necessary to hang a former type belt again, there is no trouble resulting from a belt or its switching organization.
Moreover, 33 It has the fine-tune thumb which became independent 1/3.45rpm, and the coordination of the rotational frequency is enabled by ±2% of within the limits.

The polyurethane belt is adopted as a belt.

S character type is adopted as a tone arm, and the sensitivity is improved by using the support organization of a new method for a bearing part to it. Moreover, the head shell has also adopted the lightweight type of a hole difference, and its flattery nature is improving sharply in addition to the improvement in trances capacity of a tone arm.
After a stylus-force coordination maintains balances in front and behind focusing on the supporting point, it can be easily adjusted only by uniting the numerical character of a wait with a Direct-reading type tick mark.

The original anti skating organization of Pioneer in which the magnetic repulsion was applied is adopted as the denial of an inside force. By the scheme in which a stylus-force tick-mark numeric value shows an anti skating bias value as it is, it did not become the obstacle of the operation for built-in [ which was included in the interior by the main unit ], but has the outstanding endurance.

The code of low capacity is adopted as output code, and the damping in a super-high region is reduced.

Rise and fall of a tone arm have adopted the hydraulic arm elevation organization of the smooth operation by button operation.

PC-20 which is man-month type cartridge is carried in the cartridge.

The large-sized insulator is adopted and a coordination of the degree of level is possible.

Rotational Tone Insulator
A

Rating of a mode
Form Record player
Motor Brushless DC servo hall motor
Drive system Belt drive
Turntable The product made from diameter aluminum alloy die-casting of 31cm (1.4kg)
Rotational frequency 33 1 / 3 or 45rpm (a fine tune is possible)
Rotational frequency adjustable range Less than ±2%, an each rotational frequency independent coordination
Rotational frequency switching Electronic formula
Rotation unevenness 0.05% or less (WRMS)
S/N 55dB or more
Tone arm Static balance scheme S character type pipe arm
Cartridge man-month type (PC-20)
An attached organization Arm elevation organization
Magnetic-repulsion type anti skating organization
Lateral balancer
Arm height adjustment mechanism
Plug-in system head shell
Large-sized insulator
Stroboscope
Level
The semiconductor used Transistor: 22 pieces
Diode: 15 pieces
IC: One piece
Hall device: Two pieces
Dimensions Width 498x height 201x depth of 429mm
Weight 11kg