Pioneer PLC-1700

Commentary

An armless player with a brushless DC servo direct drive hole motor.

The motor is a direct drive phono motor that uses a Hall element.
In place of the brush, which was indispensable for conventional DC motors, we applied the hole stopping method developed by Pioneer to the magnetic field detection of the switching mechanism. This reduces vibration compared with DC motors with mechanical switching mechanism, and improves S/N and durability.
In addition, the motor rotates at 33 1/3 ・ 45 rpm, which is the same as the number of revolutions of the record. Since the direct drive system directly drives the turntable, there is no intermediate reduction mechanism that causes uneven rotation, and excellent characteristics are obtained.

The Hall element is a kind of semiconductor. It is a cross-shaped thin film metal made of N-type Insb alloy. It uses the "Hall effect" in which a voltage is generated between two terminals when an electric current flows through two terminals and a magnetic force is applied at a right angle to the other two terminals to convert magnetism into electricity.
Pioneer has developed a new manufacturing method called the vacuum deposition method, and has reduced the thickness from the previous limit of 30-50 μ m to 0.8 μ m, realizing a low-cost and small-size Hall element.

Equipped with a DC servo mechanism to control the rotation accurately at all times.
In this control circuit, the rotation is automatically controlled by a capacitor-type oscillator that is not affected by changes in the ambient temperature or by the magnetic force of the rotor magnet, thus maintaining a stable rotational speed.

Equipped with a brake mechanism that instantly stops the turntable when the power switch is turned off.

A purely electronic system is used for changing the rotational speed, and the speed can be finely adjusted within a range of ± 4% while watching the strobe light carved on the outer circumference of the turntable.
The flash lamp is equipped with a flashing switch so that it can be turned off when it is unnecessary.

The cabinet is a double-walled 30mm-thick cabinet with a combination of plywood and metal base with a rosewood natural wood wood finish.

A large insulator is used to reduce howling and external vibration.
In addition, the height can be freely adjusted, and the level can be adjusted while looking at the level of the panel.

You can attach any tone arm to the attached panel and use it. If you remove the dust cover, you can use up to 16 type arm.
This board is a detachable type that can be easily removed with 6 screws, and you can easily exchange many kinds of arms by using sub panel sold separately.

Model Rating

Type	Armless player
Motor	Brushless DC Servo Hole Motor (18-pole 36-slot)
Drive system	Direct drive
Turntable	31 cm Diameter Aluminum Alloy Die Cast (1.4 kg)
Number of revolutions	33 1/3, 45 rpm
Rotational speed adjustment range	+ / - 4%, independent adjustment for each speed
Speed change	Electronic
Uneven rotation	Not more than 0.04%
S/N	60 dB or more
Attachable arm	Type 14, Type 16 (Hood Not Attachable)
Attachment mechanism	Rotating speed fine adjustment knob Strobe light Level Stop brake Large insulator
Semiconductor used	Transistor : 23 Diode : 15 pcs IC : 1 Hall element : 2 pieces
External dimensions	Width 570x Height 187x Depth 434 mm
Weight	15.6kg
Sold Separately	Sub-panel PP-307 (¥ 1,500)