Pioneer MU-1800
¥ 45,000 (around 1976)
Commentary
Direct-drive phono motor employing magnetic pulse detection system.
The drive motor is a brushless high-torque Hall motor using a Hall element.
A Hall element is a type of semiconductor that converts a change in magnetic field into an electric current. By applying it to motor-driven switching (magnetic pole switching), vibration and wear due to friction are suppressed, and high S/N and durability are achieved.
The servo mechanism uses a frequency control method of magnetic pulse detection.
In this system, magnetic pulses from the bottom surface of the magnetized rotor magnet are detected, and the AC signal obtained from the detected pulses is used for automatic control, so that constant speed rotation with quick response can be maintained without being affected by external temperature and humidity.
The power supply to the drive circuit and control circuit is provided by a stable circuit with a large current capacity. Moreover, by providing sufficient temperature compensation, stability of rotation against fluctuation of power supply voltage and stability index with high temperature drift and time drift can be obtained.
The turntable has a precisely machined inertial mass of 280kg-cm.2Large turntables have been adopted.
Stroboscopic lighting is lit by a special waveform shaping circuit and is easier to see than general stroboscopic lighting.
The turntable and control part are separated to increase the freedom of installation.
It boasts durability that can be used without oil for 10,000 hours.
Fine speed adjustment of ± 6% is possible for each rotation speed independently.
There was a special cabinet sold separately.
Model Rating
Type | Phono motor |
Motor | Brushless DC servo hole motor |
Drive system | Direct drive |
Turntable | 34 cm aluminum die-cast, outer circumference acrylic resin |
Turntable inertia mass | 280 kg / cm2 |
Number of revolutions | 33 1/3, 45 rpm |
Rotational speed adjustment range | + / - 6%, independent adjustment for each speed |
Speed change | Electronic |
Startup time | 1/2 rotation, within 1.5 seconds |
Uneven rotation | 0.03% or less (WRMS) |
S/N | 60 dB or more |
Temperature drift | 1% or less at -5 ° C to 55 ° C |
Time drift | 0.1% or less at 30 min start-up |
Power supply voltage | 100 VAC, 50Hz/60Hz |
Power consumption | 7.5W maximum |
Maximum external dimensions | Motor Part : Diameter 352x Height 120 mm Control : 80 mm wide x 68 mm high x 130 mm deep |
Sold Separately | Dedicated Cabinet JP-C1800 (¥ 20,000) |