Audio Database


Pioneer PL-31 PL-31: 37,500yen(? at the 1960 in-the-late time)
processor-unit-31: 32,000yen(? at the 1960 in-the-late time)

The stereo record player which adopted the belt drive.

The synchronous motor is adopted as a motor and the polyurethane system belt is used for a rubber belt.

There was player unit processor-unit-31 of only a mechanism without a cabinet.


Rating of a mode
Form Record player
Auto organization Motor electric auto switchpoint
Tone arm rise-and-fall organization
Motor 4 pole synchronous type
Turntable The product made from diameter aluminum alloy die-casting of 30cm (weight of 1.2kg)
Rotation unevenness 0.12% or less
SN ratio 45dB or more
Rotational frequency 33 1 / 3 or 45rpm
Cartridge man-month type (PL-C9)
Needle 0.65mil diamond needle
Frequency characteristic 15Hz-21kHz}2dB
Channel isolation 30dB or more (1kHz)
Output voltage 5mV (1kHz, 50 mm/s)
Output balance 1dB or less (1kHz, 50 mm/s)
Direct current resistance 500ohms
Load resistance 50kohm
Needle point compliance 12x10 to 6 cm/dyne
Tracking error }1 degree
Proper stylus force 2g-3g
Tone arm Light metal static balance type pipe arm
Main-with stylus-force Direct-reading gage wait
Stylus-force variable possible span 0-4g
Switching needle Diamond needle for stereos PL-N9 (2,500yen)
Power source AC100V, 50Hz/60Hz switching type
Dimensions PL-31: Width 460x height 166x depth of 360mm
processor-unit-31: Width 410x height 150x depth of 315mm