Sony ps-x50 (1978-1981)

A direct-drive turntable from Sony's PS-X series, known for precision engineering and high build quality.

Overview

The Sony PS-X50 is a semi-automatic direct-drive turntable built from 1978 to 1981. It came in standard and wood-grain (PS-X50W) finishes. It shares core technology with the flagship PS-X70 but leaves out full-auto operation, pitch control, Litz wiring and the carbon-charged tonearm. The design goes after resonance, with a die-cast aluminum platter, gel-filled insulator feet and an SBMC cabinet. It became one of Sony's bestselling turntables and is counted as part of a legendary product line in the company's history.

Specifications

Product type	direct-drive turntable
Production years	1978 - 1981
Original price	PS-X50: ¥54,800; PS-X50W: ¥59,800
Wow and flutter	0.025% wrms
Signal-to-noise ratio	75dB (DIN-B)
Speed accuracy	±0.003%
Turntable platter	32 cm Aluminum Die Cast
Platter weight	2.2 kg (Including Rubber Sheet)
Moment of inertia	340 kg/cm²
Start-up characteristic	Within 1/2 Rotation (at 33 1/3rpm)
Drift time	0.0003% / h or less
Motor	BSL motor
Control system	Magnedisc servo control / X-tal lock
Operation	Semi-automatic
Tone arm effective length	235 mm
Tonearm total length	330 mm
Arm height adjustment range	± 3 mm
Needle pressure adjustment range	0 ~ 2.5g (0.1g interval)
Anti-skating range	0...2.5g
Tonearm balance	static
Overhang	14 mm
Cable capacitance	50pF/m
Included cartridge	MM Type (XL-25A)
Cartridge frequency characteristic	10 Hz to 30 kHz
Cartridge output voltage	4 mv (1 khz, 5cm/s, 45°)
Cartridge needle	0.3x0.8 mil Diamond Oval Needle
Cartridge dead weight	5.2g
Shell dead weight	11.0g (SH-155)
Usable cartridge weight limit (including shell weight)	11.0 ~ 19.5g; 19.0g ~ 27.5g (Auxiliary Weight Used)
Tonearm	PUA-7
Tonearm base material	Zinc alloy
Cabinet	SBMC cabinet
External dimensions	Width 480 x Height 165 x Depth 420 mm
Weight	Approx. 11.5 kg
Attachments	45 Rotation Adapter, Auxiliary weight, Head Shell (SH-155), Cartridge (XL-25A)

Design

The PS-X50 fights resonance with a die-cast aluminum platter, gel-filled rubber insulator feet and an SBMC cabinet. The motor is a slotless BSL type with no brushes and no slots. Speed detection is Magne-disk: 512 magnetic signals on the platter's inner wall generate a 284 Hz signal at 33 1/3 rpm. A crystal oscillation phase control circuit locks the speed. The PUA-7 tonearm is J-shaped and made of a special aluminum alloy with 8x the rigidity of conventional arms. It has static balance, direct-read anti-skating and viscous damped cueing. The pivot shaft is a 5 mm hardened cemented carbide with a tapered mirror finish, supported by a single straight Longs pan bearing. The tonearm base is zinc alloy, and the shell plug is secured with a four-point wedge-locking system.

Context

The PS-X50 and the PS-X70 started Sony's PS-X series, which later added models like the PS-X60 and PS-X40. The PS-X50 was one of Sony's bestselling turntables, part of one of the most widely sold Japanese turntable lines, with tens of thousands reportedly in circulation. Sony's brand history lists it under "Legendary Products."