Sony ps-x40 (1978-1981)

Name: Sony ps-x40
Brand: Sony

Direct-drive turntable with quartz-locked speed control and full automation, introduced in 1978 as part of Sony's high-end lineup.

Overview

The Sony PS-X40 is a full-auto direct-drive turntable developed using technology from higher-end Sony models, released in September 1978 as part of a new line of larger, futuristic-looking turntables. It features the Crystal Lock D. D. Full Auto Player System with a brushless slotless linear motor and magnedisc-controlled quartz lock speed regulation. Marketed as an "entry level high end" model, it sits between the PS-X7 and PS-X70 series in Sony's 1978 lineup and was phased out by 1981 when Sony shifted to smaller, cost-reduced designs.

Specifications

Production Years	September 1978 – 1981
Platter Diameter	320mm aluminium alloy diecast
Platter Weight	2.2kg
Wow and Flutter	0.025% wrms
Signal-to-Noise Ratio	73dB (DIN-B)
Start-up Time	Within 1/2 rotation (at 33 1/3rpm)
Drift Time	0.0003% / h or less
Tonearm Model	PUA-7
Tonearm Type	Static-balanced, J-shaped aluminium
Tonearm Effective Length	216.5mm
Tonearm Overhang	16.5mm
Needle Pressure Range	0 – 3g (0.1g interval)
Cartridge Type	MM (XL-15)
Cartridge Output Voltage	4 mV (1 kHz, 5 cm/s, 45°)
Cartridge Frequency Response	10 Hz – 30 kHz
Cartridge Needle	0.6 mil diamond
Headshell Weight	10.5g (SH-145)
Usable Cartridge Weight	12g – 19g (24.5g with auxiliary weight)
External Dimensions	445mm (W) × 145mm (H) × 400mm (D)
Weight	Approx. 8 kg
Original Price	¥49,800 (1979)

Design

The PS-X40 uses a brushless slotless linear (BSL) motor with a magnedisc speed detection system: 512 magnetic pulses on the platter rim are read by an 8-pole monitoring head, enabling quartz-locked precision with a drift of 0.0003% per hour or less. The tonearm is a J-shaped, static-balanced PUA-7 model made of high-tensile aluminium tubing with a claimed eightfold increase in stiffness over earlier Sony arms, mounted on a cast zinc alloy base. It lacks VTA adjustability. The plinth is constructed from Sony Bulk Moulded Compound (SBMC), and isolation is provided by viscous, gel-filled damping feet. Front-panel controls operate with the dust cover closed, and the turntable includes electromagnetic quick-stop braking, an illuminated stroboscope, and full automation with electronic memory circuitry that disengages if the arm is obstructed.

Context

Introduced in 1978, the PS-X40 competed in a market dominated by quartz-locked, direct-drive Japanese turntables like the Technics SL-1200 and Linn Sondek LP12. It shared technology with higher-end Sony models and was succeeded by smaller, cost-reduced designs by 1981, marking Sony's exit from the serious turntable market.

Market

As of ~2018, a decent example could fetch over £250. Common issues include motor failure ("dying motor"), electrical or grounding problems, and very low output. Owners praise its reliability and sound quality, noting powerful bass, clean mids, and a broad soundstage, though some find the plinth slightly plasticky compared to rivals like the Technics SL-1200.