Sony PS-LX7 (1981)

Name: Sony ps-lx7
Brand: Sony

A compact, full-auto direct-drive turntable with quartz-locked speed stability and integrated MM cartridge

Overview

The Sony PS-LX7 is a quartz lock direct-drive full auto turntable released in 1981, designed to match the unified dimensions of Sony's Liberty Series components. It features a fully automatic playback system with electronic speed change for 33-1/3 and 45 rpm records, and includes an integrated Iori-branded XL-200 MM cartridge with a 0.6 mil-round diamond stylus. The unit emphasizes precision and low noise, using advanced motor and speed control technologies for its time.

Specifications

Drive method	Direct Drive
Motor	Linear BSL motor
Wow and flutter	0.02% WRMS
Signal-to-noise ratio	75dB(DIN-B)
Rumble	-78 dB (DIN B)
Tone arm type	Static balance type
Tone arm effective length	200mm
Tone arm total length	250mm
Overhang	15.5 mm
Tracking error angle	Within 2° 32' per channel
Needle pressure adjustment range	0 ~ 2.5g
Usable cartridge weight range	0 ~ 11.5g (including shell)
Cartridge type	MM Type (XL-200, Shell Integrated Type)
Cartridge frequency characteristic	10 Hz to 30 kHz
Cartridge output voltage	3 mv (1 khz, 5cm/s, 45 °)
Cartridge needle	0.6 mil-round diamond
Exchange needle	ND-200G(¥3,500)
Cartridge dead weight	8.2g
Platter/Turntable diameter	29.5 cm Aluminum Die Cast
Speeds	33-1/3 and 45 rpm
Speed change	Electronic
External dimensions	Width 355 x Height 82 x Depth 330 mm
Weight	5.5kg

Design

The PS-LX7 uses a 3-stage rotating system composed of a linear BSL motor, a magne-disk speed detector, and quartz lock technology to ensure stable, quiet rotation with minimal wow and flutter. The linear BSL motor eliminates cogging for smooth, efficient operation with high torque. Speed detection uses a multi-gap head reading high-density magnetization on the turntable to detect minute rotational changes. Quartz lock leverages the high oscillation accuracy of quartz to maintain stable speed despite temperature or power fluctuations. The tonearm is a static balance type with a low-mass straight design, paired with the Iori XL-200 high-compliance MM cartridge. Front-mounted feather-touch controls allow operation with the dust cover closed. A contactless luminous sensor enables end detection without applying lateral pressure to the stylus, and a muting mechanism reduces contact noise. An opto-electronic disc size selector automatically detects record size for accurate tonearm lead-in.

Context

The PS-LX7 was designed as a compact full-auto player with dimensions unified to match other components in Sony's Liberty Series, allowing for integrated system setup.