Remarks:
Anno 1978, the PS-X 7 was the largest fully automatic turntable at Sony, next to the large Sony PS-X 9, which was also offered as a studio turntable.
The chassis was made of the low-resonance SMBC material in (plain) grey. This is an extremely hard mixture of PVC, aluminum, and yet another material that Sony is silent about. It is harder than some metals, I -Phonogen - found out when installing a new (thicker) cable.
Fully-Automatic Direct-Drive Turntable (1977-1978)
Made in: Japan
Color: Silver / Grey
Platter: 317mm aluminium alloy die-cast
Motor: DC servo controlled
Drive system: direct drive with crystal lock system
Speeds: 33 and 45rpm
Wow and flutter: 0.025% WRMS
Signal to noise ratio: 73dB
Tonearm: static balance
Effective length: 216.5mm
Overhang: 16.5mm
Tracking force adjustment: 0 to 3g
Cartridge weight range: 2.5 to 9.5g (8 to 14.5g with weight)
Dimensions: 445 x 150 x 375mm
Weight: 10.9kg
Original price approx.: 350 US-$, 1'100 DM, 1978
https://www.vinylengine.com/library/sony/ps-x7.shtml