Sony ps-fl77 (1983)

A front-loading, linear tracking turntable with fully automatic operation and electronic biotracer tone arm control.

Overview

The Sony PS-FL77 is a linear tracking, fully automatic turntable released in 1983. It loads from the front. You push the record vertically into a slot, and one start button runs the whole playback sequence. The electronically controlled biotracer tone arm uses a velocity sensor to detect tracking error and corrects it in real time. That cuts the error to one-tenth that of a conventional offset arm. It also has a quick repeat function, optoelectronic disc size detection, and safety mechanisms to prevent improper operation.

Specifications

Drive system	Direct drive
Wow and flutter	0.025% WRMS
Signal-to-noise ratio	75dB(DIN-B)
Start-up characteristic	Within 2/3 Rotation (at 33 1/3rpm)
Tone arm type	Linear tracking biotracer (electronically controlled tone arm)
Tone arm effective length	100mm
Tone arm total length	170mm
Needle pressure	1.25g fixed
Cartridge type	MM Type (XL-250G, plug-in connector type)
Cartridge frequency characteristic	20 Hz to 20 kHz
Cartridge output voltage	5mV
Needle	0.6 mil-round diamond
Cartridge dead weight	6.0g
Exchange needle	ND-250G(¥3,500)
External dimensions	Width 355 x Height 90 x Depth 370 mm
Weight	7.0kg
Turntable diameter	29 cm Aluminum Die Cast

Design

The PS-FL77 tracks linearly. Its electronically controlled biotracer tone arm corrects tracking error continuously through feedback to the drive motor. For loading, the turntable retracts and the record goes in vertically. A Linear BSL motor drives the platter, and an optoelectronic disc size selector detects the record diameter on its own. The cabinet is made of SBMC material for internal damping. Every control except power is a feather-touch key switch. A muting circuit cuts the output until the needle settles. A safety mechanism keeps the tone arm from dropping when there is no record. If something blocks the loading path, the unit halts and reverses. A separately sold remote control lets it play in sync with Sony cassette decks. The cartridge connects through a standard plug-in connector, so swapping cartridges is easy.