This is as close as Sony ever got to producing a Walkman for LP records and 45 rpm singles. The bulk and sensitivity to shock made the medium unsuitable for mobile use but the PS-F9 was nevertheless battery operated and played through stereo headphones, making it a clear member of the Walkman family.
In simple terms the PS-F9 was a direct drive turntable with a linear tracking tonearm, like so many others in the Sony range. To make it usefully portable the turntable itself had been shrunk down to a hub about the same size as a record label onto which the record was securely held by a motorised clamp. Despite the machine being both small and restricted to a limited source of power the turntable motor was still quartz locked, an impressive feat given all the other engineering problems that also had to be solved.
The stubby tonearm and its moving magnet cartridge were completely contained inside the machine and were drawn across the record by a motor and cord drive. Cueing and search controls allowed any track of an LP to be found quickly and easily. Records could be played with the machine in either a vertical or a horizontal position with equal ease, for vertical use a set of small feet could be splayed out at the base as an aid to stability.
The built-in equaliser and amplifier allowed two pairs of headphones to be used, there was also an equalised line-level output for use with an external amplifier or tape recorder (the instructions showed a WM-D6C!). Although not especially popular at time or practical the PS-F9 is a very good example of Sony’s engineering ability in the early 80s, it is unlikely that they would be capable of producing such a machine today.
You can take the PS-F9 with you anywhere, since the set is compact and lightweight, and operates on batteries. Its smart, innovative design allows it to be used standing upright, lying down or hanging on a wall.
The linear torque BSL (brushless and slotless) direct drive servo motor has a high signal-to-noise ratio.
The turntable maintains an accurate and drift-free speed by referring to a frequency generated by a very stable quartz oscillator.
When you select the record size and speed and set the record in the disc holder, automatic record play and stylus up/down are operated by the “feather-touch” function buttons. When the play is finished, the tonearm automatically returns to the rest position.
A muting system activates when the tonearm is lifted and is deactivated after the tonearm lowers onto a record so there is no need to turn the volume down every time the stylus is placed on a record.
A record cleaning brush built under the tonearm cleans the surface of the record while it is playing.
Drive system: direct drive
Motor: linear torque BSL (brushless and slotless)
Control system: quartz lock variable reluctance control system
Platter: 91.5 mm strontium-ferrite
Speeds: 33, 45 rpm
Wow and flutter: 0.06% wrms
Signal to noise ratio: 62 dB
Tonearm: dynamic balanced, linear tracking, low mass type
Pivot to stylus length: 37.5 mm
Dimensions: 108 x 263 x 73mm
Weight: 1.7 kg inc batteries
Automatic system: lead-in, return, reject, arm up/down