SONY PS-B80

Commentary

A full-auto player system equipped with an all-electronic tone arm "Biotracer".

It is equipped with a biotracer that electronically controls all the complicated movements of the tone arm.
In the biotracer, a speed sensor, a position sensor and a linear motor are installed in the vertical and horizontal directions of the arm, respectively. The signals detected by the two sensors are sent to a servo amplifier, which supplies the necessary current to the linear motor and controls the movement of the arm. The speed sensor works to smooth the movement of the arm and at the same time improve the acoustic characteristics such as resonance and inside force. The position sensor works in conjunction with a 128 word x4-bit microcomputer to operate the arm such as full auto operation, needle pressure adjustment and inside force cancellation. It usually makes several hundred logical judgments for each movement, checks the arm position, speed and status of each operation switch, and processes commands at a speed of less than 1/1000 second.
With this biotracer, it is possible to suppress the peak of the low-frequency resonance frequency (fo) within 3 dB regardless of the type of cartridge used, and crosstalk is also improved.
It is also strong against warping of records, improved wow flutter, and strong against howling.

Auto lead in / Oatley turn is possible, and each time is set to ergonomically pleasant 6 seconds.

Equipped with a photoelectric record size selector, it automatically detects the size of the record (30 cm, 17 cm).
If you press the start button without setting a record, the needle returns without dropping.

Equipped with auto-repeat function.

The needle pressure can be adjusted simply by controlling the front panel knob, and the applied needle pressure value is digitally displayed.
In addition, the anti-skating force corresponding to the needle pressure is calculated and automatically applied to the arm.

An electronic non-contact mechanism is adopted.
In addition, it has a built-in muting mechanism linked with the arm lifter to eliminate the shock noise when the needle tip touches the record.

In addition to general full auto operation, auto operation of tone arm only and turntable only is possible.

It has a simple linear BSL (slotless) motor that does not require a brush or slot.
By eliminating the slots that cause cogging, torque unevenness is minimized and smooth and quiet rotation is achieved. In addition, high torque is obtained due to high efficiency, and reliability and durability are also improved.

The velocity detection unit of the servo system uses a magnet-disk velocity detection system. The inner wall of the outer circumference of the turntable, which has a wide rotating area, is coated with magnetic material. The detection signal of 512 waves is magnetized, and the average value is detected by the multi-gap head, and the control command is sent to the servo system.
Since this method has a high signal frequency of approximately 284 Hz at 33 1/3rpm, servo compensation can be performed up to relatively high frequencies of the flutter components.

Magnedisk A crystal lock is adopted by adding a phase control circuit of crystal oscillation to the detected speed servo circuit. By phase locking the detected signal, not only initial drift due to self-heat generation of the body, but also rotational speed deviation due to voltage fluctuation due to self-heat generation and rotational speed decrease due to needle pressure load are reduced, and excellent rotational characteristics are obtained.

The neck cylinder part, which is the joint part between the head shell and the arm pipe, holds the tip of the shell plug against the slope facing the bottom of the neck cylinder with a strong force due to the wedge effect. In addition, the locking nut is pushed forward by the reaction, and the root of the shell plug is tightened firmly from 4 directions.
As a result, two parts of the front and back are held in a ring shape by one operation, preventing mounting looseness.

The arm pipe is made of a special aluminum alloy with greatly increased rigidity, and by adopting a J-shape with high bending strength, rigidity approximately 8 times that of conventional aluminum pipe is obtained.
In addition, by adopting an integrated structure from the neck cylinder section to the bearing section, unnecessary joints are eliminated and resonance factors caused by joint looseness are eliminated.

The bearings use a Longs pan bearing shaft supported by a single straight shaft to prevent play caused by ball bearings. This minimizes movement at the operating point.
In addition, a tapered mirror finish of hardened cemented carbide with a diameter of 5 mm is used for the pivot shaft to improve contact with precision radial bearings and provide high rigidity support.

Model Rating

Type	Crystal Lock D. D. Full Auto Player System
<Turntable portion>
Turntable	32 cm Aluminum Die Cast
Start-up characteristic	Within 1/4 Rotation (at 33 1/3rpm)
Wow and flutter	0.02%wrms
Signal-to-noise ratio	78dB(DIN-B)
Tone Arm Section
Effective length	235mm
Total Length	325mm
Needle pressure adjustment range	0.5g ~ 3.0g
Shell dead weight	11.0g
Usable cartridge weight limit (including shell weight)	12g ~ 23g (No Auxiliary Weight) 23g ~ 34g (Auxiliary Weight Used)
<General>
External dimensions	Width 500x Height 175x Depth 430 mm
Weight	Approximately 15 kg
Attachment	45 Rotation Adapter Auxiliary weight DRIVER Head shell Cartridge mounting screw