YAMAHA P-950

Commentary

This record player was released as a high-end model of the P series.

Equipped with one touch automatic music selection mechanism with built-in optical inter-track sensor.
The P-950 uses a special cartridge CG-8000 with built-in optical optical sensor that detects the inter-track portion of the record. You can automatically select a song from the first to the eighth song you want.
This function is not available if the dedicated cartridge CG-8000 is not used.

Equipped with a full auto function controlled by a microcomputer, the operation such as auto lead-in, up / down, Oatley turn, Oatley peat and auto cut is controlled by a computer.
Auto Lead-in is operated by a photo-sensor consisting of three photo-interrupters fixed to the cabinet and a logic shutter fixed to the tone arm. The built-in computer processes the 3-bit signal emitted from the photo-interrupter regardless of the position of the tone arm, and smoothly controls the tone arm to the specified position. This photo-sensor also detects the rest position and return zone of the arm. As the detection operation is optical, there is no adverse effect on sound quality.
In addition, the Oatley turn is a speed detection type that takes advantage of the large pitch of the lead-out groove of the record. The speed signal generated by the speed detection coil built into the arm drive motor is always sent to the microcomputer. When the speed of the arm increases in the return zone, it is detected and the return operation is started.
Other than that, Up down of tone arm and manual access of right feed and left feed are also possible.

The tone arm uses an ARS (Anti Resonance Straight) arm that was developed with the aim of eliminating resonance.
By adopting a structure that is symmetrical with respect to the support axis, this arm eliminates the torsional vibration that occurs structurally in S-shaped and J-shaped arms. In addition, in order to ensure stable support of the tone arm, the span between the pivots is widened to suppress unnecessary vibration in this part. In addition, the bearing has a structure that supports the angular contact bearing with a rubber damper, which improves the sensitivity of the arm and eliminates friction.
By moving the balance weight closer to the fulcrum and forming it into a large rectangular shape, when vibration occurs in the arm, it becomes large hand force and vibration level is minimized. In addition, by making the pipe holder large and robust and making it into a double structure up to 30 mm from the fulcrum, rigidity is increased to cope with flexural vibration of the front and back of the pipe.
The effective length is designed to be 222 mm in consideration of harmonic distortion and rigidity. The low-frequency resonance frequency was set to 12 Hz after measuring the playback spectrum of direct-cutting records and finding that the spectrum of the music signal crosses over at about 12 Hz with the warping and eccentricity components. Furthermore, focusing on the fact that the low-frequency resonance frequency is influenced by the combined cartridge weight and compliance value, the arm is designed after examining the mass and dynamic compliance distribution of 20 MM/IM type cartridges and 10 MC type cartridges.

The needle pressure application method employs a sliding weight method in which a counter weight is mounted on the arm shaft and is slid back and forth to adjust the needle pressure. This method is easy to adjust, and since the needle pressure is proportional to the effective mass of the arm, it can be applied to low-compliance type cartridges such as MC type.

The head shell is an integrated resin molding type with carbon fiber for high rigidity and high lead-in position accuracy. The terminal is silver plated with surface contact.

The Tone Arm's drive system uses a computer-controlled coreless direct drive motor.
This direct drive system is a non-contact drive system, and since there are no gears or pulleys in the driving force transmission part, mechanical noise is not generated and durability is excellent.

It is equipped with a fail-safe function using a microcomputer to deal with operational errors.
When the left and right arms are stopped by external force, it automatically stops after 0.5 seconds.
Gives priority to safer action than pressing two or more buttons. The priority order is Cut-Left/Right-Up/Down-Play.

A DC4-phase 8-pole coreless Hall motor is used as the drive motor.
This motor has no cogging in principle, and is a non-contact type using a Hall element, so mechanical and electrical noise is minimized.

The servo circuit uses a quartz PLL servo that controls with the accuracy of the crystal.
In this circuit, the rotation speed of the turntable is detected by an all-around integration type FG (frequency generator), and highly accurate rotation is obtained by comparing the phase with the signal from the crystal oscillator.

The cabinet is made of BMC material and uses a 3-mm-thick acrylic resin dust cover and a special rubber W-shaped fold-back insulator to improve the howling margin.

Model Rating

Type	Record player
Signal-to-noise ratio	77 dB (DIN-B, IEC 98A weighted)
Wow flutter	0.015% (FG Direct) 0.025% (test record method)
Arm Total Length	290mm
Effective arm length	222mm
Effective mass	Needle Pressure Proportional Type (Needle Pressure 1.5g : 11g)
Arm lifter	Operation by dedicated motor
Muting	Arm lifter interlock
Anti-skating	Rotary Operated Spring Lever Type
Compatible Cartridge	2.5g ~ 10g
Head shell	Attachment
PU cable	Capacity : 100 pf Reciprocating resistance : 1 Ω
Full automatic control	Microcomputer control (manual operation possible)
Horizontal drive of the arm	Microcomputer-controlled DC coreless motor DD
Rotating system	DC4-phase 8-pole coreless Hall motor DD
Servo system	Quartz rock
Number of revolutions	33 1/3rpm, 45 rpm, with LED lock indicator
Turntable	30 cm Aluminum Die Cast, 1.6 kg (Including Rubber Sheet)
Cartridge	CG-8000
Cabinet	BMC(Bulk Molding Compound)
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption	10W
External dimensions	Width 440x Height 132x Depth 376 mm
Weight	7.5kg