YAMAHA YP-D7

Commentary

This direct drive player was developed with an emphasis on three points : accurate rotation, high sensitivity, and ability to block harmful vibrations.

A DC Hall motor with a starting torque of 1 kg ・ cm is used for the drive part.
In addition, by adopting a newly developed FG (frequency control) servo circuit, the accuracy and response speed of the servo circuit are improved, and quick response to dynamic load fluctuation is obtained.

The turntable uses a 30 cm aluminum die-cast turntable with accurate dynamic balance from the mold stage.
This turntable has an inertial mass of 270 kg ・ cm including the rubber sheet by taking a large thickness of the outer circumference.²For the first time.

The power supply section uses a power supply circuit with a constant voltage feedback circuit that maintains the voltage of 24 v even when the output current of 800 ma flows.

A newly designed aluminum S-shaped pipe arm is used for the tone arm. The pipe of this arm is filled with a special filler to prevent sound quality deterioration due to pipe resonance.
In addition, in order to realize high sensitivity, the gimbal support system has a double structure for vertical and horizontal rotation of the rotating shaft, and high sensitivity is realized by accurately holding the rotating shaft with the pivot. In addition, the pivot is made of chromium molybdenum steel with high hardness and smooth contact, which is sufficiently polished to realize high precision holding capacity and durability, and high sensitivity of 3 mg initial motion sensitivity in both horizontal and vertical directions has been obtained.
The inside force canceler uses a counter weight method for fine adjustment according to the needle pressure, and the queuing lever uses an oil dump method.
Special extremely thin and flexible lead wires are used for the wiring material so that it does not hinder the high sensitivity of the arm.

Magnesium is used for the head shell to reduce weight. Although the Young's modulus of magnesium is 60% of that of aluminum, the thickness of magnesium can be increased as much as it is lighter, and the rigidity is 1.5 times higher than that of aluminum.

Equipped with a 6 mm stroke elevation ring rotary arm height adjustment mechanism, it is compatible with most commercially available cartridges.
Since this mechanism is a tight lock type, after adjustment, it is fixed instead of a point after adjustment, making the structure resistant to vibration.

The cabinet is layered with the same high density conifer particleboards as the NS 690 II.
In addition, the arm stand and arm base are made of 1 kg zinc die cast and are firmly fixed from the root of the arm.

The insulator uses a new material with a double structure.

The dust cover is made of acrylic styrol.

Model Rating

Type	Record player
<Turntable portion>
Motor	12-pole 24-slot FG servo DC hall motor
Drive system	Direct drive
Turntable	30 cm aluminum die-cast, 1.6 kg
Wow flutter (WRMS)	Not more than 0.03%
Signal-to-noise ratio	62 dB or more
Rotational speed adjustment	+ / - 3%
Number of revolutions	33 1/3, 45 rpm
Tone Arm Section
Tone arm	S-shaped static balance gimbal support arm
Effective arm length	232mm
Overhang	16.0mm
Arm stand base	Zinc Die Cast 1 kg
Arm elevation	+ / - 3 mm
Anti-skater	Roller string counter weight system
Arm lifter	Oil dump system
Head shell	Magnesium die cast, 11g
Weight range of the mounting cartridge	2g ~ 16g
Body Part
Body Type	Solidboard
Body Material	High-density conifer particleboard
Finish	Black paint
Dust cover	Acrylic styrene polymers and copolymers Made
HINGE	Fleece Top Removable
Insulator	Height Adjustable 2-Level Type
<General>
Power supply voltage	100 VAC, 50Hz/60Hz
Rated power consumption	5W
External dimensions	Width 470x Height 155x Depth 378 mm
Weight	14kg