SANSUI XR-Q7

Commentary

A record player with a silent sync rotor.

In addition to adopting a direct drive system for the drive system, a new technology, Silent Synchrotor, has been incorporated to eliminate torsional vibration of the cabinet.
In the direct drive system, because the motor, the driving source, is located almost in the center of the cabinet housing, a rotational force is generated in the cabinet, which is the reaction of the motor drive. This is the same phenomenon that occurs when the helicopter starts rotating in the opposite direction to the rotor rotation when the helicopter leaves. If the motor does not rotate unevenly, there is no problem. However, there is actually rotation unevenness due to load fluctuation during Mura-ya record tracing. To eliminate this rotation unevenness, the motor torque fluctuation is generated by the servo, and as the reaction, torsional vibration is generated in the cabinet in the rotational direction. Therefore, the stronger the servo effect, the larger the reaction, and the torsional vibration of the cabinet increases.
The silent sink rotor generates torque in the opposite direction equal to the torque fluctuation of the turntable in the sink rotor, and combines the reaction of the turntable and the reaction of the sink rotor to eliminate the vibration of the cabinet. This reduces the rotational vibration level of the cabinet to less than 1/4 of that when the silent sink rotor is turned off.

The drive motor is equipped with a newly developed FF coreless motor that solves the problems of conventional coreless motors.
In conventional coreless motors, since the stator is made of magnetic material, a strong suction force acts between the stator and the magnet attached to the rotor, and strong mechanical friction is generated in the bearing. In addition, when the magnetic pole runs on the stator made of magnetic material, the rotor is dragged by a hysteresis phenomenon. Since the stator is made of conductive material, there are other problems, such as the braking effect caused by eddy current loss.
In the newly developed FF coreless motor, the stator is made of non-magnetic material, and the yoke rotor, which forms the magnetic circuit, is fixed to the spindle and rotates in the same manner as the rotor magnet. Therefore, there is no suction force between the stator and the magnet, and no pressure is applied to the bearing. In addition, the yoke rotor, which forms the magnetic circuit, rotates together with the magnet, enabling ideal operation without magnetic hysteresis or eddy current.
In addition, we aim for smooth and ideal rotation by adopting a linear drive system.

A quartz lock system is adopted, and excellent characteristics are obtained by coating the turntable with a precise magnetic pulse of 960 poles while reviewing the bare characteristics of the motor.

An optimum support point arm (Dynaoptimum Balanced Tonearm) is adopted for the tone arm part.
The optimum support point arm has a structure in which the pivot shaft is placed on the dynamic support point, and vibration picked up from the needle tip is not transmitted to the pivot, and vibration from the outside is not transmitted to the needle tip, thus improving the tracing capability.
In addition, the tone arm of the XR-Q7 is made of carefully selected materials. The arm base is made of zinc die-cast, the arm pipe is made of brass, and the head shell is made of aluminum die-cast. This is a highly rigid design.

The pipe of the tone arm part can be replaced at the root of the arm base, and the straight arm with fixed head shell as standard equipment and the S-shaped tone arm with universal connector can be replaced.
The height adjustment is ± 3 mm so that it can be adjusted according to the cartridge.

Equipped with photoelectric detection type non-contact full auto mechanism controlled by 4-bit microcomputer, each auto operation of auto lead in, Oatley turn, auto cut and auto repeat is possible.
Manual operation can also be performed without switching. The turntable rotates when the arm is moved from the arm rest by hand, and the tone arm can be moved up and down with the Up/Down keys.

As a protective function, if the tone arm is intentionally stopped during auto operation or if the power supply is turned off with the tone arm on the record board, all operations will be stopped after 20 seconds. If the power supply is turned off with the tone arm on the record board, the tone arm returns to the time of trouble at the next power supply ON and stops in the return after lowering.

High-density materials with high rigidity and little deformation are used for the cabinet to reduce the influence of howling and external vibration.

The composite resin is used for the material of the turntable sheet.
This is fixed to the aluminum die-cast turntable, and there is no deterioration of sound quality due to slight displacement from the turntable sheet.

Model Rating

Type	Record player
Drive system	Electronically controlled direct drive
Motor	Quartz PLL servo FF coreless motor
Number of revolutions	33 1/3, 45 rpm
Turntable	33 cm aluminum die-cast, 1.7 kg
Wow flutter	0.009% or less (WRMS)
Signal-to-noise ratio	80 dB or more (DIN-B)
Start-up characteristic	1 second (120 °) at33 1/3rpm
Rotational speed deviation	± 0.002%
Temperature characteristic	0.00003% / ° C
Load characteristic	0%
Tone arm	Static balance type optimum support point system straight arm
Effective length	245mm
Overhang	16mm
Offset angle	22 °
Applicable Cartridge Dead Weight	4g ~ 9.5g
Height adjustment range	+ / - 3 mm
Full auto mechanism	Auto lead in Auto return Autorepeat With Manual Lifter
Rated power consumption	8W
External dimensions	Width 490x Height 180x Depth 430 mm
Weight	11kg
Attachment	Universal S-shaped interchangeable arm Main Weight for S