SANSUI CD - α 907

Commentary

A CD player with Sansui's traditional technology and vibration control.

SF (Solid & Flex) mechanism is adopted for the mechanism part.
The SF mechanism has a double structure consisting of a mechanical chassis and a play chassis. The mechanical chassis is firmly fixed to a solid chassis. The play chassis is also floated from the mechanical chassis by a double suspension consisting of an oil dump-type NR damper and a stainless steel coil damper. Each chassis is made of a newly developed copper-clad material, in which 40 μ m copper plates are molecularly bonded on both sides of a steel plate, to improve vibration resistance.
The tray is made of BMC material for high rigidity and high accuracy. It is also equipped with a center guide with built-in coil spring and a CD centering function with a magnet clamper. In addition, attention is paid to details such as a turntable made of special material with high friction coefficient that accurately holds the CD when rotating, and a 4-point disk supporter that protects the CD.

The servo circuit uses the NEW Sansui Dynamic Servo System, which was developed using the know-how of VFD (video film disk) development.
This circuit smoothly controls the four servos (tracking, focus, CLV, and feed) to achieve higher stability than before.

A specially developed brushless and slotless motor is used as the drive motor.
Excellent rotational performance has been obtained by the adoption of 3 mm diameter motor shaft and die-cast housing.

The pickup part uses an original 3-beam system pickup.
In this pickup, the spot interval between the three beams is set at 16 μ m, which improves the stability of the trace and enables quick response to scratches and dirt on the disk.
In addition, in order to increase the tracing capability, the support part of the pickup has been strengthened, and the rail support part where the pickup part moves is made to be die-cast structure, and moreover, it is made to be wide span, so that the stable operation of the pickup part is possible.

The digital filter employs a 4 x over-sampling digital filter with less passband ripple and pre-echo and greater noise attenuation. By shifting the sampling frequency by 4 x to 176.4 kHz, digital noise is greatly attenuated.
In addition, low-pass filters with moderate characteristics can be used to improve sound quality.

The D/A converter uses a 16-bit linear-type twin D/A converter that is independent on the left and right. In combination with a third low-pass filter, it achieves excellent phase characteristics in the high-frequency range.

A master clock system is adopted to prevent beam generation due to clock asynchronous of D/A converter and LSI.

Photo isolation is used between the digital filter and the D/A converter.
For photo isolation, a high-speed photo coupler with excellent signal conversion characteristics is used after careful consideration of response speed and signal conversion efficiency. Digital signals are guided to the coupler and transmitted while converting the signal form from electrical signals to optical signals to electrical signals, thereby cutting off digital noise components.

Α -X balanced output is used for the output part.
In the α -X balanced output, the influence of common-mode noise is reduced by making the + side and - side of the signal path and grounding independent, and the output can be done without digital noise during transmission.

Equipped with balanced output terminal.

To order to avoid interference between the digital and analog sections and the drive section, the power supply section employs a 2-transformer, 4-power supply configuration in which the servo system, digital system and audio system are independent. This prevents noise from entering the audio system from the servo system and digital system.
It also has a built-in AC line noise filter.

The analog section after the D/A converter uses a discrete configuration using carefully selected high-performance materials to improve the sound quality.

A solid chassis is adopted for the chassis structure, and high rigidity is achieved by separating the mechanism, digital and analog sections with a high rigidity separator. This prevents external vibration and also prevents adverse effects of vibration generated by the mechanism. In addition, the high conductivity of the separator shuts out electromagnetic noise, reducing the influence of noise in the mechanism and digital sections on analog circuits.
In addition, the CD - α 907 has copper plating on the entire chassis for high shielding.

The CF5 (Chassis Fixed 5-point Support) insulator is used for the insulator. By supporting it with five large insulators, the load applied to the insulator is equalized, and the structure is resistant to external vibration.
In particular, the CD - α 907 is made of solid wood and the central insulator is made of a special material for compliance. Thus, excellent installation stability is achieved.
CF5 CF5 insulator is mounted directly on a solid chassis to improve the overall structural integrity.

Equipped with a digital output terminal.

It has functions such as 20 songs music calendar and 20 songs random program.

Wireless remote control is included.

Model Rating

Type	CD Player
Reading system	Noncontact optical
Pickup type	High-precision 3-beam semiconductor laser system
Number of revolutions	200 ~ 500 rpm
Number of channels	2 Channel
Sampling frequency	44.1kHz
Number of quantization bits	16-bit linear
Frequency characteristic	2 Hz to 20 kHz
Harmonic distortion factor	0.002%(1kHz)
Dynamic range	98dB
Wow and flutter	Measurement detection limit or less
Signal-to-noise ratio	106dB
Output voltage	Normal:2V Balance:2V
Rated power consumption	30W
External dimensions	Width 448x Height 98x Depth 405 mm
Weight	10.5kg
Attachment	Wireless Remote Control