What is stereo?




There are now two system of high fidelity, monophonic (monaural) and stereophonic. Monophonic is a system that starts from one microphone and is fed through a single high fidelity set. Stereophonic is a double system. Two separate microphones are placed at different sides of the orchestra and two different systems are used to keep the two signals or channels separated. Two separate speakers are used, placed on different sides of you room. Stereo is much like 3-D photography, two slightly different sound reach your ears giving you a new dimension in sound.




H.H. Scott '59





Sansui XP-99

A turntable's dreaded enemy is vibration. Sansui's exquisite new XP-99 vanquishes this villain completelyy, and in unusual ways, as you'll see. Vibration robs music of its immediacy by making sound dull and lifeless. This happens beacuse vibration, when allowed to reach the tonearm, alters the actual geometry between the stylus tip and the record groove during play. The XP-99 activly and passively suppresses vibration. Actively suppressing vibration is our revolutionary Silent Synchrotor System. It is assisted by our "friction-free" linear coreless motor, D-O-B straight tonearm and solid, anti-vibration cabinet. Just one listen will convince you that the XP-99 sounds far superior to all other direct-drive turntables. It offers better definition, greater musical sonority and aharper transients.

Silent Synchrotor System

Despite the tremendous improvements that the direct-drive turntable has brought to hi-fi, many "golden eared" audiophiles have noted that they sound distant, fuzzy and unfocused. We have proven that there is a grain of truth to this complaint. In most direct-drive turntables, the motor is located near the center of the cabinet . When the motor rotates the platter clockwise, it applies a torque to the cabinet in the same direction. To compensate and restore balance, the cabinet attempts to create counterclockwise torque. This leads to a serious problem.

All direct-drive motors "cog" that is , they imperceptibly speed up and slow down in a jerky manner as the servo system tries to compensate for wow and flutter and other speed irregularities. These minute speed variations cause matching variations in motor torque, which in turn set up variations in countertorque generated in the cabinet. These variations are turned into actual physical vibrations that eventually find their way to the stylus. It is these vibrations that cause sound to be fuzzy and unfocused, because they change the delicate geometric relationship between the record groove and stylus.

The Sansui Silent Synchrotor System has felled this shortcoming of direct-drive turntables in a single blow. The second motor is mounted directly below the main drive motor and ahares the same axis. Controlled by the same servo system as the main motor, it rotates in the opposite direction, creating torque which exactly offsets the countertorque created in the cabinet.

Friction-free linear coreless motor

The motor we use in our Silent Synchrotor System is of an entirely new, high-precision design called the 'friction-free linear coreless motor'. It was expressly developed to overcome problems encountered by conventional coreless designs: Mechanical friction at the bearing due to strong magnetic attraction between rotor and stator; Drag on the rotor by the stator; Breaking effect on the rotor caused by eddy currents in the stator.

All these problems lead to ubeven rotation and undue mechanical wear.

Our new linear coreless motor has extremely low friction for the attraction between the rotor and stator is very low. Both drag and breaking effect applied to the rotor are reduced because the yoke rotor and rotor are mounted on the same spindle. Indeed, the motor of the XP-99 presents such low friction that, when spun by hand it keeps rotating on and on, almost like magic.

Straight D-O-B tonearm

The fulcrum of our D-O-B (Dynaoptium Balanced) tonearm is at the exact point of dynamic balance. As a result, there is no longer a mutual dynamic influence between the parts of the tonearm on either side of the fulcrum; vibrations picked up by the stylus never jeopardize the fulcrum's delicate balance, while outside vibrations never travel from the arm base to the stylus tip to alter the geometry between the stylus and the record. This is one more reason why the XP-99 delivers eminently superior sound.


Precision Double-Servo Quartz PLL System

A double-servo speed control system affords our linear coreless motor its highly accurate performance. As the platter starts up, the FG (Frequency Generator) servo applies a powerful accelerating torque to the motor, bringing the platter up to operating speed in 2 seconds. Then the Quartz PLL servo takes over, dynamically smoothing out the minutest fluctuations in speed. Our elaborate servo system and linear coreless motor provide amazingly low wow and flutter specs of a mere 0.012% (WRMS).

Computer-controlled fully automatic operation

A custom-made 4-bit microcomputer is at the heart of the XP-99, overseening every facet of turntable operation. It makes a number of automatic operations possible, including one-touch play, stop and repeat. It also fully protects the XP-99 from damage to turntable parts or the record on the platter . Manual operation, using the arm UP/DOWN button, is possible any time, of course.

Attractive solid cabinet

To prevent acoustic feedback and provide a solid base for the motor and tonearm, the cabinet is constructed of solid, high-density wood. Its exterior surface is finished to a deep piano-like luster. Controls, including tonearm UP/DOWN, are positioned outside the closed dust cover on a slanted front panel. The cabinet is exactly 430 mm wide, the same as other Sansui components.

A DC type head Shell

The tonearm comes with an ADC type head shell so you can easily change cartridges.

Moving-coil cartridge

The XP-99 comes complete with a moving-coil cartridge (AT-3100S) for crisp, transient sound. Unusual for an MC it features a user-replaceable sytlus.

Specifications

Type: direct-drive turntable

Speeds: 33 and 45 rpm

Platter: aluminium alloy diecast

diameter: 308 mm (12-1/8")

weight: 1,5 kg (3,3 lbs)

Motor: Coreless and Brushless DC with Quartz PLL servo

Wow and flutter: 0.012% (WRMS)

Signal-to-noise ratio: better than 78 dB (DIN-B), 62 dB (IEC-B)

Tonearm: statically-balanced type

Effective length: 230 mm (9-1/16")

Power voltage: 110-120V/220-240V 50/60 Hz

Power consumption: 15 W

Dimensions (W x H x D): 430 x 170 x 418 mm (16-15/16" x 6-11/16" x 16-15/32")

Weight net: 8.9 kg (19,6 lbs)

Specifications AT-3100S cartridge

Type: Moving-coil

Output voltage: 0,4 mV (1 kHz, 35,4 mm/sec)

Correct load impedance: 100 ohms

Frequency response: 20 - 23,000 Hz

Tracking forece: 1.7 ±0,3 g

Stylus: 0,5 mil diamond stylus

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