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Teac Esoteric Transport mechanism = VRDS-NEO

Posted by DevillEars (A) on April 8, 2007 at 14:19:56

In Reply to: Still researching, but it seems nearly all benefit from modding - but one company spurns clock upgrades! posted by John C. - Aussie on April 7, 2007 at 19:20:08:

This mechanism is the latest incarnation of their first VRDS mechanism:

The goal of the VRDS transport is to eliminate any vibration of the disc, as well as to correct small inconsistencies in disc flatness. It accomplishes these tasks by clamping the disc with a circular plate that runs the full diameter of the disc.

According to Esoteric, this also serves to reduce read and timing errors. Construction highlights of the UX-3’s VRDS-NEO include a duralumin turntable and a bridge made from 10mm SS400 steel.

The following is copied without permission from Teac's own documentation:

VRDS-NEO Mechanism:

Ultra-high-precision turntable system

When a SACD or DVD disc is played, the higher-speed rotation required for playback causes increased and unwanted vibrations. These vibrations cause the disc surface to shake, making it difficult for the laser pick-up to accurately read the data.
The VRDS turntable is designed to physically correct all vibrations and completely stabilize the disc so that adverse effects during high-speed rotation can be minimized. High-speed rotation also necessitates that the spindle shaft be more rigid. The turntable, (the heart of the VRDS mechanism), is supported by several high-precision, highly rigid mechanical components.

Coreless motor with no rotational irregularities

ESOTERIC has developed a long-life three-phase brushless spindle motor for high-speed rotation. Development of the magnetic circuit, consisting of a neodymium magnet structure, was completed through numerous tests and scientific validations, including magnetic field analysis. The optimized magnetic circuit minimizes rotational irregularities in the motor and makes it possible to reduce fluctuations in the motor drive current, thereby lessening any effects on audio circuits and other areas that may be subject to the injection of noise.

Duralumin turntable

During Super Audio CD (SACD), or DVD playback, the maximum rotation speed is approximately 4.5 times greater than the rotation speed during conventional CD playback. To ensure that the turntable can handle this high-speed rotation, ESOTERIC selected duralumin as the turntable material. This material is best known as the outer body material used in hi-speed hi-elevation aircraft. ESOTERIC has developed new technology for processing duralumin into lower mass with higher precision. As a result, P-03 Universal enables smooth turntable response and stable data acquisition properties by preventing disc vibration. The turntable is dyed a black color in order to absorb any diffused reflections of the laser beam from the pick-up.

Rigidity and precision are significantly improved by the use of highly specialized ball bearings used in the spindle shaft bearing assembly

A pair of precise ball bearings, is used in the spindle shaft bearing unit and a pre-load is applied to the bearing inner rings to
significantly reduce rattling and shaft shaking during use. This dramatically increases the precision of the bearing unit and greatly improves rotational and positioning accuracy. As a result, the correlation precision between the disc and pickup is improved—a factor which is closely related to transport performance and data acquisition. ESOTERIC has collaborated with a bearing manufacturer and has newly specified and developed an original bearing optimized exclusively for the VRDS-NEO mechanism. A pair of ceramic ball bearings support precisely controlled turntable rotation from low speed to high speed.

Massive bridge unit made from SS400 steel supports the turntable and spindle unit

The precision and rigidity improvements to the turntable and spindle alone will not ensure good results if the bridge supporting them has not also been improved. Therefore, ESOTERIC selected 20 mm (3/4”) thick, SS400 steel for the support bridge. Any vibrations originating from the spindle during rotation are subsequently attenuated by the mass of the bridge.

Advanced pick up technology --- thread servo section

ESOTERIC developed an ingenious component structure for driving the pickup lens and a horizontal sled structure to move the pickup unit with an extremely high level of accuracy. This system ensures that the laser optical axis is always positioned at the very center of the pit track for optimal reading. These modifications to earlier VRDS mechanisms (P-0), make it possible to minimize the adverse effects of disc surface shaking and eccentricity at higher rotational speeds.

Pickup structure designed to prevent laser optical axis tilt during lens movement

Optical pickups in ordinary players are designed so that the lens hangs from a wire or a group of wires. This design is not only low in rigidity, but allows the laser optical axis to tilt away from a vertical orientation to the disc as the lens moves. When this occurs major error correction is required (data is lost and must then be interpolated). In contrast, the pickup used in the P-03 Universal (and in other ESOTERIC players), has a shaft-sliding structure that prevents the laser optical axis from tilting, even when the lens is moved. ESOTERIC has also increased the rigidity of the parts supporting the lens on a horizontal platform.
Although this is expensive to accomplish, ESOTERIC design implementation greatly improves data acquisition and eliminates
the need for off axis error correction.

Speed feedback-controlled sled transport with superior response and minimal extraneous pickup lens movement

In order to provide a very high-performance pickup capable of smooth, continuous movement, a proprietary hall element sensing-type three-phase brushless motor is used in the sled transport. Powerful electronic speed feedback circuits control this sled mechanism.

Vibration isolation for spindle motor system and sled moving system

The spindle system, which may generate fine vibrations during rotation, is isolated from the sled moving system. Since the sled mechanism requires very delicate movement control, this isolation from high-frequency vibrations is another ESOTERIC implementation that ensures superior data read and acquisition.

High-precision mechanism and new software controlled servo system for superior playback

This precision-machined proprietary mechanism combines with new system software to provide optimal servo control for each type of disc.

Wasn't sure if you'd be interested, so included it on the off-chance...

DevillEars

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