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Pioneer PD-T07A
180,000yen(1992 release)
Description
compact-disk turntable scheme compact disk player which carries a high speed pulse flow digital analog converter.
compact-disk turntable scheme which holds a disk the whole surface from the bottom is adopted as a mechanism part by moving a pickup and a spindle motor to a upper portion from a disk lower.
Compared with the conventional tray scheme, moment of inertia improves by about 3 times, and an extraneous vibration, the influence of sound pressure, a disk's hanging down, and the unnecessary oscillation by field Bure are also suppressed low.
The high speed pulse flow digital analog converter of an original development is carried in the D-A-conversion part.
In this digital analog converter, by operating a noise shaper on a high oversampling frequency called 384fs, a fine sampling is enabled and the noise floor by re-quatization is reduced greatly. Since a noise shaper degree can also be used by the sub- and a low degree as a result, the influence on the tone quality by the analog low pass filter which negates an out-of-band noise and it has been reduced.
Furthermore, in order that the influence of a Jitter may come out notably so that the frequency of a master clock is high, a master clock is operated with a clock frequency as low as 16.93MHz, and the influence of a Jitter is reduced.
Moreover, since the duty which is a timing ratio of on/off of a 1-bit output is improved from 50% to 100% and an Output voltage doubles by this, the audio output of the high SN ratio and the low distortion has been obtained.
The direct construction to which even an output-terminal leads the music signal which took up by the shortest distance was adopted, the center tray design was begun, the digital & servo and the audio substrate were separated, and the cross interferencee is prevented.
Furthermore, seal dead PCB (double-sided printed circuit) is adopted as a digital system and an analog system, and the shielding effect effective in the noise from a digital system to an analog system flying is demonstrated. Moreover, an analog substrate uses OFC (oxygen free high conductivity copper) for a Copper-foil part, connects it with the shortest distance simultaneously, and is considered as the symmetrical stream composition.
The proprietary clean laser pickup is adopted as a pickup part.
By reduction of optical components, such as a collimator lens, reduction of the aberration in an optical path, etc., the laser efficiency ratio was raised and reading of little distorted signal is realized.
Moreover, the photodetector with built-in I/V head amplifier is adopted, and it amplifies for about 200mV order. In combination with an Accu Focus system, signal transmission with little Jitter occurrence by a reading error and disturbance of a signal is made possible.
Furthermore, the highly precise engineering plastic body is adopted as the pickup body, and the high rigidity and the Takauchi part loss are conjointly realized with highly precise form.
Class-A operation FET buffer amplifier is adopted as an audio circuitry.
When this lowers an Output load impedance, the influence of the load intensity of the amplifier connected etc. was suppressed, and also the variation of the power consumption at the time of an operation could be reduced to write with a Class-A operation, and low-distortion-ization is realized.
The large-sized brushless hall motor of starting torque 65 g-cm is carried in the spindle motor. With the phi4.5mm very-thick shaft, conjointly, it is strong to a load variation and the stable rotation property has been acquired.
Moreover, the silence linear motor servo mechanism excellent in the responsibility is employed as a pickup drive, and the quiet and quick access is realized.
In PD-T 07A, the whole mechanism's vibration proof is improved by raising the vibration proof of a turntable scheme further and newly covering a mechanism part with a silence chassis.
Furthermore, a Mechanism-base piles up two heterogeneous metalses, is a lamisert Mechanism-base which carried out molding by the special resin, raises a periodic-damping property, and is suppressing the occurrence of a magnetic distortion by giving a copper plating. Moreover, this Mechanism-base has mounted special rubber and a spring on a mechanism chassis through the coaxial-ized coaxial suspension,The turntable base is similarly mounted through a coaxial suspension, and the extraneous vibration from a chassis is intercepted by considering it as a float structure, respectively.
The newly developed multilayer structure honeycomb chassis is adopted as a chassis.
Based on the honeycomb chassis by BMC (Bulk Molding Compound) of the Takauchi part loss and a high rigidity, this is the steel plate excellent in the electromagnetic shielding, and the thing which piled up cushion material, by the outstanding vibration suppression nature, reduces an unnecessary oscillation and is also suppressing the reflection of the sound from a floor.
Moreover, in addition to the large-sized honeycomb insulator which absorbs an extraneous vibration, the 5th insulator is adopted and the center mechanism is certainly held by obtaining vibration proof and a weight balance.
The twin power transformer of digital one / analog separation is carried in the power-source part, and the power circuit has employed 5 part 14 regulator as it. The independent rectification of the five parts of + of a servo/digital one, a servo drive, a digital analog converter, and an audio and - was carried out, and the cross interferencee is eliminated.
The push pull power source of a discrete stream composition is adopted as an audio circuitry, and the influence from other power sources is eliminated using an exclusive coil and a power circuit to digital analog converters.
Moreover, since the by filer volume is adopted as the transformer for audio circuitries, degree of balance of installations, such as an Output load impedance, improve and the power source by the side of + and - is supplied on the same requirements, the tone-quality modification can be aimed at.
The very-thick 4 core code which divided the cable into only the servo/analog from the power plug is adopted.
OFC (high purity oxygen free high conductivity copper) is adopted as a material, and the influence of the circuitry [ AC power source / itself ] on others is eliminated by the isolation structure.
The balance output which cannot be easily influenced by an exogenous noise is carried.
The aluminum extrusion top bonnet excellent in vibration suppression nature is adopted.
Moreover, the aluminum panel stabilizer which improves rigidity and prevents an occurrence of a fine oscillation of the front panel is adopted.
The display-deviceoff switchpoint which prevents a scanning noise is carried. Moreover, the clean microcomputer is carried and a scanning noise can be canceled. (The backup is supported)
Digital one / analog out circuit changing switch is carried (the backup is supported). |
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發表於 2010-10-2 13:09
樓主
..不過自從買咗比大陸就
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