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





Pioneer Elite PD-75 CD player

How a concept called the stable platter turned the CD upside down.

 

In airline pilots, brain surgeone, and CD players, steadiness is a pretty fundamental requirement. In the case of our newest CD player, the Elite PD-75, its rock-solid stability has rocked the world of music lovers and audio critics. As the reviews have rolled in and the awards have been bestowed, it is apparent that the standard for CD players has been advanced dramatically. Behind this success lies a principle that Elite has brilliantly exploited. The mechanical elements of a CD player are just as critical to its quality as its electronic components.

The first significant innovation to come out of this insight is at the heart of the PD-75. the stable platter.

Two basics of physics - mass and inertia - combine to make the stable platter an obviously superior platform to support a disc spinning at high velocity.

Next, the stable platter, by supporting the entire area of the CD disc, minimizes wobble and chatter.

A wobbling disc presents a difficult target for the laser, while a chattering disc creates resonance, distorting the signal, which distorts the sound.

Another problem for CDs is gravity. Spinning above the laser pickup and supported only in the center, the disc sags microscopically. Which to a laser beam is significant degradation.

But on the Elite CD platter, the disc is turned upside down - that is, label down, information side up. The disc lies firmly clamped to a solid surface. Meanwhile, the laser pickup reads the disc's digital code from above, where it is immune to dust settling on the laser optics.

 


Specifications

Type: Compact disc digital audio system

Channels:  2-channels Stereo

Frequency Response:  2 Hz - 20,000 Hz

Signal-to-Noise Ratio:  112 dB or more (EIAJ)

Dynamic Range:  98 dB or more (EIAJ)

Channel Separation:  108 dB or more (EIAJ)

Total Harmonic Distortion :  0,0018% or less (EIAJ)

Output Voltage:  2,0 V

Wow and Flutter:  limit of measurement (±0,001% W Peak) or less (EIAJ)

Balanced Type Audio Line Out:  2 V (600 )

Power Requirements:  AC 110/120V; AC 220 - 230 V, 50/60 Hz

Power Consumption:  30 W

Dimensions (W x H x D):  459 x 330 x 130 mm (18-1/16" x 13" x 5-2/16")

Weight:  12,0 kg (26 lb 7 oz)


 

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