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

Marantz CD-73

Marantz CD-73 is a front-loading player in which the disc I spins in the horizontal plane. So the height has been kept to a slim 80mm, though width 415mm, and depth 300mm are "full size". The disc drawer is mechanically complicated: pressing the open-close button causes the drawer to slide out while the front tilts forward and the disc-clamp panel pops up simultaneously. Green illumination allows the disc to be seen during play through windows in the top and front. An extended display panel carries numbered green lights from 1 to 15 showing the total number of tracks on the disc, with amber lights underneath indicating the track being played.

Apart from simple playing of a disc straight through from the beginning, there are selfexplanatory rewind, fast forward, 'next program', repeat and pause controls. Programming tracks (up to 15) in any desired sequence is achieved by pressing a 'select' button the required number of times (or holding it down until the required track number is indicated on the display) for each track and entering this in the memory by pressing a 'preset' button. This takes a little time to arrange for a complicated sequence, but works impeccably-and the whole sequence can be set to repeat itself indefinitely. Individual tracks in a sequence can be cancelled, or repeated, with the visual display at all times showing the particular tracks in the stored programme.

Grouping of the controls along the lower edge of the front panel is logical, but some practice will be needed to master the flexible facilities offered. The state of play is always clearly displayed, except for the omission of any 'real time' indicator. No sound is heard during fast forward or rewind, so that trial and error has to be used for locating a cue within a track-the fast wind operating for as long as the button is held down, and play being resumed when the button is released.

The Marantz CD-73 therefore comes in the middle category as far as features and displays are concerned. It scores high marks for smooth operation and smart appearance-having the attractive finish of all the current Marantz "separates", such as the PM-350 amplifier and ST-450 tuner. Rear panel connections include the usual pair of phono sockets for audio output, plus sockets for an optional infra-red remote control kit. Mains connection is via a two-pin socket: mains cable and phono leads are supplied.


Sampling frequency: 44.1 kHz

Number of quatizations: 16-bit linear

Modulation technique: EFM

Channel bit rate: 4.3218 Mb/sec

Error correcting system: CIRC

Encode scheme: Two's complement

Semiconductor laser wavelength: 0.78 micrometer

Numerical aperture (NA): 0.45

Depth of focus: ±2 micrometers

Diameter of the beam spot (disk top layer): About 1 mm in diameter

Output: 2.0 V

Play frequency band: 5 Hz - 20 ,000 Hz

Signal-to-Noise ratio: 90 dB or more

Dynamic range: 90 dB or more

Channel separation: 90 dB or more

Total Harmonic Distortion (1kHz): 0.004%

Wow and flutter: Quartz-crystal precision (below a limit of measurement)

De-emphasis: Automatic switching

Power source: AC 100, 120, 220, 240 V, 50/60 Hz

Power consumption: 30 W

Dimensions (W x H x D): 416 x 81 x 300 mm

Weight: 8 kg

Nessun commento:

Posta un commento