Marantz CD-84

Commentary

In order to improve sound quality, stability, and operability, a CD player was developed by developing original technology and investing a number of know-how and technologies.

Equipped with a Z filter that is an improved and developed digital filter.
The Z-filter consists of a digital filter, a D/A converter and a low-pass filter. The Z-filter oversamples the sampling frequency by a factor of four, so that 44.1 kHz becomes 176.4 kHz, which is processed by a low-pass filter with gentle characteristics. This eliminates the deterioration of phase characteristics and transient response characteristics caused by the high-order filter.
The low-pass filter of the Z filter uses a Bessel filter with excellent phase characteristics in addition to the low order of 3rd order. It ensures good phase characteristics up to high frequencies, and at the same time, expands the pass band to 30 kHz to improve transient response characteristics.
In addition, a left-right independent 2D/A converter is used for D/A conversion to prevent phase rotation.

Swing arm pickup is used for the pickup part.
The swing-arm pickup has a structure with a laser pickup at the tip and a counterweight at the rear to achieve a dynamic balance, enabling a stable pickup trace at all times.

The world's smallest semiconductor laser pickup is used in the pickup section.
Through miniaturization, the components of the pickup have been simplified, and the optical system components have been reduced to two lenses and one beam splitter, thereby maintaining high assembly accuracy and improving reliability.
In addition, the miniaturization of the entire pickup makes it possible to achieve a high-efficiency design that effectively uses only the central portion of the laser beam.

A unique swing arm pickup is mounted on an aluminum die-cast base to suppress external vibration and microvibration of the rotating system and improve stability.

The power supply section is equipped with a large transformer and a large-capacity capacitor. In addition, the power supply for circuits that generate switching noise, such as audio circuits, digital circuits, servo circuits, and digital displays, is separated, and a completely independent power supply is used to suppress noise.

For each stage, we use parts that have been learned through hearing.
In addition, the earth point, an important factor in determining sound quality, also determines the best focus by hearing.

It is equipped with a random access program and a delete program for up to 24 songs, an auto music scan for playing only the intro, a head-start function, a skip function, a back-stop function, a repeat function, and a music standby function.

Equipped with a large display capable of displaying digital display + program indicator.

Equipped with digital interface terminal.

It can be operated from a remote location by the attached dedicated remote controller.
It is also compatible with the Marantz Bus System that carries out remote control and easy operation using a dedicated microcomputer. Remote control is possible by using the audio timer AT333R together with the remote control transmitter RMC-10.

Model Rating

Type	CD Player
<disk>
Outer Diameter	12cm
Number of channels	2 Channel
Track pitch	1.6 μ m
Scanning speed	1.2 ~ 1.4m/sec
Signal Format
Sampling frequency	44.1kHz
Quantization number	16-bit linear
Modulation system	EFM
Channel bit rate	4.3218Mb/sec
Error correction system	CIRC
Encoding	2's complement
Optical Pickup
Semiconductor laser wavelength	0.78 μ m
Numerical Aperture (NA)	0.45
Depth of focus	± 2 μ m
Beam spot diameter (disk surface)	About 1 mm in diameter
Electrical Characteristics
Output Level / Impedance	2.0V/60 Ω
Playback frequency band	4 Hz to 20 kHz
Signal-to-noise ratio	96 dB or more
Dynamic range	92 dB or more
Channel separation	94 dB or more
Harmonic distortion factor	0.003% or Less (1 kHz)
Wow flutter	Crystal accuracy
De-emphasis	Automatic switching
<Others>
Pwer	100 VAC, 50Hz/60Hz
Power consumption	28W
Maximum external dimensions	Width 416x Height 90x Depth 300 mm
Weight	8.0kg
Attachment	Infrared Remote Control RMC-84