NEC CD-10

Commentary

CD player announced as new reference of NEC.

The digital filter uses a 16 fs Transversal Filtering Circuit (TFC).
Using an 8 fs digital filter, the signal sampled at a given sampling period and the signal delayed by half of the sampling period with respect to the signal are subjected to arithmetic averaging to produce average value complementary data.
With this 16 fs TFC, the hold aperture time is 14 μ sec, and even at 20 kHz, the highest recording frequency for CD, a smooth waveform is obtained without the need for a low-pass filter.
The CD-10 uses a 16 fs TFC gate array to achieve a simpler and straighter configuration.

The D/A conversion circuit is equipped with a 4 dac B. S. S (Balanced Summing System), a balanced return circuit that uses two D/A converters on the left and right, each of which is specially selected for accuracy at a small level from among the DACs selected for good linearity.
The balance operation of unipolar DACs eliminates the need for a coupling capacitor and simplifies the analog signal circuit.

The power supply uses an extremely thick DFC ACF cord and is equipped with an A/D completely independent 2-transformer.
In addition, we have adopted an independent power supply system in which the secondary winding is divided for each stage to prevent mutual interference between analog and digital systems in the power supply.
In addition, as a result of pursuing dynamic dynamism, all electrolytic capacitors are made of high-voltage products with a margin. In addition, important parts of power supply lines are wired with wires (#18) with a large cross-sectional area and a thick film without relying on pattern wiring to improve the quality.

The chassis structure uses a fully A/D separated 2 box chassis to prevent digital noise from entering.
The inside of the chassis is separated into a mechanism digital system and a D/A conversion / analog system. In addition, the digital system and analog system each have a base and an earth point is independent, preventing the mixing of digital noise.

Focusing on the relationship between vibration and sound, direct mechanical ground construction is adopted.
The mechanical base legs are made of sintered alloy and the mechanical tray is filled with anti-vibration material to prevent resonance. The power transformer, which is the source of vibration inside the CD player, is fixed to the transformer base of 3.2 mm thick steel plate insulated from the chassis through a special anti-vibration material of 1 mm, so that it is vibrationally and electrically separated.
In addition, the chassis base plate adopts a 3-layer structure consisting of an ordinary 1 mm thick steel plate plus 2 mm thick and 1.6 mm thick steel plates. The entire high-rigidity housing is monocoque. Simple and controlled vibrations with reduced natural vibrations are transmitted to the ground through giant heavy-weight legs (65 φ 380g).

Balanced output jacks are provided, and unbalanced output jacks are provided with positive and negative output jacks.
The unbalanced output terminal uses a stand-alone, high-ground type that does not share a common ground.

Uses a simple LED9-digit display.
In addition, in order to eliminate the adverse effect on sound quality caused by turning on the display, it is equipped with an off position. When turned off, a relay is used to shut off the power supply.
In addition, it is equipped with 3 levels of dimmer switch which can choose bright display or dim display.

Equipped with an absolute phase (signal polarity) change-over switch that adjusts the polarity of the whole system.

Model Rating

Type	CD Player
Frequency characteristic	DC ~ 20 kHz ± 0.5 dB
Total harmonic distortion factor	Not more than 0.0018%
Dynamic range	98 dB or more
Signal-to-noise ratio	110 dB or more
Channel separation	103 dB or More (1 kHz)
Wow and flutter	Measurement limit value or less (crystal oscillation accuracy)
Output level	Analog : 2.5 Vrms Digital : 0.5Vp-p/75 Ω (Coaxial)
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption	21W
External dimensions	Body : Width 430x Height 110x Depth 290 mm Maximum : 430 mm wide x 117.5 mm high x 367 mm deep
Weight	13.5kg
Attachment	Wireless Remote Control AR-10