Audio Database

PD-7030LTD
Commentary

Based on the PD 7030, this is a limited model CD player that uses copper plated honeycomb chassis, 4-circuit independent power supply and digital filter.

The audio circuit uses a digital filter with 2 x oversampling.
A digital signal sampled at a sampling frequency of 44.1 kHz is pulled up to 88.2 kHz, which is apparently twice as high as that of the digital signal, and unnecessary signals near 44.1 kHz are removed. This eliminates the need to use a high-order low-pass filter and realizes a low distortion factor with small phase rotation up to the high frequency band of 20 kHz.

In order to prevent the slight vibration of the disc itself, which adversely affects the performance, the material and shape have been improved, and a new disc stabilizer with newly developed special resin has been adopted on the surface of the material.
In addition, by using a ball-aligning disk stabilizer composed of four ball bearings, the rotational axis of the disk stabilizer is automatically aligned with the rotational axis of the disk table. This eliminates the misalignment of the rotational axis while maintaining the necessary play of the disk stabilizer.

A linear servo system has been adopted to further improve the basic characteristics of the pickup, eliminate unnecessary resonance and crosstalk of the actuator, and prevent sound skipping by appropriate servo characteristics and gain control.

A newly developed small-size pickup is used for the pickup part.
It uses a new type actuator and has a structure in which the lens base, which is measured while ensuring sufficient secondary moment of section, is supported by a beryllium copper spring with a special hardened surface.
This spring has a waveform shape that takes into consideration the vibration dynamics. It efficiently drives the center of gravity of the movable part with a simple magnetic circuit and follows the pit together with the servo circuit.
In addition, the magnetic circuit is supported by a base with high internal loss, making it resistant to external vibration.
In order to achieve sufficient rigidity and compact shape, the body is box-shaped and thin-walled precision aluminum die-cast is used.

A pure transmission system has been adopted in pursuit of high-purity transmission.
The digital part reduces unnecessary vibration of the disk due to the disk stabilizer and eliminates the adverse effect of external noise on the digital signal.
In the audio section, a low-noise low-output impedance regulator is placed close to the audio circuit on the PCB to supply each block circuit with reduced impedance rise.
In addition, the use of IC common to L and R is eliminated, and L and R symmetrical straight pattern is adopted.

Digital signal processing performed by multiple LSIs is processed by a single master clock to prevent jitter components from being included in digital signals and beats between signals, thereby minimizing the influence on servo circuits and audio circuits.

In addition to the digital servo system, audio system, and FL display system, the power supply section uses a 4-circuit independent power supply with a separate transformer for the D/A converter.
In addition, the power transformer is attached to the sub-chassis, and the floating structure itself is supported by four insulators to reduce vibration caused by the power transformer.

High rigidity is achieved by incorporating honeycomb ribs in the chassis.
In addition, copper plating is applied to reduce magnetic strain.
In addition, in order to protect the optical system mechanism from external vibration, the center of gravity is designed to be lower than the support part of the mechanism.
As a result, unstable lateral vibration is reduced and more stable signal reading is possible.

The insulator is made of material with high rigidity and high vibration damping rate.
In addition, the optical system part that avoids vibration is equipped with audio insulation that only floats the mechanical part inside the equipment and blocks external vibration.

High-quality parts such as copper foil Styrofoam capacitor, electrolytic capacitor for audio, power cord with polarity display and copper plated screw are used.

It is equipped with an auto program edit function. Just by indicating the number of songs you want to listen to and the playback time, the microcomputer determines up to how many songs can be played in full within the time and programs it automatically.
When dubbing to a tape, if you set the recording time for each side, you won't end in the middle of the song.

It is equipped with a pause program function, and by pressing the pause button between songs to be programmed, you can also incorporate poses into the program.

It is equipped with a reservation program function. If you program a song you want to listen to during normal play, it moves to program play as soon as the song is finished.
If you want to listen to a programmed song immediately, press the play button to interrupt the current song and play the programmed song.

It is equipped with a subcode terminal and a headphone terminal with volume.

Equipped with a direct programming function that instantly programs the currently playing music just by pressing the program key.

It is equipped with an FL8-digit display that displays the performance status.

If a CD is loaded in the tray, playback will automatically start from the first track when the power is turned on.

Gold-plated terminals are used for output terminals and headphone terminals.

Model Rating
Type CD Player
Pick-up Three beam semiconductor laser system
DA Conversion 16-bit straight line
Frequency characteristic 4 Hz to 20 kHz, ± 0.3 dB
Signal-to-noise ratio (EIAJ) 100 dB or more
Dynamic Range (EIAJ) 96 dB or more
Channel Separation (EIAJ) 94 dB or more
Wow & flutter (EIAJ) Measurement limit (± 0.001% W. Peak) or less
Total Harmonic Distortion Factor (EIAJ) Not more than 0.003%
Output Voltage (EIAJ) 2 V ± 0.5 V
Number of channels 2 channels (stereo)
Pwer 100 VAC, 50Hz/60Hz
Power consumption 12W
External dimensions Width 420x Height 84x Depth 290 mm
Weight 4.7kg
Attachment Remote Controller CU-PD002