ONKYO DX-30
¥ 150,000 (around 1984)
Commentary
A CD player developed using the know-how accumulated through the Integra series of amplifiers.
Uses a super turbo system that cuts off the power transformer purely electrically.
This system uses two circuits, a delta turbo circuit and a turbo filter circuit, to solve the problem of harmful modulation noise caused by the transformer, and suppresses the modulation noise generated by flux generated from the transformer and harmonic spectrum generated by pulse wave for Chemi-Con charging.
An 11th-order low-pass filter is used to prevent beat interference (aliasing noise) that occurs between the harmonics of the audio frequency and the sampling frequency of 44.1 kHz.
In addition, it employs a super servo circuit that cuts out unnecessary DC components (ultra-low frequencies) that cause intermodulation distortion. It does not use a capacitor that affects sound quality from the output of the D/A converter to the audio output terminal, ensuring flat characteristics from low frequencies of 2 hz to high frequencies of 20 khz.
To prevent interference between the four stages of the control (servo) system, digital system, display system and audio system, each stage is equipped with an independent DC power supply section to supply DC power.
Three dedicated ICs are used for the focus servo circuit and tracking servo circuit of the laser pickup to improve reliability. In addition, dedicated microcomputers are installed for the operation of these servo circuits and for the drive of the display, respectively, to realize a compact printed circuit board and a thin player.
A horizontal loading system is adopted in the tray section, and a motor for moving the tray is installed separately from the disk chucking motor (mechanism for fixing the disk to the center spindle) to achieve stable loading and chucking.
The mechanism of the pickup, pickup drive motor, and disk rotation motor uses an integrated structure with precision finish by aluminum die casting. Moreover, the head block is a vibration-proof structure completely floating from the chassis, making it less susceptible to external vibration and impact.
The disc rotation motor uses a small DD brushless servo motor developed especially for CD players.
It is equipped with functions such as 8-track random memory, jump selection function, 2-speed fast forward function, index search, repeat performance, pause, etc.
Equipped with a pickup position display function, a 16 point LED bar shows where the pickup position is on the disc.
Equipped with headphone port and headphone volume.
Model Rating
Type | CD Player |
Number of channels | 2 Channel |
Number of revolutions | Approximately 500 ~ 200 rpm |
Linear velocity | 1.2m/s ~ 1.4m/s |
Available computing time | 75 minutes (maximum) |
Sampling frequency | 44.1kHz |
Number of decoded bits | 16-bit straight line |
Frequency characteristic | 2 Hz to 20 kHz ± 0.5 dB |
Signal-to-noise ratio | 95 dB or more |
Channel separation | 90 dB or More (1 kHz) |
Harmonic distortion factor | 0.003%(1kHz) |
Wow and flutter | Below Measurement Limit (Crystal Accuracy) |
Output level | Line : 2 Vrms Headphones : 30 mW |
Output impedance | Line : 560 Ω Headphone : 32 Ω |
Pick-up | Semiconductor laser |
Motor | Two DC servo motors (disk pickup) Two DC motors (chucking, loading) |
AC outlet | Unswitched, 400W capacity |
Pwer | 100 VAC, 50Hz/60Hz |
Power consumption | 40W |
External dimensions | Width 435x Height 114x Depth 380 mm |
Weight | 9.3kg |