SONY MDS-JA30ES
¥ 120,000 (released in August 1997)
Commentary
MD deck with newly developed S-TACT IC while inheriting high sound quality of MDS-JA50ES.
Wide bit stream technology using newly developed DSP for ATRAC is introduced.
Using the new 4.5 generation DSP as a key device, we have made it possible to record and play back with a wide dynamic range with 20-bit accuracy exceeding the 16-bit MD format. This is achieved by changing the input / output to 20-bit and expanding the operation vocabulary.
In data compression, adaptive high-frequency control technology has been introduced that effectively uses a limited amount of data based on human audibility.
Depending on the input signal, if the number of quantization bits is small, the high frequency range is limited and the quantization bits are increased for signals that have a poor sense of distortion. If the number of quantization bits is small, the reproduction band is extended to higher frequencies for signals that are less affected by the insufficient number of quantization bits to improve the reproducibility of the high frequency range.
As a result, the accuracy of signal processing is improved, and the total harmonic distortion is improved by about 8 dB compared to the conventional one.
In the pulse generation part of the MD deck, noise shaping (digital part) and pulse generation (analog part) were composed of one IC. However, in the MDS-JA30ES, newly developed S-TACT IC is adopted, and the IC structure of only the pulse generation circuit and the clock generation circuit realizes separation and independence from the digital operation part.
This reduces the effect of digital noise on the time axis of the pulse.
It is equipped with a sampling rate converter that automatically converts 32 kHz and 48 kHz sampling 48 kHz to 44.1 kHz and enables digital recording with quality degradation.
The D/A converter uses the current pulse D/A converter used in Sony's ES series CD players. The current pulse output as voltage is replaced with a current that is less affected by voltage-induced noise and transmitted. It has a stable current source and is not affected by voltage fluctuations, enabling stable low-frequency playback.
The power supply section uses an R-core transformer with no breaks in the iron core of the transformer and a circular doughnut type section to reduce magnetic flux leakage and vibration.
FB chassis is adopted for the chassis. Metal material with sufficient strength and thickness is used. The whole chassis is firmly fixed as one box by surrounding brems and beams passed in front and back. By combining members of different shapes and sizes in each part, natural vibration is mutually cancelled, and vibration of the whole chassis is reduced.
By using an eccentric insulator whose mounting hole to the chassis is offset from the center, signals transmitted from the outside are mutually canceled, making it difficult for signals to be transmitted to the chassis. As a result, it is effective in damping vibration components in the middle and high frequency range, which affect auditory sense in particular.
Equipped with a digital REC level control, the gain can be controlled from - ∞ dB to a maximum of + 12 dB around a gain of 0 dB. The volume change curve can also be selected from three curves, Sin, Linear, and Log, depending on the mood of the song.
In addition, it is equipped with a non-clip circuit that automatically lowers the recording level gradually when a level clip occurs by increasing the recording level too much.
Equipped with a V. C. (Variable Coefficient) digital filter, it can be used during MD playback to change the cutoff characteristics of the digital filter to obtain subtle sound changes. There are four positions of the Variable Digital Filter to adjust the sound quality according to your preference.
A tray loading system is used for loading disks.
The tray loading section and base unit section are floating with an insulator and a compression coil spring. In addition, a material with excellent vibration damping characteristics called PBT is used for the mold to hold the base unit section. This reduces vibration to the disk and improves signal reading accuracy.
Equipped with a music sync recording function, it automatically starts recording MD just by starting the performance of the device you want to record.
Equipped with an evenly spaced track marking function, music numbers can be automatically added at equal intervals of 1 minute or 5 minutes.
The track number is an indication of the elapsed time.
It is equipped with a time machine recording function. If you press the multi-jog dial in the recording pause state, the sound recorded up to 6 seconds before is recorded on the disk.
When recording an analog source, it is equipped with an auto-track marking function that automatically assigns a song number when a song starts from a silent state. In addition, the variable level sync function allows you to set the signal level and time at which sound is judged to be silent in more detail.
Equipped with a fade in / fade out function. Fade time can be adjusted.
It is equipped with a resume playback function so that playback continues from the point where playback stops or from the next song.
The bit tone of the optical digital output can be switched between 16 bit and 20 bit.
Equipped with an UNDO function that allows you to cancel the last edit operation and redo it.
It is equipped with a rehearse function that allows you to check edit points in COORDINATE or DIVIDE.
To move edit points, you can fine-tune the DIVIDE edit point in minutes, seconds, or frames (approximately 0.01 seconds).
Equipped with an A-B ERASE function that allows you to erase between two specified points in a song.
Equipped with a disc name copy function, you can save typing time when you want to give the same name to a disc and a song, or when you only need to correct a part of the name.
It is equipped with a title function that can record up to approximately 1,700 characters of disc names and song titles on the disc. Katakana characters can be used in addition to conventional alphabets, numbers and symbols.
Input can be made with the main unit and remote control even during recording and playback. Direct input is possible by using the remote commander for katakana input (sold separately).
Mono format discs are play-only.
The SCMS (Serial Copy Management System) allows digital recording only for one generation and does not allow digital recording for two or more generations.
Wireless remote control is included.
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Model Rating
| Type | MD deck |
| A/D converter | 20-bit ⊿∑ |
| D/A converter | Current pulse D/A converter Variable (V. C.) filter |
| Voice compression system | ATRAC |
| Recording and playback time | Stereo : up to 74 minutes Monaural : up to 148 minutes |
| Frequency characteristic | 5 Hz to 20 kHz ± 0.3 dB |
| Dynamic range | 104 dB or more (during playback) |
| Signal-to-noise ratio | 107 dB or more (during playback) |
| Total harmonic distortion factor | 0.002% or less (during regeneration) |
| Wow and flutter | Measurement limit (0.001% W peak) or less |
| Input terminal | Line : 1 system Optical digital : 2 systems Coaxial digital : 1 system |
| Output terminal | Line : 1 system Optical digital : 1 system Headphone : 1 system |
| Power supply voltage | 100 VAC, 50Hz/60Hz |
| Power consumption | 24W |
| External dimensions | Width 430x Height 125x Depth 345 mm |
| Weight | Approx. 9.3 kg |
| Attachment | Wireless Remote Control RM-D14M |
| Sold Separately | Katakana Input Dedicated Remote Commander RM-D10P (¥ 7,500) |