SONY MDS-JE640
¥ 49,000 (released in 2000)
Commentary
MD deck that supports MDLP mode.
The ATRAC DSP employs a Type-R DSP for ATRAC with twice the signal processing capability of the conventional DSP. In addition, the Intelligent Bit Re-Location Algorithm makes full use of the increased processing capability and re-analyzes the spectrum converted music data to search for minute levels of redundant bit allocation that have been difficult to find until now, and redistributes the bits preferentially to the frequency bands that are important for the listener. This further refines the bit allocation and makes it closer to the waveform of the original music source.
By introducing wide bit stream technology, the dynamic range of the core ATRAC DSP and the audio data word length of peripheral circuits such as digital in / out have been increased from 16 bits to more bits, enabling recording and playback with a wide dynamic range.
It is equipped with the MDLP mode, which is an improvement of the ATRAC audio compression technology and realizes about twice the compression performance of the conventional system.
ATRAC reduces the data size by eliminating sound components that are hard to hear. ATRAC3, which is used in the MDLP mode, further improves the compression ratio while minimizing degradation of sound quality.
As one example, we have adopted a data encoding method called Huffman coding, which focuses on the frequency of data occurrence. Shorter codes are assigned to frequently occurring data sequences, and longer codes are assigned to infrequently occurring data sequences to improve compression efficiency.
In addition, in order to maintain high sound quality even with high compression, we are also improving the accuracy of band division and spectrum blocking, which are pre-processes for compression processing, prior to compression processing. As for band division, conventional ATRAC divided it into three bands (low band up to 5.5 kHz, middle band from 5.5 kHz to 11 kHz, and high band from 11 kHz to 22 kHz) and passed it to the next circuit. However, ATRAC3 divided it into four bands (high band divided into 11 kHz to 16.5 kHz and 16.5 kHz to 22 kHz) to allow extra processing space. Spectrum blocking is divided into 1,024 samples, which is twice as large as ATRAC, and employs a circuit configuration that recognizes the signal more finely and compresses it.
In MD, data consisting of one pair of Lch and Rch is recorded alternately at a fixed time interval (11.6 ms in ATRAC). ATRAC3 controls the content of signal processing precisely every 1 ms so that appropriate signal processing can continue even when the nature of music suddenly changes.
Furthermore, ATRAC3 has a new step called tone component separation, which extracts tone components and encodes (compresses) them separately from other components in order to maintain high sound quality.
The MDLP has two modes : LP2 stereo recording (playback) mode, which enables recording at twice the disc recording time, and LP4 stereo recording mode, which enables recording at four times the disc recording time.
The LP2 stereo recording (playback) mode reflects the high compression ratio of ATRAC3 and is suitable for long-duration music recording and playback. The LP4 stereo recording (playback) mode uses a compression method that allocates a large number of bits for center localization signals (vocals, bass, etc.), which play an important role in music signals. By reducing the amount of data to be recorded, the LP2 stereo recording (playback) mode even longer recording times.
The MDLP cannot be recorded or played with the conventional model because the data allocation on the disk is different from the conventional format. However, the MDLP compatible model can record or play with the conventional format.
Also, high-speed recording in the MDLP format is up to 2 x speed, and S. F Edit cannot be performed on discs recorded in the MDLP format.
The S. F Edit (Scale Factor Edit) function allows you to adjust the volume and fade in / out after recording. The scale factor is a parameter that represents the peak above the level of a 52-part floating unit. You can adjust the volume by changing this value. With this function, even if the recording level of a disc becomes uneven, you can adjust it later. This function reads the recorded data from the disc, edits the data, and writes it back to the disc.
It is equipped with a sampling rate converter that automatically converts 32 kHz and 48 kHz sampling frequency to 44.1 kHz.
Equipped with digital REC level control, the gain can be controlled from - ∞ dB to + 18 dB at the center of gain 0 dB.
It also has a built-in memory function that can store the set recording level for each input channel.
With the built-in pitch control function, you can listen to it by changing the playback speed (pitch).
It is equipped with a music sync function. Simply by pressing the music sync button on the remote control and then starting performance on the connected device, it senses the input of a music signal and automatically starts recording.
It is equipped with a time machine recording function, and if you press the multi-jog dial in the recording pause state, you can record up to 6 seconds before the sound on the disc.
It is equipped with a monaural recording and playback function that allows you to use the MD twice as long as the display.
You can DIVIDE, COMBINE, and MOVE songs, and it also has an UNDO function to cancel the last edit operation if you make a mistake.
It is equipped with a rehearsal function that allows you to check edit points in COMPASS or DIVIDE. To move edit points, you can fine-tune the DIVIDE edit point in minutes, seconds, or frames (approximately 0.012 seconds).
The time of one frame is 0.023 seconds in the MDLP LP2 mode / monaural mode and 0.047 second steps in the LP4 mode.
Equipped with an A-B ERASE function that allows you to erase between two specified points in a song.
It is equipped with a title function that can record up to 1,700 characters of disc names and song titles on the disc.
In addition to alphabets, numbers and symbols, katakana characters are also supported. You can input characters from the FOMA phone or remote controller during recording or playback.
It is compatible with PC Link and can be connected to a PC by USB using PC Link Kit (PCLK-MN10).
This allows you to perform basic operations on the MD deck from a PC and to edit the disc on the PC screen. You can also enter Kanji / Hiragana from the PC keyboard using the included operation software. In addition, you can record CD → MD/PC CD → MD, manage music content on the hard disk using the database function, record to MD, and create MD labels.
There is a connector on the front of the body that can be connected to a commercially available DOS/V PC keyboard (PS/2 connector), including a Sony character input keyboard.
Wireless remote control is included.
The SCMS (Serial Copy Management System) allows digital recording only for one generation and does not allow digital recording for the second or later generations. However, some programs from CS broadcasting cannot be recorded.
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Model Rating
| Type | MD deck |
| A/D converter | 24-bit ⊿∑ |
| D/A converter | Hybrid pulse D/A converter |
| Voice compression system | ATRAC/ATRAC3 |
| Recording and playback time | Stereo : up to 320 minutes (MDLP LP4 mode) Monaural : up to 160 minutes |
| Frequency characteristic | 5 Hz to 20 kHz ± 0.3 dB |
| Dynamic range | 96 dB or more (during playback) |
| Signal-to-noise ratio | 98 dB or More (at Playback) |
| Total harmonic distortion factor | 0.006% or less (during regeneration) |
| Wow and flutter | Measurement limit (0.001% W peak) or less |
| Input terminal | Line : 1 system Optical digital : 2 systems |
| Output terminal | Line : 1 system Optical digital : 1 system Headphone : 1 system |
| Power supply voltage | 100 VAC, 50Hz/60Hz |
| Power consumption | 9W |
| External dimensions | Width 430x Height 95x Depth 285 mm |
| Weight | Approx. 3.1 kg |
| Attachment | Wireless Remote Control RM-D46M |
| Sold Separately | PC Connection Kit PCLK-MN10 (¥ 15,000) |