SONY MDS-JB920

Commentary

This MD deck inherits the high sound quality design of the ES series.

In order to make maximum use of the ATRAC audio compression technology format and to further improve sound quality, we have introduced wide bit stream technology using the ATRAC 4.5 generation DSP as a key device.
With 24-bit input / output and extended operation word length = 24-bit (data) x24-bit (coefficient), recording and playback with a wide dynamic range of 20-bit accuracy is possible.

For the DSP for the 4.5 generation ATRAC, we have newly developed an adaptive high-frequency control technology to improve high-frequency reproducibility and natural sound spread. This technology effectively uses limited data based on the human auditory sense. In response to an input signal, if the number of quantization bits is small, the high-frequency range is limited and the number of quantization bits is increased for a signal that feels distorted, and if the number of quantization bits is small, the high-frequency range is limited and the number of quantization bits is increased. In response to a signal containing a complex frequency component that is less affected by the lack of quantization bits, the reproduction band is extended to higher frequencies to improve high-frequency reproducibility.
The signal processing system has been improved by the combination of this adaptive high-frequency control technology and the extension of the operation word length in the wide bit stream, and the total harmonic distortion rate has been improved by about 8 dB compared to the conventional system.

The newly developed S-TACT IC is used for the pulse generator. This realizes the separation and independence of the noise shaping (digital part) and pulse generation (analog part) which were conventionally composed of only one IC. The IC is composed of only a pulse generation circuit and a clock generation circuit, thereby suppressing the effect of digital noise on the time axis direction of the pulse.

It is equipped with a sampling rate converter that automatically converts 32 kHz and 48 kHz sampling frequency to 44.1 kHz.

The D/A converter uses the current pulse D/A converter used in Sony's ES series CD players.
It is transmitted by replacing it with a current that is output as a voltage and is less affected by pulse voltage noise. It has a stable current source and is not affected by voltage fluctuations, making it possible to achieve excellent low-frequency reproduction.

In order to reduce the resonance of the circuit board, a slant (non-parallel) mounting circuit board is adopted. This is a method of reducing the sound pressure applied to the circuit board by making the circuit board and chassis non-parallel, which greatly reduces the resonance.

The power supply section uses an R-core transformer with no breaks in the iron core of the transformer and a circular doughnut type in cross section to greatly reduce magnetic flux leakage and vibration.

Uses an eccentric insulator whose mounting hole to the chassis is offset from the center.
As a result, the vibrations transmitted from the outside cancel each other, making it difficult for them to be transmitted to the chassis. In particular, it is effective in attenuating the vibration components in the middle and high range that affect the sense of hearing.

Equipped with digital REC level control, the gain can be controlled from - ∞ dB to + 12 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.

Equipped with a pitch control function, you can listen at different playback speeds from -98.5% to + 12.5%.

It is equipped with a music sync function. When you press the music sync button on the remote control and the connected device starts playing, it senses the input of a music signal and automatically starts recording.

It is equipped with a time machine recording function. If you press the multi-jog dial in the recording pause state, the sound recorded on the disc is traced back to the sound of up to 6 seconds before.

Equipped with a monaural recording and playback function that allows the disc to be used twice as long as the display.

It has a TOC EDTI function that allows you to divide, combine, and move songs. It also has an UNDO function that allows you to cancel the last edit and redo it.
It is also equipped with a rehearsal function so that you can make decisions while checking edit points in COMBINE or DIVIDE. You can move edit points finely by minute, second, or frame (approximately 0.01 second).

Equipped with the A-B ERASE function that allows you to easily 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 conventional alphabets, numbers and symbols, katakana characters can also be input, and input can be done from the main body or remote controller.

The SCMS (Serial Copy Management System) allows digital recording only for one generation and does not allow digital recording for two or more generations.

It uses a 2-line FL display that separately displays track name and elapsed time, disc name and track name, track name and program step in two upper and lower columns.

Equipped with a Control A1 connector, it can be combined with a Sony CD player equipped with a Control A1 connector to enable easy recording from CD to MD using the Rec IT function and CD TEXT copying function.

It is equipped with a smart space function that automatically adjusts silence periods of 3 seconds or more to approximately 3 seconds during digital recording.

Equipped with a timer standby function that can be combined with an optional timer for recording and playback.

Connection with a PC is possible by using MD-PC link kit PCLK-MD1 (sold separately).
By using this function, basic operation of MD deck, editing of disc, character input, etc. can be done from PC.

There are 2 color variations, black and gold.

Wireless remote control is included.

Model Rating

Type	MD deck
A/D converter	20-bit ⊿∑
D/A converter	Current pulse D/A converter
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	98 dB or More (at Playback)
Signal-to-noise ratio	100 dB or more (during playback)
Total harmonic distortion factor	0.003% 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 Coaxial digital : 1 system Headphone : 1 system
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption	16W
External dimensions	Width 430x Height 108x Depth 285 mm
Weight	Approx. 4.9 kg
Attachment	Wireless Remote Control RM-D18M
Sold Separately	MD-PC Link Kit PCLK-MD1 (¥ 15,000)