SONY CDP-MS1

Commentary

A CD player that can tune up sound with a digital equalizer and variable digital filter.

Equipped with a 3-band digital equalizer.
In this circuit, the data is converted into 24 bits immediately after the signal is read from the disk, and the sound quality can be adjusted with a 3-band parametric equalizer that can independently adjust Bass, Mid and Treble. Bass and Treble are shelving type, and Mid is peaking type. The peaking type Mid has a slope (Q value) that can be selected from 3 levels (W (wide), M (mid) and N (narrow)). By combining the 3 bands and tuning, the sound quality balance can be adjusted more finely than that of an analog graphic equalizer.
Tuning can be adjusted from the listening position using the included remote control.

The digital filter is equipped with a 24 bit variable digital filter.
In the variable digital filter, you can select filter characteristics according to your preference by registering multiple calculation formulas with different cutoff characteristics and phase characteristics.
In CDP-MS1, 24-bit processing is realized by using the newly developed device VC24. In addition to as a digital filter is dramatically improved by increasing the calculation speed and expanding the coefficient simultaneously in addition to greatly expanding the calculation vocabulary. Four positions are selectable in total. In addition to the standard position with sharp roll-off characteristics, you can choose No1 clear, No2 plain, or No3 fine with slow roll-off characteristics.

You can use the player's custom file function to store the tuning data of the digital equalizer and the selected position of the 24-bit variable digital filter up to 500 discs.
By simply loading the disc, the stored settings are recalled from memory and can be played back in a tuned state.

The D/A converter is equipped with a current pulse D/A converter.
In this method, a stable current source is prepared, and the current pulse is generated by switching using the output of the pulse generator. Since the current pulse is independent of voltage fluctuation, it is not affected by the voltage noise of the arithmetic circuit.

The mechanism uses a top-loading optical system fixing mechanism. The disc is mounted by sliding the lid of the top panel and fixed with a stabilizer.
The disk, lid, and chassis are not parallel to each other, but are designed at different angles to eliminate resonance.

A high-precision digital servo is used for the servo circuit, and by adjusting the servo amount of the optical pickup for each disc being played, servocontrol reflecting disc conditions more accurately is realized.

The chassis has an Anti Standing-wave Construction (ASC) structure.
In this method, not only each surface of the chassis but also the internal substrate is a slant mount substrate, eliminating parallel surfaces and suppressing standing waves generated by repeated reflection of vibrations such as sound waves on parallel surfaces.

The power supply section uses an R-core transformer with greatly reduced magnetic flux leakage and vibration, reducing the strain generated in the power supply section.

An eccentric insulator is used for the legs.
This insulator has a structure in which the mounting hole of the chassis is offset from the center, and the vibration transmitted to the chassis is reduced by mutually canceling the vibration transmitted from the outside.

A fine drive circuit is adopted, and noise contamination to the earth line is prevented by configuring the disk rotation system and the drive circuit of the optical pickup with balanced push-pull capable of canceling in-phase noise.
In addition, a digital minimum board has been adopted to reduce the impact on the audio section by arranging the digital circuit board in the minimum volume, separating it from the audio circuit board and placing it on the mechanical deck.

A static lighting FL tube that does not blink is adopted for the part where there is no change in the display to reduce the noise generated in the display.

It is equipped with various functions such as shuffle play and delete shuffle.

A 3-step volume switching headphone jack is installed on the back.

Equipped with 3 types of digital outputs : optical, coaxial and balanced.
These jacks allow you to output signals that have been adjusted using a digital equalizer. You can also turn off unused digital outputs to prevent interference with analog and other digital outputs.

Wireless remote control is included.

Model Rating

Type	CD Player
D/A converter	Current pulse D/A converter
Digital filter	Variable digital filter
Frequency characteristic	2 Hz to 20 kHz ± 0.3 dB
Dynamic range	100 dB or more (EIAJ)
Total harmonic distortion factor	0.003% or less (EIAJ)
Wow and flutter	Below the measurement limit (± 0.001% W. peak) (EIAJ)
Digital output	Light : -18dBm (emission wavelength 660 nm) Coaxial : 0.5Vp-p/75 Ω Balance : 5V/50k Ω
Analog output	Variable : 2.1 Vrms to 0.5 Vrms
Headphone out	28 mw (32 Ω load)
Pwer	100 VAC, 50Hz/60Hz
Power consumption	18W
External dimensions	Width 430x Height 125x Depth 260 mm
Weight	Approx. 7.5 kg
Attachment	Wireless Remote Control RM-MS1

　

Position and outline of variable digital filter

Position	Cutoff characteristic	Sound impression
Sharp roll-off
Standard		It has the largest amount of information and is characterized by its wide range and spatial expression. Suitable for playing classical music.
Slow roll-off
No1 Clear		It a smooth touch and energy feeling, sound image localization is clear. Suitable for jazz band, jazz vocal, etc.
No2 Plain		It is fresh and energetic, and especially rich in expressive power of the luster of vocals. It is suitable for vocal music.
No3 Fine		It has a balanced natural sound with a sense of scale and rich reverberation. Perfect for enjoying a relaxed mood regardless of the genre of music.

Variable range of the digital equalizer

Bass	Variable level ± 6.0 dB	Turnover frequency 50 Hz to 560 Hz
Mid	Variable level ± 6.0 dB	Turnover frequency 90 Hz to 10.0 kHz
Treble	Variable level ± 6.0 dB	Turnover frequency 1.4 kHz to 14 kHz
Output	Variable level -9.0 to + 3.0 dB