SONY CDP-XA50ES

Commentary

ES series CD player with fixed optical system mechanism and variable digital filter.

An optical system fixing mechanism has been adopted for the mechanism, and the optical pickup is fixed to the strong base part and the disk side is moved. This greatly reduces vibration of the pickup, and the current required for servo is limited to relatively slow movement to compensate for distortion and eccentricity of the disk, and the fluctuation of servo current is reduced.
In this system, the disk is fixed from above using a stabilizer to eliminate vibration of the disk, and a BSL motor with less rotational unevenness is used as the disk drive motor.
The CDP-XA50ES uses zinc die-cast as the pickup base to greatly reduce resonance and enhance the ability to reproduce minute sound.

The digital filter is equipped with a newly developed variable (V. C.) digital filter.
The cut-off characteristics and phase characteristics of digital filters can be set by equations, and sound quality can be changed by changing these characteristics. Therefore, we have registered multiple equations for newly developed digital filter ICs so that you can select your favorite position according to your audio equipment, room environment, and music.
In addition to the standard position with sharp roll-off characteristics, the ES series is equipped with No1, 2, 3, and 4 with slow roll-off characteristics. In addition, No3 and 4 can be selected from 3 levels each, for a total of 9 positions.

In the standard and spline positions of the variable digital filter, a full feed-forward digital filter is adopted.
This digital filter employs a three step coupling of a double-type digital filter, which first generates complementary data at the midpoint between the data obtained from the disk and the data, and then uses the resulting data to create the next complementary data. Conventional digital filters use only the high-order bits by rounding the low-order bits of the calculation results obtained here, but this rounding error causes requantization noise.
The full-feed-forward digital filter realizes an oversampling operation that also reflects low-bit data by performing a full-feed forward (FF) operation that combines the low-bit data with the result of the next stage operation. This eliminates almost all requantization noise in the audible band, greatly improving the quality of low-level signals.

A current pulse D/A converter is used for the D/A converter.
In this method, a stable and clean current source is prepared, and the current pulse is generated by switching using the output of the pulse generator. This eliminates the influence of voltage fluctuations and the influence of voltage noise in the arithmetic circuit, which are problems with conventional pulse D/A converters that use voltage.
It also employs a complimentary service PLM that differentially synthesizes the output of the pulse D/A converter to reduce harmonic distortion.

The line amplifier section employs a DC servo amplifier configuration that eliminates the coupling capacitor from the signal path. This eliminates the colorization characteristic of the capacitor and achieves stable amplification in the ultra-low frequency range.
The audio I-V conversion circuit op-amp has improved bandwidth and slew rate characteristics, and the buffer stage op-amp has reduced noise level and distortion, providing a sharp sound.

The servo circuit uses a high-precision digital servo, and by adjusting the servo amount of the optical pickup for each disc being played, servocontrol that more accurately reflects the disc condition is possible.

A fine drive circuit has been adopted for the disk rotation system and the drive circuit of the optical pickup, and it is composed of a balanced push-pull capable of canceling the in-phase noise, thereby preventing noise from entering the earth line.
In addition, the digital circuit board is reduced to a minimum volume, separated from the audio circuit board, and placed on the mechanical deck to reduce the influence on the audio.

A static type FL tube is used for the display where there is no change in the display.
This reduces the noise generated in the display area and reduces the influence on the audio circuit.

Two R-core transformers are installed in the power supply section, and mutual interference between circuits is reduced by feeding digital, servo system and audio system independently.
The R-core transformer has a circular doughnut type cross-section with no gaps in the iron core, greatly reducing magnetic flux leakage and vibration.

A center mechanical mounting system has been adopted for the internal layout, and the mechanical deck, which is the only mechanical operation section of the CD player, is placed in the center of the chassis to minimize the rotational moment applied to the chassis and improve the stability against vibration.

The FB chassis is used for the chassis, and the whole chassis is firmly fixed as one box by a frame (Frame = frame) surrounding the outer circumference and beams (Beam = beam) passed in front and back. By combining members of different shapes and sizes, natural vibrations are mutually cancelled, and vibration of the chassis as a whole is greatly reduced.
The top plate is equipped with a double-structured top plate.

An eccentric insulator is used for the legs.
This insulator is designed with the mounting hole offset from the center, and vibration propagation to the chassis is reduced by mutually canceling external vibration. The position and diameter of the hole are determined through repeated trial production and trial listening. This is particularly effective in attenuating mid - and high-frequency vibration components that affect audibility.

The rotary music selection method using the jog dial is used for AMS, which is used to cue a few songs before or after.
This makes it possible to make music selections that take advantage of the sense of the fingertips, such as quickly to the target music and slowly to the rest.

Equipped with a custom edit function, you can control functions such as peak search, time edit, just edit, program edit, time fade, manual fader and variable fade.

It is equipped with a custom file function and memory of custom index and delete bank is possible.
The maximum number of cards is 224.

It is equipped with functions such as delete play, shuffle play, delete shuffle, auto space, timer play (auto start), 8-mode repeat and index search.

It is equipped with two digital outputs which are coaxial with the optical system.

There are two analog outputs, fixed and variable.
In addition, it is equipped with a headphone port with volume that can also be used for lineout.

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	0.0017% 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
Analog output	Fixed : 2 Vrms Variable : 2 Vrms to 0 V
Headphone out	28 mw (32 Ω load)
Pwer	100 VAC, 50Hz/60Hz
Power consumption	18W
External dimensions	Width 430x Height 125x Depth 375 mm
Weight	Approx. 15.2 kg
Attachment	Wireless Remote Control RM-DM950

　

Position and outline of variable digital filter

Position	Cutoff characteristic	Phase	Impulse response	Type / Method	Sound impression
Sharp roll-off
Standard				Conventional Digital Filter / Full feed-forward system	Wide range Sense of spaciousness
Slow roll-off
No1 Spline				Cubic spline function / Full-feed system	Smooth feeling Sound image localization clear
No2 Plain				Requantization noiseless / Direct 8 x system	Fresh sound Strength
No3 Analog type				7th Butterworth / Direct 8 x system	An atmospheric warm sound Depth feeling
No4 Butterworth				Variable Butterworth order (5th to 9th) Linear phase / Direct 8 x system	A well-balanced and pleasant sound