SONY CDP-X7ESD

Commentary

This CD player was developed as an integrated new reference model following the separate R1 by putting in the technology cultivated in CDP-R1 and DAS-R1.

Digital sync ICs are used to reduce jitter that occurs when digital signals are transmitted.
In the digital sync IC, the timing of the digital signal generated by the signal processing LSI is adjusted to the accuracy of the master clock immediately before the D/A converter. The master clock that determines the time axis accuracy of the signal is directly connected to the D/A converter. By adjusting the timing to the accuracy of the clean master clock that does not include jitter, the digital signal is adjusted again and output to the D/A converter. Since the effect of jitter does not affect the D/A converter and beyond, D/A conversion with accurate phase and faithful D/A conversion is possible.

The digital filter is equipped with CXD 1244 which is an 8 fs 45-bit noise shaping digital filter.
This digital filter performs 8 times oversampling and resamples the signal from 44.1 kHz to 352.8 kHz (8 times the sampling frequency) to increase the distance between the audio signal and the unwanted high-frequency components. This enables the use of a low-order low-pass filter with gentle cut-off characteristics in the analog portion after D/A conversion, greatly improving the group delay characteristics.
The CXD 1244 achieves the in-band ripple characteristics of ± 0.00001 dB and the echo level of -124dB or less due to its 45-bit high-order computing capability.

The CXD 1244 is capable of performing extremely high-precision operations with a 45-bit operation bit length. However, since the D/A converter can have only a limited number of bits, round-off errors occur and remain as quantization noise. To solve this problem, we have adopted a high-resolution D/A converter with excellent characteristics and introduced a noise-shaping method, which is incorporated into the CXD 1244.
Noise shaping takes advantage of an over-sampling time interval to incorporate low-order bit information that is normally lost by round-off errors into high-order data.

Equipped with digital de-emphasis function.
In digital de-emphasis, the de-emphasis process conventionally composed of analog circuits is digitally processed inside the digital filter, eliminating sound quality degradation caused by parts and circuits, and achieving ideal gain and phase characteristics.

The D/A converter IC is equipped with a high-precision linear D/A converter.
This is a high-speed operation type that corresponds to the data output speed of the 8 fs digital filter. It enables more advanced D/A conversion. This improves linearity for small-level signals. In addition, this D/A converter is an IC composed of one chip with high stability of conversion operation and realizes linear operation from the most significant bit to the least significant bit. Therefore, there is no nonlinear element in the input / output characteristics in principle. This eliminates the need for additional circuits such as gain switching and simplifies the analog circuit section.
In addition, by making the left and right channels independent of each other, the phase shift between the channels is eliminated.

The audio circuits after the D/A converter are twin-mono in accordance with the signal flow, eliminating phase shift and mutual interference between channels.
In addition, the CDP-X7ESD uses an ES substrate that prevents adverse effects on sound quality due to internal vibration and electrostatic floating capacity, and uses high-strength glass epoxy that has excellent humidity and temperature characteristics.

The power supply section is equipped with two large and large-capacity transformers that independently house the digital / servo section and audio section, thereby eliminating interference from the power supply.

The pickup mechanism uses a linear motor tracking mechanism that enables high-speed access with quiet operation.
The mechanism uses an aluminum die-cast base unit to effectively suppress unwanted vibrations and further improve trace stability. In addition, the entire base unit has a floating structure with double suspension containing highly viscoelastic gel rich in vibration absorption, strictly eliminating the influence of external vibrations.

The servo circuit is equipped with S Servo III.
The SS Servo III, noise components that cause adverse effects are removed through a low-pass filter, and the influence on the audio circuit is reduced by sending a smooth servo current to the servo circuit. Moreover, unnecessary vibration of the optical system mechanism is also suppressed.

A damper made of a special rubber material is installed in the opening of the front panel where the disk tray is stored to improve airtightness when storing the tray. This eliminates the effect of air vibration entering from the front.

The chassis structure uses the FB chassis, which follows the trend of the separate CD player R1. In addition to selecting members with sufficient thickness and strength, the entire chassis is firmly joined by the frame surrounding the outer circumference and the beams before and after passing the front and rear to ensure high strength.
In addition, the CDP-X7ESD employs a new construction that further develops the idea of no vibration and no resonance. In this construction, the power transformer, which tends to be a source of vibration and noise, is placed on the left side farthest from the audio board, and the mechanical deck, which tends to be susceptible to vibration from the floor, is placed closer to the center, away from the insulator.
In addition, as a countermeasure against high-frequency noise, the digital circuit board and audio circuit board are separated by a shield plate, the FL display is placed under the mechanical deck, and the internal chassis is entirely plated with copper.
The selenium mic insulator is used for the leg part to increase stability.

You can use the program edit function from the remote control.
In program edit, you program the songs you want to put on the A side of the tape in the order you like, then press the pause button and continue to program the B side.

It is equipped with a manual fader function that can be operated from a remote control, and fade in / out is possible within approximately 5 seconds from where the button is pressed.

It has a custom file function.
The custom index allows you to set an index of up to 10 points at any location on a single disk, even if no index information is recorded on the disk itself. The index set includes a rehearsal function that allows fine tuning in steps of approximately ± 0.15 seconds.
In the Program Bank, you can directly record a program set with the Program Performance function that can play up to 20 songs continuously. You can call up the program with the File Recall button, or you can directly bank the contents of a program set with Custom Edit.
The CDP-X7ESD does not have a disk memory function.

The File Recall function can be operated from the remote control so that you can check what files have been stored so far without having to insert a disk.
This allows you to check without having to insert a disk, and also to erase the file contents on the spot.

Equipped with a multi-mode timer function, you can start from your favorite music, shuffle play and repeat.
By combining the custom index function, it is also possible to play the alarm clock with any phrase.

There are two types of analog output terminals, fixed and variable. Gold-plated terminals are used.
It also has a balanced output terminal.

Equipped with headphone terminal with lineout linked volume.

It is equipped with two digital outputs which are coaxial with the optical system.
The digital output can be switched on / off, and the coaxial digital output has a latch for time axis compensation just before the output, making it a latched digital output in which minute jitter components are eliminated more strictly.

Equipped with a display on / off function that turns off the FL display when necessary.

Wireless remote control is included.
This remote control allows for delete shuffle and 6-mode repeat of one song, all songs, part (remote control only), program, shuffle, and custom index.

Model Rating

Type	CD Player
Reading system	Non-contact optical reading (using semiconductor laser)
Laser	GaAlAs double hetero diode
Number of revolutions	200 ~ 500 rpm (CLV)
Playing speed	1.2m/s ~ 1.4m/s (constant)
Error correction method	Sony Super Strategy Cross Interleaved Read-Solomon Code
Number of channels	2 Channel
Frequency characteristic	2 Hz to 20 kHz ± 0.3 dB
Total harmonic distortion factor	0.0015% or less (EIAJ)
Signal-to-noise ratio	115 dB or more (EIAJ)
Dynamic range	100 dB or more (EIAJ)
Channel separation	115 dB or more (EIAJ)
Wow and flutter	Below the measurement limit (± 0.001% W. peak) (EIAJ)
Output level	2Vrms(Fixed) 0 V ~ 2 Vrms (Variable) 2 vrms (Balanced out, Fixed)
Digital output	Coaxial : 0.5Vp-p/75 Ω Optical : -18dBm (emission wavelength 660 nm)
Headphone output level	28 mw (32 Ω)
Power consumption	22W
External dimensions	Width 470x Height 125x Depth 375 mm Side Wood Removal : Width 430 mm
Weight	17.0 kg (Including Side Wood)
Attachment	Wireless Remote Control RM-D770