SONY CDP-C315M
¥ 29,800 (released in 1991)
Commentary
A mini component size CD player with a CD roulette function.
The disc tray features a CD roulette that allows you to load five discs at once, allowing you to play five discs in a row, play programs across five discs, and play shuffles.
The D/A converter consists of a high-density linear converter system, a 45-bit noise-shaping digital filter and a pulse D/A converter.
The CDP-C315M uses a single-mode pulse D/A converter. A single pulse D/A converter provides a 4D/A output that outputs positive-phase and negative-phase signals for each LR.
The Pulse D/A converter consists of a current source and an electronic switch. It expresses music waveform by switching two values of 0 and 1 at high speed. By this, the amplitude level is always constant and changes only in the time axis direction. The PLM (Pulse Length Modulation) wave is output. By passing it through a low-pass filter, unwanted high-frequency noise outside the audio band is removed and music waveform is obtained.
To reduce quantization noise in the audible band up to 20 kHz, the pulse D/A converter is equipped with a multi-stage noise shaping operation that employs 64 times oversampling and the Sony Extended Noise Shaping method. Oversampling reduces quantization noise in the audible band by increasing the sampling frequency. Noise shaping reduces quantization noise in the audible band by feeding back the requantization error to the input side when the number of bits is reduced. These technologies ensure a high dynamic range.
The pulse D/A converter operates at 45 mega pulses per second, and it completely eliminates differential non-linear distortion, glitch, and 0 cross distortion, which were difficult with conventional methods.
A 45-bit noise-shaping digital filter is installed in front of the pulse D/A converter to ensure a high dynamic range by performing high-precision oversampling operation and first order noise-shaping operation on the operation result.
A direct digital sink is included to eliminate jittering issues.
In this system, the master clock is formed on the same chip as the pulse D/A converter, and jitter is eliminated in principle by eliminating jitter immediately before the electronic switch, which is the final stage of the pulse D/A converter.
The servo circuit is equipped with S Servo III.
In the S Servo III, the high-frequency noise component of the servo current is removed with a low-pass filter to supply a smooth servo current, which stabilizes the power supply from the power supply and prevents adverse effects on sound quality.
A digital CLV servo is installed in the drive system servo circuit that controls disk rotation.
The digital CLV servo detects the rotation of the spindle motor and controls it with 10-bit resolution to maintain an accurate linear velocity regardless of the disk's inner or outer circumference. It also detects the difference in inertial mass between the 12 cm CD and 8 cm CD disks to drive more appropriately.
Low noise and high stability are achieved by incorporating an RF amplifier in the pickup section.
The digital signal processing LSI uses the fourth generation LSI for the Sony CD player. Previously external RAM has been upgraded to a capacity of 32 kbit and built into the digital signal processing LSI. The precision of the signal processing capability is further enhanced by adopting the strict 6-fold error correction method.
It has a custom edit function and eight functions : peak search, time edit, program edit, multidisk program, link edit, time fade, variable fade, and manual fader.
In peak search, all songs are searched at high speed, and they are repeatedly played for about 4 seconds before and after the point where the volume level is highest.
Time Edit enables efficient editing of the A-side and B-side when recording tapes.
If you want to edit to fit the length of your tape, use the TIME SET button or AMS button to set the length of the tape (you can also use the direct key to set the length in seconds). Press the Edit button. First, program from the first song for side A. When you encounter a time-over song, select the longest song that fits within the time. Then press the Edit button to edit side B.
Also, if you select and edit a half disk with the AMS button, tracks are distributed so that the A side and B side of the tape are about the same length without changing the order of the songs.
Program Edit allows you to manually edit your favorite songs in any order.
With the AMS key or direct key, you can program your favorite songs in any order while checking the accumulated time. If you turn on Auto Space at this time, you can edit each song by adding a 3-second blank to the playing time. When you press the pause button, you can program the A side and then the B side together.
Multi-disc programs allow you to enjoy your favorite songs in any order with up to 32 steps on 5 discs.
This function is only available between disks loaded in the tray.
Link Edit allows you to add music to the remaining tapes from Time Edit or Just Edit.
If you have programmed all songs and there is room for more songs within the editing time, the track number of the song to be entered and the LINK display will blink, and you can add a song by reselecting from the songs with the blinking track number.
Link-edit also allows you to swap disks and continue editing.
Time Fade allows you to fade out at a specified time, which can be set with the TIME SET button or the AMS button.
You can set the fade-in / fade-out time for the variable fade from 2 seconds to 10 seconds in units of 1 second.
The manual fader allows you to fade in and fade out at the desired location.
Equipped with Music Search, you can fast forward / rewind while listening to music.
It is equipped with AMS function that can quickly start a song.
Equipped with 7-mode repeat function of 1 disc All Tracks / All Discs / All Disc Programs / 1 disc Shuffle / All Disc Shuffle / Select Disc Shuffle / 1 song.
The display has a 5-disc + 20-track music calendar.
Equipped with a headphone port with volume.
Wireless remote control is included.
Model Rating
| Type | CD Player |
| Frequency characteristic | 2 Hz to 20 kHz ± 0.5 dB |
| Total harmonic distortion factor | 0.005% or less (EIAJ) |
| Signal-to-noise ratio | 100 dB or more (EIAJ) |
| Dynamic range | 98 dB or More (EIAJ) |
| Wow and flutter | Below the measurement limit (± 0.001% W. peak) (EIAJ) |
| Output level | 2Vrms(Fixed) |
| Headphone output level | 10 mW (32 Ω) |
| Power consumption | 12W |
| External dimensions | Width 355x Height 120x Depth 385 mm |
| Weight | 4.9kg |
| Attachment | Wireless Remote Control RM-D315 |