Comparison Denon DCD-600NE vs Cambridge AXC25

The model of the digital-to-analogue converter (DAC) installed in the CD player.

The DAC is one of the most important components of any modern CD player. It is this module that is responsible for converting digital data recorded on an optical disc into an analogue audio signal that is fed to an external device (amplifier, speakers, etc.). Accordingly, the characteristics and overall quality of the DAC largely determine the sound quality in general. Knowing the DAC model, you can find detailed data on it — characteristics, reviews, test results, etc. — and evaluate how the capabilities of the converter meet your requirements.

The audio file formats that the player can handle. This list includes popular formats MP3, WMA, AAC, OGG, WAV, FLAC, but is not exhaustive.

— MP3. The most famous of modern digital audio formats; supported by almost all devices. Provides so-called. lossy compression, where some of the audio frequencies are lost. However, during compression, the sound is processed in such a way that it "disappears" mainly frequencies, the loss of which is imperceptible to the human ear.

— WMA. An audio format that was once specially created for the Windows operating system. The default is lossy compression. WMA is especially suitable for low bitrates, under such conditions it provides better quality than MP3 and takes up less space. On the other hand, in high-quality digital audio, this format is much less popular.

— WAV. Another popular audio standard, originally developed for storing sound on a PC. It can technically be used to store audio in a variety of formats, but is most commonly used for uncompressed audio. Due to this, the sound quality can be quite high, and its processing does not require special computing power. The downside of this is the large volume of audio files — many times more than MP3s.

— AAC. A format d...eveloped as a potential successor to MP3. Also provides lossy compression (see above), but allows you to achieve better quality with the same file size; this difference is especially noticeable at low bitrates. Actively promoted by Apple; nevertheless, it is noticeably inferior to MP3 in terms of prevalence.

— OGG. A lossy compressed digital audio format is one potential alternative to MP3. One of the key features of OGG is that as audio is encoded, the bitrate is constantly changing; at the same time, on fragments where there is no sound, the bitrate drops to almost zero (unlike MP3, where the data stream is constant, including in sections of complete silence). This allows you to achieve small file sizes while maintaining sound quality. Also note that the OGG format is open and not limited by patents.

— FLAC. One of the formats that uses lossless audio compression. With this compression, all the details of the original sound are preserved, so lossless formats are especially appreciated by sophisticated music lovers and audiophiles. The reverse side of this quality is large volumes of files. Specifically, FLAC is perhaps the most common of today's lossless formats. This is largely due to the fact that this standard is not particularly demanding on the processing power of the player. Thanks to this, its support can be implemented even in relatively simple and inexpensive players (unlike another popular format — APE, see below). On the other hand, FLAC files are larger than APE files.

— A.P.E. One of the popular lossless audio compression formats. Compared to another common standard — FLAC (see above) — APE allows you to achieve smaller file sizes with the same quality. On the other hand, to play such files, electronics with a fairly high processing power are required, so APE compatibility is relatively rare in compact players.

This list

Sampling frequency of a digital-to-analogue converter (DAC) installed in a CD player.

A DAC is an indispensable element of any system designed to reproduce digital sound. Such a converter is an electronic module that translates sound information into analogue pulses fed to speakers through amplification stages. The technical features of such a conversion are such that the higher the sampling rate, the better the signal at the output of the DAC, the less it is distorted during conversion. And in the case of CD players, this indicator must also be no lower than the sampling rate of the reproduced digital sound — otherwise the device simply will not be able to "digest" digital data from the media. So, an indicator of 92 – 96 kHz allows you to listen to CD-Audio (sampling frequency 44.1 kHz), but for DVD you need at least 192 kHz. In the most advanced DACs, the sampling rate can be 384 kHz. The latter, however, is rare: in most cases, high frequency is not critical, and such electronics are expensive.

Another indicator that determines the overall quality of the digital-to-analogue audio signal converter. For details on the converter, see "DAC Sampling Rate"; here we note that the bit depth is standardly expressed in bits, and the higher it is, the more accurately the signal at the output of the DAC corresponds to the original signal and the less distortion is introduced into it. In the case of CD players, 24 bits is considered the minimum necessary and at the same time quite sufficient; higher values — 32 bits — are rare, only in premium-level equipment.

The range of audio frequencies that a CD player can reproduce. In general, this parameter determines how full the output bandwidth is, whether too high or too low sound is cut off. However, it is worth noting here that the human ear is able to perceive sound only within the range of 16 – 20,000 Hz (deviations from the upper threshold in different directions are possible, but small, and it decreases with age). All modern CD players cover this range, therefore, in the case of such devices, the sound frequency indicators are reference and practically do not affect the sound. And impressive numbers like 2 – 40,000 Hz, 5 – 60,000 Hz, etc. — this is a kind of "side effect" of the design of a high-quality device; manufacturers use these numbers for marketing purposes, but again, they do not affect sound quality. Also, do not forget that actually audible frequencies are also limited by the characteristics of the speaker system, external amplifier and other equipment connected to the CD player. For example, speakers with a lower frequency range of 150 Hz will “cut off” all lower frequencies, and it doesn’t matter what the lowest bass the player can produce is 16 Hz, 20 Hz or 50 Hz.

The ratio between the level of the useful signal and the level of extraneous noise at the output of the player.

This indicator describes the total amount of extraneous noise (of any origin) that affects the sound quality: the higher the signal-to-noise ratio, the less such noise and the clearer the sound, which is especially important for Hi-Fi and Hi-End systems. The minimum indicator for CD players is 85 – 90 dB, indicators up to 100 dB can be considered good, up to 110 dB — good, more than 110 dB — excellent.

The dynamic range of a CD player.

Technically, dynamic range is the logarithm of the ratio between the maximum input signal at which the level of distortion is low enough (tolerable) and the sensitivity of the amplifier. In a simplified way, this parameter can be described as the difference between the minimum and maximum sound levels that the device is capable of reproducing with high quality. The higher the dynamic range value, the better the device handles with sound that has significant volume differences, such as orchestral parts.

Note that when playing different sound standards (see "Playback"), the dynamic range of the player will also be different — for example, for SACD its value is usually much higher than for Audio CD. CD players typically list the highest value that gives the best impression of the device's performance. However, manufacturers often specify for which type of digital audio the dynamic range data is given.

The coefficient of harmonic distortion (harmonics) output by the CD player.

This parameter, along with the signal-to-noise ratio described above, characterizes the overall sound quality of the player. It is calculated by dividing the total sum of harmonics by the value of the main signal at a reproduced sound frequency of 1 kHz, and is expressed as a percentage. Significant levels of harmonics lead to deterioration in sound — from a general feeling of "roughness" and "excessive density" of the sound to the appearance of clearly audible noise; accordingly, the lower the harmonic distortion, the better. In relatively inexpensive CD players, this figure is measured in tenths of a percent, in top models it may not exceed several thousandths of a percent.

Outputs provided in the design of the CD player (in addition to analogue connectors for connecting general-purpose acoustics — they are described in separate paragraphs below).

— Coaxial S / P-DIF. Interface for transmitting sound in digital format. Allows you to work with multi-channel audio up to 7.1 format inclusive. Technically an electrical variation of S/P-DIF; differs from the optical variety described below, on the one hand, by greater sensitivity to electromagnetic interference, and on the other hand, by a less delicate connecting cable. Note that this interface uses RCA connectors and a coaxial cable (hence the name). However, unlike "regular" analogue RCA (see below), in this case, all audio channels are transmitted over a single cable, and the cable itself must be shielded — when connected through a regular wire, there is a high probability of distortion due to external interference.

— Optical. A modification of the S/P-DIF standard (see above), which involves signal transmission via a TOSLINK fiber optic cable. Being identical to the coaxial interface in terms of audio transmission capabilities, the optical connection is at the same time completely immune to electromagnetic interference, which makes it possible to achieve extremely high signal fidelity. The disadvantage of this connection is the fragility of the cable — it does not allow sharp bends and strong pressure, whic...h can damage the fiber.

— Balanced digital (AES/EBU). The AES / EBU standard itself can use different connection interfaces, however, XLR connectors are usually used in audio equipment. However, unlike the "regular" XLR output (see below), this interface transmits audio in digital format, not analogue. A common feature of these standards is a balanced connection, which provides noise suppression due to the characteristics of the cable itself, has a positive effect on sound quality and at the same time allows the use of fairly long wires. AES/EBU is considered a professional interface; such an output can be useful, for example, for connecting a CD player to a high-end external amplifier.

— Trigger. A service output used to turn on other components of the audio system (for example, an amplifier) at the same time as a CD player. When the player is turned on, this output sends a signal to the input of the controlled device and wakes it up, saving the user from having to press extra buttons. This is especially useful if the device being controlled is located in a hard-to-reach place.

— Headphones. Output for connecting conventional audio headphones. There is no single standard for such a connector, however, the vast majority of both players and “ears” use one of the varieties of the Jack type connector — full-size 6.35 mm or mini-Jack 3.5 mm. At the same time, in stationary audio equipment, including CD players, the full-size version is quite common, but 3.5 mm plugs are very popular in headphones — they can be connected both to the “native” jack and to the 6.35 mm jack, through a simple adapter (many models even come with adapters. Anyway, the ability to listen to music through headphones will be useful in cases where loud sounds are undesirable — for example, at a late time when others are sleeping, or if there is a small child in the house.

— Subwoofer. Separate output for connecting an active subwoofer — a specialized low-frequency speaker with its own built-in amplifier. The need to use subwoofers is due to the fact that general-purpose speakers do not cope well with low frequencies, as well as some acoustic features of these frequencies. And a dedicated output for such a speaker greatly simplifies the connection: this output is supplied with a filtered low-frequency signal, so you can do without crossovers and other external equipment (the only exception is a passive subwoofer, which will require an external amplifier for this connection).

— Control output (IR). Auxiliary output used in remote control systems. With this connector, the CD player's built-in IR receiver can be used to control other audio system components from the remote control, such as an amplifier in another room, out of range of the remote control. In fact, the player in such cases plays the role of a remote sensor, receiving commands and transmitting them through the control output to another device. Note that the very presence of control inputs and outputs does not guarantee the compatibility of various devices, especially if they are produced by different manufacturers; the nuances of sharing should be clarified according to the official documentation.

— BNC. By itself, BNC is a type of connector related to coaxial; similar in size to RCA, but differs in internal dimensions and mounting features. In CD players, a connector with such an output can be used both for outputting digital sound, similar to coaxial SP-DIF, and for working with special equipment for synchronizing digital sound pulses. The specific use case should be specified separately, there are both at once. Note that in the second case, the BNC output is responsible for switching the synchronization signals received by the CD player from an external clock generator to other devices in the audio system. For more information about synchronization, see "Inputs — BNC".

— Power output. This output is a power connector installed directly on the body of the player. From such a connector, you can power another component of the audio system — for example, an external amplifier or active acoustics; in some cases, this may be more convenient than connecting such components to the network separately. Please note that power plugs are usually different from standard 230 V sockets and are not compatible with plugs for such sockets.