Comparison Denon DCD-A110 vs Denon DCD-2500NE

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.

Inputs provided in the design of the CD player.

Note that the specific use of the inputs used for audio transmission varies by model. So, in some cases, it is possible to process sound with the built-in means of a CD player (adjusting the balance, frequencies, etc.); in others — signal conversion from analogue to digital format or vice versa (for example, broadcasting sound from the optical output of a Blu-ray player to acoustics), in others — real-time recording of the input signal, etc. But for service connectors, the purpose is quite clear.

Specific types of inputs can be as follows:

— Mini-Jack (3.5 mm). A standard connector widely used in modern audio equipment and other electronics, mostly portable. Technically, the mini-Jack input can be used for different types of signal, but in fact in CD players it most often plays the role of a line interface and is mainly used to connect the mentioned portable equipment — for example, audio players.

— Trigger. Service input used to automatically turn on the CD player. If you connect this input to the trigger output of another audio system component (for example, an audio receiver), this component, when turned on, will supply a control signal to the player and wake it up. In other words, the control device and the player will turn on at the same time, at the touch of a button — this is more convenient than turning on th...e equipment separately.

— 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 one described below, on the one hand, by greater sensitivity to electromagnetic interference, on the other hand, by a less delicate connecting cable. Note that this interface uses RCA connectors and a coaxial cable. However, unlike the "regular" analogue RCA (see above), in this case, all audio channels are transmitted over a single cable, and the wire itself must be shielded — when connected through a regular wire, there is a high probability of distortion due to interference.

— Optical. A modification of the S/P-DIF standard (see above), which involves signal transmission via a TOSLINK fibre 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, which can damage the fibre.

— Balanced digital (AES/EBU). Digital audio output in balanced format. This format provides noise immunity even with a long cable length, which is especially important in professional applications; in fact, the presence of an AES / EBU input indicates a rather high class device. Technically, this interface can use different connectors, but CD players usually use XLR jacks and plugs. From the "normal" (analogue) XLR, such a connection differs, in fact, in a digital format.

— RCA. Similar to the RCA outputs (see above), in this case we mean an interface for transmitting an analogue audio signal in the “one wire per channel” format, and one input is a pair of connectors for the left and right stereo sound channels.

— Control input (IR). Connector for connecting an external infrared remote control receiver. When properly placed, such a receiver will allow you to use the remote control even in places where the signal from the remote control cannot reach the main (built-in) sensor — for example, in another room. Note that not only individual sensors can be used as external receivers, but also other components of the audio system that are compatible with the remote control — for example, receivers or tuners.

— BNC. A type of coaxial connector used for various purposes. However, in this particular case, the BNC input is most often provided for working with an external clock generator responsible for timing the digital audio signal pulses. The need to use such equipment is due to the fact that when transmitting a signal between the components of an audio system, for various reasons, deviations of pulses in time may occur. This phenomenon is called "jitter". Deviations, it would seem, are very small (measured in picoseconds), but even such a small thing can significantly degrade the sound quality and increase the noise level. To avoid this, premium audio systems can use an external clock generator: by transmitting service pulses to other components, it sets the “general rhythm” under which the data packets move, and prevents desynchronization. To connect such a generator, a BNC input is usually provided. However, in some models this connector can also be used as a digital audio input, similar to the S / P-DIF described above.

— XLR. Formally, XLR is the name of a connector that has a round shape, several pins and a retainer to hold the plug in the socket. However, in this case we are talking about a very specific interface: an audio input with a three-pin plug used for balanced connection of an analogue audio signal. The peculiarity of this connection is that the cable itself plays the role of an interference filter, which allows you to transmit an audio signal with high reliability even over a rather long wire. At the same time, such reliability is rarely required for ordinary consumer audio equipment, so XLR is considered to be a professional connector. Note that, like RCA, in this case, one channel of sound is transmitted through one connector, and the standard XLR input consists of two jacks (for a stereo signal).

The power consumed by the CD player. Usually, unless otherwise noted in the notes, this refers to the power during normal operation. Note that the actual power consumption at a particular point in time may differ from this indicator — for example, when a model with its own power amplifier (see "Built-in amplifier") is operating at low volume or vice versa, when playing a song with sudden volume jumps. However, when organizing the power supply of the audio system, it is necessary to focus on this indicator.

Note that the power consumption cannot be lower than the power of the built-in amplifier (if present, see above). However, some manufacturers may go for tricks — for example, indicate power consumption only in preamplifier mode. As a result, the power consumption stated in the specifications is significantly lower than the actual value when the amplifier is turned on (and sometimes even lower than the rated power of the amplifier alone). In such cases, the actual power consumption can be estimated by adding the claimed power consumption to the power of the amplifier and taking a margin of 20 – 30% for energy losses due to non-perfect efficiency of electronic circuits. For example, for a 50 W model with a 2x60 W amplifier, this value will be about 200 ... 220 W (50 + 2x60 \u003d 170, plus a loss correction).