DAC
Model of the digital-to-analogue converter installed in the device.
The DAC is one of the key components of any player: it converts the digital data recorded in the audio file into an analogue audio signal, which is fed through an amplifier to the headphones. The quality of the DAC directly affects how accurately the output sound will match the original signal, as well as whether the player can work with advanced digital signal formats: many of them require high computing power, which is not available in every DAC.
Note that the DAC model is indicated only if it is a high-end converter with above-average sound quality. On the modern market, in particular, DACs from such manufacturers are represented:
AKM,
Cirrus Logic,
ESS Saber,
Texas Instruments,
Wolfson. And players with such equipment usually refer to
Hi-Fi devices(see "Type").
It is also worth mentioning that the number of DACs can be different. The simplest option is
one module for both sound channels, however, there are players equipped with two converters at once — one per channel. This "division of labor" affects the cost, but reduces the load on each individual DAC, which has a positive effect on the quality and reliability of the sound.
Sampling frequency
Sampling frequency of the digital-to-analogue converter installed in the player (see "DAC").
Sample rate and bit depth are two key characteristics of a digital audio signal; the higher they are, the better the sound quality, other things being equal. Without going into technical details, the meaning of this parameter can be described as follows: for normal sound reproduction, it is necessary that the sampling rate of the player's DAC is not lower than that of the file being played. Otherwise, playback will not be possible even if the audio format is natively supported by the player. (The exception is DSD, see "Supports audio formats" for more on that).
Note that most popular audio formats use a sampling rate of 44.1 kHz, and all modern portable players are guaranteed to support it. So this parameter is relevant mainly for Hi-Fi models (see "Type") that work with advanced digital sound formats.
Bit depth
The capacity of the digital-to-analogue converter installed in the player (see "DAC").
Bit depth, along with sampling rate, is one of the key characteristics of a digital audio signal; the higher it is, the better the sound quality, other things being equal. Without going into technical details, in this case, the meaning of this parameter can be described as follows: for normal sound reproduction, it is necessary that the bit depth of the player's DAC be no lower than the bit depth of the reproduced digital sound, otherwise playback will be impossible.
It is worth noting that the bit depth used in most popular music formats like MP3 is supported by all modern players. So this parameter is relevant mainly for Hi-Fi players (see "Type") that work with advanced digital sound standards.
Signal to noise ratio
The ratio between the level of the useful signal (clear sound) and extraneous noise, given by the player at the output. This parameter directly characterizes the quality of the built-in amplifier: it mainly takes into account the intrinsic noise of electronic circuits, and the higher the signal-to-noise ratio, the less these noises and the clearer the sound.
Note that in the case of players, this characteristic is often not particularly critical: the noise of the amplifier can be lost against the background of ambient sounds, especially in an urban environment, and for such situations even the most modest indicators, at the level of 70 – 80 dB, are enough. At the same time, for Hi-Fi models (see "Type") this moment is one of the most important; in the most advanced devices, the signal-to-noise ratio can exceed 120 dB.
Power
The higher the power, the louder the sound you can get on the headphones, all other things being equal. In addition, higher power allows you to connect "ears" with higher impedance to the device (although there is no hard correlation here, and models with the same output power may have different headphone impedance limits). However, in the case of ordinary (non-Hi-Fi) players, this parameter is more of a reference than practically significant: usually, the power of the amplifier in such models is quite enough to “rock” most consumer-grade headphones. But for Hi-Fi devices (see "Type") models, output power is of key importance: it determines compatibility with high-resistance studio-class "ears". Detailed help on this issue can be found in special sources.
Harmonic distortion coefficient
The coefficient of harmonic distortion produced by the player.
This parameter directly characterizes the amount of distortion introduced by the device into the original sound: the lower the coefficient, the clearer the sound, the less such distortion. It is impossible to completely eliminate them, but they can be reduced to a level that is practically not perceived by a person. So, it is believed that distortions at the level of 0.5% are already invisible even to an experienced listener. At the same time, in modern audio technology, there are also much lower values \u200b\u200b- up to ten thousandths of a percent. In the case of players, such indicators play mainly an advertising role — they are a sign of a high level of the device.
Note that the coefficient of harmonic distortion is indicated mainly for Hi-Fi players (see "Type"), for which the maximum purity of sound is critical; in conventional models, it is of secondary importance.
Features
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CUE support. The player's ability to recognize and use .cue files. Initially, such files were used as lists of tracks on an Audio CD; the sequence of tracks, their duration and name were recorded in them; Nowadays, .cue files often accompany albums and collections recorded on the principle of “all tracks in a row in one audio file.” If the player
supports CUE, then you can listen to such an audio file on it as a set of separate tracks, switching between them at will - the player will take data from the .cue file about the starting point of each track and automatically skip playback. In other words, the listening format will be the same as when playing music in the “one file per track” format.
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Lossless formats. The player supports audio formats that use lossless compression. Unlike lossy compression (including MP3), with this compression the sound is not cut down, all its details are preserved as much as possible. Nowadays, there are several lossless formats, the most popular are FLAC and APE (see “Supports audio formats”); The specific set of standards with which the player is compatible should be clarified separately. However, in any case, this function will be useful to those who value the most complete and reliable sound. It is worth considering two nuances. Firstly,
lossless files are quite large - one album can ta
...ke up several hundred megabytes. Secondly, in order to fully appreciate such sound, you will need high-quality headphones, and ideally a Hi-Fi player (see “Type”).
— Formats without compression (uncompressed). The player supports audio formats that do not require data compression. Most of these standards are professional; they provide very high quality and reliability of sound, but they also take up a lot of space. Examples of uncompressed formats include DSD and DXD (see “Supports Audio”).
— Work in DAC mode. The ability of the player to operate in digital-to-analog converter (DAC) mode - when the device receives a digital audio signal from an external source (usually a computer USB port) and outputs analog audio. This function is found mainly in Hi-Fi models (see “Type”). It will be useful primarily when outputting sound from PCs, laptops or portable gadgets: the native sound cards in such models are often quite “weak”, and when using an external DAC you can achieve much better sound quality.
— Equalizer. This function allows you to adjust the sound volume of individual frequency bands, thus changing the overall color of the sound. Equalizers in modern players can have a different number of bands - from 2 (low and high frequencies) in the simplest models to 8 - 10 in advanced ones. In any case, such a setting can be useful both for adjusting the sound to your own preferences, and for compensating for the shortcomings of connected headphones or speakers - if they “fail” certain frequency bands. In addition, many players have a set of equalizer presets (presets), usually designed for different styles of music - “Classical”, “Rock”, “Pop”, etc.
- FM receiver. Built-in tuner for receiving radio broadcasts in the FM range. It is this range that the vast majority of modern music radio stations use, since it allows broadcasting sound in stereo format. However, some player models also support other standards - for example, AM, in which talk stations are widely represented. To listen to the radio, you usually need to connect headphones - their wire acts as an antenna.
— Recording from an FM receiver. Possibility of recording radio programs received by the player’s own tuner (see above). This function is useful if you want to “save for history” some event from the broadcast - an interesting talk show, a live performance of your favorite band in the radio station’s studio, a live call, etc.
- Dictaphone. The player can operate in voice recorder mode to record sound. Typically, the built-in microphone is used. The general functionality of such a recording is noticeably more modest than in specialized voice recorders, but for simple tasks it may well be useful.
— Built-in speaker. Its own built-in speaker allows you to listen to music without connecting headphones or speakers. In some situations - for example, when watching a movie together from the player screen - this function can be very useful. However, it is worth considering that the capabilities of the built-in speaker are usually quite modest; as a result, the volume and sound quality are low.
- Digital camera. Your own digital camera that allows you to use the player to take photos and videos. The quality of filming in most cases is not high, but there are exceptions - some player models are not inferior to middle-class smartphones in this indicator. In addition, the cameras in this case are intended not so much for highly artistic filming, but for “capturing the moment.” It is also worth noting that the location of the camera may vary. Most often it is installed on the back side, but there are also players with front cameras that allow you to take selfies and use video calling. And the most advanced players (usually models with OS, see above) may have a pair of cameras - main and front.Bluetooth
The player supports
Bluetooth technology.
This technology is designed for direct wireless communication between different devices. There are different ways to implement it in players. The most common option is to broadcast sound to wireless headphones, acoustics or other similar equipment (aptX is highly desirable, see “Features/capabilities”). Other methods of application may also be envisaged - in particular, exchanging files with other devices and remote control (player or from the player). The specific set of additional functions should be clarified separately.
Bluetooth wireless protocols from the 4th revision and newer are relevant today:
- Bluetooth v 4.0. Revision 4.0 introduced a Bluetooth Low Energy (BLE) connection mode with low power consumption. This communication standard is intended mainly for transmitting small amounts of information - in particular, service data packets to maintain a connection. At the same time, the creators managed to combine economical energy consumption and a long communication range - it can reach 100 m, which has a positive effect on the stability of the connection.
- Bluetooth v4.1. Development and improvement of Bluetooth 4.0. In terms of players, the key innovation in this version was improved noise immunity when working near 4G (LTE) mobile communication devices (in earlier standards, Bluetooth and LTE signals could overlap, which led to failures).
- Bluetooth v4.2. Further..., after 4.1, development of the Bluetooth standard, which mainly presented a number of general improvements in the reliability and noise immunity of the connection.
- Bluetooth v5.0. Major Bluetooth update released in 2016. One of the most notable innovations was the introduction of two additional operating modes of Bluetooth LE: an increased speed mode (by reducing the range) and an extended range mode (by reducing the speed). The key benefit of these innovations is to improve the overall reliability of communications, increase their range and reduce the number of breaks.
- Bluetooth v5.1. Update to revision v 5.0, in which, in addition to general improvements in the quality and reliability of communication, it became possible to determine the direction from which the Bluetooth signal is coming. Thanks to this, the location of connected devices is determined with centimeter accuracy, which has a positive effect on the quality of the wireless connection.
- Bluetooth v5.2. The next update, after 5.1, is Bluetooth 5th generation. The main innovations in this version are a number of security improvements, additional optimization of power consumption in LE mode and a new audio signal format for synchronizing parallel playback on multiple devices.
- Bluetooth v 5.3 came into use at the dawn of 2022. Among the innovations in it, they accelerated the process of negotiating a communication channel between the controller and the device, implemented the function of quickly switching between the operating state in a low duty cycle and a high-speed mode, and improved the throughput and stability of the connection by reducing susceptibility to interference. When unexpected interference occurs in Low Energy mode, the procedure for selecting a communication channel to switch from now on has been accelerated.
- Bluetooth v 5.4 was introduced at the beginning of 2023. This edition has increased the range and speed of data exchange. Also in Bluetooth v 5.4, the energy-saving BLE mode has been improved. This version of the protocol uses new security features to protect data from unauthorized access, has increased connection reliability by selecting the best channel for communication, and prevents connection losses due to interference.
Outputs
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micro-Jack (2.5 mm). The micro-Jack connector belongs to the category of TRS connections (Tip, Ring, Sleeve). The 2.5mm plug is the smallest diameter TRS plug. Micro-Jack connection (2.5 mm) is typical for mobile devices and compact portable audio equipment. The connector is backwards compatible with mini-Jack (3.5 mm) and Jack (6.35 mm), but for this you must use the appropriate adapters. Of course, when using adapters, note that the presence of an additional connection reduces the overall quality of the audio signal. To prevent degradation in quality, some MP3 players are equipped with a micro-Jack output in parallel with the mini-Jack or Jack.
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mini-Jack (3.5 mm). The mini-Jack (3.5 mm) connection is the most common type of TRS (Tip, Ring, Sleeve) interface. The mini-Jack output is found on the vast majority of consumer-grade MP3 players. The mini-Jack connector has a 3.5 mm plug — this is the middle (intermediate) type of TRS connections. The mini-Jack output is capable of transmitting an audio signal of sufficiently high quality. The mini-Jack connection is ready to satisfy the needs of both beginners and advanced music lovers.
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Pentaconn (4.4 mm). Pentaconn connection — 5-pin balanced output. Thanks to this connection, you can connect powerful amplifiers or DACs to your MP3 player. Additionally, the connector is also suitabl
...e for connecting good high-impedance headphones. Pentaconn uses a larger than the mini-Jack plug, its diameter is 4.4 mm, it is stronger and more reliable than the 3.5 mm connection. The Pentaconn's balanced connection makes it possible to handle higher power audio signals. Thanks to this connection, it is possible to transmit a signal over a fairly long distance.
— Coaxial. The coaxial connection (S/PDIF) enables the transmission of an enhanced audio signal. In the coaxial signal algorithm, there is no digital to analogue conversion stage, which has a positive effect on the quality characteristics of the sound. RCA or TOSLINK connectors can be used for coaxial connection. Coaxial output is found mainly in Hi-End MP3 players. This is an expensive technique that requires the use of fairly expensive accessories. But in return, these players provide high-quality sound, designed for professional musicians and advanced music lovers.
— Optical. The optical connection is represented by a TOSLINK connector and a fibre optic cable. The essence of the optical connection is that the audio signal is converted from electrical to optical. At the other end of the cable, the optics are transformed back into digital sound. Being in optical form, the signal ceases to be subjected to interference and other interference. The optical signal does not lose its original quality even when transmitted over long distances. MP3 players with optical output provide the ability to listen to audio in high quality. The vast majority of MP3 players with a TOSLINK connector are premium models that can satisfy the needs of musicians, music lovers and advanced audiophiles.