Comparison Astell&Kern KANN vs Astell&Kern AK300

The maximum size of the memory card that can be used in the player. This parameter is directly related to the card type (see above): each type has its own volume limits. At the same time, the ability to work with capacious media is limited not only by the type of card, but also by the player's hardware. Therefore, many models have a lower capacity limit than the memory card suggests — for example, 128 GB in a model that supports the SDXC format (the theoretical maximum for which is 2 TB).

Note that the reverse situation also occurs — for example, when a device with a maximum capacity of 16 GB only supports microSD cards (theoretical maximum is 4 GB). This usually means that the player can work with newer formats (in our example, at least microSDHC), but for some reason this point is not mentioned in the official specifications (for example, the manufacturer could make a mistake in the documentation).

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.

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.

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.

Audio file formats that the player is able to work with.

— MP3. The most famous of modern digital audio formats; supported by almost all compact players, the name MP3 has even become a household name for them. 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. As a result, the sound quality can be quite high, and you can clearly distinguish high-quality MP3 from lossless format only on Hi-Fi equipment.

— 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.

— WMA. An audio format, at one time specially created for the Windows operating system. By default, it uses lossy compression (although there is also a lossless version of the WMA codec). WMA is particularly suitable for low bitrates, under such conditions it provides better quality than MP3 and takes up less space. On the other hand, this format is much less popular in high-quality digital audio.

...— AAC. A format developed 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 in iPod players; nevertheless, it is noticeably inferior to MP3 in terms of prevalence, although it is supported by a considerable number of players.

— 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 makes it possible 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.

— DSD. A specific digital audio format using the so-called. sigma-delta modulation (as opposed to pulse code used in most other formats). Such modulation provides a very high sampling rate — 2822.4 kHz; however, it cannot be compared with the usual sampling rate (see above): in this case we are talking about a specific signal format. Its properties are such that DSD support can be provided even if the player's DAC formally has a much lower sampling rate. In general, this format is considered professional, its support is found mainly in Hi-Fi models (see "Type").

— DXD. Professional audio format originally created for editing DSD files (see above) — For technical reasons, original DSD is not well suited for editing. DXD uses a bit depth of 24 bits (8 bits higher than Audio CD format) and a sampling rate of 352.8 kHz (8 times higher than Audio CD). Like the original DSD, it is found mainly in Hi-Fi players.

— AIFF. Audio format developed by Apple for Macs and Macbooks; a kind of "apple" analogue of the WAV described above, also in most cases used for uncompressed audio.

— Audible. Proprietary file format used by the online audiobook store of the same name. One of the features of this format is that file playback is available only if you enter a login and password for the Audible online store; thus, supporting this standard usually means having a client programme to access the store.

This list is not exhaustive, modern players (especially the top category) may support other types of audio files.

Streaming services supported by the player.

The principle of operation of any streaming service is that music and other content is initially located on a server on the Internet and, if necessary, is broadcast to the user's device — that is, it is played, but not stored in permanent memory. First of all, streaming services are convenient for this: they allow you to access the vast collections of content without taking up extra space in the player's memory. Of course, an Internet connection is required for playback (so support for streaming services automatically means that the player is equipped with Wi-Fi — see below); however, in the modern world, this most often does not cause problems.

As for specific services, among the most popular nowadays (in alphabetical order) are Amazon Music, Deezer, Pandora, Soundcloud, Spotify, Tidal.

The player supports Bluetooth technology.

This technology was developed for direct wireless communication between various devices. The ways in which it can be used can vary; in the case of players, the most common option, which is almost mandatory for any model with Bluetooth, is to broadcast sound to wireless headphones, speakers or other similar devices (aptX is highly desirable, see “Functions/capabilities”). In addition, other methods of using Bluetooth may 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 specified separately. And Bluetooth versions (the latest of which at the end of summer 2021 is Bluetooth 5.0) indicate the advancedness of the device and its increased capabilities.

— 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.

— 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.

— 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.

The capacity of the battery installed in the player.

Theoretically, a larger battery can provide longer battery life. However, in fact, battery life will depend not only on the capacity of the battery, but also on the power consumption of the player, and it is directly related to the functionality. Therefore, when evaluating battery life, it is better to focus not on battery characteristics, but on the operating time directly stated in the characteristics (see below). And only models with similar characteristics can be compared with each other in terms of battery capacity — for example, media players on Android with approximately the same screen sizes.