Comparison Astell&Kern A&norma SR15 vs Astell&Kern KANN

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).

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 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.

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.

Characteristics of the display installed in the player.

— Color(color/monochrome). The display color is selected by the manufacturer taking into account the functionality of the player. So, for a device that supports video and graphic materials (see “Other formats”), a color display is mandatory, and if the player only works with audio, a monochrome (one-color) screen is quite sufficient for it, especially since such screens are cheaper and consume less energy.

- Size. The diagonal dimensions of the display is directly related to the type of device (see above). Thus, classic audio players do not require large screens, in most of them this figure does not exceed 1.5"; but for a media player, 1.5" is, in fact, the absolute minimum, usually the diagonal is 3" or more. Also large Hi-Fi players are equipped with screens, they also provide a similar feature for the convenience of working with special tools.In general, a large screen, on the one hand, is convenient to use, on the other hand, it affects the dimensions and price of the device.

— Display resolution. Display dimensions in pixels vertically and horizontally. With the same diagonal, a higher resolution provides a clearer and more detailed image, but increases the cost of the player. In addition, not every player needs high detail: if the screen is used only for service information like the title of a so...ng, you can get by with small resolutions. Therefore, you should pay attention to this parameter only when it comes to a media player (see “Type”) on which you plan to often watch videos. In other cases, we can assume that the screen resolution is guaranteed to be sufficient for the tasks for which the device is intended.

— Sensor type. The type of matrix used in the screen.

• OLED. An OLED matrix in which each pixel is actually a separate LED. In portable players, most of these screens are monochrome; for color displays it is more convenient to use other technologies.
• TFT. General name for liquid crystal displays. In this case, the TFT designation is used mainly for relatively simple screens that do not use advanced technologies like the IPS described below and have rather limited characteristics. However, such screens can be made in color and have high resolution.
• AMOLED. A development of the OLED technology described above, designed to create high-quality color displays. AMOLED screens are characterized by high brightness, rich colors and good viewing angles. Among their disadvantages, we can note a slightly shorter service life than the same IPS, as well as a tendency to fade in areas where bright parts of the image are often displayed.
• IPS. One of the most popular color screen technologies used in modern portable technology. Provides good color rendering quality and wide viewing angles; The picture quality is somewhat inferior to AMOLED, but is cheaper and lasts longer.

- Touch screen. The touch screen is similar to tech used in modern smartphones. On-screen controls are often more convenient and versatile than using buttons and other hardware controls. For normal use, such a display must be quite large. We also note that a touch screen is mandatory for models with a full OS (see above).

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.