Comparison Casio CTK-2500 vs Casio CTK-2400

The number of auto accompaniment styles (see above) originally provided in the synthesizer, in other words, the number of accompaniment options available to the user.

The more extensive this set, the higher the probability of finding among these melodies suitable options for a particular case. At the same time, the abundance of styles in itself is not yet a 100% guarantee that among them there will be a suitable one, especially since different synthesizer models can differ markedly in a specific set of melodies. So the list does not hurt to clarify before buying. Also note that the situation can be corrected by user styles (see below) — many synthesizers with auto accompaniment support them.

The range in which you can change the tempo of the programme played by the synthesizer — auto accompaniment, lesson tune (see above), metronome (see below), recorded sample, etc.

Pace is measured in beats per minute. Changing it allows you to adjust the speed of the synthesizer to the specifics of the situation — for example, slightly slow down the tutorial if it is too hard to master at the initial pace. The wider the range of tempo adjustment, the more options the musician has to choose from, especially in the area of very slow and very fast tempos.

Note that the traditional range of musical tempos covers values from 40 beats / min (“grave”, “very slowly”) to 208 beats / min (“prestissimo”, “very fast”), however, in synthesizers it can be more extensive — for example, 30 – 255 bpm.

Synthesizer support for sampling.

Samples are short sound fragments used in the creation of musical compositions. Such a fragment can contain almost any sound — from a note on a musical instrument or a fragment of a drum part to a siren signal, a bird's chirp, the sound of a mechanism, etc. Specifically, the sampling function implies the ability to use the synthesizer to record samples for further use. Recording can be done either through the built-in microphone or through the audio input (from an external microphone or other audio device). At the same time, many synthesizers with this function are able not only to keep the sound not only "as is", but also to pass the incoming signal through the processing circuits, adding various effects to it — echo, "wah-wah", metallic sound coloring, etc. And ready-made samples can usually be "bound" to individual synthesizer keys and played back in real time. Other functions are possible, depending on the level of the instrument.

The ability to fine-tune the synthesizer by sound frequencies. Often, such models also indicate the range in which such adjustment can be carried out.

The standard tuning, which is used by default in all synthesizers, is designated as “440 Hz” — this is the frequency of the “la” note of the first octave, as well as the standard frequency of the tuning fork, all other notes are tuned to it. With fine tuning, the musician can set a different base frequency, raising or lowering the overall tone of the synthesizer. At the same time, unlike the transposition described above, in this case the frequency does not change in steps (by tones-semitones), but smoothly, with an accuracy of a hertz or even a tenth of a hertz. Such an opportunity can be useful in some non-standard situations — for example, if you have to accompany a guitarist whose instrument is tuned slightly higher or lower than the standard, and for one reason or another it is impossible to change the guitar's tuning.

— Digital. Digital audio output, usually via coaxial S/P-DIF interface. It is similar in purpose to the line outputs (see below), differs only in the type of connector and the digital signal format. It can be useful, in particular, for connecting the synthesizer to a device that does not have line inputs, or if these inputs are occupied.

— USB B. A connector designed to connect the synthesizer to a computer or laptop as a peripheral device. Such a connection provides very extensive possibilities: it allows you to load new timbres, auto accompaniment styles and melodies into the synthesizer, edit existing ones; record the played music on the computer (or rewrite the music recorded in the memory of the synthesizer itself); use the instrument as an external MIDI keyboard; change various fine settings and troubleshoot, etc. The specific functionality available with a USB connection depends on the synthesizer model.

— MIDI. Output for transmitting MIDI signals (MIDI events) to external devices. MIDI is a specialized type of digital control signal used in musical instruments. Such a signal is generated when a key is pressed, it contains data about the pressing itself (duration, strength and speed), as well as the note number; Based on this signal, as well as the set settings, the electronic “hardware” of the synthesizer generates a sound of the required duration, timbre and other characteristics. Accordingly, the MIDI output allows you to transmit MIDI events to...an external device — a sequencer, sampler, another synthesizer, a computer (although it is more convenient to connect the instrument to a computer via USB), etc. This interface can be used for various purposes — MIDI recording, playing music through an additional synthesizer if the main model does not have the desired tone, etc.

— MIDI thru. An output designed to transmit to another device MIDI events received by the synthesizer via a MIDI input (see "Inputs"). In this case, the stream of MIDI commands is transmitted unchanged, pressing the keyboard of the synthesizer does not affect it. This function can be useful in some situations where the instrument is connected to several external devices at the same time. For example, if you need to control two others at once from one synthesizer, you can compose such a system as follows: the MIDI output of the control synthesizer is connected to the MIDI input of the first controlled one, and the MIDI thru output of the first one is connected to the MIDI input of the second one. Thus, the control signal goes to the first controlled synthesizer, and, through it, to the second one, while it would be difficult to connect both instruments directly.

— Headphones. Dedicated headphone output. It usually uses a mini-Jack 3.5 mm or Jack 6.35 mm connector — the vast majority of modern headphones are equipped with the first, the second is less common in the “ears”, but more reliable, and is also compatible with 3.5 mm through a simple adapter. Using "ears" when playing the synthesizer is convenient because only the musician hears the music played — this can be useful in situations where you need to practice, but it is undesirable to make noise (for example, at late hours of the day). In addition, some instruments do not have built-in acoustics, and you can listen to them normally only through additional equipment — the role of which can be played just by headphones.

The number of line outputs provided in the design of the synthesizer.

The line output is used to transmit the sound produced by the synthesizer to external devices. At the same time, unlike the MIDI output, a “ready” sound is transmitted through such a connector — an analogue line-level audio signal that can be connected to another audio device — for example, to a power amplifier or active speakers for playback, to a computer or mixing console for recording, etc. Keep in mind that the line outputs can use different types of connectors — for example, 3.5 mm mini-Jack or 6.35 mm Jack; Specifically, these connectors are described in more detail in the “Inputs” section, but the matter is not limited to them.

Multiple analogue inputs make it possible to connect the synthesizer to several external audio devices at the same time — for example, to an amplifier for playback and a recorder for recording.

Rated power consumed by the tool during operation. Modern synthesizers, even the most powerful and advanced ones like workstations (see "Type"), consume very little energy — up to 100 W, and often noticeably less. Therefore, it is rarely necessary to pay attention to this parameter in fact, mainly in rather specific situations — for example, when working from an autonomous generator, when you need to take into account the entire load connected to such a power supply.

Synthesizer operating time from autonomous power supply (see above) without replacing or recharging batteries. This parameter is quite approximate, because. Actual power consumption of the instrument may vary depending on the length of the songs, the duration of the breaks in the game, the volume of the built-in speakers, the additional functions used, and other factors. In addition, the capacity of replaceable batteries can also be different, depending on the brand. However, the run time listed in the specifications gives some idea of the synthesizer's capabilities and how many sets of batteries may be needed for long-term autonomous use.