Comparison Yamaha NP-32 vs Casio Compact CDP-130

The number of keys provided on the digital piano keyboard.

The immediate range of the instrument depends on the number of keys — that is, the set of notes that can be played on it without resorting to octave transfer or transposition (see below). Most digital pianos have 88 keys, the same number as a regular piano; thus, the ranges in electronic instruments most often match those of real pianos. However, smaller models are also produced — usually 61 or 73 keys (as in most synthesizers). This number of keys is found in two types of digital pianos — in inexpensive entry-level models and in some professional instruments designed mainly for "genre" music (rock, gospel, etc.), and not for classical piano parts.

Type of action used in digital piano keys.

— Hammer. A mechanic that mimics the feel of playing a real piano as closely as possible. Hammer action keyboards not only provide velocity and force-dependent sound dynamics, they also provide a distinctive response with each press. These mechanics are complex and expensive, but they are considered the most advanced and suitable for digital pianos, and therefore are used in most models.

— Active. In the case of digital pianos, the active keyboard can be described as a simplified version of the hammer action described above. The sound produced when pressing such keys also depends on the force and speed of pressing, however, the keys themselves have less rigidity and do not give the full feel of a piano keyboard. On the other hand, such mechanics are cheaper. As a result, it is found mainly in low-cost models, as well as some professional instruments, positioned more like electric organs.

The third type of mechanics — passive — assumes that each time you press a key, the volume will be the same, regardless of the strength and speed of pressing. Such keyboards are not used in digital pianos — they are too primitive and not very functional for this class of instruments; however, models with adjustable sensitivity may provide switching the keyboard to a "passive" format (see below for more details).

The number of voices supported by the digital piano — more precisely, the maximum number of voices that the instrument can play at the same time.

This parameter should not be confused with the number of notes that can be played simultaneously on the keyboard. The fact is that in many timbres, several voices (tone generators) are used for each note at once — this is the only way to achieve a more or less reliable sound. Thus, the required number of voices can be many times higher than the number of notes — for example, the simplest chord of 3 notes may require 9 or even 12 voices. In addition, tone generators are used to play auto accompaniment parts and built-in songs (see below), and here the number of voices can already be measured in tens.

In light of all this, polyphony of less than 90 voices is typical mainly for relatively simple and inexpensive instruments that are not designed for complex tasks. The smallest number found in modern digital pianos is 32 voices. It is desirable for a more or less solid instrument to have at least 96 voices, and in top models this figure can reach 256.

The range over which the tempo of the sound played by the instrument can change. It can be either a built-in melody or a part recorded on a sequencer, or an auto accompaniment, a tutorial or a metronome. For more information on all of these features, see the corresponding glossary entries. Here we note that a change in tempo is often required in fact — for example, to speed up an initially "sluggish" accompaniment or slow down a training programme that is difficult to master at the original tempo.

Tempo is traditionally indicated in beats per minute. The classical, "academic" range covers options from 40 bpm ("grave", "very slow") to 208 bpm ("prestissimo", "very fast"), however, in modern digital pianos, the working range of tempos is often significantly wider.

The presence of a sequencer in the design of a digital piano.

This function allows you not only to play music on the instrument, but also to record it with the possibility of later playback. However, this is at least; in addition to recording the parts of the instrument itself, the sequencer can provide recording an audio or MIDI signal from the corresponding input, mixing several parts (including recording the music being played over the music being played “on the go”), working with the parameters of individual tracks (volume, tone, timbre), as well as specific functions such as quantization (smoothing uneven tempo). The specific functionality of the sequencer may be different, it's ok to check it before buying. However, anyway, this function can be a good help for the musician; it is especially useful for those who are not limited to the performance of ready-made music and want to compose their own compositions.

The presence of an octave shift function in the digital piano.

This function makes it possible to "shift" the sound by a certain number of octaves up or down — for example, in such a way that the bass register sounds on the keys of the first octave, or vice versa, the first octave "slid" lower, into the bass, and notes of the second sounded in its place or even the third octave.

This feature significantly expands the range of the instrument, allowing you to play notes that were not originally covered by the keyboard. This is especially important for instruments with 61 or 73 keys (see "Number of Keys"), but octave shifting is not uncommon in full-sized 88-key models — it can be useful when splitting the keyboard (see above), when available for each hand the range is noticeably reduced, and the batch can be very low or very high. However, there are other options for using transfer — for example, so that when playing an updated version of the melody, you do not have to move from the usual octaves.

The presence of the chorus effect in the digital piano.

Initially, this effect was developed as an attempt to simulate the choral sound of several instruments of the same type. Even a perfect choir never plays 100% in sync, which is what the creators of the chorus tried to reproduce. This effect works as follows: several copies are taken from the main signal, which are played along with it — but not strictly simultaneously, but with a small (up to 30 ms) delay, selected randomly for each individual signal. This really allows to imitate the effect of polyphony to a certain extent, however, such sound is still far from a full-fledged choir. However, the chorus itself is quite interesting as an additional effect.

The presence of a pitch controller(Pitch Bend) in the design of a digital piano.

Such a controller allows you to smoothly change the pitch of the note being played within a small range (usually up to a semitone up or down). In this case, control is carried out using a wheel, a lever, or another similar element that allows the musician to manually adjust the speed and limits of frequency change (including creating the effect of a note “trembling” in frequency). This function allows you to simulate the playing techniques of some instruments (for example, tightening the strings on a guitar) and gives an unusual sound to timbres that were not originally intended to have such effects.

Additional features and sound customization options provided by the instrument in addition to those listed above. In this paragraph, usually, various original proprietary technologies and solutions are indicated; the specific meaning of these functions is best specified in the documentation for the tool.