Polyphony
The polyphony supported by a synthesizer, in other words, is the number of “voices” (tone generators) that can simultaneously sound on it.
This parameter is often described as the number of notes that can be played simultaneously on the keyboard. However, this is not entirely true due to the fact that in many timbres one note can activate several tone generators. As a result, for example, to play a chord of 3 notes in a timbre with 4 tone generators per note, polyphony of at least 3 * 4=12 voices is required. In addition, Auto Accompaniment and Preset Songs (see related sections) also use tone generators, requiring even more voices to work effectively with these features.
The minimum value for a more or less functional modern synthesizer is polyphony for 32 voices — and even then such an instrument can be used mainly for initial training and simple melodies. For a more solid application, it is desirable to have at least 50 – 60 voices, and in professional models (in particular, workstations where you have to deal with several audio tracks at once), there are models with polyphony for 150 tone generators or more.
In general, a more advanced synthesizer is likely to have more extensive polyphony, however, it is only possible to evaluate the class of an instrument by this parameter very approximately — instruments with the same number of voices can differ greatly in level. The only exception to this rule are children's synthesizers (see "T...ype"), which support up to 20 voices.
Built-in timbres
The number of built-in sounds provided in the synthesizer.
The number of timbres is often described as the number of instruments that a given model can imitate. However, this is not entirely true — rather, this parameter can be called "the number of instruments and sound effects." For example, the same instrument — an electric guitar — with different "gadgets" (distortion, overdrive) will sound differently, and in the synthesizer each such gadget will be considered a separate timbre. The “drums” timbre usually combines different types of drums and other percussion instruments — in other words, it allows you to portray both the “bass drum” and the cymbals without switching settings, just by pressing the desired keys. And some timbres may not have analogues among real instruments at all.
The more built-in timbres, the more extensive the possibilities of the synthesizer, the more diverse the sounds that can be extracted from it. At the same time, in high-end models like workstations (see "Type"), this number can reach 1000 or even more.
Accompaniment styles
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.
Learning mode
The presence
of a learning mode in the design of the synthesizer.
The purpose of this function is clear from the name. It is most often based on the following principle: the synthesizer itself tells the student which keys to press, displaying the keyboard on the display or highlighting the necessary keys using the backlight (if available, see above). Of course, at different levels of learning, the format of such prompts will also be different: for example, at the very beginning, the synthesizer highlights the necessary notes until they are pressed, and at the final stage it highlights them at the tempo at which you need to play the melody, and evaluates the accuracy of the student pressing the desired keys. There are also other features and nuances of learning — for example, the mode of separate learning of parts for the left and right hands, when the instrument itself plays one part and tells the student how to play the second. In addition, a metronome function is practically mandatory for a synthesizer with this mode (see below).
Regardless of the specific functionality, this mode will be very useful for those who are just developing their keyboard playing skills.
Pitch controller
The presence
of a pitch controller(Pitch Bend) in the design of the synthesizer.
This function allows you to smoothly change the pitch by a small amount. In this way, specific playing techniques on some instruments are imitated — for example, tightening the strings on a guitar, which gives a characteristic, “floating” sound in frequency. The pitch control usually has the form of a wheel or lever.
Inputs
— mini-Jack (3.5 mm). Line-level analogue audio input using a 3.5mm mini-jack. The line input itself is used to connect an external analogue audio signal to the synthesizer — for example, from a computer sound card. The use of such a connection can be different: playing accompaniment through the built-in speakers of the instrument, switching the signal to an external amplifier with “mixing” the sound of the synthesizer itself into it, etc. Specifically, the 3.5 mm mini-Jack connector is small in size, it is popular mainly in portable equipment and inexpensive stationary devices — “serious” audio equipment is usually equipped with more reliable connectors, like Jack (see below). As a result, an input with this type of connector is typical mainly for entry-level synthesizers.
— Jack (6.35 mm). Line-level analogue audio input using a 6.35 mm jack. By purpose, such an input is completely similar to the input with a 3.5 mm mini-Jack jack described above, however, the Jack connector is larger, provides a more reliable and high-quality connection and is considered more suitable for stationary audio equipment, especially high-end ones. Therefore, in synthesizers of an average and advanced level, usually, this type of line input is used. At the same time, we note that a 3.5 mm plug can be connected to a 6.35 mm jack using a simple adapter.
— Digital. Input for connecting to a digital audio signal synthesizer. It is similar in purpose to the linear interfaces descri
...bed above, but differs both in signal format and in connector type — most often it is a coaxial S / P-DIF interface using an RCA connector, although other options are possible. Digital outputs are quite popular both in professional audio equipment and in home appliances like PCs and even TVs, so such an input may be useful.
— MIDI. MIDI is originally a digital signal format used in electronic musical instruments. Each key pressed on the synthesizer gives just such a signal: it contains data on the duration, force and speed of pressing, as well as the note number, and based on the control signal (MIDI event), the “hardware” of the synthesizer generates the desired sound. Accordingly, the MIDI input allows the synthesizer to receive MIDI events from external electronic musical devices — other synthesizers, MIDI controllers, etc. This connection can be useful, for example, if the external instrument does not have the desired timbre; in addition, many synthesizers are capable of recording received MIDI signals. In some cases, the possibility of switching such a signal via MIDI thru may also be useful (see "Outputs").
— USB (type A). A classic USB connector that allows you to connect various external devices to the synthesizer — primarily flash drives and other drives, other peripherals are rarely supported. The features available when working with a flash drive depend on the general functionality of the synthesizer and may be different in different models. So, some instruments are capable of playing music from such a carrier, which plays the role of accompaniment for the main part — this can be more convenient than using auto accompaniment. Others are able to record music on a flash drive. It may also include updates to the Voice Set and/or Auto Accompaniment Styles (see above), firmware updates, etc.
— Card Reader. A slot for reading memory cards, most often SD: this is a universal format widely used in many types of modern electronics. Like a USB flash drive (see above), the card reader can be used for different purposes — most often for playing musical accompaniment or recording music, but there are other options (loading additional timbres, updating firmware, etc.).
