Comparison Universal Audio Apollo Solo TB3 vs Audient ID4

The number of input and output channels that the audio interface is equipped with. See below for more details on each type.

— Input channels. Input (in) channels on audio interfaces designate the number of different audio signals a device can accept for recording overnight. Their number plays a decisive role in multi-channel sound recording, connecting several instruments or vocals at the same time. When choosing an audio interface, consider not only the number of input channels, but also the types of connectors (see “Inputs”).

— Output channels. Output channels output (out) is the number of audio signals that can be sent to other devices or equipment for playback. The outputs of the audio interface can be used to connect to amplifiers, monitors, speaker systems, headphones, etc. A large number of output channels will come in handy when creating sound mixes, multi-channel recording or multitasking in a studio environment. For simpler tasks, it is enough to have from 2 to 4 output channels. When choosing an audio interface, consider not only the number of output channels, but also the types of connectors (see “Outputs”).

Connection interfaces that the audio interface is equipped with.

- USB A. Connection via standard USB port. Until recently, this was the most popular interface for external peripherals, found in almost all PCs and laptops. Nowadays, it is often replaced by a USB type C port (see the corresponding paragraph). Most USB A audio interfaces draw power directly from the PC or other host device.

- USB type B. The connector has a characteristic square shape, noticeably different from the well-known rectangular USB A ports. In audio interfaces, it is used to transmit signals from external sources to a computer for recording and processing.

- USB type C. A peripheral connector with a symmetrical contact group, which often replaces full-size USB ports on board modern PCs and laptops. Many new models of audio interfaces are being made for this interface. An exception to the rule is individual instances for Thunderbolt. For them, it is Thunderbolt that is indicated, and not USB type C.

- Thunderbolt v2. Initially, Thunderbolt is a universal connector used primarily in Apple computer equipment. On board audio interfaces it is used as a general peripheral connector (similar to USB). This uses the miniDisplayPort hardware port. The data transfer speed in this version reaches 20 Gbit/s. Recently, the v2 edition has been rep...laced by the Thunderbolt v3 version (see the corresponding paragraph).

- Thunderbolt v3. A universal interface that is found mainly in Apple technology. In audio interfaces it is used as a general peripheral connector (similar to USB). Specifically, Thunderbolt v3 provides data transfer speeds of up to 40 Gbps and uses a USB type C hardware connector (as opposed to earlier versions based on miniDisplayPort).

- Lightning. A connector used exclusively in Apple portable electronics (since 2012). Accordingly, audio interfaces with such a port are aimed at ease of connection to iPhones and iPads. Note that today there has been a transition from proprietary Lightning to the common USB type C - the latest generations of Apple gadgets are produced with just such a peripheral connection connector.

- mini-USB. A smaller version of the full-size USB interface, created for portable equipment. It is found very rarely in audio interfaces.

- FireWire. Universal connector, also known as IEEE 1394 or i-Link. In terms of functionality, it is analogous to USB, and in some characteristics it even surpasses it. However, FireWare is much less common. Used to connect to computers and some types of specialized audio equipment.

— Dante Dante connectors are used to connect audio interfaces to a network to transmit audio digitally. In this case, a standard Ethernet port (RJ-45) is used for physical access to the network.

Characteristics of the built-in DAC - a digital-to-analog converter for converting digital audio into line-level analog audio, usually in stereo format.

— Bit depth. Bit size of the digital-to-analog converter (DAC) used in the device. In this case, the meaning of this parameter is as follows: the bit depth of the DAC must be no lower than the bit depth of the audio signal with which the converter is planned to be used, otherwise the device will not be able to effectively cope with the conversion. As for specific values, the standard options in modern audio interfaces are 16 bit, 24 bit and 32 bit.

- Sampling frequency. The sampling rate of the digital-to-analog converter (DAC) installed in the audio interface. Let us recall that such a converter is responsible for converting digital audio into an analog audio signal. The paragraph usually indicates the maximum value of the sampling frequency, for which one of the standard values corresponding to a certain sound quality is used ( 48 kHz, 96 kHz, 192 kHz).

The audio frequency range supported by the device. Most often we are talking about the range of frequencies that a device can produce in an analog audio output signal.

In general, the wider the frequency range, the fuller the sound, the lower the likelihood that the audio interface will “cut off” the upper or lower frequencies. However, it must be taken into account that the human ear is capable of hearing sounds at frequencies from 16 to 22,000 Hz, and the upper limit decreases with age. So from a practical point of view, it makes no sense to provide a wider range in audio technology. And the impressive numbers found in high-end devices are rather a “side effect” of advanced electronic circuits and are given in the specifications mainly for advertising purposes. Also remember that the overall sound quality is affected by many other factors besides frequency range.

The number of preamplifiers in the design of an audio interface, designed to work with a weak signal - which directly comes from a microphone, pickup, etc. Each preamp corresponds to one low-level input channel. For example, if an audio interface has four preamps, it can simultaneously process signals from four microphones or other devices connected to those preamps. Professional studio audio interfaces are often equipped with a large number of preamps to provide flexibility and the ability to record from a large number of sources simultaneously.

— Total audio inputs Jack / XLR. The total number of analog audio inputs such as Jack (6.35 mm) and/or XLR (this interface can be combined with a “jack”). Note that such connectors can play the role of both a line input and a microphone or instrument input. For more details, see the relevant paragraphs.

— mini-Jack. The standard 3.5 mm mini-Jack is usually used in audio interfaces as an analog (line) input for two stereo channels, as well as as a microphone audio input (see the corresponding paragraphs).

An input jack used to record audio from a microphone, which may transmit low signal levels and requires amplification. It often includes a microphone preamplifier - it amplifies a weak signal to a level that is suitable for recording or processing in an audio interface. The most common types of microphone inputs are:

— mini-Jack (3.5 mm). The standard mini-Jack audio connector (3.5 mm) provides average signal quality, which is why it is poorly suited for professional tasks such as studio recording. As a result, the “purely microphone” variety of the 3.5 mm jack is relatively rare, but still has a right to exist. It is also worth considering that microphones can use mini-Jack plugs for different numbers of contacts (from 2 to 4).

— Jack (6.35 mm). The shape and arrangement of contacts of Jack sockets (6.35 mm) are similar to the corresponding varieties of the 3.5 mm standard, but they are larger in size. Due to the larger contact area and less tendency to interference, plugs of this format are found in microphones of all price categories. In addition, a balanced connection is often made through the 6.35 mm jack - a special type of connection used in professional audio equipment that allows signal transmission even over fairly long wires without interference.

- XLR. In audio equipment, three-pin XLR connectors are most often used to connect a micropho...ne. XLR provides a reliable and tight connection, and the interface sockets often have locks to secure the plugs. Connection through this connector is also carried out in a balanced way - using three wires instead of two. The peculiarity of this signal transmission is that external interference is filtered, in fact, by the wire itself, which allows you to transmit a high-quality audio signal even with long cable lengths. Often the XLR connector can be combined with Jack (6.35 mm).

The type of line input provided in the device. Uses the line input to feed audio from an external source to the audio interface.

The following types of connectors can be used for line input:

— mini-Jack (3.5 mm). A socket for a standard mini-Jack plug (3.5 mm). The connector serves as an audio input for two stereo channels. It is designed primarily for portable electronics such as smartphones, pocket players, etc. In stationary devices, Jack (6.35 mm), XLR and RCA are more popular.

— Jack (6.35 mm). A common audio connector for transmitting an analog signal. In design, this type of socket is as similar as possible to a mini-Jack (3.5 mm), but differs in size. Jack connector (6.5 mm) provides tight contact and is less susceptible to interference. It also supports a balanced connection - high-quality transmission of audio signals over fairly long wires with effective protection against interference.

- XLR. The XLR standard is considered professional - not only because of the high quality of signal transmission, but also because of its fairly large size and the presence of locks for securely securing the plugs. However, only one channel of audio can be transmitted over one cable, so XLR outputs are usually installed in pairs - based on stereo sound. Also note that these connectors can be combined with Jack sockets (6.35 mm). They also allow y...ou to implement a connection in a balanced format with a high degree of noise immunity and the use of fairly long wires without affecting the frequency of the analog signal.

- RCA. Connector for coaxial cable with tulip type plug. The standard RCA input consists of two jacks - for stereo sound, left and right channel. One analog RCA connector can only transmit one channel of audio, so the number of such connectors corresponds to the number of channels supported by the device.

— Total audio outputs Jack / XLR. The total number of analog audio outputs such as Jack (6.35 mm) and/or XLR (this interface can be combined with a “jack”). Note that such connectors can play the role of both the Main output and the linear output. For more details, see the relevant paragraphs.

— mini-Jack. The standard 3.5 mm mini-Jack is usually used in audio interfaces as an analog (line) output for two stereo channels, as well as as an output for connecting headphones (see the corresponding paragraphs).