Number of channels
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”).
Optical
Input for digital audio signal transmitted via TOSLINK fiber optic cable.
The optical interface has the same capabilities as the coaxial input (see the corresponding paragraph) - in particular, it allows you to transmit multi-channel audio. The key difference and main advantage of this connection is its complete insensitivity to electromagnetic interference. On the other hand, fiber optic cable is quite fragile and sensitive to damage - it must be protected from strong pressure and kinks.
Total Jack/XLR audio outputs
— 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).
Line
The type of line output provided in the audio interface design. It outputs a line-level analog audio signal. This interface is mainly used for connecting recording devices, outputting a signal to playback equipment or to an external amplifier. And the types of connectors used for linear output can be as follows:
—
mini-Jack (3.5 mm). A standard socket for the popular mini-Jack plug (3.5 mm), used as a line output. This connector is mainly used to connect some models of active speakers, while two stereo channels are usually output through one mini-Jack (3.5 mm). Note that headphone outputs, which also use a mini-Jack, are considered separately - see the corresponding paragraph.
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Jack (6.35 mm). A larger analogue of the mini-Jack connector (3.5 mm) for outputting an analog stereo signal. The Jack output provides a more reliable and noise-free connection, making it ideal for professional applications. Effective protection against interference is possible with a balanced connection method. To save space, the 6.35 mm output can be combined with an XLR connector (see the corresponding paragraph). The disadvantage of this design is the impossibility of using both interfaces simultaneously. Jack line outputs (6.35 mm) adhere to the “one channel per connector” principle.
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XLR. A round three-pin connector for outputting a line-level analog audio signal, oft
...en with a balanced connection type. Transmission is carried out over three wires instead of two, and during it the noise induced on the wire is eliminated. This allows the use of fairly long cables without compromising the “purity” of the signal, making this type of connection excellent for professional audio equipment. XLR is also considered a professional interface, both due to the ability to work with a balanced signal and due to increased reliability: such connectors are often equipped with locks to secure the plugs.
- RCA. Analog linear audio output using RCA connectors - so-called “tulips” (due to the characteristic shape of the plugs). The standard output of this type consists of two connectors - for the left and right stereo channels. Also note that RCA connectors can be used in other output interfaces, but they have their own names.External power supply
The presence of
an external power supply in the device, which is located outside the case. This design feature is designed to reduce the amount of interference that affects the electronic components of the device and can distort the sound. Also, due to the external power supply, the device becomes more compact and lightweight.
