Signal to noise ratio (RCA)
Signal-to-noise ratio when operating the audio receiver through the RCA line input (see below).
Any signal-to-noise ratio describes the ratio of the level of pure sound produced by the device to the level of extraneous noise that occurs during its operation. This parameter is the main indicator of the overall sound quality — and very clear, because. its measurement takes into account almost all the noise that affects the sound in normal operating conditions. A level
of up to 90 dB in modern receivers can be considered acceptable,
90 – 100 dB is not bad, and for advanced audiophile-class devices, a signal-to-noise ratio
of 100 dB or more is considered mandatory.
Outputs
Outputs provided in the design of the device. Note that for receivers (see "Type") the presence of outputs for passive acoustics is mandatory by definition, and the players, on the contrary, do not have such outputs. Therefore, the presence / absence of such connectors is not separately indicated.
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Preamplifier output (Pre-Amp). A preamplifier is an electronic unit designed to amplify an audio signal to line level. Accordingly, outputs of this type are actually line outputs for outputting sound to an external power amplifier, active acoustics, etc. For players (see "Type"), these are the main analogue audio outputs, and in receivers, Pre-amp outputs can be used in including for connecting equipment that works in parallel with passive speakers, which provides additional features for expanding the audio system. Most often, this interface uses paired RCA connectors (“tulips”), one for each stereo sound channel; less often — balanced XLR, also paired, for more details see "Inputs".
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To the subwoofer. A separate output for connecting a subwoofer — a specialized speaker designed for low frequencies. Usually uses an RCA ("tulip") interface, but there may be other options. Anyway, this output receives the signal from the crossover, which "cuts" the mids and highs, leaving the bass with which the speaker works. This simplifies the connection and eliminates the need to look for external equipm
...ent for the normal operation of the subwoofer — for example, the same crossover (although an external amplifier may be needed for passive "subwoofers").
— Coaxial S/P-DIF. A kind of S/PDIF digital audio interface that uses an electrical coaxial cable with RCA connectors (“tulip”) for connection. Such a cable, unlike optical, is subject to electromagnetic interference to a certain extent, but is more reliable and does not require special care in handling. And the connection bandwidth is enough to transmit multi-channel audio up to 7.1. Note that, despite the identity of the connectors, the coaxial digital interface is not compatible with analogue RCA; and even cables for S / P-DIF are recommended to use specialized ones.
— Optical. A variation of the S/PDIF digital audio interface that uses a TOSLINK fiber optic cable connection. In terms of throughput, it is completely similar to the coaxial interface, but it compares favorably with its complete insensitivity to electromagnetic interference. On the other hand, due to their design, optical cables are sensitive to sharp bends and mechanical stress — for example, accidentally stepping on such a cable can damage it.
— Balanced digital (AES/EBU). An interface used primarily in professional audio equipment. It can use different types of connectors, but is most often implemented via XLR. For more information about this connector and the principle of balanced connection, see “Inputs — XLR (balanced)”, however, these two interfaces should not be confused: AES / EBU works with a digital signal transmitted over a single cable, regardless of the number of channels.
— Composite (video). This output is usually provided in models equipped with a video input of the same standard. For composite connectors in general, see "Inputs". Here also note that the role of composite audio outputs in this case is played by the main outputs of the receiver, to which acoustics are connected — in other words, the sound accompanying the video is output directly to the standard speakers of the audio system.
— BNC. Bayonet type connector used to connect coaxial cable. Theoretically, it can be used for various purposes, but in fact it is most often used similarly to coaxial S / P-DIF (see the relevant paragraph), for digital analogue audio. BNC connectors are more reliable in connection due to the bayonet lock; there is also a version with a threaded fixation.
— Trigger. The trigger output is used to automatically turn on other audio system components connected to the receiver. When the receiver itself is turned on, a control signal is sent to this output, which “wakes up” the connected device (for example, an amplifier) and relieves you of the need to turn it on manually. Of course, to use this function, the external device must be equipped with a trigger input.
— Control output (IR). The control output allows you to use the receiver's built-in IR receiver to control other components in your audio system from the remote control, such as an amplifier in another room, out of range of the remote control. With this scheme of operation, the audio receiver actually plays the role of a remote sensor, receiving commands and transmitting them through the control output to another device. Note that the very presence of such inputs and outputs does not guarantee the compatibility of various devices, especially if they are produced by different manufacturers; Sharing details should be clarified in the official documentation.Power consumption
The power consumed by the audio receiver during normal operation. Note that this parameter can be indicated in different ways: for example, some manufacturers measure it when the amplifier is operating at full power, while others measure it at 80% or 50% power. In addition, the power consumption of modern receivers is usually not so high as to put a serious strain on the power supply systems. Therefore, power consumption information usually plays a supporting role.
