Tubes type
The model of tubes installed in a tube or hybrid type amplifier (see "Element base"). The capabilities of the device largely depend on the lamps used in the design, including small details of the sound, not directly spelled out in the characteristics. In addition, this information allows, to some extent, to assess the overall level of the model. On the other hand, in fact, it can only be useful to extremely demanding listeners, attentive to every detail; most users, including audiophiles, will only need information about the type of tubes when they need to be replaced.
Capacitor capacitance
The total capacitance of the capacitors installed in the power supply of the amplifier. Usually, for ordinary lovers of high-quality sound, this indicator is not practically significant: the capacitance is selected in such a way as to optimally (or at least minimally) match the characteristics of the amplifier. However, for demanding audiophiles who pay attention to the smallest details of audio system components, capacitors are also often of interest.
The fact is that they are an important part of the rectifier circuit — they smooth out current fluctuations that arise both due to the imperfection of the rectifiers themselves and due to various external factors. Knowing the total capacitance of the capacitors, one can also evaluate the efficiency of their work: the higher this indicator, the more stable the power supply will work and the lower the likelihood of sound distortion due to its fault. There are special formulas that allow you to derive the optimal capacitance of capacitors depending on the type, power and other parameters of the amplifier; they can be found in specialized sources.
Power per channel (8Ω)
The nominal sound power output by the amplifier per channel when operating with a load having a dynamic resistance (impedance) of 8 ohms. In our catalog, this parameter is indicated for the mode when all channels of the amplifier work under load (see "Number of channels"); in the presence of unused channels, the rated power may be slightly higher, but this mode cannot be called standard.
Rated power can be simply described as the highest output signal power at which the amplifier is able to work stably for a long time (at least an hour) without negative consequences. These are average figures, because in fact, the audio signal is by definition unstable, and individual level jumps can significantly exceed the rated power. However, it is she who is the main basis for assessing the overall loudness of the sound.
This indicator also determines which speakers can be connected to the amplifier: their rated power should not be lower than that of the amplifier.
According to the laws of electrodynamics, with different dynamic load resistance, the output power of the amplifier will also be different. In modern speakers, the standard values \u200b\u200bare 8, 6, 4 and 2 Ohms, and power levels are indicated for them.
Power per channel (4Ω)
The nominal sound power output by the amplifier per channel when a load with a dynamic resistance (impedance) of 4 ohms is connected to it. See Power per Channel (8Ω) for more information on power rating and its relationship to impedance.
Signal to noise ratio (Phono MM/MC)
signal-to-noise ratio when the amplifier is driven through the Phono input. This interface is for connecting turntables; its features are described in the “Inputs” section below, and for the meaning of any signal-to-noise ratio, see the corresponding section above.
Phono MM/MC
The sensitivity and dynamic impedance of the amplifier when a signal is applied to the Phono MM/MC input.
Under the sensitivity of any input (except optical) is meant the lowest signal voltage at this input, at which the amplifier is able to provide normal nominal power values (see "Power per channel (8Ω)"). This parameter determines, first of all, the requirements for the signal source. On the one hand, the voltage provided by this source must not be lower than the input sensitivity of the amplifier, otherwise the latter simply will not give the claimed characteristics. However, a significant excess in voltage should not be allowed, otherwise the sound will begin to be distorted. More detailed recommendations on choosing an amplifier by sensitivity are described in special sources.
For any input other than optical, it is believed that the higher this indicator, the less distortion the amplifier introduces into the signal. The minimum level of input impedance in modern models is considered to be 10 kOhm, and in high-end devices it can reach several hundred kOhm.
Outputs
— Preamplifier (Pre-Amp). The presence in the design of the device of a separate output for the signal from the preamplifier. In the type of amplifiers of the same name (see "Type"), such an output is available by definition and is the main, and sometimes the only one. On integrated models (see ibid.)
, the Pre-Amp output allows you to connect an external power amplifier and use it instead of the internal one. This feature can be useful, for example, to connect a more powerful speaker instead of the original one, or to work in Bi-amping mode. It is worth noting that the Pre-Amp output can also be installed in power amplifiers, playing the role of a "splitter".
— Subwoofer. The presence in the amplifier design of a separate
subwoofer output. Usually, such an output uses an RCA connector (see "Input to the amplifier (Main)"), and the function itself is implemented through a crossover, which selects the low-frequency range in the signal and redirects it to a subwoofer. The "own" output makes it much easier to connect a subwoofer : it does not require any additional equipment, the amplifier itself is enough. This usually provides for the possibility of working with any type of subwoofer — both passive and active; however, in the first case, you will need an additional external amplifier.
— Coaxial S/P-DIF. The presence in the design of the amplifier of the S / P-DIF output of an electric typ
...e, with signal transmission via a coaxial cable. For more information about this interface, see the relevant paragraph in the "Inputs" section.
— Optical. The presence in the design of the amplifier output for transmitting a digital audio signal over a fiber optic cable TOSLINK. For more information about this interface, see the relevant paragraph in the "Inputs" section.
— Jack (6.35 mm). Presence of TRS type outputs in the design of the amplifier. These outputs are jacks for 6.35 mm Jack plugs and may look like the corresponding headphone jack (see below). However, this similarity is misleading: TRS produce sound on the principle of "one channel per plug" (an exception may be information amplifiers). This type of Jack connector is found mainly in high-end professional amplifiers.
— Speakon. An interface used in professional audio equipment to connect acoustics to a power amplifier. It has become widespread in high power equipment, including concert amplifiers (see "Intended Use"), due to its increased reliability and suitability even for working with very powerful audio signals. But in household appliances it is rarely used.
— Control output (IR). The control output allows the amplifier's built-in IR receiver to be used to control other components in the audio system, such as a DVD player in another room, out of range of the remote control, from the remote control. With this scheme of operation, the amplifier 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 amplifier during normal operation. Some manufacturers may indicate average power values, some — indicators at maximum load. However, anyway, this parameter allows you to quite adequately assess the power consumption of the device and the requirements for connected power.
In addition, it can be useful if you have doubts about the accuracy of the claimed data on the output power (see "Power per channel (8Ω)"). The basic rule is that the total power rating of all channels cannot exceed the total power consumption of the amplifier. In addition, there are special formulas that allow you to derive the maximum possible rated power depending on the power supply and type of amplifier; they can be found in special sources.
Standby consumption
Power consumption of the amplifier in standby mode.
In this mode, most amplifier components are disabled; power is supplied only to the control circuits. Their only task is to accept a command from the user at the right time and put the device into operation. The consumption of these circuits is extremely low and is unlikely to have a significant impact on electricity bills; at the same time, the exit from the standby mode is faster than turning it on from scratch, and the command can be accepted from the remote control (which is impossible in the absence of power). Therefore, most "off" amplifiers are usually in the standby mode.