Comparison Parasound Halo P6 vs Parasound P 5

Most modern amplifiers have toroidal transformers - with a toroid-shaped core, in other words, a donut. This type is considered optimal for amplifiers of any level up to Hi-End: it creates a minimum of "extra" electromagnetic radiation and, accordingly, interference. Some time ago, E-core transformers were also widely used, but they are considered obsolete and are becoming less common today.

The maximum number of channels the amplifier can handle. The choice for this parameter depends primarily on the intended format of using the device.

Most modern amplifiers have two channels for normal stereo sound, which is enough for listening to music or radio programs. There are also models designed for multi-channel "surround" sound, but they are much less common. This is due to the fact that such sound is most often used as an accompaniment to high-quality video — and therefore a home theater receiver is usually used for processing, rather than a separate audio amplifier.

Among the top-class models, there may be single-channel amplifiers — they provide maximum opportunities for fine-tuning the sound, but you have to purchase several such devices, one per channel. Another specific variety is amplifiers designed to add a certain number of channels to those already available; the most popular of these options is 3-channel, capable of turning an existing stereo system into a multi-channel one.

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.

The sensitivity and dynamic impedance of the amplifier when a signal is applied to the Main 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.

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.

Signal level and dynamic impedance provided by the device at the preamplifier output (see "Outputs" for details).

The signal level must not be lower than the sensitivity of the power amplifier (see "Type") to which the signal is received — otherwise the power amplifier will not be able to provide a normal signal level already at its outputs.

Dynamic resistance (impedance) of the preamplifier output. This value is exactly the same as the input impedance of the REC output — see the relevant paragraph above. For more information about the exit itself, see "Exits".

The number of trigger inputs provided in the design of the amplifier.

The trigger input is intended for power management and is used to build audio systems, where one of the components (for example, a player) plays the role of a control device for the rest, including and amplifier. When such a device is turned on, a signal is sent to the trigger inputs of the “slave” that also wakes them up. This saves the user from having to enable each component separately.

— 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.

The type of connector used to connect headphones to an amplifier.

— 3.5 mm (mini-Jack). The most popular audio connector in modern portable electronics, also found among stationary equipment. However it is considered not as suitable for high-quality sound as 6.35 mm Jack, since it gives an increased likelihood of interference at the connection point. On the other hand, the vast majority of modern headphones, of all price categories, are made specifically for this connector. This means that the presence of a mini-Jack socket in most cases will allow you to connect headphones directly, without the use of adapters — that is, in the best way.

— 6.35 mm (Jack). This connector is typical mainly for stationary audio equipment, including professional class. It provides a better connection quality than the mini-Jack (in particular, less resistance due to the larger contact area), and is also more durable and reliable. At the same time, it is worth noting that only some high-end headphone models are equipped with a “native” plug under such a connector; and to connect the popular 3.5 mm mini-Jack you will need an adapter, which can affect the sound quality.