Comparison Denon PMA-1600NE vs Denon PMA-1520AE

The sensitivity and dynamic impedance of the amplifier when a signal is applied to the RCA line 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".

— Euroblock. Analogue audio input (usually line level) using a Euroblock connector. This connector, used mainly in professional audio equipment, is remarkable in that it is attached to the wire using terminals. This is extremely convenient when working with stripped wires (which is often required in professional applications): screwing such a wire to the plug once and connecting / disconnecting the plug to the Euroblock connector is much easier than constantly unscrewing / screwing the terminals. In addition, such a connection is often made balanced (see "XLR (balanced)" below). Inputs of this type are found mainly in information and information-concert amplifiers (see above).

— Phono. Dedicated input for connecting to the amplifier turntables; often has a suffix indicating the type of cartridge that is compatible, such as "Phono MM" or "Phono MM/MC" (see "Advanced — Phono Stage" for details). Despite the proliferation of digital formats, these players are still highly regarded by audiophiles for their high quality and fidelity, and are often used in premium audio systems. However, connecting a "turntable" has its own characteristics — in particular, it requires a phono stage (for more details, see ibid.) — and standard inputs are unsuitable for this purpose. Therefore, a Phono jack is a must if you want to connect your turntable directly, without an external phono stage.

— USB B. The USB interface is widely used in...computer technology for various peripherals. The presence of a type B input means that the amplifier can be connected to a computer as an external controlled device (slave). Most often, with this connection, it is used as an external sound card or audio interface — this provides higher sound quality and more extensive options for its settings than most built-in sound cards, even expensive ones. However, the matter is not limited to this: in some models, via USB type B, you can update the firmware or change the special parameters of the amplifier.

— Coaxial S / P-DIF. Digital audio input, a variation of the S/P-DIF interface based on a conventional electrical signal (the second variation, optical, is described below). Usually uses a common RCA connector, known as a "tulip", but has rather strict cable requirements. The bandwidth of any version of S / P-DIF is quite sufficient even for high-quality multi-channel sound, and the coaxial version itself is simpler, cheaper and more reliable than the optical one, but more susceptible to interference.

— Optical. Input for transmitting digital sound using light signals, via TOSLINK fiber optic cable; one of the versions of the S/P-DIF standard. The main advantage of optical fiber over traditional electrical cables is complete insensitivity to electrical interference; at the same time, it is more expensive and requires rather careful handling (in particular, it does not tolerate sharp bends).

— Balanced digital ( AES/EBU). The AES/EBU interface is used in the professional field to transmit audio in digital format. It can use several connection types; in this case, it means transmission over the so-called balanced line using an XLR connector. Both the principle of balanced connection and the connector itself are described in detail in the “XLR (balanced)” section below — however, in the case of AES / EBU, we are talking about a digital signal, not an analogue signal.

— COM port ( RS-232). A connector used to control the amplifier from a computer. Through it, you can change the settings, incl. and quite thin, and in some models even update the firmware. Usually, for such purposes, special software is required, which can be supplied with the amplifier.

— Control input (IR). Connector for connecting an external infrared remote control receiver. When properly placed, such a receiver will allow you to use the remote control even in places where the signal from the remote control cannot reach the main (built-in) sensor — for example, in another room. For such purposes, not only sensors can be used as a separate device, but also system components that are compatible with the remote control — for example, players or tuners.

The number of line inputs in the amplifier design using the RCA interface. Unlike the Main input (see above), which can work with the same connectors, when connected to a linear RCA, the signal goes through all the stages of processing provided for in the amplifier — for example, adjusting the balance or frequencies (see "Adjustments"), etc. .P.

See “Amplifier Input (Main)” for details on the connector itself. Here we note that when using RCA as a linear interface, a pair of such connectors is considered one input. This is due to the fact that only one channel can be transmitted over one coaxial cable, so a pair is needed to work with stereo sound.

The number of signal inputs (of any type) determines how many signal sources can be simultaneously connected to the amplifier. Accordingly, it is worth choosing a model according to the number of inputs, taking into account the expected number of such sources: after all, it is easier to connect them all and select them through the amplifier’s remote control or control panel than to fiddle with reconnecting every time.

— 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 electr...ic type, 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.

— Display. The presence of a display on the front panel of the amplifier. Such displays may have a different design and size, but they are all used to display service information: operating mode, selected signal source, special notifications, overload messages, errors, etc. This provides additional ease of use.

— Indicators. In this case, it means that there are indicators on the front panel that indicate the currently used signal source. Usually they look like a row of light bulbs with the appropriate signatures — "Phono", "CD", "Tuner", "AUX", etc. Such pointers are not as versatile as the display, but they are still very convenient.

— Arrow indicators. Presence on the front panel of indicators in the form of scales with arrows. Usually, such indicators are designed to display the peak level of the output signal. They make it easy to track overloads, and many users find this option more convenient and visual than displays. In addition, the arrow scales give the amplifier a stylish appearance, and, unlike the same displays, do not have complex electronics that can distort the sound. However, this category also includes other types of indicators with scales; some of them may not use an arrow, but other indicators (for example, light ones).

— Regulators behind a hidden panel. The presence of a cover on the front panel that hides the controls of the amplifier. Many models...are equipped with additional controls on the front panel; they can be used to adjust both the sound — volume, bass / treble, balance, etc. — and other operation parameters (for example, selecting a signal source or switching between the main and additional speakers). Sometimes these controls (as well as the front panel inputs) are provided with a cover, usually for aesthetic reasons. an abundance of small elements would give the device a sloppy appearance. The cover can also perform protective functions — for example, it reduces the amount of dust that enters the connectors.

— Input audio jack. The presence on the front panel of an input for connecting an audio signal — usually linear, in analogue format. On the one hand, such an input greatly simplifies work with signal sources that need to be connected only occasionally and for a short time — for example, MP3 players: the front panel is always in sight, while getting to the connectors on the back is sometimes very difficult. On the other hand, usually the role of the front audio jack is played by AUX IN with a 3.5 mm mini-Jack jack. This connector is not used among the main inputs, but it is quite popular in portable electronics, in particular, the players already mentioned. Some models may have a pair of RCA jacks on the front panel (see "RCA (pair)"), but this option is less common.

— Headphone output. Headphone output on the front panel of the amplifier. Headphones are portable devices, and on average you have to reconnect them significantly more often than most other components of the audio system; the output located on the front panel greatly simplifies the process.