Comparison Onkyo M-5000R vs Onkyo A-9000R

— Preamplifier. Preamplifiers are designed to initially process a weak signal and bring it to a level sufficient for transmission via a linear interface to a power amplifier (see below). Such models are able to work directly with sound pickups, microphones and other similar devices, may have additional sound correction functions, play the role of switches for connected signal sources, etc., but are not suitable for outputting sound to passive speakers or headphones.

— Power amplifier. Such models are designed to take the signal processed by the preamplifier and output it to the power sufficient to operate the connected speaker system. They can already work with passive type speakers, but they cannot do without a preamplifier for the input signal. However, it is worth noting here that most modern players are equipped with built-in preamps and can be used directly with power amplifiers.

— Integrated amplifier. Amplifiers that combine the capabilities of both of the above types in one package. The main advantage of such models is obvious: instead of two specialized devices, you can buy one universal one. This saves money, time and installation space, and reduces the chance of interference as there are no external connecting cables between the preamplifier and main amplifier and the components are usually optimally matched to each other. On the other hand, th...e integrated model provides fewer options for choosing the option for your own preferences: you have to purchase the device "as is", without the ability to separately select a preamplifier and power amplifier.

— Amplifier-processor. Professional models, typically for live use, are rack mounted and often use Euroblock jacks as Main inputs (see below). In terms of general application, processors are similar to power amplifiers, however, in addition to these features, they are also characterized by an abundance of settings that facilitate the work of sound engineers.

— Subwoofer amplifier. Specialized power amplifiers designed for low-frequency speakers — subwoofers. The design of such models usually provides for crossovers with an upper limit of the transmitted range at the level of 150 – 200 Hz; this allows only “native” frequencies to be fed to the subwoofer and has a positive effect on sound quality. In addition, many amplifiers of this type have specific settings such as phase control.

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 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.

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.

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.

In itself, the signal-to-noise ratio is the ratio of the level of pure sound produced by the amplifier 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 70 – 80 dB in modern amplifiers can be considered acceptable, 80 – 90 dB is not bad, and for advanced audiophile-class devices, a signal-to-noise ratio of at least 100 dB is considered mandatory.

If the specifications do not specify for which output the signal-to-noise ratio is indicated, it usually means its value for the linear input (see "RCA (par)"). This is quite enough to evaluate the quality of the device for this parameter. However, some manufacturers indicate it for other inputs — Main, Phono; see below for more on this.

Signal-to-noise ratio when the amplifier is operating through the Main input. For more details on the value of the signal-to-noise ratio, see the relevant paragraph above, about the Main input — p. "Input to the amplifier (Main)".

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.

This indicator describes the amount of non-linear distortion introduced by the amplifier into the processed signal. Such distortions are not necessarily perceived as extraneous noise, but they degrade the quality of the sound anyway — for example, they can make it more deaf. It is almost impossible to avoid them, but it can be reduced to levels inaudible to the human ear.

As a result, the harmonic distortion factor (harmonics) is one of the main parameters describing the overall sound quality in Hi-Fi and Hi-End amplifiers. The lower it is, the clearer the sound. Hundredths of a percent are considered a good indicator for modern amplifiers, thousandths and below are excellent. The exceptions are tube and hybrid models, for which rather high harmonic coefficients are allowed; see "Element base" for more details.