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An amplifier to remember: how to choose an amplifier for your home theater?

ā€¦So youā€™ve finally decided to listen to music on something better than a boom box or a jukebox. In that case, youā€™ll have to assemble a so-called component audio system at home, that is, a sound complex consisting of separate devices. In addition to the amplifier and loudspeakers, this set includes the signal sources ā€“ the devices from which the sound.

Preamplifiers

Most often itā€™s a CD player and tuner radio , but experienced amateurs may also come across vinyl record players and tape or minidisc recorders. The audio signal sources also include video equipment, both outdated analog VCRs and up-to-date DVD and Bluray players. Modern digital devices such as media players, smartphone docking stations or Internet media servers are all audio sources, as are computers. But quite often at home they play synthesizers, sing karaoke, etc.p.

All of these different types of gear will eventually make their way into your speakers, but to do so, they must go through the heart of your audio system: an amplifier. So letā€™s talk about amplifiers.

There are quite a few types and varieties of preamplifiers, so we first need to classify them and then understand their function and features.

Audio equipment

AV receiver

Preamplifier

The level of the electrical signal at its output is such that if it is fed to the loudspeakers, we wonā€™t hear anything. So whatā€™s it for??

First of all, itā€™s for switching. All of the above sources are connected to the preamplifier in the optimum mode for each of them.

The thing is that different sources have different signal output levels: the CD player or the tuner give out a t.n. line level on the order of half a volt , and a vinyl player many hundreds of times less.

Besides, the user should be able to switch sources, and they should sound at approximately the same volume. This requires matching the signal levels of the different sources and boosting them to a level that is sufficient for the input stage of the power amplifier.

Another function of the preamplifier is to set up and switch t.n. of the loop-through channels, t.e. The ability, while listening, to also record the signal to a recorder, including performing these two processes independently.

Another important function is to control the output volume and frequency correction of the signal, for which there are volume and treble and bass controls on the front panel. Often there is also a direct signal button, t.e. frequency corrector bypass, and a so-called tone compensation button, designed to boost low and high frequencies when listening at a lower volume. The preamplifier can have an extra low pass filter which is especially useful with record players.

On the rear panel of the preamplifier are input jacks to connect sources, usually 5 or 6 and they are made by t.n. unbalanced circuit for connecting the RCA-type jacks colloquially called ā€œtulipsā€ , and there are also jacks for the outputs. There are usually two ā€“ the main one for connecting to the power amplifier and the auxiliary one for recording. The sound is blurred in the sound picture.n. XLR type symmetrical connections, usually used in professional equipment. Their main advantage is possibility to transmit weak signal without problems to a very big distance, dozens of meters, but for usual domestic listening it is not so important, so there is no sense to overpay for the function you are unlikely to use.

Virtually all modern amplifiers have remote volume control and source control, and they can often be used to control certain functions of other units from the same company, such as CD player playback, etc.p. of the same company. Note that the separate amplification, t.e. Both a preamp and a power amplifier are expensive, since each cost starts at about 20k for a single .Dollars.

AV processor

Subwoofer Amplifier

A power amplifier, sometimes called a subwoofer termination

Functionally it is very simple ā€“ it has a single input, usually stereo otherwise two mono amplifiers would be required , and the volume knob is often the only control. But this is a very serious device with very simple functionality, that is why it costs more than a ā€œsmartā€ preamplifier. High sound quality is ensured by using heavy duty transformers and high capacity capacitors capable of outputting high levels of input signal to the load.e. loudspeakers, very high current. So a good amplifier is always heavy.

For a power amplifier, the load rating is important, t.e. loudspeaker impedance. Amplifiers are usually designed for speaker impedance of 4 or 8 ohms. You can connect a higher impedance speaker to the amplifier, but never a lower impedance! This could, under certain circumstances, damage the output stage!

A very important parameter in a power amplifier is its damping factor. The damping factor helps to prevent inertia, t.e.Parasitic oscillation of the speaker cone, which makes the sound clearer, more detailed and accurate. The more the damping factor is, the better the quality of the amplifier.

Another important parameter is the output slew rate, which is the slew rate of an amplifier. The faster this speed measured in microseconds , the better the amplifier plays t.n. Transient, or ā€œunsteadyā€ processes, t.e. The small fast high-frequency components of the signal. For example, playing cymbals, percussion, stringed plucked instruments, etc.p. It is clear that a ā€œslowā€ amplifier will not work well with such sounds and will blur the sound picture.

Preamplifiers

Power Amplifiers

Integrated or full-range amplifier

This is the most popular on the market, combining a preamp and a power amplifier in one box. All of the above features and characteristics of each of the components are present in the integrated amplifier. Fairly decent full amplifiers are available to almost everyone, their price starts from about 8000 rbl.

If you are not going to experiment with frequent changes to the components of your audio system, an integrated amplifier is a better choice, but if you are planning on gradually upgrading your setup to a higher class, separate pre and post amplifiers are probably your best bet.

AV receiver

Audio equipment

receiver

Itā€™s a universal device, a kind of combine: an integrated amplifier which also has a radio tuner and often a digital signal processor for effects.

Those effects include a multiband equalizer, reverb, and in the case of the Surround receiver, a Dolby Digital multichannel phono decoder. Not only that, but this unit may also have microphone inputs for karaoke, and the latest models have an Internet radio receiver and Ethernet port to connect to the network.

If you want an all-in-one amp, this receiver is for you. But we must consider that there are no miracles, and the price of a good universal device should correspond to the cost of its components. If a fancy multifunctional device costs as much as a simple amplifier, it means that developers seriously saved on components and circuitry.

Choosing your amplifier

This question has already been partly addressed in the section on amplifiers. Now letā€™s dig a little deeper into it.

Do you listen to the amplifier in the store?

If it is available, yes. Another thing is that the practical value of such listening is not very high ā€“ your perception will be influenced by very many different factors, both technical and psychological.

For an accurate subjective evaluation of the sound you need a lot of experience and a trained ear. You should also keep in mind that modern equipment of the same class i.e.e. of value sound almost identical, with minimal difference, so there is a danger of falling into self-deception, or even deception from those who want to sell you equipment.

Anyway, in the store, listen to the sound in the ā€œfirst approximationā€: how the amplifier sounds at very low volume, at very high volume, how effectively deeply the tweeter/timbre and tone-compensation controls work, how high the self noise is when you set the volume control to maximum with the source turned off, whether the volume changes smoothly when you turn the control. This will give you an overall idea of whether this unit is right for you.

tube or solid state?

This is an important question, but for those who place a higher value on sound quality than the average music lover. Many connoisseurs appreciate the tube for its comfortable sound, but not everyone is able to grasp these nuances, and not everyone sets out to savor the purely acoustic features instead of just listening to their favorite music.

Furthermore, tube amplifiers have not only pros but also well-known cons. For such parameters as signal to noise ratio and harmonic distortion factor tube amplifiers are much inferior to transistor amplifiers. They have much lower output power although I might point out that tube power and transistor power are not the same thing . The tube amplifiers have a much lower energy efficiency, t.e. At low sound power they consume electricity ā€œwith all their heartsā€.

The tube technique in a life is more capricious and handling it requires training and care, including in terms of safety. Finally, tube amplifiers are more expensive than solid state ones: a ā€œsensibleā€ tube power amplifier is less expensive than 70k for most people. See. You canā€™t find any, and integrated tube amplifiers with at least 40 Watt are starting from 40 thousand. Dollars. In short, a tube amplifier is not for beginners, but for connoisseurs.

How to Match Loudspeakers and Amplifier?

Here it is necessary to take into account that even an inexpensive amplifier is less critical component of audio circuit than MSS, and it generally causes less problems in the sound than loudspeakers do.

So if you already have speakers you are happy with, consider the following factors when choosing an amplifier:

ā€“ Nominal load resistance of the amplifier should match the loudspeakersā€™ resistance ā€“ if you have 4 ohms loudspeakers, you should choose an amplifier designed for 4 ohms load as well.

ā€“ The output of your amplifier should not be more powerful than the speakers, itā€™s better for your speakers to be a bit more powerful than the amplifier, it will save them from damage if you turn on the amplifier at full volume.

ā€“ If your speakers generally sound fine but you feel they lack a little bit of treble or bass, you should investigate the quality of the tone controls on your amplifier: very often it is enough to boost the treble or bass with the existing bi-band compensator. If thatā€™s not enough, you canā€™t do anything about it, youā€™ll have to replace your speakers.

How to choose components in a set?

Donā€™t forget that all of the components of your set should be of the same class in terms of price and quality. Too cheap will reduce the benefits of more expensive ones, and too expensive, on the contrary, will not sound at its best.

But if you bought it to ā€œgrow outā€ and are going to eventually pull other components to it, getting a higher class system, buying an expensive component can make sense. This is especially true for loudspeakers. But thatā€™s another topic altogetherā€¦

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John Techno

Greetings, everyone! I am John Techno, and my expedition in the realm of household appliances has been a thrilling adventure spanning over 30 years. What began as a curiosity about the mechanics of these everyday marvels transformed into a fulfilling career journey.

Home appliances. Televisions. Computers. Photo equipment. Reviews and tests. How to choose and buy.
Comments: 2
  1. Waverly

    When choosing an amplifier for your home theater, what factors should be considered to ensure the best performance and compatibility with your audio setup? Are there specific power requirements or connectivity options that are essential? Any recommendations on brands known for their quality and reliability?

    Reply
  2. Ethan Young

    What are the key factors one should consider when selecting an amplifier for a home theater system?

    Reply
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