Amplifiers, or amps as they’re more popularly known, are indispensable parts of the sound industry. Concerts, clubs, and conferences would be incomplete without them. So, what exactly are these things, what do they do, and how do you use them?
This article aims to tackle exactly that. If you’re curious about these technological inventions that have forever changed the map of communication, this article will take you through all the aspects of amplifiers, their types, and how they’re used.
Affiliate Disclosure: AmplifierZone is reader-supported. As an Amazon Associate, we may earn commissions from qualifying purchases at no extra cost to you.
What is an Amplifier?
At the risk of oversimplifying it, an amplifier is a device that amplifies a signal. In this article, we will be talking about sound amplifiers, but let’s first talk about the general terms associated with it for a bit.
The word amplifier comes from the physics term amplitude. It is defined as the maximum extent of a vibration or oscillation, measured from the position of equilibrium. In layman’s terms, the bigger the amplitude, the more the intensity of the signal is. In this case, the bigger the amplitude, the louder the signal.
And this is exactly what an amplifier does. If a musician is playing his guitar on the stage and singing along with it, there is no way he can be heard past the first two or three rows. Amplifiers make it possible for the signals from his microphone and his electric guitar to be at a level that can be heard throughout the arena.
If you’re interested in knowing more about the physics aspect of amplifiers, check out this article on how amplifiers work.
We take things like our headphones and speakers (even the ones on our phone!) for granted, but most of these have built-in amplifiers that make it possible for them to produce sound. Sound from any source is read in the form of electric signals, and these signals are then transmitted via preamplifiers (or preamps).
What is a Pre-amp?
Ever wondered why your voice on audio recordings sounds so terrible? It’s because there’s no preamp on the mic when it comes to most recordings.
The difference between a preamplifier vs amplifier is that the former picks up signals of much lower intensity. In the sound industry, the level of these low-intensity signals is called the mic-level. Preamplifiers make sure that the mic-level or instrument-level signal is picked up and amplified properly.
When we say properly, we mean that not all signals have to be amplified. The reason voice recordings sound bad is that there is too much background noise in them. The human ear has adjusted itself to ignore the sounds around us due to their perpetual nature, but machines are unbiased, and they pick up on everything.
Therefore, a preamplifier does an important job. It amplifies the relevant noise and sends it to the main amplifier (also called the power amplifier), letting it do its own job of making these important signals even louder for the loudspeaker.
This technology, however, has been modified and improved to ensure that you do not need two separate instruments to get this done. This is where integrated amplifiers come into the picture.
What is an Integrated Amplifier?
When you listen to music on your phone speakers, you are not getting the real experience of what the artists intended it to sound like. This is because the artists used top quality instruments in professional studios while recording their music, while your phone speakers do not have the required hardware to accurately recreate it.
Integrated amplifiers are your workaround for this problem. If you’re looking for high quality, smooth, and background noise-free sounds, you need both an amplifier and a preamplifier in your setup.
An integrated amplifier puts together (or integrates) the preamp and the power amp in a single instrument. This not only helps you save infrastructure and space, but also gives you excellent audio quality.
There are several other engineering and audio advantages to integrated amplifiers. When you have all your amplifying functions in a single setup, you are essentially isolating the source signals from the integrated amplifier.
When it comes to audio advantages, the engineering advantages themselves help in cleaner sound quality. But besides this, the source signals might be of different kinds of sources, and when they interfere with each other, it reduces the quality of the audio. The source signals generated with an integrated amplifier do not interact or interfere with one another by design, giving you audio that is low in distortion.
Stability is an important part of sound systems. Several high-quality sound systems rely on inverting their outputs by a phase to improve this aspect, and this brings us to a different type of amplifier: Inverting Amplifiers.
What are Inverting Amplifiers?
This is where things get a little technical. Now as you probably know, sound travels in waves. And each of these waves has a particular phase.
The difference between an inverting amplifier vs non inverting amplifier is in the output that both these types of amplifiers produce. While non inverting amplifiers have an output which is in the same phase as their input, inverting amplifiers switch the output by 180 degrees out of phase with the input signal.
This does not make a difference when there is just one output channel. For example, if you’re listening to mono audio, the difference between the sound outputs from an inverting amplifier vs non inverting amplifier will be negligible. The main difference is when there are multiple output channels.
For example, if you’re listening to stereo speakers, you will have two output channels. For this, you will need a non inverting amplifier for the best quality audio. Delay or inversion of the signal does not matter when you’re listening to a single channel.
The reason why inverting amplifiers are used is that the relative inversion between channels matters. If there is not a proper phase relationship between the channels, the perceived sound position from the source won’t be correct, and you will hear a distorted version of the sound you were originally meant to hear.
Look at this way. Let’s say there’s a recorded audio and instrumental part each to a song. This would be completely fine on a non inverting channel. But as you know, songs are not recorded this way, and there are multiple layers of vocals and instrumentals that are put on over the original beat.
Now, if you add more vocals to the previous mix on the same channel, the original vocals would disappear, because the new vocals are not being added to the song, but are replacing them. Therefore, to make a proper soundtrack (or other similar processes in the sound industry), you need an inverting amplifier.
Classes of Amplifiers
If you look at the specifications of any amplifier, you will notice that every amplifier comes with a class of its own. These classes are a depiction of how these amplifiers function at a core level. The most common amplifier classes that you can see are A, AB, D, G, and H.