How Small Will Audio Amplifiers Become?
Recently, you may have noticed that audio amplifiers have become small. In fact, they have become so small that some of them easily fit into a portable device such as a smart phone. However, having a small size also brings about some limitations. So how small can audio amplifiers become without sacrificing performance? Let me look at some technical specifications that you need to understand in order to figure out the answer.
The main purpose of an audio amplifier is to convert an envelope audio signal into a voltage which is strong enough to drive some speakers. Different types of amplifiers have a different number of channels. A stereo amplifier, for example, has two channels. It usually drives two speakers which connect to an audio source. Obviously, having two channels requires more space than having an amplifier only offers a single channel.
Multi-channel amplifiers such as the ones used for surround sound setups are even larger. They include up to 10 channels. Usually, each channel is designed individually on to the circuit board. However, some integrated devices offer multiple channels. Obviously, integrating an amplifier into a circuit is an easy way to minimize the footprint.
However, keep in mind that amplifiers also require a certain amount of external components. For example, class-the audio amplifiers require inductors and low-pass filters. Obviously, each channel needs its own components. Therefore, integrating the main part of the amplifier only offers limited space savings.
By reducing the size of the external components, the footprint of the amplifier can really be minimized. Also, there some unique designs of audio amplifiers such as filter-less amplifiers. These types of amplifiers reduce the number of components which are required. However, keep in mind that these amplifiers have a larger in mission. Therefore, filter-less amplifiers are usually only suited for fairly low wattage.
One of the limitations of audio amplifiers is the power efficiency. The lower the power efficiency, the more wattage is being radiated as heat. Whenever there’s heat, there has to be some mechanism for distributing and radiating off the heat from the amplifier. Therefore, amplifiers with low power efficiency usually require fairly large heatsinks. However, some manufacturers are using their products enclosures to act as a heatsink.