One of the more exciting innovations in audio equipment to come along in recent years has been digital audio amplifiers. While they don’t actually have anything to do with digital music, they provide many advantages over regular amplifiers. Choosing any new amplifier is a difficult choice and there are many features that need to be considered, such as the power output and number of channels. Consumers also have to decide if they need a standalone amplifier or one that has a receiver built into it.
Digital audio amplifiers are part of a group of amplifiers that increase the power of an audio signal. They are typically the last stage before the speakers in the chain of audio equipment. They are essential because the input signals that come from the microphone or playback device generally do not have enough power to drive the speakers. Out of the many different classes of power amplifier, Class D is the most commonly used for audio setups because it has a high power efficiency.
Digital is a great marketing term and it can be used to trick consumers. Many wrongly believe that digital audio amplifiers are essential for listening to music from digital devices, like DVD players and MP3 players. This is false because the conversion from digital to analogue happens before the amplifier stage. Digital actually refers to the switching-mode power supply used inside the amplifier. These power supplies are lighter, quieter, cooler, and more efficient that the ones used in regular amplifiers. Apart from this difference, digital audio amplifiers are just like other audio amplifiers.
There are many other features to consider when comparing digital audio amplifiers. A good amplifier has high gain, low distortion, low noise, crossovers, and enough channels to drive the speakers. It should have thermal and current protection and sufficient cooling to remove the large amount of heat produced. Most importantly, the amplifier should be matched to the speakers. It is a misconception that an amplifier with a higher power rating is always better than one with a lower power rating. Choosing the right amplifier can be a difficult choice so it is best to consult an audio professional.
Another important feature to consider when looking at digital audio amplifiers is whether they are balanced. The wires inside audio cables pick up electrical noise from the environment because they are essentially antennas. The noise gets added to the audio signals and fed into the amplifier. It is usually small enough not be noticed but there will occasionally be a spike that is noticeable. The noise component can be identified and reduced by comparing the signal with a mirror image of itself. Balanced audio equipment requires special cables and plugs to carry this extra signal.
Expensive digital audio amplifiers used by professionals are usually balanced but the cheaper models used in home setup are often unbalanced. It is easy to identify the type by looking at the plugs on the back. Balanced amplifiers typically have XLR plugs or audio jacks, while unbalanced amplifiers have only RCA plugs. The most common XLR plug has three pins but there are others with different pin numbers. RCA plugs have one large pin and a shield surrounding it. Plugs are often color coded so that the audio channels are not mixed up.
Several digital audio amplifiers also come with a receiver built into them. These combined units are popular because they take up less space, require fewer cables and are easier to setup. But having separate units may provide better audio quality, as design compromises may occur when two units are combined. For this reason, many audio enthusiasts prefer to keep their amplifier and receiver separate to give them greater control over their setup. It may be more expensive but this hardly matters to those who want the best possible sound system.