Power Amps
Power amps boost your music so you can crank it to 11
What does a power amp do and how does it work?
Power amplifiers are a critical component for being able to hear music. These devices sit between the audio source (such as a CD player, microphone or an electric guitar) and the speakers. The amplifier takes the electrical signal produced by the source, then amplifies it and outputs this to drive speakers that produce audio. Originally, amplifiers used vacuum tubes, but most current versions now use solid state transistors. The more powerful the amplifier, the louder the resulting sound can be.
What’s the difference between power amps and a pre-amplifier?
This is one of those cases where the name really does say it all.
A pre-amplifier is a low power amplifier that picks up a very faint electrical signal, boosting it enough for an audio power amplifier to then take it to the next level of amplification and send it on to the speakers. The classic case where a pre-amplifier is used is with a turntable. The turntable itself puts out a very weak signal and plugging it directly into power amps that lack a PHONO input results in poor quality, weak, low-volume music. But plug the turntable into a pre-amplifier, then connect the pre-amplifier to any power amplifiers, and the results are high quality music.
What is a headphone amplifier?
Headphone amplifiers are very popular among music fans. Like other power amps, they sit between an audio source and the speakers—but in this case the speakers are inside headphones. They amplify the signal to get the best quality output from the headphones.
Many people today listen to music by plugging high quality headphones into a laptop or smartphone. These devices have their own amplifier, but it’s usually not audiophile quality and may not have sufficient power to properly drive high end headphones. For superior playback, the source and headphones are both plugged in to the headphone amplifier. The results can be very impressive, including more volume on tap, richer and more balanced sound, and better stereo separation.
Some portable headphone amplifiers also include a high-quality DAC (digital audio converter) which makes digital or streamed music sound even better, by replacing the DAC built-into the PC or smartphone.
Finding your perfect power amp
How do you find the best power amplifier? First you need to identify what type of power amp you’re looking for. For example, are you trying to integrate a turntable into your audio system with a pre-amplifier? Or do you want to plug in a guitar? Maybe you need to a new speaker power amp, or a headphone amplifier.
Once you’ve decided on that, you need to drill down into specific features. For example, if you’re looking at power amplifiers as part of a home stereo system, you need to know details like how many watts of power output are needed (i.e., how loud you want it to be), how many pairs of speakers will be connected, how many inputs are required and whether you want a PHONO input. Once you know what you need, finding a power amplifier for sale that’s perfect for you will be as easy as following a checklist.