What is a Headphone Amp?
A headphone amplifier is simply a miniature power amplifier specifically designed to drive the tiny speakers inside headphones.
Headphone amps are most useful with certain power-hungry high-impedance audiophile headphones that can benefit from the improved clean power of a dedicated amp. A headphone amp can improve detail resolution and dynamic range extension and maximize overall musical clarity.
Because headphones are often used with portable devices, some headphone amps are battery-powered for use on the go.
Some headphone amps also include built-in digital to analog converters (DACs) with a USB or optical port to connect directly with a laptop, PC or tablet, as well as optical and coaxial connections for compatibility with other digital audio sources.
Why do I need a headphone amp?
Just like a good speaker, good headphones can benefit from the clean power of a headphone amplifier to sound their very best. With top headphones, an uncompressed music source and a great headphone amp, you'll be astonished at the level of pure clarity, huge dynamic range and deep musical detail you'll be able to hear.
In fact, while big speaker systems may out-perform headphones in terms of visceral sonic impact, great headphones can deliver much superior audio resolution and access to nuanced low-level information obscured in the recording. The most common reaction folks have with their first experience listening to high-end audiophile headphone systems is, “I heard stuff I’ve never heard before. I need to listen to my music collection over again.”
How do I know if my headphones need an amp?
Most good headphones can be improved with amplification, but a few absolutely require a headphone amp to perform well. When deciding whether to acquire a good headphone amp, it's important to consider how much a pair of headphones can benefit from an amp. In other words, their "performance ceiling"
If you spent more than $200 on your headphones, you probably want to consider an amp. An entry-level headphone amp like an SMSL SH-6 Desktop Headphone Amplifier will help you get your money’s worth from your headphones and is an affordable gateway to the benefits of headphone amplification. If you want to move up a notch in musical performance, see our full line of headphone amps to find the best one for your needs.
Of course, an audio system is only as good as its weakest link. If you have well-recorded music and great audiophile headphones, but are relying on the power-limited headphone amp inside your smartphone, laptop or tablet to make the headphones sing, you likely won't be driving your headphones to their full potential.
What does a headphone AMP do?
Adding an amp between the player and your audiophile headphones can provide a significant, audible improvement in clarity, detail and dynamics.
You may know about a headphone "impedance rating". Impedance is the combined resistance and reactivity the headphones present to the amp as an electrical load.
High-impedance cans usually need more voltage to get up to a solid listening level, so they can benefit from a headphone amp especially with portable players that have limited voltage available from their internal batteries. But very low-impedance cans lower the damping factor between the amp and headphones and actually require more current. So while low-impedance headphones may be loud enough from a portable device, sound quality can be significantly improved by adding a headphone amp.
The size and dimensions of your headphone may provide some basic clues as to whether an amp is warranted. Most earbud and in ear headphones are typically very efficient and less likely to benefit strongly from an amp. However, many larger over ear headphones will become clearer and better sounding with an amp. A few select audiophile models may even require a headphone amp to reach listenable volume levels and sonic performance, especially if connected to portable devices.
With a portable device, use a “line output” when available to connect to a headphone amp. If no line-out is available, use the headphone jack to send the signal over to the headphone amp.
When NOT to use an amp
Most in-ear headphones or IEMs are typically highly efficient so they work well with smartphones or other portable devices without requiring an amp.
You do not need a headphone amp when using noise-cancelling headphones, as they essentially already have a built-in headphone amp inside. It prevents an external headphone amp from adding any significant audio benefit.
What about a DAC?
If you are listening to your music on a computer, laptop or tablet, a headphone amp with an internal digital to analog converters (DAC) can significantly improve your listening by employing the better processing power available in outboard DACs.
The typical rule for personal audio is that headphones make by far the biggest difference, then amps, then DACs (all of this assumes decent files or streaming). Indeed, you’ll see this rule expressed and repeated commonly in many places online, and these days you can get an ‘all-you-need’ setup at modest price tags.
For more context, and a step-by-step guide to choosing components, check out our Buying Guide 2022: How to Navigate the Headphone Hobby
To learn more about DACs and how they work, check out this guide