Like most people, you probably don’t think twice about plugging your headphones directly into the headphone jack on your computer, laptop, or smartphone. For the typical pair of mobile headphones, this is acceptable, but as you move up the level in headphone quality, the output from these devices just doesn’t cut the mustard.
If you want high quality audio and expect to be blown away then a headphone amplifier may be just what you need.
What is a headphone amplifier?
Essentially, any audio amplifier is a device that takes a signal of relatively low strength and reproduces it at a higher power level. We experience that higher power level as more loudness.
However, not all amplifiers are created equal. A good amplifier does more than just make your music louder. It will also try to preserve the details and intent of the original signal. Good amps will not add noise and will work to clear up problems with the original audio.
There are many different approaches to amplifier design and headphone amplifiers are no different.
For example, some only accept analog input, meaning your device’s own internal amplifier and audio hardware gets to work on the sound first.
If your audio source is analog (eg vinyl records) then this is not a problem for the headphone amplifier, as you avoid unnecessary analog to digital conversion.
Then there are headphone amplifiers that have their own DAC (digital to analog converter) that connects to your computer via USB. These amps have complete control over the sound, as they only receive digital audio data and can handle every step it takes to get it out of your headphone speakers and into your ears.
Many headphone amps offer both types of input, which can be useful as many mobile devices do not work with an external USB DAC.
Why do we need headphone amplifiers?
Whether in headphones or on a desk, speakers require electrical current to create the air vibrations we perceive as sound. If there isn’t enough energy on tap, the resulting audio will be weak and quiet. As a result, it lacks detail and punch.
The internal amplifiers in smartphones and computer sound cards are at risk. They have to fit in an incredibly small amount of space shared with other components. In battery-operated devices, amplifiers must be carefully designed and balanced so that they are not power guzzlers. Honestly, there’s a lot to admire about these devices, which deliver usable, enjoyable audio despite seemingly impossible technical hurdles.
It also helps that most headphones these days are explicitly designed to work with smartphones and other similar devices, so they’re loud enough. This has to do with the sensitivity of a particular set of headphones.
Headphones designed for use on mobile devices have a high sensitivity, which essentially means that they can reach a certain level of sound with very little power. The downside to this is that high sensitivity levels often muddy the audio, compromising the integrity of the sound.
It’s not so bad if you listen to compressed streaming music while jogging in the morning but for intentional listening the problems are there if you pay attention.
To solve this problem, you have to reduce the sensitivity of the headphones, but the less sensitive the phones, the lower the volume that you can achieve with the output power of a smartphone or computer.
Which headphones are suitable for amplifiers?
The short answer is that high impedance headphones require a dedicated headphone amplifier to reach their full potential.
†Impedance” is the resistance that electrical energy encounters as it passes through the headphone wiring on its way to the speakers. Impedance is measured in Ohms and generally high impedance, low sensitivity headphones are rated at 25 Ohms and above. Higher-end headphones usually have an impedance greater than 100 Ohms.
So if your headphones have an impedance of less than 25 Ohms you don’t need an amp, the higher you go from that number the more important an amp becomes.
Bluetooth headphones obviously don’t require an external amplifier as they have one built in, but some Bluetooth headphones also have a wired option. This option usually bypasses the internal amplifier, so depending on their sensitivity level, an amplifier may be suitable there as well.
Types of Headphone Amplifiers
Internally, there are several ways in which amplifiers can be designed, which are discussed in detail on audiophile forums. For the rest of us, though, there are two main types of headphone amps to consider: solid state amplifiers and tube amps†
Solid-state amplifiers use nothing but microchips in the chain of components that lead to your actual eardrums. It’s fully digital, clear and, as some claim, cold. Solid state amplifiers are usually cheaper, more durable and more compact.
Tube amplifiers go back to a time before transistors and integrated circuits overtook the audio industry. They are easy to spot thanks to the prominent glass tubes that protrude from the chassis. More expensive ones usually have more tubes, cheaper models tend to use solid-state components in combination with analog tubes.
Many audiophiles swear by the warm tone and color that tubes give to music and sound, but it’s very subjective. What’s not so subjective is that tube amps are generally more expensive, more fragile and take up more space. The truth is that a good solid state amp will be fine for most people, but you should taste the tube amp audio to see if it appeals to you.
Headphone Amp Suggestions
So, if you’re planning to invest in a set of high-quality cans and know you need an amp to make the most of it, what should you buy?
We took a look at the best-selling headphone amps on Amazon and found three options that look promising for someone looking for headphone amps. As a bonus, they also represent three different categories of headphone amps.
The FiiO E10K Headphone Amplifier is a very affordable solid-state amplifier with a clean shell and minimal controls. All you have to do is plug everything in and turn the volume to a comfortable level.
The E10K only supports digital input via USB, but has a variety of outputs that go beyond just a headphone jack. If you connect this to your computer and use it with high impedance headphones, you should enjoy powerful, detailed sound with low noise and distortion.
While it won’t make the mouth (ears?) of true audiophiles water, based on the amp’s many positive reviews, it’s an affordable and effective upgrade for just about anyone.
The Neoteck amp doesn’t inspire much confidence at first with its poorly translated marketing copy, but it’s a well-reviewed and undeniably interesting product. The big selling point of this amp is that it runs on batteries.
With support for headphones between 16 and 150 Ohms, there is a great selection of mid-range headphones that would benefit from a simple amp like this one.
If you are looking for an amplifier for public transport or for work or school, this is a very affordable option.
Finally, we have the Loxjie P20 tube amp. It’s one of the cheapest entry-level tube amps we could find and represents a perfect way to dip your toes into the signature tube sound before buying something with a more serious price tag.
You can taste the warmth and softness of tubes and decide if it’s for you. Although most buyers seem blown away by the amp as a daily driver solution in its own right.
Need a headphone amplifier?
Now it’s your turn to tell us what you think about headphone amps. Have you tried them? Are they worth it? Which would you recommend? Let us know in the comments!