Headphones have miniature speakers, and just like full-size speakers, some headphones will require the help of an amplifier to sound best.
High impedance and power-hungry headphones, like the Sennheiser HD600 (300 Ohms) or Beyerdynamic DT 880 Premium Edition (600 Ohms), require a headphone amp. What is a headphone amplifier, and do you need one for your headphones?
What is a Headphone Amp?
A headphone amplifier is specifically designed to be used with headphones. Our smartphones and other playback devices come with built-in amplifiers. However, these built-in amplifiers sometimes cannot power . That is where a headphone amplifier comes into the game.
Why You Need a Headphone Amp
1. High Impedance Headphones
If you have a pair of high-impedance, HiFi, or audiophile-grade headphones, you may require a headphone amp to get the best sound out of these headphones. Typically, headphones above 100 Ohms are considered high impedance headphones. Most playback devices might not power these headphones sufficiently; thus, a headphone amp is required.
The Beyerdynamic DT 880 Require a Headphone Amp to Sound Best
2. Improve Audio Performance
If you’re looking to improve the audio performance of your headphones, a headphone amp is a gadget you need for the job. A headphone amp will reveal subtle details, significantly improving the listening experience. Some headphone amps also have built-in Digital-to-Analog converters (DAC) to improve the digital signal. A good example is the FiiO BTR5 shown below.
The FiiO BTR5 is a Small Portable Headphone Amplifier and DAC
3. Lower Sensitivity Headphones
The sensitivity values of a headphone directly correlate to the volume level. Most headphones have a sensitivity range of between 90 and 100 dB. The lower the sensitivity, the higher the power you need to supply to achieve a better listening volume. Therefore, a headphone amp could be a nice boost if you have lower-sensitivity headphones. The good thing about lower-sensitivity headphones is their durability compared to higher-sensitivity headphones. The headphone driver is not damaged even when fed more power.
Types of Headphone Amplifiers
There are three headphone amplifiers: tubes, solid-state, and hybrid systems. All these refer to the inner circuitry you choose. Though your preferences will determine the headphone amp you choose, all sound different.
Tube Headphone Amps
Tube amplifiers, vacuum tubes, or valves are those amplifiers with glowing glass cylinders. These are the likes of Monoprice Monolith Liquid Platinum, Woo Audio WA7, or the Little Dot MK2 MKII. The vacuum tubes in these amps form part of the audio circuitry by letting electrons burn off to amplify the audio signal.
The Little DOT MKII Tube Amplifier, Sennheiser HD655 Headphones, and IPhone
Tube amplifiers are usually described as ‘warm,’ which defines the spacious sound with a good bass response and mids. The warm sound in tube amps is reproduced once the tubes are overloaded, which results in a warm euphonic distortion sound. These subtle distortions ‘wow’ reason why people prefer tubes over solid-state amps.
Though they sound good, the major downside of vacuum tube amplifiers is their cost. The tubes are made of glass, and there is a constant possibility of breaking, especially when moving them around. Tube rolling or replacing tubes to alter the sound is also costly. Compared to solid-state amps, you spend a lot of hours and money doing this.
Solid-state Headphone Amps
Solid-state amps grew in popularity due to the low production price of silicon transistors. Unlike tube amps, solid-state amps tend to be more robust, durable, and power-efficient. Solid-state amps use electronics to amplify the audio signal fed to them.
JDS Labs Objective 2 Headphone Amp
The sound of solid-state amps depends mainly on the amp’s circuitry. However, listeners who prefer the sound of solid-state amps cite their clean, sharp, and detailed sound. This especially holds for high-end solid-state amps that reproduce music close to the original minus sound colorations. Also, a lower noise floor avoids distortions when listening to music. The sound is why classical and electronic music fans prefer solid states over tubes.
Some great solid-state amps include the likes of FiiO BTR5, Rupert Neve Designs RNHP, and JDS Labs The Element II. Most solid-state amps like the BTR5 are portable, making moving around very convenient.
Hybrid Headphone Amps
Hybrid amplifiers have both the components of solid-state and tube amplifiers. The idea behind solid-state amps is to create an amplifier that combines the strengths of these two amplifier types.
So, with a solid-state amp, you’ll get the warm and organic sound of tubes and the power of a solid-state amp. The hybrid amp uses tubes on the input stage and the solid state on the amplification stage.
Like tube amplifiers, you can also swap the tubes in a hybrid amp to change the sound to your liking. Hybrid amps are great for people who need powerful headphone amps but crave the tube sound.
Headphone Impedance Explained
Headphone impedance, in simpler terms, is how much your headphones will resist the power they are being fed. The higher the impedance, the more the resistance, while a lower impedance means low resistance to the power.
The impedance rating of headphones is one of the main reasons headphone amplifiers exist. Most lower impedance headphones (Less than 50 Ohms) don’t require an amplifier to deliver a better audio level. Therefore, they will work well with weak amplification equipment like phones and portable music players.
High-impedance headphones will demand more power to deliver high audio levels. Thus weak amplification from portable devices does not cut it. A headphone amplifier is required to help power up these headphones for better audio quality. Read more about headphone impedance and sensitivity.
Matching a Headphone to an Amplifier
Which headphone amp should you pair with your headphones?
Choosing the good headphone amp for your headphones is the key to getting the most out of your headphone drivers. Plug the Sennheiser HD 650 into an iPhone, and you’ll get a fraction of their capacity. However, pair them with a good headphone amplifier, and there will be an improvement in the sound quality.
Most headphone amplifiers (including our budget ones) can drive most headphones to a suitable volume. The key to choosing a headphone amp boils down to the amp’s power output ratio vs. the headphones’ impedance. The higher the impedance, the greater the amplifier’s power needs to be.
