Like any other device, headphone amplifiers have specifications that tell more about their performance and overall characteristics. Reading and analyzing the specs of different headphone amps can help you choose the right amp for your headphones.
However, with all the jargon in the specs, how do you know what to look for? Below we have broken down different headphone amplifier specs to help you better understand and choose the right one. Enjoy.
Output Power
This is the equivalent of how loud you want to pump out music from your headphones. The higher the impedance, the more power you want to get for a higher volume. With most headphone amplifiers, the output power varies between 10mW and 2W. Generally, you will not need that much power to drive most headphones efficiently.
Output Impedance
The output impedance measures the headphone amp to drop the voltage flowing when the headphones draw out power. Impedance values are calculated in Ohms (Ω); the smaller the value (0.5 Ω to 120 Ω), the better an amp is.
A lower output impedance also means a higher damping factor. The damping factor indicates how well an amplifier controls the headphones. Having a headphone impedance eight times the amp’s impedance yields a damping factor of 8:1, which allows headphones to perform well.
Noise Floor or Signal-To-Noise Ratio (SNR)
The signal-to-noise ratio compares the power signal level to the noise power level and is measured in Ohms. This is the noise from electrons whizzing around inside the amplifier.
The goal of any amplifier manufacturer is to bring down the noise level to imperceptible proportions such that it does not interfere with your music.
THD+N
Total Harmonic Distortion plus Noise (THD+N) is a noise and distortion measurement that is added to the audio signal by the amplifier’s circuitry. More distortion means more color to the sound; the lower the THD+N levels, the better the audio output is closer to the original recording.
Crosstalk or Channel Separation
Right is Right, Left is Left, and crosstalk measures how much-unwanted proper signal is mixed with the left output or vice versa. An amplifier tries as much to separate each channel and ensure you can tell when a singer is standing slightly to the right and instruments towards the left. More crosstalk means it will be harder to pick out the position of the singer or instruments.
Gain – Low vs. High
Gain is the ratio between the volume (signal amplitude) at the input level and the volume at the output level in an amp.
Most headphone amplifiers come with low and high-gain settings.
Here at Soundphilia, we recommend you use your amp with the low gain whenever possible. This suppresses the amplifier’s noise floor to an inaudible level and allows reasonable volume control adjustment to minimize audio fidelity loss.
Adjusting the gain to high will affect the quality and tone of the audio but does not increase the maximum power output of the amp. This makes the amp distort easier and can cause higher noise levels in sensitive low-impedance headphones.
However, we advise using high gain if your headphones don’t get loud enough for you.
Frequency Response
The frequency response refers to the ability of a headphone amp to handle and reproduce the audio frequency range. Most headphone amplifiers will provide a frequency range with a variation, e.g., 20-20kHz ±3dB.
Input Connectors
Input connectors are present in most playback devices and stand for what the device can take. Input connectors can vary between different headphone amp models. Input connectors allow you to connect the amp to a playback device such as a phone, computer, or digital audio player (DAP). Some standard input connectors include optical, coaxial, 3.5 mm (1/8″) TRS, 6.35mm (1/4″) TRS, RCA, USB-A, USB-B, Optical, XLR, and many others.
Output Connectors
Output connectors allow the headphone amp to feed the headphones with audio. When choosing a headphone amplifier, consider the connector of your headphones. This will help you avoid using adapters when connecting to your headphone amp. The standard headphone amp connectors include XLR-3, XLR-4 Balanced, 3.5mm (1/8″) TRS, 6.35mm (1/4″) TRS, and RCA.
