Why Do I Need a Headphone Amp?

Previously we talked about the importance of a DAC and why you need a good audio source as a starting point. Today we’re going to talk about why headphone amps are a critical part of your audio chain.

If you read our article about DACs, we talked about how even though you may have never heard of a DAC before, virtually every device that you use to play digital audio has a DAC built into it. Amps are the same way – if a component has a headphone output on it, it has an amp built in. So why do you need a separate headphone amp, and how do they work?

Amplification Basics

To make a sound, you need to deliver the music to the transducers along with enough energy to generate sound. So how do you get add power to your signal to make those headphones thump? To understand this, you need to learn the three basic concepts for headphone amplification: signal, power, and impedance. 

Driving Your Drivers: Signal, Power, and Impedance

Signal is the audio that you want to play out of the transducer. It could be an MP3, a music stream, or a podcast being played from your device. Power, measured in voltage (note that if you’re used to guitar amps, or amps designed for speaker systems, they usually measure power output in watts, while headphone amps often measure it in volts), is added to a signal. This is the primary function of an amplifier: to amplify the signal enough that it can be transmitted out of your headphones. Impedance is measured in ohms and represents the resistance that occurs in the circuitry between the amp and the output.

Now that we’ve gone over the broad technical details, what we really want to know is, “how do you get great sound out of it?”

Getting the Best Sound

If you booked Eric Clapton to play Madison Square Garden, would you plug his guitar into a $20 amp from Walmart? Of course not. That $20 amp isn’t powerful enough to fill the stadium with sound, and you'll lose a lot of quality – the passion and musical dynamics – through a cheap amp. Power and quality are also the two main reasons to purchase a dedicated headphone amp.

First, many Hi-Fi headphones cannot get sufficient power from the amps built into a phone or laptop. This can result in an overly quiet signal and losing aspects of the music. In some cases, particularly with high end planar magnetic headphones, like the LCD-4, you might find that you simply cannot get any usable amplification from low powered outputs like your phone.

Second, much like we discussed in our article on DACs, the amp in your laptop or phone is generally created to be cheap and small – not painstakingly designed to clearly and accurately output your music. Built-in amps are also prone to distortion and compression which ruins the character and dynamic range of the music. Hi-Fi headphone amps are designed, first and foremost, to preserve the original signal, and deliver it to your headphones. Even the most untrained of ears will be able to tell the difference between a high quality stream played from a headphone jack on a laptop and one played from a Hi-Fi headphone amp.

Choosing the Right Amp for Your Headphones

Now that you understand why you need a dedicated headphone amp, you need to decide which amp is right for you. There are three major factors in deciding on a headphone amp:

  1. Will it play well with your headphones?
  2. Do you want a combination DAC/amp or just a dedicated amp? 
  3. Does it fit into your lifestyle?

Generally speaking, most high end headphones and high end amps will play well together, but not every headphone will work well with every amp. Some amps might not have sufficient power to drive the aforementioned high end planar magnetic headphones. In other cases, a highly sensitive IEM might have an undesirable background hiss if it has an impedance mismatch.

Next, you need to ask if you want a combination DAC/amp or if you just want a standalone amp. If you already have a DAC that you love then you’ll probably want a dedicated amp. You may also have headphones with very specific power requirements, in which case you’ll need to carefully choose your amp and find a DAC to go with it. Alternatively, many DAC/amp combos provide top of line examples of both in one package, which could be easier to set up and easier on your budget.

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Once you have all the technical aspects sorted out, you need to find something that fits in with how you listen to music:

  • Do you mostly listen on the go – like during your commute or at work? Have a look at our collection of portable products or some dedicated digital audio players that won’t need a separate amp in most cases.
  • Do you mostly listen at home or in a space dedicated for music? We also have a selection of desktop amps that are excellent for that, or check out something like the stylish Auris Euterpe which will also add to the visual aesthetic of your space.

The Bottom Line

If you want to get the optimal sound from your headphones, and the best reproduction of the original audio from your source, you’re going to need a high quality headphone amp. You may have specific requirements for driving a specific set of headphones, or you may just be looking for the best portable option to listen to music while you commute. Either way, you won’t regret investing in a headphone amp to take your music to the next level.

And remember, while choosing an amp can also be one of the more complicated aspects of building your system, we’re here to answer your questions and help you with any technical details. Always feel free to reach out (callemail, message)!