Headphone Amplifier Overview

When we talk about the term “headphone amplifier” in front of someone, we often get an O mouth or a surprised look like we’re talking on Mars. The headphone is a headphone; there is no other amplifier – it is the “ideal life” of most young people today.

With headphones, we need to plug and enjoy music, no need to tweak, no support equipment, and crawl around to ponder, think or set up.

However, there is an irony here, that is, when using the headphones on music devices such as iPods, smartphones, or laptops, we are using a true headphone amplifier.

Remember, every music device you plug your headphones into has a built-in amplifier dedicated to it. And this is also the main reason why most young people do not think about a separate amplifier for headphones.

In essence, a “headphone amplifier” or “headphone amp” is a low-power amplifier specifically designed to optimize headphone performance. The headphone amp is usually connected to music devices via analog or digital input; its main function is to receive signals from music devices, then increase the power of the sound and output it to headphones through the headphones via headphone jack or XLR.

Compared to speakers, headphones need very little power to operate. Usually, its power demand is only measured in milliwatts (mW), equivalent to 1/1000 of 1 watt.

At this point, many people will ask a question, which is why need a separate amplifier for headphones when its power demand is very small?

The answer lies in actual need.

Currently, manufacturers of mobile devices, laptops, or even prestigious receivers want to cut production costs as much as possible to maximize their profits, and a built-in headphone amp is a perfect solution. So instead of choosing good components, they use cheap and poor-quality circuit boards for headphones.

Today, many young people spend a lot of money buying good headphones from high-end brands, which shows their “ability to listen to music” and is a tool for proving their class.

It must be admitted that listeners still receive loud, clear sound when plugging in good headphones on regular mobile devices. If you pay attention, you will find that combining a high-end headphone with an integrated headphone amp is lame. The received sound is often not vivid, lacks detail, high noise, poor separation, and no power.

As a result, to get the sound quality you deserve, you need an amplifier designed and optimized specifically for the headphone.

Headphone amps for a long time were still considered luxury equipment, used only in the professional recording field or in the studio. However, with the rapid growth of the headphone market and especially the emergence of high-end products, it has become a fairly popular device among audiophiles.

Today, we have a wide variety of headphone amps with rich designs and features, able to satisfy all the needs and desires of listeners in terms of quality. Because of that abundance, spending money to buy a suitable product is not a simple job. To do this, you need to have money and possess a certain amount of knowledge.

In general, the consideration of a headphone amp is usually based on four main factors: type, features, specifications, and price.

1. Types

Currently, there are three basic types of headphone amp on the market, including:

– Portable headphone amp is the most compact type, designed for portable music devices such as iPhones or laptops. This type of amp is usually small enough that you can slip it into your pocket and get power from a battery or via a USB connection.

– Desktop headphone amps are larger than portable ones; they are designed for use in confined spaces such as offices, bedrooms. These amps are very suitable for pairing with PCs, laptops, or music servers.

– Full-size headphone amp is the same size as standard amplifiers for speakers. They typically offer the highest performance levels, are built to be rugged, weigh much more than the other two, and are commonly used in systems like 2-channel dedicated audio systems.

Like speaker amps, headphone amplifiers are also class A, A/B, D… and can use a transistor, lamp, or transistor-lamp hybrid technology. There are also single-ended and fully balanced versions available. Some headphone amps can even be very complex in design, involving point-to-point wiring and heavy-duty transformers.

Each type of headphone amp has its advantages and disadvantages. The type is not the only factor that determines the processing performance. Still, more importantly, it is the design and the overall coordination of the internal and external components. Therefore, to buy a good product, sometimes we should not attach too much importance to our needs and forget about other things.

2. Features

The most basic features of a headphone amp are an analog input (RCA or 3.5mm jack), volume/gain control, and a 3.5mm analog output. This configuration will allow you to connect to most typical music players (portable music players, smartphones, CD players, or computers) and transfer to the headphones via RCA cable or mini- 3.5mm stereo.

One of the features that are becoming more and more popular in headphone amps is the built-in DAC. This feature lets users connect the amp to the source via digital ports such as USB or S/PDIF (Coaxial or Toslink/optical). That is a common connection when using a music source that is a computer/laptop or a music server.

Many people believe that the integrated DAC circuit will interfere with the headphone amp signal, thus reducing the system’s audio performance. In some cases, this is correct, but a manufacturer can isolate and eliminate those negative effects with a well-designed product.

Another strange feature that is also often encountered on headphone amps is the ability to support pre-amplifier or support amplification for speakers. This feature usually only increases production costs but does not improve the sound quality of the headphone circuit. So you really should weigh everything and prioritize the more important features.

The design trend of amplifiers for great headphones is currently towards DSP (Digital Signal Processing) digital signal processing systems such as Dolby Headphone audio formats, allowing users to experience surround sound emulated on a standard format.

Finally, it’s a rare feature on a headphone amp, the electrostatic headphone support feature.

3. Specifications

Like any other technology product, the most important thing when choosing a headphone amp is considering its detailed specifications. That will help you assess the quality of the product and ensure its compatibility with the headset at home.

– Distortion: parameters related to common distortion are Total Harmonic Distortion (THD) and Intermodulation Distortion (IMD). A distortion of 1% or more is standard; the lower, the better.

Signal-to-Noise Ratio: is a measurement made based on the amount of noise an amplifier has compared to the audio signal from the source and expressed in dB. The larger the ratio, the more accurate the sound. That is an important parameter and is easy to distinguish when you press the headset to your ear tightly.

– Output impedance: determining this parameter will ensure compatibility between your amp and headphones. In general, in most cases, higher impedance is better.

– Power: as mentioned above, the power of headphones is usually only measured in milliwatts (mW). A typical headset will have less than 20mW of power. Most headsets today require less than 200 mW to achieve maximum power; however, in some cases, depending on impedance and sensitivity, this number can be higher. A headphone amp with a capacity of about 500 milliwatts is enough to “treat” most types of headphones.

– Damping Factor value: is a measure of the stability of amplifiers in handling loads – in this case, headphones. The larger this number, the better.

In the vast majority of cases. Specifications never lie; however, it is not a manufacturer’s commitment to actual performance. So, just like buying equipment for a 2-channel stereo system, you should try it out before you decide to buy a headphone amp. It’s best to try it out in quiet places and with your headphones, as well as your own source devices.

4. Price

The last important factor is price. Remember, money is always limited, so there will also be a certain limit to the quality and features of the headphone amp you plan to buy.

You must identify what you need and what you do not need to optimize the quality you receive. For example, a headphone amp with built-in DAC and preamp will only increase the cost, so if you feel unnecessary, you can choose another headphone amp in the same price range but with more expertise.

Conclude

Playing with headphones is a lot cheaper than playing with speakers, but anyway, when participating in any game, you must have the correct direction of the path that you will go. Headphones are a professional hobby, and as speakers, it’s easy to have fun and exciting experiences when studied carefully.