Amplification Guide

Do You Need an Amp? Quick Amplification Guide

Do You Need an Amp? Quick Amplification Guide

Amplification Guide: Let’s clear up a few things first. An amplifier is a crucial audio system component for room speakers and headphones. Audio source devices, including analog turntables and digital CD players, typically incorporate a built-in DAC for converting digital audio signals into analog format. Often, they output a fairly low-voltage audio signal that needs boosting.

That’s where amps or amplifiers come in. Their main job is to boost the weak input signal. Amps are a part of everything that outputs sound. But sometimes, the built-in amplifier isn’t strong enough. Like with a modern DAC (digital to analog converter), the main question is whether you need an external headphone amp or a built-in one inside your laptop/audio dongle is fine. Let’s learn more with our amplification guide.

When Is An Expensive External Amp Not Needed?

Using portable devices with consumer-grade headphones eliminates the need for an expensive amplifier, as they function adequately in such scenarios.

Investing in an expensive amplifier is unnecessary if you possess a modern computer or an audio dongle from Apple or Samsung.

Bluetooth headphones are exempt from requiring an external amplifier, as they already possess a built-in one.

When Is An Expensive External Amp Needed?

If the current amplifier does not adequately power your power-hungry headphones, it becomes necessary to acquire a stronger one. This situation arises when:

1. The headphones produce insufficient volume.
2. The sound is unexpectedly low.
3. Audible background noise (the noise floor) is present, possibly due to inferior circuitry.

To determine the power requirements of your headphones, you need to examine their specifications. Within these specifications, you will find two values: impedance and sensitivity.

The impedance value indicates the level of resistance the headphones offer to an electrical current.

The sensitivity value indicates how loud the headphones can produce sound at one milliwatt or 1 volt of voltage.

How Strong Are The Built-in Amplifiers?

An average consumer audio device typically produces slightly less than 50mW of peak power (or 31.6mW of continuous power), although the actual output can vary among different devices.

Amplification Guide

Let’s consider the Sennheiser HD 650 headphones, which are known to be challenging to power due to their high impedance of 300 ohms. However, they have an increased sensitivity of 103dB at 1V.

By utilizing a power calculator from digiZoid, you can observe that to achieve 110dB, only 16.73 mW of power is required. While your smartphone can drive the headphones to a reasonably loud level, it’s important to note that achieving 115dB requires more power than most smartphones can provide. Additionally, it’s crucial to consider that prolonged exposure to such high volume levels can harm your ears.

Amplification Guide: What Is The Function of An Amplifier?

An amplifier receives a signal and increases its volume using transistors or transformers. This process requires additional electrical current and voltage to push the signal at a higher power level. Since raw audio sources are typically faint and weak, amplification is necessary to achieve normal listening levels.

Many headphones, particularly contemporary ones, can be easily powered by portable devices like smartphones and dongles. However, professional or audiophile-grade headphones may be less efficient in this regard. These headphones often have higher impedances and lower sensitivities, making driving more challenging.

Can An Amplifier Enhance The Sound Quality?

Headphone amplifiers have the potential to enhance the performance of headphones by providing greater control and dynamic range to the sound. However, this improvement is typically noticeable only when headphones require additional power to function optimally.

Having ample power headroom when driving headphones is generally beneficial. While built-in amplifiers are usually sufficient to deliver adequate loudness, they may struggle to maintain power.

This struggle can manifest in two ways:

  • Sluggish and subdued sound: Fast-paced music may lack punch in the bass, resulting in softer and muddier tones. High-frequency details may also be less defined.
  • Distortion: Your amplifier might be underpowered if you need to turn the volume knob up to achieve a sound loudness. This can lead to signal clipping, causing distortion and potentially overheating driver coils.

Component quality significantly affects amplifier performance. Some manufacturers may set their amplifiers to high gain to give the impression of greater power. However, adding unnecessary gain can introduce distortion and noise, negating the desired improvements in sound quality.

Headphone Types That Benefit From An Amplifier

Amplifying the sound can benefit two types of headphones: audiophile-grade and professional.

The first type is high-impedance headphones, which have higher resistance. This makes them more durable in powerful sound studios and may offer slightly better resolution in the upper midrange and treble than low-impedance headphones.

The second type is low-sensitivity headphones, which require more power to reach higher volume levels. Sensitivity is measured in decibels and indicates how loud headphones can get with a given power input.

It’s important to note that even headphones with high impedance and sensitivity may benefit from an amplifier, although the changes might only be noticeable to discerning users.

Amplification Guide: Selecting the Right Amplifier

Amplification Guide

Firstly, know whether you need an external headphone amplifier or not. This can be done by calculating the power required to drive your headphones.

  1. Calculate the power needed based on your headphones’ impedance and sensitivity values.
  2. Use the digiZoid website to input these values and obtain information on the required power for achieving a specific loudness level. Remember that most smartphone or laptop audio jacks provide around 50mW of power.
  3. Check if this power is sufficient to drive your headphones to a comfortable level, typically around 110 dB. If not, consider opting for an external amplifier. It is recommended to have some headroom, as certain headphones may have impedance spikes at different frequency ranges.

If you have concluded that you require a headphone amplifier, here is essential information to consider before purchasing.

1. Power

Using the calculations, you have determined the minimum power necessary to operate your headphones adequately.

With this information, you can search for an amplifier with sufficient power for your headphones. Power specifications are typically indicated as “maximum power” at various ohm values.

For instance, if the amplifier specifications state that the “maximum power at 300 ohms is 320mW,” and you have calculated that you only require 32mW to drive the headphones to 110dB, it implies that the amplifier is more than powerful enough and could potentially cause harm to your ears.

Also, ensure the amplifier’s output impedance is significantly lower than your headphones’ impedance to prevent frequency response changes caused by impedance spikes.

2. Features

Headphone amplifiers offer various options:

  1.  Basic amps have unbalanced analog inputs (RCA, 3.5mm) and outputs (3.5mm, 6.35mm).
  2. Upgraded amps may include a gain switch for more power and a bass boost switch.
  3. Premium amps feature balanced inputs (2x 3-pin XLR) alongside unbalanced inputs and additional outputs like 2.5mm or 4.4mm.
  4. High-end amps may offer 4-pin XLR or 2x 3-pin XLR outputs.

3. Size

External headphone amplifiers are available in various sizes, ranging from compact USB drives to larger units resembling shoe boxes.

Ensure sufficient space for the headphone amplifier. Smaller models suffice, but extra desk space is necessary if you desire a more noticeable presence.

Thankfully, most consumer amplifiers are approximately the width of a credit card or a larger smartphone, making it easy to fit them on your desk.

This brings us to the different types of headphone amplifiers.

4. Desktop amplifiers

Desktop amplifiers require AC and USB-powered power that draws power directly from the source device.

USB amps, like AudioQuest, power 300-ohm headphones effectively. Choose a dedicated desktop amp with a power supply capable of handling 600-ohm headphones for maximum power.

It is worth noting that electrostatic headphones require specific energizers to function properly.

5. Portable amplifiers

Portable amps are powered by batteries for on-the-go music, suitable for 150-300 ohm headphones. However, they require battery charging and add bulk to your pocket.

Note that a USB amp can serve as a portable headphone amp, with a small USB extension cable to avoid direct plugging into your phone’s port, preventing potential damage.

6. Integrated amps

Integrated amplifiers can be found in devices equipped with a headphone jack. The quality of these amplifiers varies, but modern ones are typically capable of adequately powering most headphones available.

Some PC motherboards have advanced audio circuitry with high-quality DAC and amplifier components, enhancing sound quality and eliminating the need for external amplifiers. However, they may not offer sufficient power for demanding, power-hungry headphones.

The Different Between Solid-State vs. Tube Amps

Solid-state amps excel in technical performance, while tube amps introduce a distinct sonic character.

Solid-state amps offer a transparent and detailed sound with minimal distortion. They amplify audio using transistors and currents.

On the other hand, tube amps provide a smoother and warmer sound reminiscent of the appeal of vinyl records. They introduce a touch of distortion and utilize voltage and large output transformers. Tube amps are easily recognizable by the glowing tubes they employ.

External amplifiers are designed to assist wired headphones with high impedance and low sensitivity in achieving adequate volume levels for everyday listening.

If you own headphones with such demanding specifications, an amplifier is essential to appreciate their sound fully.

However, if you already possess efficient headphones, investing in an amplifier will not significantly enhance your audio experience, making it difficult to justify spending a substantial amount of money. After you read our amplification guide, we hope you learn something new, and don’t forget to drop comments if you have any questions.

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