What is a tube headphone amplifier?

This is arguably the best time to be an audiophile.

We say this because there are so many sleek, portable headphones on the market, so much that the brands are struggling to outdo the other. The best part is that there are hordes of cheap, high-grade headphones to pick from.

But what’s an audiophile without a headphone amplifier?

The uninitiated might wonder why you need a headphone amplifier (amp for short) since the quality of headphones has improved so much over the years. Some might even wonder which of these products will serve them the best.

If you ever wondered about any of these questions, then you are reading the right article.

Why?

It’s simple.

You are about to find out why the tube headphone amplifier is such a rave among that species of people who are looking to explore music to the fullest.

Let’s dive in.

What Are Headphone Amps?

It makes sense to start by defining what headphone amps are.

They are low-powered amplifiers that increase the low-voltage audio signals to a level where the speakers in your headphones can convert them into sound waves—they kind of work like the amplifiers for the speakers you see at shows and events.

The only difference is that they are much smaller.

So, in essence, this gear amplifies sound and increases sound quality in the process. It also happens to be a key component of most devices that we listen to music on these days: PCs, smartphones, iPods, or tablets.

However, the older headphone amps are built a bit differently.

They were built for tape decks and turntables and were designed to handle low-voltage audio signals. On the flip side, the newer headphone amps need a DAC to function on our modern music devices. DACs are crucial because most audio files played on these devices are in digital formats since they are easy to share.

 A DAC converts digital information into the low-voltage signal that the headphone amp amplifies.

Why then would anyone need an external headphone amp when modern audio devices already come with in-built amps?

The reason is that the in-built amps are not that great. In some cases, audio signals get distorted before they are amplified.

It is different with external headphone amps. They power audio signals and keep them undistorted even at their musical peak. This allows the normal listening volume for sounds to stay clean even when it’s at the loudest. So even when the volume coming from a music device is low, it gets a clean boost.

Headphone amps cannot function without electric current, so they are comprised of input and output components. The input element is something like a multiplication factor that grows the signal coming into the headphone amp.

At the same time, the output aspect converts this signal into the sound that we hear over the headphones or speakers. In essence without a balance in these inputs and outputs, the amplifier will not function at its best.

There are two main types of headphone amplifiers:

the solid-state/ transistor amplifier and the tube amplifier.

Solid-state amplifiers/transistor derive their amplification from electronic transistors, while the tube amplifier use vacuum tubes.

What Does A Headphone Amp Do?

They make your headphones work better by improving the sound quality.

But here’s the thing.

Although these gears guarantee amplification and improved sound quality, they are not magical gadgets that magnify all kinds of sound regardless of the headphone. Their capability to amplify sound is restricted to the quality of the headphone. They can never exceed the production capability of the headphone that they work with.

That said, headphones are often built with impedance in mind. Impedance here refers to the resistance to the flow of current, and a headphone with low impedance needs less voltage to power it.

Sadly, the best headphones out there are not low-impedance because they are often built with several coil windings that make them produce great sound.

In transferring the audio output from a source to the headphone amp, the voltage level increases to the point where it can power the headphone while amplifying the sound.

Now that we are clear on what headphone amps are and what they do, let us look at the two main types of headphone amplifiers: the solid-state or transistor headphone amplifier and the tube headphone amplifier.

What Is a Solid-State Headphone Amplifier?

As the name suggests, the solid-state amp is powered by a transistor circuit that alters electrical signals to audio signals.

Unlike with the vacuum tube, the transistors are made from silicon, although silicon is not the best at conducting current.

However, it can be managed in such a manner that allows it to work in headphone amps.

This involves creating something like a sandwich that has three layers of silicon. Two of the outer layers are negatively charged, covering a positively charged layer between them. The two negatively charged layers have electrons that conduct electricity, while the positively charged layer is built so that there are holes for these electrons to pass through.

The transistors in the solid-state headphone amplifiers have a base electrode which is its power source. The first negatively charged layer is the emitter; the middle positive layer is the base, while the other negatively charged outer layer is the collector. They come in desktop and portable versions each with corresponding benefits to be had from using it.

What Is A Tube Headphone Amplifier?

Tube headphone amps are also called vacuum amps/vacuum tubes because they amplify sound by using vacuum tubes that control electrical current.

Tube amps are used to deliver both smooth and responsive sound that high-gain pedals could also enhance. They have remained popular over the years because they allow great precision in music production.

The vacuum tube looks like glowing glass lightbulbs and comprises a cathode, anode, grid, and a few more components, and some rarified gases. These components are encapsulated in something like a vacuum that permits the flow of electric current.

Unlike solid-state headphone amplifiers requiring transistors, tube amps convert electrical currents into audio signals using the audio signals that your speakers and headphones deliver.

They could either be desktop or portable versions.

The desktop version is designed for the desktop and comes with a range of benefits like increased gain and clean power stages.

On the flip side, the portable versions are more flexible and can have dual functions where they double as a desktop unit too.

What are Tube Headphone Amplifiers Used For?

A combination of premium-grade headphones and the right tube amplifiers will produce a sound that is so many things simultaneously: natural, clear, smooth, rich, warm, and ultimately more balanced. There is less distortion of signals, and once that is settled, your listening experience will get better.

Here are some instances when a vacuum tube is a must-have (regardless of price):

• When Mixing & Critical Listening

If you work as a professional audio mixer or any sound-related profession, you’d need to catch every element in the music at varying volumes. That way, you can ensure that all the elements of what you are mixing are balanced.

Depending on the menu of features, the right tube amplifiers, you get filters that help you hear every little detail of the sound you are mixing. The best part is that you can customize the songs you are mixing to get the flavour you are looking for.

The same applies to folks who are in the business of critically listening to songs and such. Tube amplifiers give you a blend of sound that you can’t get elsewhere. Your listening tasks become a lot simpler and enjoyable while using a vacuum tube amp.

• Studio Recording & Tracking

Studio sessions often require more than one person to listen in.

That requires a lot of power for the multiple headphones that might be in use. A good vacuum tube allows you to power as many headphones at once. All you need is a jack. With the right vacuum tube jack, your studio sessions become less chaotic.

The best part is that you do not have to compromise on the quality of sound being listened to because tube amplifiers have great range.

• Musical Performances

Tube headphone amps are a big deal in high-end hi-fi circles.

A lot of musicians like to play using tube headphones for their musical performances. So you probably find that a lot of guitarists using electric guitars and electric basses prefer to play with tube headphone amplifiers because of their famed  ”tube sound” and the range too.

How Do Tube Headphone Amplifiers Work

We already know that the vacuum tube amplifiers are built differently, but some folks don’t know that the elements of a vacuum tube amp pack a very strong kick. These elements have been known to function with voltages that are as high as hundreds of volts which might prove fatal if touched.

So if you are one of those DIY types that love to tinker around with stuff, you might want to leave out touching anything inside a vacuum tube if you don’t have experience with an electrical circuit.

That said, let’s get into how vacuum tube amps work.

This amplifier functions the way they do because of the peculiar audio characteristics of vacuum tubes. Vacuum tubes are extremely great at amplifying signals, splitting and mixing signals, and reversing their polarity.

Like you read a few headings back, a vacuum tube is essentially a unit that is comprised of a tube with several electrical components and no air. The vacuum tube is either oxide-coated or has some thorium, so it emits electrons when the filament is heated up. These electrons are then passed into a grid, which controls a current.

That way, the current which serves as the input is amplified and sent to the output.

Electrons can travel through space in a vacuum, and so the idea of the vacuum tube is to regulate the flow of electrons.

Interestingly, the vacuum tube design still hasn’t changed in years, which is a testament to its functionality. Let’s look at some of the parts of a tube headphone amplifier.

The Cathode

This is a positively charged pole that is situated at the heart of the vacuum tube.

It releases negatively charged electrons that pass through the vacuum to another extremely positively charged second-plate. Since opposite charges attract more electrons, this increased flow of electrons can be used to manipulate signals.

Heating Filament

Heat increases the electron flow, so the cathode needs to be heated to get the electrons flowing freely. To do that a heating filament is situated right next to the cathode.

In some cases, the filament might serve as the cathode. In such situations, there is some special coating to provide the flow of electrons.

Plate

The plate surrounds everything else inside the vacuum tube.

It has a high positive charge, and it functions by attracting the negatively charged electrons inside the vacuum tube, thus making it the anode. This plate serves as a pool for the electrons emitted by the cathode which is at the centre of the tube headphone amp. In addition, it also detects signals from audio sources.

Grid

The grid is designed to be between the plate and the cathode. It is a piece of metal connected to the input from an audio source so that it charges it and provides a small positive or negative charge based on the incoming signal.

For this reason, the cathode is not negatively charged and has a slightly positive charge instead. When there is no current flowing in it, the grid stays negative so that the electrons in the anode are kept in place until a voltage attracts them.

Capacitors

The capacitors in the vacuum tube amplifier work act like dams as they are designed to store electrical charge and release in a steady way that smooths any kinks in the flow. You want to be wary of them because they are known to pack a fatal dose of electrical current even when the tube amp is switched off. This is why we advise you not to touch the inside of this headphone amp except you are a trained technician or have a death wish.

The capacitors generate a high DC voltage that goes to the plates in the tubes, which often needs a high positive potential to attract electrons from the cathode.

Resistors

The resistors serve to regulate the amount of voltage and current in the vacuum tube amplifier. They are designed to disperse electrical energy based on their resistive value. Resistors can be either carbon-comp resistors or metal film resistors.

What Is The Point Of Tube Headphone Amps?

We have already established that some headphones come with inbuilt amplifiers.

However, we have not dealt with why tube headphone amps are such a big deal in some circles.

The truth of the matter is that most high-grade headphones need amps to function properly. The reason is that they are built to be high-impedance headphones that give an electrical signal(s) more resistance and ultimately require a lot of amplification power to get the headphone to work. So while they give great audio output, they take a lot of power.

Why would anyone design high-impedance audio gear that drains so much power?

You’d find that these kinds of headphones are the most popular in the music industry. They are built with a lot of coils because of the precision that having so many coils provides. Now, while the modern audio gear is designed to have low impedance so that they don’t consume so much power, they do not have enough voltage to power the woofers.

To get the most from a high-impedance headphone, you’d need an amplifier that has a lot of voltage (preferably more than what is contained in the headphones) to make it function optimally.

That is not to say that there are no low-impedance headphones that perform at high levels. The thing is that they work best with low-power gear.

As an audiophile, you might not work with them because of your preferences. Your preference would probably be a headphone with significant impedance. Some experts believe that any headphone with a minimum of 50 ohms needs a headphone amplifier for you to get the most from it.

Why You Might Choose Tube Amplifier

Here are some reasons why a lot of audiophiles opt for this amplifier:

Great Sound Quality

If you opt for tube amplifiers, you’d be guaranteed to enjoy warm, clean sounds. Tube headphone amplifiers implement a level of distortion that can produce great sound quality that improves your sonic experience.

Distortion

The tube amplifier is great at effecting a benign distortion of audio signals. The distortion is the gradual type that harmonizes as it approaches the maximum point. That way, the sounds are better, and you run less risk of damaging the drivers in your headphones. A large number of audiophiles agree that tube amplifiers distort sounds the best when they have been pushed to the maximum point.

Improved Capabilities

The tube amp functions with high voltages. That means that it is built to handle wider voltage swings. That is why they provide higher audible energy storage with lower value capacitors. This improved capability at handling high voltage makes tube amplifiers great at producing the “tube sound” that many an audiophile can’t get enough of.

Are Tube Headphone Amps Better?

That depends on who’s asking and what you intend to do with one.

The transistor headphone amplifier does the amplification work just well. It might even be the more affordable option since the price for vacuum tubes are always high.

However, if your job involves analyzing and working with decibels and other sound elements, you would have a different opinion.

The Positives of Having a Tube Amp

For one, the vacuum tube has a sleek design that just looks cool. It has a design that is easy on the eyes; transparent, glowing tubes can be quite nice to look at.

 But the positives of having a tube headphone amp go beyond aesthetics. For many “sonic aficionados” (for want of a better term), tube headphone amps offer a different vibe or sound, if you will.

Granted, they are the more complicated of the two options, and so you can expect a bump in the price for this device. But you get some things that most experts believe their transistor counterpart does not give: control and quality performance. Let’s start with the sound effects.

Tube headphone amps distort the audio signal(s) that they receive, and it is these distortions that give the audio output that unique, warm, smooth yet quality that they are famed for producing. The circuit in solid-state headphones, on the other hand, is not built to cope with heavy amp distortion effects.

Tube headphone amps essentially provide an immersive sonic experience that loads of audiophiles can’t get enough of. Plus, a lot of audiophiles believe that it has more power and is definitely quite louder than its counterpart.

Then there is the fact that you could use different tubes on different vacuum tubes.

So should you choose to get a tube headphone amp, you can do all the experimenting you want. The best part is that all that tinkering affects the sound, so you might just be able to customize the sound that comes in through your headphones. The ability to customize sounds is probably one of the biggest selling points of tube headphone amps.

A lot of audiophiles find the control that it offers to be irresistible to them. Especially when you factor in the volume!

The Downsides

There are downsides to owning a tube headphone amp too.

They are the more delicate of the two options because of their exposed glass tubes. The nature of the tubes makes them more susceptible to damage, and given the price of these tubes, that is a drawback.

One other major downside with tube headphone amps is that they need to get warmed up before they start functioning optimally. In some cases, it might take a tube amplifier up to 30 minutes to do that. Interestingly once this is done, there is also the tendency for the unit to overheat.

Tube amplifiers come at a high price too. There is the fact that the tubes require more maintenance because of their fragility. So you might need to replace the glass tubes after some hours of runtime, say after a few thousands of hours use.

On the flip side, solid-state headphone amplifiers are built from more durable material, so you needn’t have to be worried about damaging your headphone amp whenever you are using it, or you are in transit. They are also cheap and easier to carry around although there are some portable tube amplifiers that are quite handy too. Plus a dual purpose amplifier is a great way to save the steep price of desktop versions.

Are Tube Amps Better?

The truth is that they are simply different, and it all boils down to what you want to achieve.

So the answer to that question is relative. It all depends on your style(read love for volume sound quality), budget, and how much time you are willing to invest in maintaining and caring for something as delicate as glass tubes. Here are some questions to help you decide if the tube headphone amp is the right choice for you.

• Are you big on listening to “vacuum sound”?
• Are you okay with having to maintain your gadget regularly?
• Can you change tubes when needed?
• Can you afford to buy high-end gear?
• Does your livelihood/lifestyle depend on the exceptional performance it guarantees?

If your answers are in the affirmative, then you might need a tube headphone amplifier. You’d be surprised that the next audiophile might be satisfied with a transistor headphone amplifier.

Conclusion

For some people, the high price of vacuum amplifiers is a fair deal for the power, range, volume, quality, control, performance, response and other sound-related benefits. They also don’t mind the stress involved in maintaining the tubes because to them “tube sound” is all that matters.

There is only one way to find out if all this is true. Get yourself a unit (possibly one with dual-purpose)!

Else, what’s the point of just reading about it?