What Are Tube Amps?
Amplifiers are electronic devices that are designed to increase the power or voltage of a signal. Amplifiers were first developed with tubes, then soon with transistors. Tubes, also known as valves, use vacuum tubes to increase or amplify the power or voltage of a signal.
Tubes are used in several technologies since Thomas Edison’s existence. They are used massively in radios, telephones, televisions, and amplifiers.
Transistors work similarly to tubes. They have semiconductor components that intensify electronic signals and power. This might be the reason why some manufacturers switched from tubes to transistors, which are more modern and technological.
Amplifiers that use transistors are called “solid-state”, while those that use tubes are called “tube amps”.
While modern inventions use transistors, experts claim that tubes, though retro and “old,” still sound better in amplifiers than transistors.
The big question that plagues many new musicians is this: are tube amps better than solid-state amps? The answer to this question often determines what sort of amp they buy. Unfortunately there’s never really one clear answer. The trouble is the answer to that question comes down to personal preference.
A lot of people swear that tube amps produce a better sound than solid-state ones. Particularly when adding a tube amplifier to your turntable’s phono output, there is quite a change in the sound. The usual words that come up are “more vibrant” and “warmer.” It can be hard to determine the truth about such statements. However, there are measurable differences in performance between solid-state amps and tube amps.
What Are The Differences?
Physically, tube amps use vacuum tubes to amplify signal and power. The usage of tube amps is more complex because the sound quality would become poor if the operating mechanisms (i.e. transformers, heater, and output) are not maintained and managed. Additionally, the tubes would eventually need replacing because they wear out.
Transistors, on the other hand, are ubiquitous in modern electronic inventions. In fact, transistors are considered to be one of the most powerful inventions in human history. Why are transistors a trend in modern technology? It is because they are able to use small signals and turn it into much higher signals which are why they are efficient for amplifiers.
The circuitry operation of transistors is simpler and cleaner. For amplifiers, solid-state amps use fewer components than tube amps which made them lighter and more portable than a heavy tube amps.
Tubes were invented first before transistors, though and serve as a template or a pattern that tells us how music should really sound.
Apparently, solid-state amplifiers are known as a much-improved version of tube amps. The internal structure is more modern and sophisticated. The design is a classic.
Transistors Vs Tubes
The main difference between tube amps and solid-state amps is the heart of their construction. Tube amps use vacuum tubes, while solid-state amps use the more modern transistors. Tube amps started out in the first part of the century and dominated the market until the 1970s.
Tube amps work thanks to three elements: the cathode, the plate, and the grid. The cathode heats up and creates a cloud of negatively-charged electrons. The plate is a positively-charged electrode which then attracts all of these electrons. In the middle is the grid. It disrupts the electron flow between the cathode and the plate depending on the input it receives from an instrument, which helps reproduce the sound faithfully.
Solid-state amps work differently. There are still three sections though. First, an input driver circuit directly amplifies the input signal by a factor of 20 to 50. Next is the output circuit. This has output transistors adding current to the amplified signal. The signal is then sent to the speaker. The third section powers it all by converting 110V / 22OV AC mains to 2 DC. This powers the entire amp.
Solid-state amps have that name is since electricity moves through solid material instead of the vacuum of a tube. Theey first hit the scene in the 60s and have become a major part of the market since then.
Whether tube amps are better because of these differences is up in the air though. Let’s go through them anyway so that you can learn more about the factual basis of the tube amp/solid-state amp debate.
One of the big advantages that tube amps have is in the creation of harmonic distortion. Distortion sounds like a bad thing but for musicians it is something they want to happen. Guitarists early in the 20th century managed to create distortions by turning their amps to their highest volume setting.
Distortions from tube amps are usually second-order. This means it is the same sound, but an octave higher. The result is an interesting musical effect that is actually quite pleasant to the ear.
Solid-state amps do not have this because they actually reduce the amount of distortion. The result is a clearer sound. But, there are no pleasant surprises that come with the distortion. This is why a lot more people think of tube amp-produced sounds as more natural.
Tube amps also encourage distortions. Distortions naturally occur as you play an instrument louder. The distortion created is harmonic in nature, which means it actually sounds like it is a natural part of the sound instead of an addition.
Tube amps add even more to the distortions as the sound progresses higher. When sound technicians measure tube amp performance, the distortions increases as the sound goes up in volume. Solid-state amps actually reduce the distortions as the volume increases. It actually starts to clip as it goes higher, resulting in low-quality sound.
Clipping is a specific sort of distortion that happens when an instrument hits its audio limits. A lot of people like it when it happens. Electric guitar players are one example of those who want their guitars to clip.
The effect is like having a sound hit its limits and go no farther. Audio recordings of solid-state amp sounds have this as a wave form with a flat top. Tube amps have a different way of handling overloads. Instead of a flat clip, it is actually gradual. This is because there is no definite limit to their capacity, so their waveforms curve more than a flat termination.
Tube amps have a more realistic setting for power levels and sound outputs. Solid-state amps often have strange extremes. They often reach wattage that is unreasonable and have a range of sound that is too wide.
Most of the time, music only needs a few watts to perform well. Tube amps range from 8 to 80 watts. Solid-state amps can reach 300 watts. This is terribly inefficient since only concert hall performers would need that high a range.
The audio differences are just one part of the mix. Tube amps and solid-state amps exhibit physical differences, too, thanks to their mode of construction. For one, tube amps tend to be heavier.
This is because of all the components that require. Tube amp parts also tend to be a lot bigger than solid-state amp parts. Solid-state amps have circuit boards and not much else to worry about.
Another problem that pops up with vacuum tubes is their fragility. Notice that the cathode heats up during operation. You can only guess how much punishment it goes through when it is in use. Eventually, the tubes break down and need replacement. Solid-state amps keep on working no matter what.
You may also notice the price tag. A lot of tube amps have hefty price tags. For beginning musicians, a solid-state amp is their primary choice for a starting amp.
TUBE AMPS & SOLID STATE AMPS: PROS & CONS
- Tube amps are perfect for purists who want to get a pure sound reminiscent of an earlier era.
- Tube amps provide a high dynamic range.
- Most tube amps have vintage designs.
- The channels or overdriven sounds are smooth to the ears.
- Durable external structure.
- Components, such as valves or vacuum caps, eventually wear off and would need replacement.
- Replacement parts are rare in the market. Traders sell parts pretty high-priced which makes maintenance costly and expensive.
- Tube amps heat up while on use.
- Solid-state amps cost less than tube amps.
- They do not require much maintenance and system replacements.
- Solid-state amps require smaller transformers, which mean less weight.
- Solid-state amps are reliable and can perform well in an assortment of genres.
- Compared to tube amps, solid-state amps are more budget-friendly.
- Solid-state amps will eventually die. Tube amps allow for a greater flexibility in replacing parts.
- Low-priced solid-state amps are poorly designed with plastic corners, low-grade speakers, and cheap wirings.
WHAT’S DIFFERENT IN THE TONE
Although there are factors which make solid-state amplifiers favorable than tube amplifiers, solid-state do not perform well when it comes to crossover and transient intermodulation distortion whereas tube amplifiers have this second order harmonic distortions rendering the beautiful music. Here are more of the top reasons why tube amps sound better.
Distortion often means something is distorted, or incorrect. However, that is not the case when you ask a guitarist. Nowadays, it is essential in a heterodyning procedure to improve the quality of the sound produced. Heterodyning is a method of processing a signal to produce heterodynes and new frequencies by introducing it to the signal path.
Distortion in its simplest definition is the alteration of the sound’s waveform. The analog distortion the tubes create produces a set of frequencies that are harmonic. Harmonics are two times the standard frequency which makes it one octave higher. Tubes sound better because it produces a musical effect by just adding an increased level of harmonic distortion and monotone.
WARM AND SMOOTH
“Fuzz”- it is a guitarist’s jargon term for a particular form of distortion. It can be heard a lot from speakers and preamplifiers. For them, it adds a musical effect. How?
Clipping happens when the amplifier tries to produce a charge it could no longer hold during the phase where it’s already overloaded generating some kind of a distortion. Soft clipping prevents distortions by bringing down the peaks to a line level not allowing it to square off every time it clips. The peaks get camouflaged by having its tops rounded during an excessively high-intensity energy which in turn leads to a loud fused sound often depicted as “smooth” and “warm”. The tubes sound better because the tubes clip in a better way to the point that the sound becomes soft and warm.
LOUD AND CLEAR
“Love works in mysterious ways” – according to famous romance author Julia Quinn in her book “The Duke and I”. It is almost true with tubes. Tubes have its mysterious ways as it may not deliver quality sound in the beginning.
Burn-in is a process of stabilizing a tube and checking its reliability by having the unit constantly switched on for a period of time. This makes re-biasing unnecessary and easy tube rolling as the initial matching might not drift and the sound produced further improves without waiting for the tube to be stabilized. Tubes sound better because the tube inside is cleaner and has been deoxygenated to produce a loud and clear sound when the device operated at a higher frequency under full voltages for hours.
Biasing plays a huge role in using tubes for a system of amplification. It works by regulating the amount of current passing through the tube when the tube grid runs out of signal. It is what biasing does. It is necessary so that signals are properly amplified which in turn properly distributes the right amount of distortion.
There are two ways to perform tube bias: under-biasing and over-biasing. The idle voltage when under-biasing is increased so that the headroom is decreased and the signal in an earlier state can be distorted. Tubes sounds better because it allows biasing which in turn produces a subtle sound by controlling the current flow while preserving tube life.
How does tube make sound quality seamless? Aside from “burn in”, clipping, and biasing, it also has something to do with lesser or no negative feedback at all and the circuit design. Negative feedback is the amplification output signal directed back as an input signal to create a circuit to minimize the fluctuation in the output.
You should know that the lower the negative feedback; the greater the harmonic distortion. However, the effects of utilizing lower negative feedback depend on the phase shifts of the circuitry. In other words, tubes sound better because it can produce a seamless sound which depends on a good circuitry design to employ lower negative feedback.
OUTSTANDING SOUND QUALITY
At least for audio signals, you need to focus on the quality of the sound input delivered by your amp. Unless the amp is doing something dramatic to improve the sound quality, you might as well not go for such a device. What tube amps give, and the solid amps don’t, is excellent sonic quality – just ideal for musical instruments. No wonder, guitarists (and naturally guitar manufacturers) prefer the tube amp over other amps, each time, every time. You don’t want to have your guitar playing wonky with the notes, after all, do you?
Another merit that tube amps boast of is the simplicity of the circuit, making its construction quite a breeze. So much so that guitarists and electrical hobbyists prefer to make their own tube amps rather than go for the mass produced variety that’s flooding the market these days. Even the number of components used in tube amps is relatively small. And this simplicity ensures minimal interference with the input signals, and relatively fewer chances of distortion or deterioration of the signal.
In addition, with fewer components, the chances of failure also get reduced, which means less chances of the amp ditching you just when you’re about to woo your audiences with an excellent guitar performance. In fact, tube amps tend not to deviate from the circuit design, enabling purer performance of your gadgets/instruments.
BETTER OVERLOAD RESISTANCE
You’ll also find the overload resistance of tube amps much higher than that of other amps. The reason for this is the gradual onset of overload when the amp reaches its maximum power. Consequently, the distortion that occurs with increasing power load is of low even-order harmonic quality. And studies show that even-order harmonic distortion does not jar the ears as much as odd-order harmonic distortion, which the solid-state amps tend to create on reaching their maximum power. Since transistor amplifiers usually move towards their maximum power limit quite quickly, the distortion also goes up fast. This can lead to the destruction of the drivers of the loudspeakers in these devices.
CHECK OUT GUITAR AMPS FOR THE DIFFERENCE
The difference in the distortion levels can easily be seen in guitar amps, where the design itself is such that the overload distortion is achieved with the help of the circuit in the output stage to deliver what guitarists call the `tone.’ While in a tube amp, this tone enhances the amplification effect, it ends up destroying the speakers in the case of solid-state amps, which simply can’t withstand the distortion beyond a point. The way this works is through the production of a sound known as the third harmonic, which intrudes into the original sound to trigger a harsh audible effect.
In contrast, tube amps usually only create the second harmonic, which is almost inaudible, but at the same time, has the effect of making the sound seem fuller. Hence, you get the characteristic pleasant tone of tube amps, which make your guitar more musical, just the way it ought to be. What you get with a tube amp therefore is a richer tone, which is music for your ears, and that of others around you too.
If you’re new to tube amplifiers, check out the best tube amplifiers for home use.
TUBE AMPS DELIVER LINEAR AMPLIFICATION
As you might know, tubes amplify the signal with the help of voltage variation while solid-state amplifiers or transistors operate through amplification of current. The linear amplification process involved in the functioning of tube amps doesn’t need as much negative feedback as transistors in order to make a linear circuit. This kind of circuit further helps in the reduction of distortion and also prevents slow-down of the amplifier. The sound quality is a direct result of the feedback level, with high negative feedback leading to dull and monotonous music and low or zero feedback, thus delivering more natural sound quality.
BUT ARE ALL TUBE AMPS GOOD?
Now that is a moot question. Not all tube amps are good, nor are all solid-state amps bad. Certain varieties of music, in fact, demand the solid-state amp kind of sound with its odd-order distortion. And with some of the modern transistors actually copying the technological quality of tubes, you’ll come across certain varieties of solid-state amps that actually work almost as well as tubes, if not better
Tubes definitely brought music to the next level as it allows you to listen to edgy instruments without fatigue. Tube amps may not be as popular as solid-state amps but they surely give you the warm sensational tone. It was a guitarist’s fault from way back in the ’60s as to why tube amps sound better and solid-state amplifiers sucks. You might find it humorous but solid-state amplifiers were terrible in amplifying sound at high frequency. In contrast, vacuum tubes operate in the point of an overload without the addition of an unpleasant distortion.
To wrap things up, tubes sound better because it is able to produce a musical, smooth, warm, loud, clear, subtle and seamless sound at high frequency because it affixes harmonic distortion. It clips better, “burn in” cleans and frees the tube with oxide contaminants to run under high voltage for a time period, and under-biased to control the current flow. However, this does not justify the closure to whichever amplifier sounds better but rather explains that tubes work well in manipulating distortions to create a musical effect with the addition of making the sound warm, making it a good material for music reproduction.
For more info and opinions about solid state amps and how they stack up against tube amplifiers, here are some resources I hope you find as helpful as I do:
- The Difference Between Tube And Solid State Amps from sageaudio.com
- Tube Amps vs Solid State: How To Choose The Right Amp from beginnerguitarhq.com
- 5 Differences Between Tube And Solid State Amps from guitartricks.com
- Solid State vs Tube Amplifiers from theleadguitar.com
- Tube Amp vs Solid State: What Sets Them Apart? from happynewguitarday.com
- Tube Amp vs Solid State: Choose Both For Best Results from sound-beat.com