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. We’ve covered this topic in the past (here and here, for example) and 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. 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. This traces back to the difference in construction.
Transistors versus 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.
Are They Really Better?
The question of whether tube amps are better keeps coming back to the issue of sound. Thanks to the modern advances in speaker technology, we are better able to hear the subtle differences in the sound they produce. However, some people prefer the sound that solid-state amps produce to tube amps. So in the end, it comes down to what sort of sound you want to make with your instrument. The answer to that question will decided whether tube amps are better for you or not.