Tube and solid state - what's the difference?
At the most basic level, amplifiers work by receiving signal and playing it back at an increased amplitude. Early versions of amplifiers used vacuum tubes to power the amplification process, which, because of their construction and the materials they’re made from, introduced harmonics and filtered the sound to produce a more mellow tone. Multiple tubes for the pre-amplifier (i.e. gain, EQ etc.) stage as well as power amplifier tubes (where the increase in amplitude happens) would result in a fairly heavy product. Tubes also break down and wear over time, impacting both the sound and a musician’s bottom line. The advent of the transistor in 1947 bought solid-state amplification to the masses.
Pre 1947, solid-state amplifiers were more stable, or solid (as their name suggests), but would be susceptible to distortion at the volumes that contemporary music was pushing for. For this reason, guitar and instrument amplifiers were largely amplified via vacuum tubes until the invention of the transistor, which was able to handle a much higher workload without distorting or breaking down.
A collection of transistors
The transistor allows sounds to be amplified to much higher levels and maintains much more headroom (i.e. the gap between your maximum signal and the threshold where distortion would start to occur). What this does mean though, is that the full frequency spectrum is amplified, including all the potentially crisp high end, and transistors usually don’t add any colour to your sound like a vacuum tube would. Vacuum tubes (‘tubes’ or ‘valves’ in the biz) distort in a more pleasant way, as well as attenuating and shaping the sound that passes through them, depending on their construction materials, size and design. While the dictionary definition of ‘attenuate' makes a case for a weaker guitar tone, when valves attenuate a tone they remove certain frequencies and allow others to shine in a really pleasing way.
A famous 'Svetlana' KT88 vacuum tube
When discussing audio terms, tube tone is often associated with terms like ‘warm’, ‘fat’ and ‘analogue’ which are all great attributes to have when searching for a great sound. However, with the advent of pedals, effects and different equipment, players may also be looking for a cleaner, less coloured base to add whatever flavour they’re after.
So there you have it! Admittedly we’ve only just scratched the surface of the tube/solid-state debate, but at its most basic level, you can see the merits and downfalls of both camps. The best way to learn is to play, and trying out equipment of varying builds, constructions and price ranges is the best place to start. Take the new range of Super Crush amplifiers from orange, for example. These are super stable, reliable solid-state amplifiers with the power and headroom of transistors, but tuned and designed to sound like tubes! The best of both worlds.
Shop Orange Super Crush
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Shop Marshall vacuum tube amplifiers