Tube headphone amplifiers
Lamp
— amplifiers in which at least part of the element base (“hardware”) is built on radio tubes (as opposed to most modern models that use exclusively transistors). We emphasize that we are talking here exclusively about the internal structure; according to the general type, such models can be both stationary and portable (although the first option is most widely used for a number of reasons).The main advantage of this technique is the notorious "warm tube sound" — a special soft coloring of the sound, which is appreciated by some audiophiles. At the same time, purely formally, tube amplifiers are noticeably inferior to transistor ones in terms of performance — in particular, they have a narrower frequency range and a higher harmonic distortion factor. However, it is precisely such distortions that give the "tube" sound its characteristic colour, they are more pleasant for human hearing than "cold" errors in transistor technology. So this point in itself is not a disadvantage, and some consider it an unambiguous advantage.
It is also worth mentioning that tube amplifiers are more resistant to overloads and allow for a smoother frequency response. In addition, the lamps can be made open, which gives the device a special style. On the other hand, such an element base has a number of serious drawbacks. Firstly, it turns out to be noticeably more expensive than a transistor one. Secondly, the lamps are rather bulky and fragile (which makes them difficult to use in portable models, although such solutions are also found). Thirdly, after switching on, it takes some time to warm up the elements. Fourth, lamps have a more limited lifespan than transistors. In light of all this, tube headphone amplifiers are now much less common than transistor ones and are intended mainly for principled adherents of such technology.