Though the exact components vary between models, many DIY tube amplifier kits include a circuit board, several vacuum tubes, a power supply, a speaker and the necessary wires and adapters to connect the components. Some kits also come with a housing case to protect the speaker and internal components.
Regardless of the style or complexity of a DIY tube amplifier kit, all models include a set of vacuum tubes and a mounting circuit board, as well as a power supply. Kits vary with the inclusion of different input jacks or preamp effect control panels. Some basic kits exclude the speaker, despite it being necessary to produce sound. The housing case is another optional item in many kits, as it is not strictly necessary for the function of the amplifier.
A tube amplifier varies from other forms of amplifiers in that it uses one or more vacuum tubes to receive the electrical input from the source, often an instrument or sound replay device, and increases the sound as it passes through a speaker. This stands in contrast to solid-state amplifiers, which process the sound amplification exclusively through diodes and other electronics. Tube amplifiers generally produce a warmer, richer tone that covers a different section of the audio spectrum.