Tube

There are effects pedals that use vacuum tubes, also known as valves, in their circuit. These tubes are similar to the ones used in vintage amplifiers and are known for their warm, natural, and dynamic sound.

Tube-based pedals typically use one or more vacuum tubes in the preamp section of the pedal circuit. These tubes amplify the guitar signal before it is processed by the other components of the pedal. The tubes can be used to add distortion, overdrive, or other effects to the sound. Some pedals also use tubes in the power amp section, which can add even more warmth and character to the tone.

Using vacuum tubes in pedals can have some downsides as well. Tubes require regular replacement and maintenance, and they can be sensitive to temperature changes, which can affect their performance. They also tend to be more expensive than solid-state pedals, due to the cost of the tubes themselves and the additional circuit design required to accommodate them.