Tube amplifiers, also known as valve amplifiers, are electronic devices that amplify audio signals using vacuum tubes. These tubes, which were widely used before the advent of transistors, are known for producing a warm, rich sound that many audiophiles prefer. Tube amplifiers are commonly used in high-fidelity audio systems and by musicians for electric guitars. The design of tube amplifiers typically includes a power supply, input stage, and output stage, all working together to enhance sound quality. While they can be more expensive and require more maintenance than solid-state amplifiers, many enthusiasts appreciate their unique tonal characteristics and vintage appeal.