KT66

The KT66 is a beam tetrode vacuum tube designed for audio amplifier applications. It was originally produced by The General Electric Company plc in the United Kingdom and became popular in the 1950s and 1960s. The KT66 is known for its rich and detailed sound reproduction, often described as having a warm and slightly sweet character. Its construction features a metal shell with a glass top, and it typically uses a six-pin base. The KT66 is capable of producing significant power output for its size, making it a favored choice for high-fidelity amplifiers. It was notably used in the Leak TL12 Plus and later models of the QUAD II amplifier, both considered classics in the audiophile world. Due to its desirable sonic qualities and historical significance, KT66 tubes are still sought after by enthusiasts and are manufactured by various companies today, often as reissues or modern interpretations of the original design. While it shares some characteristics with other beam tetrodes like the 6L6, the KT66 is generally considered to have a more refined and powerful output.