The 6BH6 or 6666, is an NPN type of vacuum tube. It was first introduced by RCA in 1953 and is now produced by various suppliers, including the Russian manufacturer, Sovtek and Svetlana. It is a medium-mu dual triode, having two sections and is used for pre-amplification and low-level signal duties. The 6BH6 has a maximum plate voltage of 75 volts and a maximum plate dissipation of 2.5 watts per section. It is often used in amplifiers, compressors, and preamplifiers as a voltage amplifier, voltage regulator, and phase splitter.