6H30

The 6H30 (6N30P) is a Russian dual triode developed for military radar and missile guidance systems, characterized by very low plate resistance (~800 ohms per section) and high transconductance. Its ability to deliver substantial current into low-impedance loads makes it behave almost like a solid-state buffer with tube character, excelling in line stages and output buffers. The tube was popularized in Western hi-fi by Balanced Audio Technology (BAT), whose preamps and amplifiers are designed around it. Available primarily as NOS Soviet military stock or current Electro-Harmonix production, the 6H30 occupies a unique niche as a current-delivery powerhouse among small-signal tubes.