6P1P
The 6P1P (Russian: 6П1П) is a Soviet-made miniature 9-pin beam tetrode vacuum tube with ratings similar to the 6AQ5, EL90 and the 6V6. Because of a different pinout (a 9-pin base versus 7-pin base) than an 6AQ5/EL90, it cannot be used as a plug-in replacement for these types, however, it will work in the same circuit with component values unchanged. Its maximum plate/screen voltage and dissipation ratings are actually slightly higher than a 6AQ5. A ruggedized/extended ratings version of the tube is designated 6P1P-EV (Russian: 6П1П-ЕВ) roughly equivalent to the 6AQ5W. A Chinese-manufactured version of the tube also exists, labeled 6P1.
The type was commonly used in Soviet-built vacuum tube radios and TV sets as an output audio amplifier, until it was replaced by the higher-performance 6P14P (an exact equivalent of the EL84).
The tube is no longer believed to be in production.
Also see 6AQ5, 6V6 and Russian tube designations.