The 12AU7 and its variants are miniature nine-pin (B9A base) medium-gain dual triode vacuum tubes. It belongs to a large family of dual triode vacuum tubes which share the same pinout ( RETMA 9A). 12AU7 is also known in Europe under its

Mullard–Philips tube designation In Europe, the principal method of numbering vacuum tubes ("thermionic valves") was the nomenclature used by the Philips company and its subsidiaries Mullard in the UK, Valvo( de, it) in Germany, Radiotechnique (''Miniwatt-Dario'' b ...

ECC82. There are many equivalent tubes with different names, some identical, some designed for ruggedness, long life, or other characteristics; examples are the US military 5814A and the European special-quality ECC82 and E182CC. The tube is popular in hi-fi vacuum tube audio as a low-noise line amplifier, driver (especially for tone stacks), and phase-inverter in vacuum tube

push–pull amplifier Push–pull may refer to: In electronic technology *Push–pull output, type of electronic circuit *Push–pull converter, in electronics, is a type of DC to DC converter that uses a transformer * Push–pull connector, an electronic cable connec ...

circuits. It was widely used, in special-quality versions such as ECC82 and 5814A, in pre-semiconductor digital computer circuitry. Use of special-quality versions outside of the purpose they were designed for may not be optimal; for example, a version for digital computers may be designed for long life without cathode poisoning when mostly switched to low-current mode in switching applications, but with little attention to parameters of interest only for linear applications such as linearity of transfer characteristic, matching between the two sections, microphony, etc. This tube is essentially two 6C4/EC90s in the same envelope. However, this latter type is officially described in manufacturer's data as "a special quality R.F. power amplifier or oscillator for frequencies up to 150 MHz". The 12AU7, on the other hand, is described as an "A.F. double triode". Data sheets suggest an upper frequency limit of 30 kHz for the 12AU7/ECC82 and it is not described as a "special quality" device. Brimar application report VAD/513.4 for 12AU7/ECC82 dated January 1952 gives a gain of -1 to -2 dB at 30 kHz This contrasts with the 6AB4/EC92 and

12AT7 12AT7 (also known in Europe by the Mullard–Philips tube designation of ECC81) is a miniature 9-pin medium-gain (60) dual-triode vacuum tube popular in guitar amplifiers. It belongs to a large family of dual triode vacuum tubes which share the ...

/ECC81 which are both R.F. devices operating up to

VHF Very high frequency (VHF) is the ITU designation for the range of radio frequency electromagnetic waves (radio waves) from 30 to 300 megahertz (MHz), with corresponding wavelengths of ten meters to one meter. Frequencies immediately below VHF ...

. Double triodes of the 12AU7 family have a center-tapped filament for use in either 6.3V 300mA or 12.6V 150mA heater circuits. the 12AU7 continued to be manufactured in Russia, Slovakia ( JJ Electronic), and China. Hitachi 12AU7

References

{{reflist

External links

12AU7 datasheet from the RCA RC-29 Receiving Tubes Manual
(NJ7P Tube Database)

Reviews of 12au7 tubes.

(JJ Electronic ECC82 Datasheet) Vacuum tubes Guitar amplification tubes

See also

References

External links