12AU7 is a miniature nine-pin medium-gain dual triode

Triode

A triode is an electronic amplification device having three active electrodes. The term most commonly applies to a vacuum tube with three elements: the filament or cathode, the grid, and the plate or anode. The triode vacuum tube was the first electronic amplification device...

 vacuum tube

Vacuum tube

In electronics, a vacuum tube, electron tube , or thermionic valve , reduced to simply "tube" or "valve" in everyday parlance, is a device that relies on the flow of electric current through a vacuum...

. It belongs to a large family of dual triode

Triode

A triode is an electronic amplification device having three active electrodes. The term most commonly applies to a vacuum tube with three elements: the filament or cathode, the grid, and the plate or anode. The triode vacuum tube was the first electronic amplification device...

 vacuum tubes which share the same pinout (EIA 9A). 12AU7 is also known in Europe under its Mullard-Philips tube designation

Mullard-Philips tube designation

In Europe, the principal method of numbering vacuum tubes was the nomenclature developed and used by Mullard in the UK and applied Europe-wide thanks to their parentage by Philips who had subsidiaries in Germany and France , plus the support of Telefunken, from 1934...

 ECC82. Base for this valve is B9A

The tube is popular in hi-fi vacuum tube audio as a low-noise line amplifier, driver and phase-inverter in vacuum tube push-pull amplifier circuits. There are opinions which indicate that this popularity is caused by audiophile industry/media polarization, not by its performance.

The tube has a center tapped filament so it can be used in either 6.3V 300mA or 12.6V 150mA heater circuits.



Current production of 12AU7 takes place in Russia

Russia

Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

, Slovakia

Slovakia

The Slovak Republic is a landlocked state in Central Europe. It has a population of over five million and an area of about . Slovakia is bordered by the Czech Republic and Austria to the west, Poland to the north, Ukraine to the east and Hungary to the south...

, and China

China

Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

.

External links

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