The 12AU7 is a double triode with separate cathodes. An amplification factor of 17 is quoted.

The side view of the anode shows the ridges pressed into the sheet to aid rigidity. The coating helps improve radiation efficiency for better cooling.

See also ECC82 from Mullard that designates the valve with both the Mullard ECC82 and the American 12AU7 designations.

The thin glass tube envelope is 19 mm in diameter and the length excluding the B9A base pins, is 48 mm.

 
Pin Connections

B9A	1	2	3	4	5	6	7	8	9
	a(2)	g(2)	k(2)	h	h	a(1)	g(1)	k(1)	hct

 
Absolute Maximum Operating Conditions

Triode	Vh	Ah	Va	Vg	mAa	gm
	6.3	0.3	250	-8.5	10.5	2.2

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 19 May 2009 {find valves by name}