12AX7

12AX7
12AX7
Classification	Dual triode
Service	Class-A amplifier
Height	2.2 in (56 mm)
Diameter	0.8 in (20 mm)
Cathode
Cathode type	Indirectly heated
Heater voltage	12.6 V (series) 6.3 V (parallel)
Heater current	150 mA (series) 300 mA (parallel)
Anode
Max dissipation Watts	1 per section
Max voltage	300 V
Socket connections
Typical class-A amplifier operation
Amplification factor	100
Anode voltage	250 V
Anode current	1.2 mA
Bias voltage	−2 V
Anode resistance	62.5 kΩ
References
Sylvania 12AX7 datasheet

12AX7 (also known as ECC83^[1]) is a miniature dual-triode vacuum tube with high voltage gain. Developed around 1946 by RCA engineers^[2] in Camden, New Jersey, under developmental number A-4522, it was released for public sale under the 12AX7 identifier on September 15, 1947.

The 12AX7 was originally intended as replacement for the 6SL7 family of dual-triode amplifier tubes for audio applications. As a popular choice for guitar tube amplifiers, its ongoing use in such equipment makes it one of the few small-signal vacuum tubes in continuous production since it was introduced.