12AX7 Vacuum Audio Tube Specifications and Characteristics

AMPEREX TUBE TYPE 12AX7 / ECC83

The 12AX7 / ECC83¹ is a miniature, high-mu twin triode, eachsection of which has an individual cathode connection. The construction of the 12AX7/ ECC83 is such that noise and microphony are reduced to a minimum. Hum is reducedby the use of a coiled tungsten heater. A center-tapped heater permits operation ofthe tube from either a 6.3 volt or a 12.6 volt heater supply.

The 12AX7 / ECC83 is particularly suited for use in resistance - coupledvoltage amplifiers such as those used in the preamplifier and input stages of Hi-Fiamplifiers, phase inverters, multivibrators and numerous industrial control circuits wherehigh voltage gain is desired.

GENERAL CHARACTERISTICS

ELECTRICAL
Cathode	Coated, unipotential
	Series	Paralleled
Heater Voltage, AC or DC	12.6	6.3 volts
Heater Current²	0.15	0.3 amps
Direct Interelectrode Capacitance's	With Shield³	Without Shield
Grid to Plate (each section)	1.7	1.7 uuf
Input (each section)	1.8	1.6 uuf
Output (section 1)	1.9	0.46 uuf
Output (section 2)	1.9	0.34 uuf

MECHANICAL
Maximum Overall Dimensions
Length		2 3/16 inches
Seated Height		1 15/16 inches
Diameter		7/8 inches
Mounting Position		any
Base		Small button, 9 pin RETMA #9A

¹ The 12AX7 / ECC83 is a direct,high-quality replacement for other brands of the 12AX7.

² When used in equipment which employs series -connected heaters, a current-limiting device must be inserted to limit the current whenswitching on.

³ With external shield (RETMA #315) connected tocathode of section under test.

Vacuum Tube Data Sheets