The 12AU7A Vacuum Tube is a miniature type used as a
phase inverter or push-pull
amplifier in AC/DC radio equipment and as a
multivibrator or oscillator in industrial control
devices. It is also used as a combined vertical
oscillator and vertical-deflection amplifier, and as a
horizontal-deflection oscillator in TV receivers.
These tubes are also used in headphone preamplifiers.
It requires a miniature 9-contact socket.
The picture showing is for general purposes only to give
you an idea of the size and shape of 12AU7A tubes.
Electrical Data:
Heater Voltage ................. 6.3/12.6 V
Heater Current ................. 0.3/0.15 A
Preferred Substitutes .............. 12AT7
Substitutes .................. 12AZ7 12BH7