Dating rca vacuum tubes
Dating rca vacuum tubes - Sex Chat
Grid bias is most often provided by a cathode resistor.
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.It is popular with tube amplifier enthusiasts, and its ongoing use in such equipment makes it one of the few small-signal vacuum tubes in continuous production since it was introduced.The 12AX7 is basically two 6AV6 triodes in one package.The 6AV6 was a miniature repackaging (with just a single cathode) of the triode and twin diodes from the octal 6SQ7 (a double-diode triode used in AM radios), which itself was very similar to the older type 75 triode-diode dating from 1930.
As of 2012 the 12AX7 was made in various versions by two factories in Russia (Winged C, formerly Svetlana, and New Sensor, which produces tubes under the Sovtek, Electro-Harmonix, Svetlana, Tung-Sol, and other brands for which the firm has acquired trademark rights), one in China (Shuguang), and one in Slovakia (JJ), for a total annual production estimated at two million units.
The vast majority are used in new-production guitar amplifiers or for replacements in guitar and audio equipment.
The 12AX7 is a high-gain (typical amplification factor 100), low plate current triode best suited for low-level audio voltage amplification.
In this role it is widely used for the preamplifier (input and mid-level) stages of audio amplifiers.
It has relatively high Miller capacitance, making it unsuitable for radio-frequency use.
Typically a 12AX7 triode is configured with a high-value plate resistor, 100k ohms in most guitar amps and 220k ohms or more in high-fidelity equipment.