The 12AX7 high impedance amplifier triode was designed specifically for audio use and has a high amplification factor of 100. The original American 12AX7 design was copied by many companies.
ATES denotes the Italian arm of RCA.
The twin triode sections.
One anode seen face on. The ribs pressed into the thin nickel sheet add rigidity and allow a thinner gauge of anode material to be used.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 47 mm tall.
References: Data-sheet, 3002 & 1040. Type 12AX7 was first introduced in 1947. See also1947 adverts.
