The ECC83 high impedance amplifier triode was designed specifically for audio use and has a high amplification factor of 100. The name on the valve is that of a trading company and not the manufacturer.
The valve seen end on to the anodes.
This valve type is still found in todays designs of hi-fi audio amplifiers. In the classic Mullard designs of the 1950s and 1960s the valve's two halves were used as second stage amplification and cathode coupled phase splitter.
The phase splitter being required so that the push-pull output stage was driven correctly.
This valve is another badged by this company.
The second valve seen end on to the two anodes.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 46 mm tall.
References: Data-sheet, 3002 & 1040. Type ECC83 was first introduced in 1954. See also1954 adverts.