The ECC808 is essentially an improved ECC83 audio double triode. It was designed to be anti microphonic, to reject hum from the heater circuit and be low noise.
This example was made in West Germany by Valvo.
The twin triode sections with central screen. Hitherto the central screen was only found in RF valves.
Face view of one triode. Note that there is screening below the lower mica.
The control grid is wound on copper rods.
The thin glass tube envelope is 20 mm in diameter, and excluding the B9A base pins is 48 mm tall.
Reference: Data-sheet. Type ECC808 was first introduced in 1963. See also1963 adverts.
