E80CC, 6085, CV5989, SMALL SIGNAL, B9A

The E80CC is a special quality double triode introduced by Mullard in 1957. It has a ruggedised design and was made to have a long service life with a lack of microphony courtesy of the electrode cage's torsional rigidity.  The design purpose was for computing, switching and scaling with each of the two triode sections within the envelope - box anode ala CV4004 - being of frame grid construction and possessing a noise factor of 4.6dB which makes it eminently suitable for RF, IF as well as audio usage.

Many valve amplifier aficionados use the E80CC as a low distortion, low microphony substitute for the ECC82 albeit with slightly different operating parameters and double the filament current requirements.  Personally, I feel that this gold pinned beauties are a scarce and supremely high performing device rewarding users with an ultra-long service life with a smooth deep uncoloured sound stage - very nice indeed.