KT77 GEC brown base used/70-75% 1960”s good top getter

61.5ma

Gm=9650

General Information

The KT77 is designed primarily for use under ultra-linear conditions (43% taps, Class AB1 push-pull)
and this connection is recommended. Similar performance can be obtained in the tetrode connected mode,
but the output impednace (zout) will be higher. Life expectancy=5000 hours when operated at maximum
ratings (32W) or 10,000 hours when operated at (25W)

– Bob Gjika KT77 guitar amp