“I’ve just been testing a pair of very expensive Takatsuki 300B valves. I get 30 watts push pull with big driver transformer. Distortion without feedback 0.16% at 30 Watts. That it real linearity.” – Tim de Paravicini

A cut away version on show at Takusuki office. They hand make the whole valve in the small factory.
Original Tim de Paravicini design back from 1995