Triple-Twin Tubes

This paper describes a new tube and circuit which utilizes the positive, as well as the negative, region of the E
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characteristic and has a negligible amount of distortion. A high input impedance is maintained. Minimum distortion and maximum output occurs at the same load impedance. The tube comprises in one envelope two sets of special triodes. The cathode of the input set is directly connected to the grid of the output. The first section supplies the power demanded by the grid of the second section. Although this paper only treats audio amplification, the development is not limited to this field. The fundamental circuit is described. Analysis of the "grid current compensation" is treated from data obtained by practical application rather than a mathematical evolution. Operating notes and a push-pull circuit are also discussed. A commercial triple-twin's output and sensitivity is compared with a pentode and a triode. All have the same plate voltage rating. The triple-twin delivers nearly twice the pentode's power and three times the triode. Its power sensitivity is many times greater than its contemporaries.