A frame-grid audio pentode for stereo output

The development and performance capabilities of a dual pentode using a single cathode, two separate Framelok grids and a twin-plate structure contained in one envelope is described. This new pentode, known as Type 6DY7, is a high-performance tube with superior characteristics of uniformity and stability obtained from its unique structure. Such factors as greater uniformity in tube-to-tube characteristics, reduced characteristic spread, and less susceptibility to characteristic deterioration at high dissipations can be obtained. This dual pentode offers extreme flexibility in application. Three basic configurations are: 1) sections operated separately (single-ended) giving 5 watts of audio power per section; 2) two sections in push-pull, Class AB
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providing up to 20 watts output at less than 3 per cent distortion; and 3) two tubes in push-pull parallel. A single tube can be used for two stereo output channels, or two tubes can be operated in push-pull for higher power requirements. The same advantages can be used for monophonic audio systems. The tube, therefore, offers the circuit designer a choice of usage not possible in presently-available tubes and at cost advantages realizable through a reduction in the number of circuit components.