Comparative Analysis of Water-Cooled Tubes as Class B Audio Amplifiers

Performance of vacuum tubes used as class B audio amplifiers has been studied with particular stress on the influence of the amplification factor, μ, on the behavior of tubes. Four types of water-cooled tubes of completely identical design differing only in μ, have been studied. The infuences of the load resistance, operating plate voltage, and no-signal current, or bias, have been graphically precalculated and compared. The limitations of water-cooling on this class of tube operation are clearly demonstrated. The methods used for this particular study are applicable to a variety of similar problems.