| 摘要 |
<p>POWER AMPLIFIER CAPABLE OF SIMULTANEOUS OPERATION IN TWO CLASSES An electronic amplifying apparatus intended for sound reproduction and for music instrument amplification wherein two parallel amplifiers, working simultaneously, each in a different class of operation, are fed from a single driver or signal source and whose outputs are combined. In the preferred embodiment at least two pairs of push-pull vacuum tubes are required and they are arranged so that one pair operates Triode Class A while the other pair (or pairs) operates Pentode Class AB (or Class B). The circuit can then be optimized so that the desirable sonic characteristics of Class A Triode operation are imparted into the Class AB (or Class B) Pentodes which actually produce all or nearly all of the power. The output power waveform has the high power and efficiency typical of Class AB (or Class B) Pentode operation but without the detrimental sonic side effects, namely, there is the complete absence of crossover or "notch" distortion, and there is a "soft" gradual onset of clip. Both of these traits are highly desirable and characteristic of the notoriously inefficient Class A Triode operation. On/Off switching of various pairs of output tubes may further be employed to add flexibility to the system with regard to power availability and sonic performance. Single ended configurations as well as solid state devices or hybrid combinations could be arranged to operate in simultaneous different classes of operation and enjoy its attendent benefits.</p> |
