The device can be adjusted continuously in an audio inter break oscillation range, and a signal is sent out by a loudspeaker through being magnified by a semiconductor triode.

这种装置在音频的间息振荡范围内连续可调，信号经半导体三极管放大后用喇叭播放出来。

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Tri-Amping - A technique commonly used in large-scale sound amplification for concerts, Tri-amping is the practice of connecting three audio amplifiers to a loudspeaker unit: one to power the bass driver (woofer), one to power the mid-range and the third to power the treble driver (tweeter).

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