Bridge Power Audio Amplifier

Here is simple circuit of bridge power audio amplifier used in application requiring more power than is provided by the single LM380 amplifier, the two LM380s can be used in the bridge configuration shown in figure 1. In this arrangement (bridge power audio amplifier) the maximum output voltage swing will be twice that of a single LM380 amplifier; therefore, the power delivered to the load by bridge power audio amplifier will be four times as much. For improved performance, potentiometer R3 should be used to balance the output offset voltage of the LM380s. Here R2 C3 for stability with high-current loads.


Resistors (all ¼-watt, ± 5% Carbon)

R1 =2 MΩ potentiometer

R2 = 2.7 Ω

R3 = 1 MΩ


C1, C2, C3 = 0.1 µF

C4 = 51 pF


IC1, IC­2 = LM380 audio power amplifier


8Ω 1-W speaker

2 thoughts on “Bridge Power Audio Amplifier”

  1. I’ve built this circuit but I’m experiencing some distortion on the output. This seems to occur at all volume levels. A close look at the ‘scope reveals what appears to be crossover distortion at the 0V (AC) on the signal which I can’t seem to null out. Does anybody have a fix and/or comment on this?


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