by Fred Nachbaur, Dogstar Music ©1998, 2000

After all that, the peak-output power meters are almost trivial. Aside from the rectifier diodes and regulator transistors in the power supply, it's our sole concession to solid-state technology. The meter is a basic application of the popular LM3915N LED bar-graph display driver, which shows output power (assuming an 8-ohm speaker system) in 3 dB steps from 200 mW to 100 watts. Note that this represents Peak power, the equivalent RMS power will be one-half of the peak value (for sine wave input). If the last light (representing 100 watts peak) lights too frequently, this is your cue that you're pushing the amplifier to its limits, and you'll start hearing signal degradation due to clipping.

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