This circuit, connected to the loudspeaker output of an audio amplifier, will indicate the instantaneous output power delivered to the loudspeaker(s) by means of six LEDs illuminating one after another by voltage values increasing little by little, providing the visual impression of a luminous bar or column, increasing and decreasing in height following the increase and decrease of the signal’s level.
Notes:
* The output power indicated by each LED must be doubled when 4 Ohms loads are driven.
* The circuit can be adapted to suit less powerful amplifiers by reducing the number of LEDs and related voltage dividers.
