This simple circuit indicates the amount of power that goes to a loudspeaker. The dual-color LED shows green at an applied power level of about 1 watt. At 1.5 watts it glows orange and above 3 watts ...

While refurbishing an ageing audio mixer, I decided that the level meters needed special attention. Their rather horrible 100 µA edgewise movements had VU-type scales, the drive electronics being just ...

Over the summer [ElectroSmash] put the finishing touches on the Arduino Audio Meter, a shield for the Arduino Uno that visualizes various aspects of an incoming audio signal on a set of four 8×8 LED ...