This circuit uses two quad op-amps to form an eight LED audio level meter. The op-amp used in this particular circuit is the LM324. It is a popular IC and should be available from many parts stores.

The circuit was conventionally designed with eight LED audio level meter made out of two low power quad op-amps which utilizes LM324. Volume Unit – an entity equal to a decibel for expressing the ...

The LM3914 LED bar graph driver was an amazing chip back in the day. Along with the LM3915, its logarithmic cousin, these chips gave a modern look to projects, allowing dancing LEDs to stand in for a ...

An instrument for measuring the level of sound pressure in DECIBELs. Such measurements are called sound level readings. See: SOUND LEVEL. Sound level meters usually ...

With a calibration DVD and sound level meter in hand, you can play a test pattern and set levels for your speakers. It also is a good idea to set all treble and bass controls to 0 as well. Set your ...

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 ...