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.

An analog VU (volume unit) meter is a splendid moving-coil measuring instrument. It is a passive electromechanical device displaying a representation of the signal level in an audio equipment. Even ...

The unbridled development of radio broadcasting in the 1920s and 1930s demonstrated the need to standardize audio equipment, studio-to-transmitter links, and methods for measuring static and dynamic ...

Depending on the music you’re listening to, watching a VU meter bounce to the music is always a good time. So why not integrate the VU meter right into the audio source? That’s what [Matikas] did, and ...

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 ...

Before starting Techaeris, I didn’t think too much about headphones, like many people I just picked up a pair of cheap buds and went about my day. It wasn’t until I started testing headphones of ...

In almost every measurable way, a lossless digital audio file is superior to any analog media. This doesn’t mean that analog audio isn’t valuable though; plenty of people appreciate the compression, ...