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 ...

It used to be a must-have on any hi-fi, a pair of moving coil meters or LED bar graphs, the VU meter. Your 1980s boombox would have had them, for example. VU, for “Volume Units”, is a measure of audio ...

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 ...

British audio experts Meters Music’s new Cubed speaker system is unashamedly cool, due not just to the minimalist design, but mainly because of the working volume unit (VU) meter built into the body ...

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 ...