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 ...

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 ...

Given its appearance in one form or another in all but the cheapest audio gear produced in the last 70 years or so, you’d be forgiven for thinking that the ubiquitous VU meter is just one of those ...