Audio level meter circuit diagrams

Audio VU Meter

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.

Audio Peak Level Meter

Using a single MOSFET Op-amp this circuit samples the audio input and displays peak readings.

Audio Level Meter

Audio levels can be monitored using a small panel meter with this circuit built from discrete components.

Audio Indicator

This circuit can be used to remotely monitor a loudspeaker, alarm, or audio source for presence of an audio waveform. It can also be directly connected across loudspeaker terminals used as a peak indicator.

Audio Bargraph Display

An easy to use LED bargraph display to monitor audio levels. Circuit monitors a single channel, so build two for stereo.