Sound Level Meter

This nifty sound level meter is a perfect one-chip replacement for the standard analog meters. It is a completely solid state and will never wear out. The whole circuit is based on the LM3915 audio-level IC and uses only a few external components.

Parts

Notes

• V+ can be anywhere from 3V to 20V
• The input is designed for standard audio line voltage (1V_P-P) and has a maximum input voltage of 1.3V
• Pin 9 can be disconnected from the ground to make the circuit use a moving dot display instead of a bar graph display

Additional Circuit