A VU meter is often included in audio equipment to display a signal level in Volume Units; the device is sometimes also called volume indicator (VI). In this project we are building a basic and low cost LED VU Metre circuit . The extent (range) display is -18 dBu to +3 dBu, spread over eight LEDs (six green and two red- but i make it  with red leds:D) the following thresholds: -18 dBu, -15 dBu, -12 dBu-9dBu, -6 dBu, -3 dBu, 0 dBu to +3 dBu.The supply voltage is single, 12 V, no need for symmetrical power. More photos on Facebook Fan Page.

Component List:

IC1,IC2= LM324

IC3= LM358

R1,R2,R3= 27K    1/4 W Resistor

R4=11K    1/4 W Resistor

R5=12K    1/4 W Resistor

R6= 7K5    1/4 W Resistor

R7= 4K7    1/4 W Resistor

R8= 3K    1/4 W Resistor

R9= 390R    1/4 W Resistor

R10,R11,R12,R13,R14,R15,R16,R17= 510R    1/4 W Resistor

R18= 220K    1/4 W Resistor

R19= 22K    1/4 W Resistor

R20= 100K    1/4 W Resistor

R21,R22= 10K    1/4 W Resistor

R23= 1K    1/4 W Resistor

C1,C3= 1uF/50v

C2= 470nf

C4= 22uF/50v

D1,D2,D3,D4,D5,D6= LED Diode (red)

D7,D8=  LED Diode (green)

D1,D2= 1N4148

Q1= BC107    NPN Transistor

Download PCB, Layout,Circuit Diagram: 8 LED VU Meter Project

Author: Remy