0 Simple Stereo VU Meter

I like to see lights move to music. This project will indicate the volume level of the audio going to your speakers by lighting up LEDS. The LEDS can be any color so mix them up and really make it look good. The input of the circuit is connected to the speaker output of your audio amplifier. You want to build two identical units to indicate both right and left channels. The input signal level is adjusted by the 10k ohm VR. If you wish to make a very large scale model of this unit and hang it on your wall there is an optional output transistor that can drive many LEDS at once. The unit I built drove three LEDS for each output. The sequence of the LEDS lighting are as follows Pin 1, 18, 17, 16, 15, 14, 13, 12, 11, 10.

Detail: Simple Stereo VU Meter

0 Sooper Digital Volume Control

This digital volume control has no pot to wear out and introduces almost no noise in the circuit. Instead, the volume is controlled by pressing UP and DOWN buttons. This simple circuit would be a great touch to any home audio project.

Sooper Digital Volume Control Schematic

Parts:

Part	Total Qty.	Description
C1	1	0.1uf Ceramic Disc Capacitor
U1	1	DS1669 Digital Pot IC (See Notes)
S1, S2	2	Momentary Push Button Switch
MISC	1	Board, Wire, Socket For U1

Notes:

1. U1 is available from Dallas Semiconductor.

2. S1 turns the volume up, S2 turns it down.

3. The input signal should not fall below -0.2 volts.

4. Using a dual polariity power supply (+-5V works fine) will cure most clipping problems. You will have to check the data sheet for the correct pins to connect your voltages. Link

Detail: Sooper Digital Volume Control