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.

Parts
C1                1           0.1uF ceramic disc capacitor
U1                1           DS1669 digital pot ic
S!,S2           2           momentary push button switch
MICS           1           board,wire,socket for u1


Notes

1. S1 turns the volume up, S2 turns it down.
2. The input signal should not fall below -0.2 volts.
3. 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.

source