I have built a guitar amp tone stack using four AD5242 digipots. They are controlled via I2C using an arduino mega and rotary encoders. They are powered from a smoothed dual rail +-2.5V supply and the signal flowing through them is within the 5v limits. I have no issues with distortion, static, tone loss etc. The only issue I have is that there is an audible "digital squeak" when the resistance of any of the digipots are changed. It seems to be the rotary encoders creating this noise rather than the digipots. Is there any way of overcoming this?