Add an RC volume control to your RPi Audio DAC
For those who want to adjust the volume of the music they listen to with analog hardware but do not want to invest in servo-controlled potentiometers here is a compromise in the shape of a so-called ‘Digitally-Controlled Analog Volume Control’. It has a serial control interface, selectable zero crossing detection and a mute function. This design was intended for use with a Raspberry Pi running Volumio, but it can be used with virtually any audio source. It even adds RC control.