This is a very simple project which uses two switches and an IC to electronically control the audio output from an amplifier. Digital Volume Control Circuit This is the circuit diagram of a digital volume controller for any sort of audio amplifiers or almost any circuit where a mechanical potentiometer is there (conditions apply).. The M62429 is a dual-channel electronic volume control primarily designed for audio applications; however, it does work with both AC and DC signals. The programming interface of M62429 is a very simple two-wire (data, clock) serial protocol with a command length of 11 bits. Key features are: The serial protocol is somewhat strange and different. 2012. 8. 5. · Digital volume controls are the same in this regard, but a whole other story. They add nothing to the signal path: instead they rearrange the digital numbers to achieve a lower volume. This is simple to understand if you remember that each loudness level in a PCM digital system is based on a number – that number representing the level of the output signal – with larger. For digitally controlling the volume, the common method is to use a weighted resistor ladder (after the ADC and pre-amp, if any) and selectively switching in (or out) the resistors by the use of electronic switches, depending on whether the volume is being increased or decreased. The resistor values are so chosen that every increment (or.