I'm not sure where to ask this question, it is related to the interaction of hardware and software, but it also pertains to computer streamed music.

Many programs such as Windows Media Player or similar have their own volume control. But exactly what is the volume control doing?

One possibility is that it is simply digitally controlling the level of the analog output of the sound card. Digital controlling analog.

But what about when you are streaming music via optical, coaxial, or USB to an external DAC. The volume control on the software player still seems to affect the output levels. But since the output is a digital stream, it is not the voltage level of the stream that is changing. It has to be the numbers contained in the stream that have been altered.

So, if the volume control is at 50%, does the software divide all the digital voltage number by TWO?

In other words, during the recording of music, the Analog-to-Digital converter made this sequence of value capturers - 10, 20, 30. So with the volume control at half, those values would be reduced to 5, 10, 15?

I'm not saying that is how it works. I'm asking, how does it work??????

How can you change the volume in a pure digital music stream???

Steve/bluewizard