Four volume controls in my signal chain - how to set?

[mcochris]

I have a system that has four volume controls in the signal chain and I'm wondering how to set them. My system:

Win 11 PC -> Foobar2000 (music file player) -> Dirac Live on PC -> DAC -> analog preamp -> power amp -> speakers

The four volume controls are:

1 - Windows OS volume control
2 - Foobar2000 volume control
3 - Dirac Live volume control
4 - analog preamp volume control

All volume controls work and adjust the volume, but I'm not sure why there are volume controls for a digital signal. Shouldn't the analog preamp be the only volume control?

To add to my confusion, the Dirac Live volume control has a "red zone" that I guess indicates "don't let the signal strength get to here". I've asked the Dirac folks for help, they are escalating the question internally.

Thanks for any help!

Dirac volume control:

 

[ppataki]

Set Windows volume to max
Set Foobar volume to max
Leave Dirac volume as-is
Play some loud recording (modern EDM for example) and check if there is no digital clipping (= check the volume meter in Dirac, it shall not reach 0dB)
If there is clipping, lower the volume in Dirac, otherwise leave it as-is
Adjust the volume on your pre-amp

Note: there are other ways to do it but it depends on the system. I for example do not have a pre-amp so I am adjusting volume in Jriver upstream and all the other volume controls are at max