Hi Peter,
I thank you so much for your information.
I got, that needing less bits and despite of that having a perfect volume control is the idea behind Leedh volume control. great 
I also understood the advantage of this approach implementing volume control in silicon 
Would you please explain why this should be better as calculating volume with floating point math as Roon does with its DSP volume? Doing volume control in a CPU I don’t have to care about additional bits!
Here are some measurements I took regarding this topic and I have no idea where volume control might be improved above that:
The final truth about DSP Volume Control in Roon | Audio Science Review (ASR) Forum
I wonder how the graphs would look like measuring Leedh volume control?
Best DrCWO