I have never liked digital control of volume, 0dB from dac gives the best signal to noise. imo
Not to mention loss of resolution.
Have you noticed that pop when you select a new track? when listening at low levels.


Some pictures of my PiPre

I used an old PS Audio case I had knocking about not pretty but functional.
On the front panel you have Volume, Selector Switch and a Pi Reset button (handy) with Led showing power to the Pi.
Rear has an Analogue in, Pi Usb and Ethernet inputs, Output and Mains switch and fuse.