Great news, we can use now DietPi for full Hi-Res 384 kHz/ 32 bit and DSD 64 playback on new DACs being shipped this month:
It started with @RBM recommending to test Moode - thank you!
It is very easy to set-up unix/ player. Just add through terminal Roon. It works perfect with all Roon, Squeeze (-C 5 sec card release), and AirPlay running same time. The unix however is having unnecessary browser graphic UI, many parallel tasks, and MPD player that is redundant if you are running Roon.
After sharing ideas, and very helpful & fast engagement of Fourdee to integrate 384 kHz/ 32 bit Kernel in DietPi, we have perfect solution - very light-weighted DietPi now playing 384 kHz/ 32 bit and DSD 64 on the best performing DACs from Allo and Audiophonics for Raspberry Pi in the market!
To get the DietPi 384 kHz/ 32 bit and DSD 64 enabled, just take these 4 steps:
apt-mark hold raspberrypi-bootloader raspberrypi-kernel libraspberrypi-bin
wget http://dietpi.com/downloads/binaries/rpi/rpi2plus-4.4.30_384khz.7z -O package.7z
7z x -aoa package.7z -o/
See, details on DietPi forum
Plus, Fourdee promised to have in the next update v138 => 384kHz kernel to be installed from dietpi-config > Audio Options