Hello,
I have been testing my latest product the PecanPi DAC heavily with Volumio and I noticed that in certain situations the noise floor increases by 20 to 30dB.
At first I though it was a HW issue with the PecanPi, so I tested the board separately without a raspberry Pi and there were no issues.
So then I tried using piCorePlayer also with the RPI-DAC driver and and no issue there either.
I believe that Volumio is doing something not quite right when this overlay is used.
Regards;
Leo