Will Volumio downsample from 24/192 to USB DAC 24/96 capability and will this loose bit perfect?

Help and Support
1

I did some testing of volumio with Prodigy Cube Black USB DAC. This dac has been recognized by Volumio and I am able to play hi res flac files, however I am concerned a bit because this dac has HW sample rate limitation to 24bit/96kHz and volumio is able to play 24bit/192kHz files uing this dac. I switched off audio resampling so I would expect that volumio will throw an error about unsupported sample rate for such files. Now I am confused and have doubts whether volumio is downsampling the audio in background and it is not bitperfect in this case. My amp does not show the rate, so I am not sure how to check the real sample rate on output.

2

This is interesting. When I play the same in foobar2000 on Windows I have to enable sox dsp resampler to be able play 24/192 and this dac does not to want to play such files natively. In Volumio, is sox resampler plugin enabled by default? I use coaxial output to connect to my amp therefore I am confused.

3

Resampling is default off in Volumio. Please check your settings in playback options, if resampling is on.

4

My playback settings are as follows:
output device is Audiotrak ProDigy CUBE
DSD Playback Mode is DSD Direct
Mixer type is none
Audio resampling is off
When I play flac file 24bit/192 kHz I checked what my alientek d8 shows when connected to coaxial input and there is 96kHz, so this sample rate comes from dac on coaxial output.

5

Maybe someone else from this community has a suggestion?

6

There is a pcm type “plug” in the alsa pipeline before hw. So, if something not supported by hw is sent, it is converted to be used. See your /etc/asound.conf

7

This one? Never too old to learn.

# There is always a plug before the hardware to be safe
pcm.volumioOutput {
    type plug
    slave.pcm "volumioHw"
}