I installed the latest version of Volumio 2 (2.041) on my Raspberry PI 3 and after having had some difficulties in the output configuration to the USB DAC of my Burson Conductor and manual installation of wi-fi dongle Edimax, now it all works
Now I would like to verify that the output stream from the Rasperry PI usb to the USB of my DAC is bit perfect, that is, whether the audio stream is truly intact (e.g. input file 24 bit 96 kHz => output 24 bit 96 kHz).
There is this feature in the interface of Volumio, as in the âPlaybackâ screen, or through some shell command during playback?
Well, itâs certainly possible, though not with a standard Volumio install. If you want to go all the way (whole system check), specifically for your setup, youâd have to capture the outgoing raw USB data stream with something like wireshark and from that recreate the actual audio data stream. Then, do a compare with the original data and you have your answer.
Not in any way a âCheck Bitperfectâ â âOKâ button solution, but hey, itâll be a challenge
You need to verify first that everything software related is set correctly to drive the âsound cardâ (in your case the USB device) with bit-perfect input.
I am not aware of any other tooling/info that can be retrieved from the snd-usb-audio driver, but that is where some more details could be retrieved from.
Certainly what was said by matjans would be the ideal test, but my intention is simply to verify that the depth of the word (bit) and sample rate (kHz) are not altered in the output stream to the dac (no oversampling and no upsampling).
Iâm not sure itâs the right thing, but looking for alsa I found references to the file /proc/asound/card*/ stream0 in which, while playback, the âMomentary freqâ parameter shows the sample rate and the âAltsetâ shows the format used (16-24-32 bit).
