Has this been tested, using multiple of these DMX512 convertors? And also, when will they be available?

Example given: I opened the volumio interface on a second device (iPad) while from another iPad I piloted the sources. Starting a movie on first device the Volumio interface on second device showed bitrate and samplingrate (16Bit, 44.1 Khz), so it was obviously processing something, just not audible. Unless I'm very much mistaken audio format should be an ordinary mpeg, Interesting point tho' resampling could be switching itself off ... that would mean it's both: volumio issue and pcm1794 (implementation) issue ...

This would mean when a video source is selected the format to the DAC is different from an audio stream? This can can only be solved by software. Or?...just a thought: if the source is video maybe resampling isn't working and if the data is 16 bit explains why there's no sound...This is something the people of Volumio must have an answer to.

well, intended or not ... In the end it's only an ordinary audio track. as mentioned above, it works flawlessly with mamboberry dac on Rpi 3B, as well as hifiberry etc.. All using volumio. And I can't see as to why it shouldn't, except a particular dac architecture  can't work away with it. E.g. in this case sabre 90xx obviously can vs. PCM17xx does not. It even works with an additional reclocking board like allo kali alongside mamboberry . It produces a latency of 0,7sec tho', so it's not syncronous with vision (useless either of course), but it still DOES play the sound! As for your Dac: I tried youtube videos. No sound. I installed the volumio youtube plug in, hoping to solve at least this issue . No success. Don't get me wrong please, I do admire how good your dac sounds! So I really enjoy listenig to music with it! I was only hoping, I could be eliminating the need of mounting platines back & forth - kali on for music, kali off for movies - to avoid latencies, by replacing the mambo & kali  via one very good platine of yours. Now I have to use two Dacs for differrent purposes, which is in the order of half step forward.  

From Volumio.org: 'Volumio is a true HI-FI Digital Music player' and 'One DAP (Digital Audio Player) for all your music: MP3, FLAC, WAV, AAC, ALAC, DSD and much more.' So 16 bit material in these formats isn’t a problem but I guess playing the audio part of a movie stream has never been their intent and probably won’t be!? It would take an application or a plugin for Volumio that splits the audio stream from the movie stream. Volumio itself doesn’t recognize the movie stream. Maybe other applications are more suitable?