Using Two Dac Simultaneously

[merterbalci]

Hello Snakeoilers

I also asked this question to upmpdcli's coder J.F Dockes but is would not be enough...
The question is:  

"When i'm plug my two dacs at the same time to my Snakeoil os based streamer, Os accepts two of them. You know actually lms can give dac change possibility to user. My theory is if i modify the upmpdcli to accept two of my dacs, i can change my dacs on lms control client simultaneously. 
Is this possible?"

Especially the question is for you @agent_kith 
Thanks!

[jose]

Hello Snakeoilers

I also asked this question to upmpdcli's coder J.F Dockes but is would not be enough...
The question is:  

"When i'm plug my two dacs at the same time to my Snakeoil os based streamer, Os accepts two of them. You know actually lms can give dac change possibility to user. My theory is if i modify the upmpdcli to accept two of my dacs, i can change my dacs on lms control client simultaneously. 
Is this possible?"

Especially the question is for you @agent_kith 
Thanks!

That would be great to hear diferences between dacs in the fastest / easiest way possible. If someone change it for you you can even do a "Blind Test" between the two

I still have a Cambridge Audio Dacmagic100 and an HRT MusicStreammer III purely because i cannot decide witch one i prefer 
Following the answer

[merterbalci]

Hello Snakeoilers

I also asked this question to upmpdcli's coder J.F Dockes but is would not be enough...
The question is:  

"When i'm plug my two dacs at the same time to my Snakeoil os based streamer, Os accepts two of them. You know actually lms can give dac change possibility to user. My theory is if i modify the upmpdcli to accept two of my dacs, i can change my dacs on lms control client simultaneously. 
Is this possible?"

Especially the question is for you @agent_kith 
Thanks!

Answer from Jean Francois (upmpdcli)

"I don't think it is, because there is no UPnP interface to do this. The
process which is choosing the output is MPD.

It's possible to define several audio outputs in the MPD configuration and
select one or several from an MPD client, but I'm even less of an expert on
this. In any case you can't do this through upmpdcli, it's impossible in
principle (with standard UPnP)."

It's clear now the keypoint is mpd.conf
http://mpd.wikia.com/wiki/Configuration#Audio_Outputs
But how? That's the new question

[agent_kith]

It's clear now the keypoint is mpd.conf
http://mpd.wikia.com/wiki/Configuration#Audio_Outputs
But how? That's the new question

That's where I will go first, as I reckon that is the easiest, but there are certain drawbacks, mainly because the audio output will not be in sync. But at least it gives you a PoC first step.

Once you get the PoC done, you may want to explore JACKd, or Pulse audio.

These two will do what you want. I personally think Pulse audio is detrimental to the sound, but I havn't tried JACKd yet. Look up on these two on the Internet, and see how it goes.

Technically you can use a computer and set it up as an active crossover. But it's not something I have explored myself.

[Snoopy8]

..mainly because the audio output will not be in sync.

Is this an inherent ALSA limitation? And JACK will solve this? And does it matter if source is PCM or DSD?

As you know, I asked about running 2 DACs from 2 USB ports simultaneously and thus, will be following this thread closely.

[merterbalci]

It's clear now the keypoint is mpd.conf
http://mpd.wikia.com/wiki/Configuration#Audio_Outputs
But how? That's the new question

That's where I will go first, as I reckon that is the easiest, but there are certain drawbacks, mainly because the audio output will not be in sync. But at least it gives you a PoC first step.

Once you get the PoC done, you may want to explore JACKd, or Pulse audio.

These two will do what you want. I personally think Pulse audio is detrimental to the sound, but I havn't tried JACKd yet. Look up on these two on the Internet, and see how it goes.

Technically you can use a computer and set it up as an active crossover. But it's not something I have explored myself.

That beats me
Can you give me an code flow example about this? By the way i use the snakeoil in headless system so i have to use ssh codes... I'm not bad in theory but awful about coding

[agent_kith]

That beats me
Can you give me an code flow example about this? By the way i use the snakeoil in headless system so i have to use ssh codes... I'm not bad in theory but awful about coding

Something like this: https://jackaudio.org/faq/multiple_devices.html

[merterbalci]

That beats me
Can you give me an code flow example about this? By the way i use the snakeoil in headless system so i have to use ssh codes... I'm not bad in theory but awful about coding

Something like this: https://jackaudio.org/faq/multiple_devices.html

And i need a little support about creation of PoC please Sorry if i'm too demanding.

[Snoopy8]

"When i'm plug my two dacs at the same time to my Snakeoil os based streamer, Os accepts two of them. You know actually lms can give dac change possibility to user. My theory is if i modify the upmpdcli to accept two of my dacs, i can change my dacs on lms control client simultaneously. 
Is this possible?"

Very late answer, but yes you can output to 2 DACs simultaneously. You need to modify upmpdcli's mpd.conf.template, please see this Wiki page which applies to  both upmpdcli and MPD.
https://www.snakeoil-os.net/wiki/Players...al_outputs