LinuxMusicians

It might be a newbie question:
Is this possible to use 2 different audio interfaces in Linux in the same time?
First: as input: Helix Stomp
Second: as master Output: Focusrite 4th gen

deathroit wrote: ↑Fri May 17, 2024 10:19 pm

It might be a newbie question:
Is this possible to use 2 different audio interfaces in Linux in the same time?
First: as input: Helix Stomp
Second: as master Output: Focusrite 4th gen

Yes. But they both have their own clock and those will drift. No matter what operating system you use: it is always discouraged.

<Edit>Have added Pipewire.</Edit> Here I have collected some meta information: 2 interfaces, 2 jackd, couple them>> viewtopic.php?p=95025#p95025

khz wrote: ↑Sat May 18, 2024 9:56 am

Here I have collected some meta information: 2 interfaces, 2 jackd, couple them>> viewtopic.php?p=95025#p95025

That is pretty good thread, beginning of thread might be out of date (jack audioadapter might not work anymore nowdays).

alsa_in/alsa_out are easiest way to use, or newer jack modules zalsa_in and zalsa_out are way to do it with jack. For combining interfaces with alsa config I don't know if it still works.

And for that 'you are trouble with sync', I have much recording with two different interfaces, and haven't had any real problems, but my recordings are pretty short, I edit them, etc, so I am not sure what level of problems there is. I should make some real test with some proper test setup to see what is problem, or is there.

tavasti wrote: ↑Sat May 18, 2024 4:06 pm

khz wrote: ↑Sat May 18, 2024 9:56 am

Here I have collected some meta information: 2 interfaces, 2 jackd, couple them>> viewtopic.php?p=95025#p95025

That is pretty good thread, beginning of thread might be out of date (jack audioadapter might not work anymore nowdays).

alsa_in/alsa_out are easiest way to use, or newer jack modules zalsa_in and zalsa_out are way to do it with jack. For combining interfaces with alsa config I don't know if it still works.

And for that 'you are trouble with sync', I have much recording with two different interfaces, and haven't had any real problems, but my recordings are pretty short, I edit them, etc, so I am not sure what level of problems there is. I should make some real test with some proper test setup to see what is problem, or is there.

What about PipeWire that every distro uses per default nowadays? I don't know for sure, but can you for instance still use good ol' jackd and PipeWire at the same time? Probably but just to make sure ...

Since PW a lot of "How To" articles have sort of been deprecated because it must be stated of the How To works with PW.

khz wrote: ↑Sat May 18, 2024 9:56 am

<Edit>Have added Pipewire.</Edit> Here I have collected some meta information: 2 interfaces, 2 jackd, couple them>> viewtopic.php?p=95025#p95025

It seems to be complicated (at least for me) and not worth an effort so I will abandon this idea.
Thank you very much anyway.

deathroit wrote: ↑Tue May 21, 2024 11:21 am

khz wrote: ↑Sat May 18, 2024 9:56 am

<Edit>Have added Pipewire.</Edit> Here I have collected some meta information: 2 interfaces, 2 jackd, couple them>> viewtopic.php?p=95025#p95025

It seems to be complicated (at least for me) and not worth an effort so I will abandon this idea.
Thank you very much anyway.

Yeah, that thread is too long and complicated. Are you running jack or pipewire?

tavasti wrote: ↑Tue May 21, 2024 11:34 am

deathroit wrote: ↑Tue May 21, 2024 11:21 am

khz wrote: ↑Sat May 18, 2024 9:56 am

<Edit>Have added Pipewire.</Edit> Here I have collected some meta information: 2 interfaces, 2 jackd, couple them>> viewtopic.php?p=95025#p95025

It seems to be complicated (at least for me) and not worth an effort so I will abandon this idea.
Thank you very much anyway.

Yeah, that thread is too long and complicated. Are you running jack or pipewire?

I'm using JACK. But my choice is due to lack of experience rather than a conscious choice.
Most of the materials about linux setup for audio production that I relied on (moving the production machine from Windows to Linux) described JACK as a stable and robust sound server (unlike PipeWire). Those might be outdated statements.

Or get cards with S/PDIF or ADAT IO, or Word Clock. Sync cards with one of those methods

There is a bit on that in Pipewire's documentation:

https://gitlab.freedesktop.org/pipewire ... properties

deathroit wrote: ↑Tue May 21, 2024 12:21 pm

I'm using JACK. But my choice is due to lack of experience rather than a conscious choice.
Most of the materials about linux setup for audio production that I relied on (moving the production machine from Windows to Linux) described JACK as a stable and robust sound server (unlike PipeWire). Those might be outdated statements.

From writings here you could get impression you did wrong thing, but actually you did what is best. Pipewire before version 1.0 does not have irq based scheduling, and therefore getting decent performance with it is matter of luck. Powerful hardware and low load helps, but does not guarantee it. And PW 1.0 is so recent (half year ago or something) that most distros don't have it. Sure there is plenty of bleeding edge hunters that come shouting 'I have been using PW from version 0.01 and no problems'. Many of them aren't recording any audio, and few xruns don't hurt, but when recording guitar, single xrun can ruin your recording.

So you have perfect system, and for it instructions are pretty clear:

• Setup you jack to use focusrite as interface, I personally use qjackctl
• run 'arecord -l' to see audio interfaces plugged, my example :

  Code: Select all

  tavasti@hermo3:~$ arecord -l
  **** List of CAPTURE Hardware Devices ****
  card 1: Ultra [Fast Track Ultra], device 0: USB Audio [USB Audio]
    Subdevices: 0/1
    Subdevice #0: subdevice #0
  card 2: io2 [io|2], device 0: USB Audio [USB Audio]
    Subdevices: 0/1
    Subdevice #0: subdevice #0
  

• run alsa_in with suitable parameters, in my case 'alsa_in -d hw:io2 -j second_interface' where that -d hw:io2 is critical part, selecting right hw.