Multichannel audio interface for Linux

I’m using a MOTU Ultralite AVB, which is an USB class-compliant unit. 8 physical IOs, plus ADAT IO. Then, if you’re into the AVB thing, you can buy more AVB racks and expand your IOs.
Classy thing about the ultralite AVB : you can set the internal DSP through a web interface, which is also OSC-controllable.

I’m using a second generation Focusrite Scarlett 18i8 and it works fine with Linux (except for the internal software controlled mixer for no latency monitoring, which is not yet supported). Recording works even with quite low power systems.

@baptiste: How do you like the interface? How does it perform/sound?

did you mean Behringer ADA8200
Yes, I did, sorry!
That USBStreamer is very interesting, you can interface any Adat device to Linux with it.
Yes, I chose that combination because my home studio system uses an RME Multiface II which includes ADAT I/O, so the Behringer can be used to extend it from 8 to 16 inputs.
MOTU Ultralite AVB, which is an USB class-compliant unit
MOTU has traditionally has zero support for Linux, so it's good to hear of a class compliant unit. Combined with a web interface for the internal DSP, that's really good news for Linux users!

@dsreyes1014
I have absolutely zero complaints. It’s performing the way it should. It’s my first audio interface with such DSP capabilities, so i’m more than happy !
Two things though :

  • for the time being i can’t access the web GUI on linux without plugging the device to my computer or to a router. On windows, you only need the USB cable, i need to investigate this.
  • it can’t be USB-powered, you need the power adapter.

The only frustrating thing comes from the OSC-side : the communication is only client to server, no feedback. I guess there is a way to work around this by using the web API, since the web GUI gets updated when i send OSC commands.

I bought a Focusrite Scarlett 6i6 2nd Gen interface. I can use it with jack & Ardour, where I get 6 inputs and 6 outputs. I didn’t test S/PDIF and MIDI, but all other ins and outs work out-of the box. The two headphone outputs are configured to out1/2 and out3/4, respectively. This is already quite nice.

However, I would like to configure the 6i6’s internal mixer and settings, e.g. to

  • Use latency free monitoring
  • Configure headphone2 to outputs 5/6 (not using S/PDIF here, so I could use these outputs for the headphone)
  • Set the gain of inputs 3 and 4 (which have no gain knob)
  • Control the "INST" and "PAD" settings
The alsamixer only shows " Clock Source", "Internal Validity" and "S/PDIF Validity", though.

@LearDigitalAudio: Did you manage to access the internal mixer or did you just use the device as-is?

I just got a MOTU Ultralite AVB like baptiste and there is no comparison to the quality when comparing it to the UMC204 I have. The GUI thing as he noted is a little annoying but aside from that happy with it.

I recently got hold of two Motu Ultralite AVB cards and think this is a really great step forward for my own need both in live and studio related situations.

One thing I find is a problem is the fact that on linux, the network provided onboard mixer/settings/gui is only accessible through the physical network port but on OSX and Windows, the usb driver provides access to the web-gui through the driver (tunneling somehow)

That means, for me, if I connect my two cards through AVB ethernet cabling I can only manage my cards by purchasing a dedicated AVB switch and use wifi or ethernet to manage them.

Is anyone aware of any reverse engineering attempt or official support for http-tunneling over USB ? I would gladly help to make this function work if possible

I mentioned this as a comment when registering my cards at MOTU.com too but I do not hold my breath.

What does the output of lsusb show? Is there perhaps another USB endpoint providing a communications class device that you would just have to configure to get communication to the interface working?

this is the output from the specific usb port.
i guess the last row is the network handle

/: Bus 03.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/2p, 480M
|__ Port 1: Dev 2, If 0, Class=Audio, Driver=snd-usb-audio, 480M
|__ Port 1: Dev 2, If 1, Class=Audio, Driver=snd-usb-audio, 480M
|__ Port 1: Dev 2, If 2, Class=Audio, Driver=snd-usb-audio, 480M
|__ Port 1: Dev 2, If 3, Class=Audio, Driver=snd-usb-audio, 480M
|__ Port 1: Dev 2, If 4, Class=Audio, Driver=snd-usb-audio, 480M
|__ Port 1: Dev 2, If 5, Class=Vendor Specific Class, Driver=, 480M

/Anders

Yeah, “vendor specific” will mean you need a custom driver, it isn’t a standard class.

If someone is interested, I did speak with some MOTU folks about these interfaces some time ago, they seemed more open to Linux support than in the past, I can see if I can dig up their emails if someone capable of development wants to follow up and see if they would be willing to help with it. No promises though.

seablade, could you say more about what MOTU told you? I just registered my Ultralite AVB through their website and want to contact them soon. I’d like to ask if they could expose the web app over the standard USB Communications Class protocol or Microsoft’s RNDIS protocol (which Linux is compatible with and Android uses for tethering).

Also, there is an issue whereby Linux can’t set the Ultralite AVB’s sample rate and the device defaults to 192 kHz when it starts up. These combine to make an annoying situation when plugging and unplugging the Ultralite AVB.

Other than that the Ultralite AVB works well with GNU/Linux (haven’t tried with Android yet, but it should work) and sounds great.

Keep in mind thisis now over 2 years ago, and the person that said it no longer works there apparently but was developing software for the AVB interfaces. That being said, while not a direct answer to your question one of the things i mentioned when looking for class compliance was Linux compatibility, and in the response was this little tidbit that may help you…

The new AVB line are all class-compliant USB audio 2 devices, unlike the previous CueMix-based interfaces. We don't test with any desktop Linuxes but they work out of the box with OS X, iOS and Android. In theory, it should work on any OS that has a class-compliant driver. Windows does not, for instance, so we provide our own USB driver.

Our driver installs do include a proxy server that forwards the web app over USB or Thunderbolt when connected, so that is unavailable on Linux. That means if you wanted to tweak the settings, the browsing device needs to be on the same network as the interface, e.g. by connecting the interface via ethernet to a WiFi router or directly to the Linux box.

I was asking specifically about the 112d, but might apply to their other AVB interfaces as well, not sure. At any rate don’t take as gospel as it is very out of date, but might give you something to go off of to play around with it since you already have one.

        Seablade

@Be: as mentioned on the lau mailing list … I have not seen the “Linux cannot set the sample rate” issue. It just takes time, way more time than anything else, and appears to be complete before it actually is.

Hi,
I’ve watched this post grow over the years. Looking to upgrade my M-Audio Fast Track Pro to something with 8 inputs. Looks like the Scarlett 18i20 is a good option. Anyone know the difference between gen 1 and gen 2. I am a pretty basic user but would like to do both studio and live recording.

I just wanted to add to this old discussion here: There is a number of digital mixing consoles that provide class-compliant USB audio. For people who need a mixer anyways, this might be an option. I regularly record live shows via a Soundcraft Impact (32 channels via USB), and I sometimes use an Allen&Heath Qu16 (24 channels via USB). However, with the latter I more often use the built-in recorder instead.

And then there are interfaces that switch to class compliant for audio but you can’t use their mixer. The Scarlett 18i20 is mentioned above, but also the RME Fireface UCX. (I haven’t tried the latter yet, though.)

The only functional differences that I know of between the first and second generation are:
1)The ability to switch the inputs between mic and line level gain stages via the Focusrite software (which I don’t know if that has actually been ported to Linux yet). On gen 1, if you use a 1/4" jack it will automatically assume line level (except input 1 & 2 will give you the instrument level option) and if you use a XLR jack it will assume mic level.
2)The second gen supports sample rates up to 192k.
Aside from that, just small aesthetic differences like the LED meters. I’ve been using a first gen 18i20 for about 3 years now and I love it. The gain-staging was a little annoying at first but I bought some XLRF-TRSm cables for my outboard preamps and now I’m fine.