glegodais

@torgeirthoresen you can also use Ray Session as a graphical tool to automate wiring in jack, I think its already included in ubuntu studio :)

Well apparently I got the same issue,  Helix is not working when not the master device. I'm not sure if it used to work or not since I almost always use the helix as master :/

Actually it even crashed jack and there was no way to restart it without a reboot.

I think it's because your Helix id is 0e41:4248 I instead of 0e41:4241, I guess you have a more recent firmware

Send a patch with your Helix ID as described in this thread :

Until this is fixed upstream you can recompile the kernel usb_audio module after adding your Helix ID to sound/usb/format.c like in this patch https://github.com/torvalds/linux/commit/d4bd30532688558a7de70f0c8edd2a7a25c3963f

Yes, all the channels (8 input/8output) are working! You can record DI from the guitar/mic as well as processed signal, playback sound, reamp...

I don't know how well you know this stuff, if you're new to this here are some simple steps to make it work:

Setting it up with jack is the same as any other usb sound interface with Ubuntu Studio Controls. If you want it to be your master device,  set Jack Master Device to USB Jack Master and USB device that should be master to HELIX. If you check Bridge USB Devices to Jack when Plugged In, you'll be able to see it in Patchage and make the connections.

Alsa focuses on the lower level audio, handling soundcards but also midi. Jack and Pulseaudio both use alsa as backend (most likely in your case). Pulseaudio is used for standard applications but is not suited for real-time use. A lot of applications like Firefox don't work with Jack (check out Pulse-Jack bridge to run Pulseaudio and Jack at the same time). Jack allows you to run audio applications with very low latency.

A good ressource to check out: https://help.ubuntu.com/community/UbuntuStudio/AudioHandbook ;)

Also, about low-latency vs generic kernel, low-latency used to work better for me but nowadays generic is definitely better the way ubuntu studio sets it up.

Hope this helps :)

@torgeirthoresen Well my Helix floor has been working out of the box for quite some time now on ubuntu 19.10 with ubuntustudio packages installed. That's with both generic and lowlatency kernels. Everything is working fine with jack, not with pulseaudio though.

I just got a line6 Helix and managed to use it as an audio interface on Ubuntu 19.04 thanks to @jensverwiebe . Everything seems to work flawlessly so far!

Here are the steps to follow:

1. get the Ubuntu 19.04 kernel source (it should be easy to transpose it to your system)

   git clone git://kernel.ubuntu.com/ubuntu/ubuntu-disco.git

    

2. download Jens' patch and unpack it into the kernel source folder

   cd ubuntu-disco
   wget www.jensverwiebe.de/Other/audio_patching.tar.xz 
   tar -xvf audio-patching.tar.xz
   cd audio-patching

    

3. if you can, plug a usb interface into the usb port you want to use for the helix, play some sound and get the runtime rate

   cat /proc/asound/<other_interface>/stream0

   you should get something like this:

   Playback:
     Status: Running
       Interface = 2
       Altset = 1
       Packet Size = 224
       Momentary freq = 48002 Hz (0x6.0010)
     Interface 2
       Altset 1
       Format: S32_LE
       Channels: 8
       Endpoint: 3 OUT (ASYNC)
       Rates: 48000
       Data packet interval: 125 us
   
   Capture:
     Status: Running
       Interface = 3
       Altset = 1
       Packet Size = 224
       Momentary freq = 48002 Hz (0x6.0010)
     Interface 3
       Altset 1
       Format: S32_LE
       Channels: 8
       Endpoint: 3 IN (ASYNC)
       Rates: 48000
       Data packet interval: 125 us

   the Momentary freq line gives you the runtime rate
    

4. Open helix_clock_patch.txt:
   1. Find the following line

      +               ep->freqn = get_usb_high_speed_rate(rate + 5); // ugly helix hack 

      Edit it to match the runtime rate that you found, in my case:

      +               ep->freqn = get_usb_high_speed_rate(rate + 2); // ugly helix hack 

       

   2. If you have a Helix, you'll have to change  both occurrences of

      USB_ID(0x0e41, 0x4244)

      to

      USB_ID(0x0e41, 0x4241))

        the usb id of your pedalboard can be found using

      cat /proc/asound/HELIX/usbid

       

5. run Jens script with admin rights and apply all changes

   sudo ./helix_patch_and_module_replace.sh

   plug your Helix into your computer, it should be recognized by jack as a USB audio interface now (working only for 48kHz)

In case of a kernel update, you'll have to make the same changes to the new kernel:

1. checkout your current kernel branch

   git checkout Ubuntu-<kernel-release>

   you can check that your source matches your current kernel

   uname -r
   git show

    

2. run the script again and apply all changes, you might have to unplug and plug again your Helix