Audio interface: how to use it as a sound card

Question

I just bought Focusrite Scarlett 2i2 since I heard good things about it, especially of its good Linux compatibility.

I connected it with my computer via the USB cable and sent its line output to my speakers, thinking that I could use this external sound card as an actual sound card. Well, I couldn't.

If I plugged in my guitar, I could hear it from the speakers. Great! However, if I listening anything on my computer, I could not hear a thing.

I thought that maybe I could use JACK to work its magic and allow me to hear everything, but I didn't put any hope into that since I had never gotten JACK to do anything worthwhile before. Nonetheless, I tried.

Since I saw in audacity that the name of my interface was hw:3 (why is it called hw, in any case?), through which I could record my guitar, but not listen it, I tried to change JACK's Interface drop-down menu setting to hw:3 as well; I couldn't, because it wasn't there.

I only had:

• plughw:0
• /dev/audio
• hw:0
• /dev/dsp
• hw:Intel
• hw:Intel,0

Even though I have no idea what any of these mean, except that one of them is my built-in soundcard, I tried all of them, but none of them gave me any sound. The "/dev/" ones even gave me errors.

I want things to work, not to spend 5 days trying to get my audio working properly. Inspiration for music comes and goes.

I want to plug in my guitar, record it using LMMS while hearing the rest of the song through my speakers and monitoring my guitar using the headphone jack on the audio interface. Is that too much to ask?

How can I achieve my goal here?

If it helps, then this is my output of arecord -l && aplay -l:

**** List of CAPTURE Hardware Devices ****
card 0: Intel [HDA Intel], device 0: VT1708BCE Analog [VT1708BCE Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 2: USB [Scarlett 2i2 USB], device 0: USB Audio [USB Audio]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
**** List of PLAYBACK Hardware Devices ****
card 0: Intel [HDA Intel], device 0: VT1708BCE Analog [VT1708BCE Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: Intel [HDA Intel], device 1: VT1708BCE Digital [VT1708BCE Digital]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: Intel [HDA Intel], device 2: VT1708BCE Alt Analog [VT1708BCE Alt Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: HDMI [HDA ATI HDMI], device 3: HDMI 0 [HDMI 0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 2: USB [Scarlett 2i2 USB], device 0: USB Audio [USB Audio]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

Solution

I have an 18i20. I had the same problem and finally got it to work. It looks like most folks on the internet know how to get it to work under Linux, except myself of course.

1. I have to plug in directly in a USB 2.0 port. Via a USB3.0 Hub jack won't start with the 18i20.
2. In jack, click Setup -> Interface and then the > button, you should see hw:USB (hw:3)
3. Exit jack and reboot.
4. Start jack.
5. You should now see the input and output channels in the jack Audio tab.

To get the audio on your headphones from your Focus-Rite:

1. Install the Jack-PulseAudio bridge.
2. Go to Ubuntu audio settings and select Pulse audio as your output device. Maybe you need to reboot here again and start jack once again.
3. If you want to hear your browser audio on your PC output, then just select the on-board audio again in Ubuntu Settings.

Note that the 18i20 (and perhaps the 2i2) do not have an ALSA mixer, so the 18i20 won't show controls in the alsamixer tool.

Comments

[psychok7]

did you get this to work with ubuntu 14.04 LTS ?

[Karl Morrison]

Why reboot after setting the interface in qjackctl?