Ubuntu 18.04.3 LTS and the Roland Quad Capture USB Sound Device

[mediatechnology]

I just installed Ubuntu 18.04 LTS alongside my Win XP test and measurement machine.

There was only one minor issue: The Roland "Quad Capture" (2 In 2 Out Analog) is mistakenly profiled as an Analog 4.0 Output.

With the 18.04 "Live" demo DVD (which is Lubuntu) the Quad Capture worked perfectly.
It was only after the actual 18.04 distribution was installed did audio fail.
I know this is not a hardware/USB problem...

Being USB and only 2 channel Analog Out the Quad Capture does not support audio transfer when it is configured for 4 channel output.

This is either a Pulse or Alsa problem and it is common to Ubuntu 16.04 which I checked on another machine.

Code: Select all

Card #1
	Name: alsa_card.usb-Roland_QUAD-CAPTURE_0000F569D4A7519F5A348C2B2B0622C0-00
	Driver: module-alsa-card.c
	Owner Module: 22
	Properties:
		alsa.card = "1"
		alsa.card_name = "QUAD-CAPTURE"
		alsa.long_card_name = "Roland QUAD-CAPTURE at usb-0000:00:02.1-4, high speed"
		alsa.driver_name = "snd_usb_audio"
		device.bus_path = "pci-0000:00:02.1-usb-0:4:1.0"
		sysfs.path = "/devices/pci0000:00/0000:00:02.1/usb1/1-4/1-4:1.0/sound/card1"
		udev.id = "usb-Roland_QUAD-CAPTURE_0000F569D4A7519F5A348C2B2B0622C0-00"
		device.bus = "usb"
		device.vendor.id = "0582"
		device.vendor.name = "Roland Corp."
		device.product.id = "012f"
		device.product.name = "QUAD-CAPTURE"
		device.serial = "Roland_QUAD-CAPTURE_0000F569D4A7519F5A348C2B2B0622C0"
		device.string = "1"
		device.description = "QUAD-CAPTURE"
		module-udev-detect.discovered = "1"
		device.icon_name = "audio-card-usb"
	Profiles:
		input:multichannel-input: Multichannel Input (sinks: 0, sources: 1, priority: 1, available: yes)
		output:multichannel-output: Multichannel Output (sinks: 1, sources: 0, priority: 100, available: yes)
		off: Off (sinks: 0, sources: 0, priority: 0, available: yes)
	Active Profile: output:multichannel-output
	Ports:
		multichannel-input: Multichannel Input (priority: 0, latency offset: 0 usec)
			Part of profile(s): input:multichannel-input
		multichannel-output: Multichannel Output (priority: 0, latency offset: 0 usec)
			Part of profile(s): output:multichannel-output

The question I have is where do I fix this persistently?
What file and where?

[billshurv]

My goto for help on Linux sound is in the office today. I will go ask them.

[mediatechnology]

Thanks Bill.

I think I need a udev rule which triggers a profile.
I found some rules for other USB sound cards that I can use as a guide.

I've pretty much given up on Ubuntu 18 due to video playback problems.
Ubuntu 16.04 video runs fine on the same hardware but in 16 I still have the Roland problem.

Curious if the Focusrite Scarlet 2i2 works as well on Linux as people say.
From an audio or test and measurement perspective the Roland leaves a lot to be desired anyway.

[billshurv]

Even with the long weekend I didn't get around to firing up the scarlet, but will give a try as I need to get it working. Watch this space.