Getting Linux apps to use your USB DAC as audio output, whether or not it's on at boot time

Roon Software Discussion Linux
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I have an IDA-8 connected to my PC to drive a pair of Boston A23’s which collectively comprises my desktop listening. I am, however, in the habit of leaving the DAC in sleep mode until I do something that involves needing sound. Typically this becomes an irritation because unless the DAC is on at boot time Chromium doesn’t use it and most audio software (Roon mostly excepted) refuses to see it when subsequently turned on, requiring a rejig of the app’s Alsa settings to get things working. Yesterday it finally irritated me enough to do something about it. As I don’t use the built in sound outputs of my motherboard I decided to disable them.

List the sound modules known to the kernel:

cat /proc/asound/modules

Ban those you never use, leaving only the USB active:

sudo nano /etc/modprobe.d/blacklist.conf

In my case I added the following line to the abovementioned file, effectively blacklisting on-board Intel sound components:

blacklist snd_hda_intel

When I now boot my desktop, whether or not the DAC is powered it’s selected as the default audio output. Playing something with the DAC in sleep mode or off complains that there’s no sound device. Enabling playback is then just a matter of turning it on.

If you’ve no desire to see all your Roon Bridge transport’s audio outputs listed you could pretty much follow the same approach.

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This is a good idea…I do the same on all of my linux endpoints. Things are much simpler without built-in devices cluttering everything…there are 42 devices on my audio settings page as it is.

Roon should react to changes in the device list coming from ALSA. It’s designed to. If you find a way to break it that I can repeat here, I’d be interested to take a look…

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[quote=“brian, post:2, topic:12421”]
Roon should react to changes in the device list coming from ALSA. It’s designed to. If you find a way to break it that I can repeat here, I’d be interested to take a look.
[/quote] Roon does see the IDA-8 when it’s brought online, however, if the desktop to which it was connected was booted whilst the IDA-8 was powered down or in sleep mode its USB audio capabilities are often not correctly detected so it can’t be streamed to. I think it’s more a question of the way the IDA-8 USB interface reports rather than a Roon issue.