# JB, some kernel mods, and external standard USB DAC?



## deltaechoe (Jul 20, 2011)

So the initial disappointment that standard USB DACs still don't work in JB...I was wondering if anyone knew of any work that was being done on this front.


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## knivesout (Dec 1, 2011)

Would be interested to know this too. Definitely was disappointing to find out that the USB audio support that they were touting only really applies to media docks, and accessories made specifically for android phones. I was thinking they mean USB DACs would be supported but apparently not. It seems that ezekeel (GlaDOS kernel) has been at the forefront of audio developments for this device so he'd be a good source of info.


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## deltaechoe (Jul 20, 2011)

The problem with ezekeel's solution is while the modules will load and the support is there, there is currently no way to switch to another sound card on ICS natively. I was thinking that maybe since JB has usb audio out that google may have added somethinginto the roms that would allow it until i realized that it is probably not accessible manually in a similar fashion to bluetooth audio out


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## mdrentz (Oct 25, 2011)

Upvote for interest


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## tmavr (Aug 1, 2012)

knivesout said:


> Would be interested to know this too. Definitely was disappointing to find out that the USB audio support that they were touting only really applies to media docks, and accessories made specifically for android phones. I was thinking they mean USB DACs would be supported but apparently not. It seems that ezekeel (GlaDOS kernel) has been at the forefront of audio developments for this device so he'd be a good source of info.


Just a few minutes ago I was reading about GlaDOS and hoped that it supports USB audio
So it seems DACs are not supported , I mean if you cant select them as a primary audio device .... it is of no use

But perhaps there is still hope
I saw this kernel that can output to a USB DAC, it is for Nexus 7 tablet ... but perhaps someone will do the hard work for the Galaxy Nexus as well


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## rester555 (Jul 20, 2011)

Are these DACs that the OP is describing for use of external audio amplification?


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## tmavr (Aug 1, 2012)

A DAC is a Digital to Analog Converter
After the DAC you have an amplifier that amplifies the audio signal
DACs usually output 2V , Line Level
You connect them to your amplifier's Line In

there are standalone wall powered DACs for your hi-fi and battery powered for use on the road along with your headphone amplifier

actually many simle 'usb sound cards' are just the same. 'USB audio devices' as described by the relevant standard.


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## morfic (Jun 25, 2011)

tmavr said:


> Just a few minutes ago I was reading about GlaDOS and hoped that it supports USB audio
> So it seems DACs are not supported , I mean if you cant select them as a primary audio device .... it is of no use
> 
> But perhaps there is still hope
> I saw this kernel that can output to a USB DAC, it is for Nexus 7 tablet ... but perhaps someone will do the hard work for the Galaxy Nexus as well


The kernels are fine, USB Audio has been in the kernel source for a long while now.
On Nexus 7 i can force use of the usb dac with a asound.conf only setting up the usb dac (googled for one, as i saw asound.conf in Nexus 7, bad news is neither my Galaxy Nexus nor my SGS TMO have the file nor can they be convinced to use it by just putting it in place.
Maybe it's too late for me to see something obvious.

If you have a USB DAC and a Nexus 7, backup your asound.conf and instead put this in place:


```
<br />
<br />
 pcm.usbdac {<br />
type hw;<br />
card Audio;<br />
}<br />
ctl.usbdac {<br />
type hw;<br />
card Audio;<br />
}<br />
pcm.!default usbdac<br />
<br />
```
On your Galaxy Nexus:

cat /proc/asound/cards

see if it is listed when it is plugged into your phone.


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