# GRC uses OSS instead of ALSA?

**URL:** <https://www.ruby-forum.com/t/grc-uses-oss-instead-of-alsa/230153>\
**Category:** GNU Radio\
**Created:** [June 2, 2014, 6:55pm UTC](https://www.ruby-forum.com/t/grc-uses-oss-instead-of-alsa/230153 "2014-06-02T18:55:46Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![jason\_sam](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/7993a0/32.png) [@jason\_sam](https://www.ruby-forum.com/u/jason_sam)\
**Post date:** [June 2, 2014, 6:55pm UTC](https://www.ruby-forum.com/t/grc-uses-oss-instead-of-alsa/230153/1 "2014-06-02T18:55:46Z")

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Hi guys,

My application requires that I use a multi-channel audio device as an  
audio  
source. I have in my system of hardware the Presonus 1818VSL external  
USB  
device. This audio source is definetely working correctly with Ubuntu  
as I  
can monitor the level of each channel using Ardour without any  
preconfiguration whatsoever.

My problem is that I am having absolutely no luck in trying to establish  
a  
connection between GRC and my multi-channel sound device (Presonus  
1818).  
I have uninstalled pulse audio and made the chages to the  
/etc/modprobe.d/alsa-base.conf file as per these directions. I know  
for  
fact that this did work about two months ago, at that time, I was  
measuring  
each audio input in GRC using a scope sink. It was beautiful and it  
worked  
fantasticly) [http://forums.presonus.com/posts/list/28993.page](http://forums.presonus.com/posts/list/28993.page)

Regardless of how my multi-channel audio source is delcared (i.e. blank,  
hw:0,0 or plughw:0,0) GRC will always report that the OSS source has no  
file or directory. I have read that OSS was discontinued quite some  
time  
ago. How can I force GRC to use only the ALSA audio source?

I have attached a couple of screen shots showing my very simple  
flowgraph  
and the ALSA mixer info.

Thanks in advance for any advise to get me rolling in the right  
direction.

John

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<div class="post-metadata">

**Author:** ![jmaenpaa](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/9de053/32.png) [@jmaenpaa](https://www.ruby-forum.com/u/jmaenpaa)\
**Post date:** [June 4, 2014, 4:32pm UTC](https://www.ruby-forum.com/t/grc-uses-oss-instead-of-alsa/230153/2 "2014-06-04T16:32:31Z")

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On Mon, Jun 2, 2014 at 12:54 PM, John M. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
wrote:

> I have uninstalled pulse audio and made the chages to the  
> I have attached a couple of screen shots showing my very simple flowgraph  
> and the ALSA mixer info.
> 
> Thanks in advance for any advise to get me rolling in the right direction.
> 
> John

John,

Any chance you’ve reinstalled anything in the meantime since this was  
working before? We haven’t (iirc) changed anything in the gr-audio  
system  
recently. Generally, this is a dependency problem. The gr-audio was  
reworked a few years ago, but it’s now less verbose about telling you  
what  
audio subsystems are and are not being built and installed. Take a look  
that libasound2-dev is installed (the’s the Debian/Ubuntu name for the  
package). If you don’t have the alsa dev package installed, it won’t be  
built. So if that’s the case, install the dev package, then rerun cmake  
and  
rebuild GNU Radio to try and recover it.

Tom