Realtek is one of the leading audio component manufacturers today, and many motherboards come with a built-in Realtek sound card. While the VCR processes sound through the video card (for HDMI output), some applications may require the 3.5mm audio jacks. If your project requires using audio out and the motherboard manufacturer does not provide Linux drivers, follow these instructions.
Navigate to http://www.realtek.com.tw/downloads/downloadsView.aspx?Langid=1&PNid=14&PFid=24&Level=4&Conn=3&DownTypeID=3&GetDown=false
Check the box to agree to the terms listed and click “Next”. We know that our motherboard manufacturer did not provide a driver, so this is quite all right.
Scroll down to the bottom of the page where the Unix (Linux) drivers are listed. Choose the latest version, and click the download mirror closest to you.
Once the tarball is downloaded, locate it in your file explorer and extract it (or do it through the terminal). Open a terminal window and navigate to the new folder containing the extracted files.
From the terminal, execute the following to extract the driver source code (where “xx” is the version number in the filename) :
tar xfvj alsa-driver-xx.tar.bz2
Now you must compile the source code:
Once the source code is compiled and installed, reboot the machine. From the terminal, execute
alsamixer and unmute the main channel.