I found this to be true when I first installed Rune (with no prior Linux knowledge) and couldn't hear audio out of the pi headphone jack. It was frustrating. I thought the unit might be broken. After digging around, I eventually found information on this forum. You need to load Alsamixer to bring up the sound level. Instructions here:
volume-t1248.html#p7374This should help make your unit function to play music/sound, however ultimately the stock pi audio out has much to be desired. Very bad quality (think 80's pocket radio earbuds) and you get consistent background static. I upgraded to a HifiBerry DAC and it sounds great for a relatively small price. A little bit of trouble shooting too install for a newbie (it's not plug and play, you have to change some coding to have the device come up in Rune settings -
can-t-enable-hifiberry-dac-plus-or-i2s-t1250.html ) but there are plenty of resources on this forum to help guide the install. Otherwise a USB DAC would likely work as well and there are several discussions on recommended model options on the forum.
