I figured it out. In terminal type:
sudo alsamixer
Select rockchip sound device
Tap right key all the way till you see left headphone and right headphone. There will be a square above with label MM. Click on it with mouse and u should see 00. Do that for each of them. Then scroll back right and raise DAC to 100%. Then exit terminal. Select headphone jack in audio volume controller and everything should work.
sudo alsamixer
Select rockchip sound device
Tap right key all the way till you see left headphone and right headphone. There will be a square above with label MM. Click on it with mouse and u should see 00. Do that for each of them. Then scroll back right and raise DAC to 100%. Then exit terminal. Select headphone jack in audio volume controller and everything should work.
