This is on the RS520 but may be the same for other devices.
I normally have software volume control turned off.
So when I plugged in my ONIX Alpha dongle DAC into the USB out, so I could use headphones…
I got 100% volume and when the music came on… poof. Blew a channel on my headphones and probably a little damage to my ear…
It was my bad and my fault. Stupid mistake.
The software volume control allows you to set the volume instead of line out.
On the dongle dac, rather than let the dac control the volume, I used the phone so its set to full out.
So I killed my headphones… 

