Comment 6 for bug 1648183

Same issue with an ASUS ZenBook 3 UX390UA. I experience the issue as a volume dependent cross-talk between the channels, predominantly affecting the left channel when a medium volume sound is being played in the right channel, but to a lesser extent (lower volume of the cross-talk) affecting the right channel as well. Going by hearing the cross-talk seems to be 1-bit audio.

The common denominator seems to be the (newly supported) Realtek ALC295 driver:

http://askubuntu.com/questions/861360/crackling-sound-when-using-headphones-16-04/861715
https://forums.linuxmint.com/viewtopic.php?t=225760