I have a Dell Precision M6800 (laptop), and I recently switched from Neon to Kubuntu. In Kubuntu I get a loud buzz from my speakers whenever nothing is playing. They're fine when I'm playing music or a video, etc., but when the music ends there's a roughly six second pause and then a loud buzz which persists until I play some other music or sound.
My guess is that this is related to power management: something is suspending power to the audio system after it's been idle for a few seconds.
When I pull the 1/8" cable out of the laptop there's silence, but when I touch my finger to the end I get the same buzz.
When I pull out the power cord and run on battery I still get the buzz but it's much quieter.
I'm confident that it's not a hardware issue: I haven't experienced this in Windows or OpenSUSE or Neon, only Kubuntu.
I think I would just need to disable this power management? It's not the same as the "Battery and Brightness" power management, I've tried disabling that and there's no change. If anyone can tell me how to do this I'd appreciate it.
Outputs of the commands are listed:
$ pulseaudio --check -v I: [pulseaudio] main.c: Daemon running as PID 1448
$ cat /sys/module/snd_hda_intel/parameters/power_save_controller Y
$ lspci | grep -i audio 00:1b.0 Audio device: Intel Corporation 8 Series/C220 Series Chipset High Definition Audio Controller (rev 04) 01:00.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Tobago HDMI Audio [Radeon R7 360 / R9 360 OEM]
$ ls -l /etc/modprobe.d/idle-audio.conf file not found