I have a desktop system based on the Gigabyte H81M-DS2V motherboard. Whenever sound starts playing there is a pop heard through my external speakers.
The problem goes away if I disable power saving (as described at https://bugzilla.redhat.com/show_bug.cgi?id=1525104).
I'll attach the output of lspci and alsa-info.
Created attachment 277617 [details]
lspci -vv output
Created attachment 277619 [details]
Output from alsa-info
Seen with kernel 4.17.9-200.fc28.x86_64
Thank you for your bug report.
(In reply to Jonathan G. Underwood from comment #3)
> Seen with kernel 4.17.9-200.fc28.x86_64
The subsys id for your motherboard is already on the power_save_blacklist for the upcoming 4.18 kernel release, closing.
Feel free to re-open this if you still see this with a 4.18 kernel.