USB DAC/AMP skipping/popping problem on Linux

2021-08-15 19:21:03

Manjaro Linux
PulseAudio
ARC MK2 AMP/DAC / Schiit Hel 2

this problem surfaced with both the ARC MK2 and Schiit Hel 2  USB AMP/DAC combos - it is exactly the same for both devices

after powering on the AMP/DAC and listening to audio for roughly 15 min. (source doesn't seem to matter), there is a 'blip' in the sound every second or two - as if the device were powered off for a 100 milliseconds or so

with the Hel 2 i could toggle the source or gain switches and it would return to normal, however with the ARC i have to power it off/on

Manjaro, based on Arch, uses PulseAudio (mixed in with this is PipeWire and ALSA) - there's a couple files for configuring PA, default.pa and deamon.conf

i've tried the default values as well as many suggested values that target this problem and nothing has worked which leaves me to suspect that this may not necessarily be a PA issue - i'm wondering whether it might be some sort of USB problem???

it seems odd that both devices do the same thing only after they are in use for the same time

ps: this is not an uncommon problem - i've seen several users report this elsewhere

Re: USB DAC/AMP skipping/popping problem on Linux

Reply #1 – 2021-08-15 21:15:25

Did you tried booting up some live distro other than Manjaro (Ubuntu, for example) and listening there? Timing looks like it could be some power management thingie.

Re: USB DAC/AMP skipping/popping problem on Linux

Reply #2 – 2021-08-15 22:22:46

i haven't and i'm not sure that finding that the problem might be solved with another distro would help me solve it with my current distro

i certainly agree that it could be a power management issue that's tied to USB and there are options that i could try in that area, but i've been screwing with this for quite a while and i wanted to see if someone might know of a quick fix before i continue experimenting

Re: USB DAC/AMP skipping/popping problem on Linux

Reply #3 – 2021-08-15 22:28:13

Try PipeWire as your audio stack instead of PulseAudio.

PulseAudio does have a hack that can be enabled or disabled, one or the other modes may fix your device: PulseAudio: Disabling timer-based scheduling

PipeWire has never needed this hack on my systems, and either works or doesn't work. PipeWire also has better Bluetooth audio at this point in time, while PulseAudio just integrated some changes last year that require GStreamer changes which still haven't even been merged into the development releases, much less a stable release.

Re: USB DAC/AMP skipping/popping problem on Linux

Reply #4 – 2021-08-15 22:44:20

yep - i actually went through that page and that's one of the things i tried

have you dumped PA completely? that's something i've been thinking about

Re: USB DAC/AMP skipping/popping problem on Linux

Reply #5 – 2021-08-16 01:50:10

The last time I used Linux on the desktop, I had dumped PA completely, except for libpulse, which everything uses to talk to the PipeWire session under compatibility layer.

Re: USB DAC/AMP skipping/popping problem on Linux

Reply #6 – 2021-08-26 01:32:51

after further research i found this isn't a Linux specific problem

a partial solution was suggested by AMD in a Reddit thread for a similar problem - this led to an updated BIOS for some AMD Ryzen boards, but the update didn't address my issue

i largely solved the problem by disabling global C-State in BIOS - the drop-outs in sound happen only once every few minutes instead of every second

see...

An Update on USB connectivity with 500 Series Chipset Motherboards
https://old.reddit.com/r/Amd/comments/lnmet0/an_update_on_usb_connectivity_with_500_series/

Updated AGESA Coming for Intermittent USB Connectivity
https://old.reddit.com/r/Amd/comments/m2wqkf/updated_agesa_coming_for_intermittent_usb/