In my case, yes, for two sources. One is roonbridge (at 192kHz S32LE into Loopback 0), the other spotifyd (at 44.1kHz S16LE into Loopback 1), both running on my RPi4. My third source (the RME ADI-2 FS Pro itself) doesn't use alsaloop. The pop only seems to arise intemittently when switching to spotifyd, and never when switching away from spotifyd.Is the alsaloop really necessary in the chain?
I've just remembered that I used to use Loopback 1 for a second roonbridge output, also running at 192kHz S32LE, and never encountered any pops switching between the two roonbridge source/configurations.