Oh! When all of the GUIs say sound is at max, but it's either really quiet or silent, and it turns out that it's because even though the PA volume is up, someh

Oh! When all of the GUIs say sound is at max, but it's either really quiet or silent, and it turns out that it's because even though the PA volume is up, somehow ALSA (which PA ultimately uses on the backend) got muted. But this is a PA box, so you have no GUI tools to set the ALSA volume!