PulseAudio volume control occurs in software when DAC (Meridian Explorer²) has hardware volume control
I'm told PulseAudio should make use of a sound card's hardware volume control if available. With both Meridian Explorer and Meridian Explorer², it does not (perhaps because of mixer name?). This means the sound is attenuated in software.
Attached is the output of alsa-info. alsa-info.txt.AFi1uLxAbP