It’s in the Menu section. From the manual:
(Startup volume)
0 - 100 (Default 70)
• The startup volume can be adjusted from 0 - 100 or disabled
Off
• In this mode, the volume control is disabled
Note: If you choose to use the DAC with an external preamp, we recommend turning the volume control off. To do this, turn the knob past 100 to “off”
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