Start it off with the knob and then drag your finger up or down on the screen while the numbers are displaying.

Sorry to ask this again (it was asked many pages ago but no answer was supplied) but how does the Sundara go with the iBasso DX160? I have a balanced cable for my Classic 99 that will plug into the Sundara (if I need it) but I'd still like a real-world opinion for both SE and balanced. Cheers...