The THD measurements at voltage levels 1 - 5.6 V were carried out with High Pass Filter "on" (2nd order Buttreworth type, 1000 Hz cutoff, HPF2-1k)
The THD measurements at voltage level 8 V were carried out with High Pass Filter "on" (2nd order Buttreworth type, 2000 Hz cutoff, HPF2-2k)