Is the earphone volume low?
I am not saying it's really low but only at a 27th or 28th step I could get a satisfactory performance.
My old phone only have 15 steps and I could easily get a good sound level at 9 or 10.
6z is supposed to have a HiFi DAC right?So what's up with the volume?
NB:Audiowizard On/off makes little difference