Hardware Volume don't work (Volumio 1.55+Rasp2)

I found that hardware volume don’t work after set option “DSD over PCM”. (Volumio 1.55+Rasp2)
When I activated this option, hardware volume don’t work (volume always on maximum), and if I turn off DSD option, hardware volume don’t work.
For repair it, I need to only rewrite Volumio.