I used Volumio last few months, but I rather use Runeaudo

But, I have a Onkyo A-5VL with BurrBrown DAC converter, so I have Rpi2 with Hifiberry Digi+ and use optical Toslink to amplifier.
Can someone write me, how can I make Digi+ working?
No answer found here and other I2S or Hifiberry DAC tips doesn't work.
Otherwise I'll have to stay on Volumio

Thx!