Picoreplayer equaliser settings

I've enabled the equaliser option and it's working, but can someone please explain what adjustment units it uses? I want to try out some headphone equaliser settings that use the common frequency band decibel gain values, e.g. +3.0 dB or -2.2 dB, but the adjustment values in the equaliser range from 0-100 with a default value of 66 for each frequency band. How does this relate to dB values? Is there a conversion formula I can use?

Apologies if this is answered elsewhere but I've had no luck with searches so far, however I'm sure I can't be the first person to ask this. :confused:

Thanks.