Lucid Labs I2S DAC and RP2

Hello Hive Mind
hopefully someone can help me here. i have a Lucid Labs DAC on my RPi 2B.
currently there is no selection in the DAC model (Playback Options) that fits my DAC apart from Generic I2S DAC…and this works for the most part, but I’m not 100% satisfied. I find i get audio distortion when i playback form the Spotify plugin or from streaming files from my HD.
I feel it has something to do with the output level but i can’t seem to get the software mixer type to work and enabling it stops audio working completely. The volume control doesn’t work at all also.

Now. when i Airplay to the pi. i have a sound quality that id expect…and with no distortion!..but i do have to turn up my pre amp volume control.

so. not sure what else i can add, questions welcome. I’m not really great at programming but willing to try if given instructions.

many thanks in advance