Volumio ok but mplayer not working

Hello,

Volumio works fine on my RPi B with a Durio Sound Pro I2S DAC, using the Hifiberry driver.
However, if I try to open a flac file with mplayer, I can’t get any sound.

Would you know how to solve this issue ?

Thanks.

Is there a daemon that I should switch off ? Or should I configure mplayer to use the DAC ?
Thanks.