ES 9023->dtoverlay Raspberry Pi->config.txt
okay,
for this ES9023:
the working dtoverlay in config.txt is:
hifiberry-dac -> (in config.txt): dtoverlay=hifiberry-dac
plays up to 384khz with no problems (in DietPi)
link+further description here:
http://dietpi.com/phpbb/viewtopic.php?f=9&t=1891&p=7243&hilit=es9023#p7243