De-Emp and Direct Which to Use


On my DAC, there are two outputs set: De-Emp and Direct. Which I should use? and What is the pro/con of each. Thank you for any advise.
atranz
Most DACs switch automatically from regular to DE-EMP if the cd was recorded with EMP! If you switch in the DE-EMP with regular CDs, you will be rolling off the HF.
I used "Direct" because I don't what "DE-EMP" does; hence this thread. On the back of AN DAC1.1X there is a push button to select the output - Direct/De-emp.