Hi. I just started using CDex. I couldn't get any sound on my PC using the built-in CD player controls.
After a lot of searching for "no sound" I found the solution in a 2007 post in this forum.
You need to tick the check box under Options > Settings > Generic > Digital CD Playback.
To avoid this problem, why not make digital output the default? This should work in all cases. In some PCs like mine the analog output from the CD drive may not be connected up.