(Hi, first of all, I posted the same question at the same time on the Serato forums as this problem involves DDJ SX along with Serato DJ)
I just bought the Pioneer DDJ-SX and tried to make it work with my PC running on Win 7 64 bits. I followed the manual guidelines (installing ASIO ..) but after some hours of searching I wasn't able to get any sound going out of the Master XLR , headphones and even from the booth out. I tested connecting XLR to my power amp and also to powered speakers. Nothing worked. I am able to control the software trhough the controller and I see the LED moving along with the sound on the channel and volume LEDs as well as on the controller master level. Trim and Gains are fine. I also use the latest version of the Pioneer firmware...So it looks like the controller is receiving sounds but is unable to output them... I am able to hear the tracks when played directly on the PC (controller disconnected). I also selected the right source on the controller : PC... Connecting my IPhone with RCA cables to one of the CD input does not change anything : no sound is output... And to conclude : I tried also on my MAC OSX computer with exactly the same problem. I feel like I tried everything and would be happy to hear from other people about their experience. My personal feeling is that the internal DDJ SX soundcard is not working properly... Thanks in advance