I am enjoying my VMS4 with Traktor and feel it is doing that which it was designed to do with it. I do have an issue when I try to use an analog input. When I move a channel to analog and bring up the volume, I hear a slight "squeel". I thought it was my source, so I tried a different device and had the same result. So I tried no external device. The sound still was there. This occurrs on all four channels but only when switched to analog.