Check that the cables are correctly routed into the soundcard. Youll need to refer to your soundcard manual for this. Make sure that you are recording the vocals on an audio track not midi or vst instrument trackMake sure that you have activated the recording drivers in your Cubase project. You can do this by going to devicesVST connections and clicking on the Imputs tab in this menu. You should see under the Bus Name the words Stereo In and underneath this left and right see image below. If you do not see this, then youll need to add a bus, by clicking on the Add Bus tab. Once done, select Stereo configuration and count 1. Now your VST connections menu should look similar to below, and when you close this and open the inspector on the vocal audio channel, you should be able to select stereo in where it says no bus underneath the volumepan controls. The VST Connections Menu again.