The best way to avoid the disturbances is to use the default settings of the plugin. Next, make sure that the volume is not set to maximum because this will affect the quality of the project. Also, you need to know that the output files are directly influenced by the quality of the monophonic signal (voice or instrument). So, if the voice or the instrument are not having a high quality, the end result will come with many problems. I strongly recommend you use the user guide in order to transpose the pitch. You can find it in (C:) > Program Files (x86) > Steinberg\ > VstPlugins > Xponaut directory.