VDJ lets you use up to two separate sound cards or audio devices. This feature
is very handy for being able to preview a song before you play it over the main
mix.
Many DJs use VDJ on a Laptop or Notebook PC. In general, the internal audio
on most Laptops is of poor quality, often with hard-disk noise entering your mix.
This is especially noticeable if you connect your laptop into a PA system.
A USB audio device will, in most cases, provide superior audio quality. Once
connected, you can use VDJ's Audio Device Options
to select the USB device as
your primary sound card, and the Internal audio for the Secondary (or CUE)
device.
Once you have done this, you can connect your headphones directly into the
laptop's internal audio, or go through your mixer's CUE or alternate bus.
Many users utilize this feature to assist with Beat matching. You can set your
CUE output to play the main mix in the left channel, and your CUE mix in the
right; then you can beat-match the files using VDJ's Pitch/Tempo control, and
once you are synced up, simply crossfade into the CUE'd song.