I am sure this is covered somewhere but cant find it, one sound card (default) installed recording two mono channels need to install second sound card to record two additional mono channels, I can put the sound card in vaguely remember there is a bit of a trick for getting the second sound card running not outputing any sound by the way, just recording, have professional version of vrs (which by the way is magic 
) - normally do a a physical switch over at mid day but going away for fourteen days and need to keep recording so need to add in extra channels. Help?????