check out this link:http://mmhamsoft.amateur-radio.ca/pages/extras-add-on/soundcard-select.php
The following info is from this Website:
What does it do?
SC_Select is an add on for MMSSTV and MMVARI that makes selecting sound card devices (different id's) for in+output possible. This can occur where the in and out channels on one soundcard have different id's. Some 5.1 or 7.1 soundcards have 1 input but 2 outputs.
Using sc_select you no longer have to work with device numbers. This can help users with a soundcard device that is not easily selected with the current device number setup or use more than one soundcard in a custom setup.
SC_Select has been tested on WinXP and Vista.
(Should work with windows 7)
I hope this helps you out.
73 de Steve KB6HOH
Echolink Node# 59728