I also have the Delta 66/Omni and I can use the ASIO drivers, but only after updating to the .29 drivers. There was a problem with the .27 drivers that would not allow any SoFo products to use ASIO. Try updating your drivers, if you haven't already...
BTW, if you are not actually recording audio, or do not require low latency recording, ASIO won't make much difference. The output quality should be exactly the same.
BTW, if you are not actually recording audio, or do not require low latency recording, ASIO won't make much difference. The output quality should be exactly the same.