If you need ASIO output for Winamp, I would stick with Otachan's driver. I have been using it for years with no issues. There is even a 64-bit version of the driver. Additionally, all source code is included.
Page is here: http://otachan.com/
Click the links under WINAMP5 for:
out_asio(exe).dll (exe version) Ver. 0.70
out_asio(x64).dll (x64 version) Ver. 0.71
Depending on your needs.