Не знаю коллеги, почему у вас Винамп 24 бита не играет..
На всякий случай, а в Винампе создана ассоциация с wav-файлами?
А рекомендации по установке MAD выполнили?
Configuration
=============
1. Start Winamp.
2. Configure the `plug-in` from Winamp's Preferences panel under the
`Plug-ins`/Input section. Choose the highest output resolution supported
by your sound card (usually 8 or 16 bits, but possibly 24 or 32 for
`high-end` cards.)
3. Disable the Nullsoft MPEG audio decoder `plug-in` by deleting the file
association extension list (version 2.7), unchecking the "Use for MP1,
MP2, and MP3 files" option (version 2.666), or unchecking the "Layer
III", "Layer II", and "Layer I" options (version 2.33 or 2.34) in its
configuration.
Alternatively, you could move the file in_mp3.dll out of your Winamp
Plugins directory (usually C

rogram FilesWinampPlugins) and restart
Winamp.