(I realize this is not a torrent question, but I figure that a lot of folks here torrent music and might be able to help.)
The usually dependable SUPER application seems to be choking on some WV files I've torrented, and I can't seem to find anything else that can convert WV.
In that case Audacity with the FFMpeg library 'plugin', should do, you can open and import WV compressed audio, but not output or export to WV compressed audio.
There is also WinFF which is a Windows 'front end' for FFMpeg