Mouseman,
IMHO, transcoding from WMA or MP3 to another lossy format is a very bad idea.
Transcoding between lossy formats can only result in anything decent if the original file if of a very high quality and high bitrate.
For example, if the original file is a MPC --insane file (with bitrates of about 250 kbps), the result will probably be acceptable.
If you want to convert e.g. a 128kbps MP3 or a 96kbps WMA to e.g. Ogg Normal (-q5), I guess the result will sound pretty bad, and there is not much you can do about it.
My advice would be:
- If you still got the original CDs, rip them again, and encode to OGG this time.
- If you only got the MP3 or WMA file, you will need to use some pretty high bitrates for the destination file to keep the "quality degradation" as small as possible (Ogg Vorbis High or MPC Xtreme or Insane). Another option is to go lossless (APE), and then the quality will be exactly the same as it is now. In any way, the resulting files will be a lot bigger than the original files.
The problem you are facing is exactly the reason why I use APE for my entire CD collection. That way, I can easily switch from one lossy codec to another, because I will always use the lossless APE files as a source, so I'll never lose quality because I have to transcode from one lossy codec to another.