WMA is Windows Media Audio. WMA is a new audio format developed by Microsoft well known as MP3. With a higher rate in files compression and better sound quality than the latter, even far beyond those of RA.

Windows bundles a snd decoder. It is easy to convert snd to wma file. 

Download WMA Converter which can convert snd to wma file. Select a snd file, set the start time, the end time or audio encoding bitrate if needed. The bitrate is bigger, the file size is bigger, the audio quality is higher, and vice versa. Click the Convert button to convert snd to wma.

CDA means CD Tracks and it is a familiar file format in CD music discs. With its biggest feature of approximate lossless and basically faithful to the soundtrack, cda is the best choice for speaker enthusiast. But the file in CD with extension of .CDA contains only an index information but not real sound information. So no matter how long a CD file is, the .cda file is always 44-byte-long. And files can not be played when CDA files are copied directly to the hard drive.

To convert cda to wma, please install the CDDA Reader filter for reading CDA file. Use WinRar unzip the file, run "regsvr32 cddareader.ax" to register it.