How do I covert CDA audio files to MP3 format on the Mac?
The CDA files have already been ripped and are sitting on my computer. Could I just change the filename extension from .cda to .mp3?
CDA is something of a misnomer. According to the top Google result, CDA files are a shortcut to a track on an audio CD. Another source provides a slightly less obvious version of the same assessment. From the first link:
"CDA files" are an attempt to provide a files-on-a-filesystem concept to something that has no filesystem. Audio CDs are burned in tracks of a specific kind of PCM data -- stereo, 16-bit, 44.1 kHz. When you put the CD in a CDROM drive, modern operating systems display the tracks as a list of CDA or CDDA files. If you copy these CDA files to your desktop, what you get is shortcuts to the tracks -- not the tracks themselves.
Consider this. CD audio data takes up approximately 10 MB per minute. So check the filesize of your CDA files. If they're around 4 kB each, you have shortcuts. If they actually take up 10s or 100s of MB, you have PCM data.
If you were on Windows, I'd recommend Exact Audio Copy aka EAC to do the ripping and LAME to do the encoding. I don't use OSX so I can't recommend another ripper aside from iTunes, though I'm sure LAME is available for OSX if you just need an encoder.