M4A is an audio-specific container file format that some see as a successor to the MP3 format. CDAs are shortcut files that link to audio disc data. CDA files can only be created once you've burned an audio disc. To convert M4A songs to CDA, you must first burn an audio disc of the M4A files.
Download and install iTunes (see Resources).
Click "File," then "Add to Library." Locate your M4A files, select them and click "Add."
Click the "+" icon beneath the playlists on the left and create a new playlist. Click "Library" and locate the tracks you want to burn to a blank disc. Drag them into the newly created playlist.
Insert a blank disc into your disc burner, then click the playlist on the left.
Click "Burn Disc" and wait for iTunes to burn your audio disc made from M4A files. Once the disc has been burned, you can insert it into a computer to see the CDA files. Put it in a CD player and it will play like any other audio disc.
Nero Burning ROM
Download and install Nero Burning ROM (see Resources). Double-click the desktop icon after installation to launch the application. Older versions of Nero Burning ROM do not feature the relevant plugins, so make sure you have the latest version.
Click "Audio-CD" from the "New Compilation" options, then click "New."
Locate your M4A files in the "File Browser" window on the right, then click and drag them into the window on the left.
Click "Recorder," then "Burn Compilation" from the list of options.
Click "Burn" and wait for Nero to burn the disc. Once the disc has been burned, you can insert it into a computer to see the CDA files. You can listen to the disc in a CD player.
Download and install Burrrn (see Resources). Double-click the desktop icon to launch the program. Click "OK" when the first prompt for settings appears. Select your disc burner from the "Writer" drop-down menu, then click "OK."
Click "Add," then locate the M4A files that you want to convert. Select the files then click "Open" to launch them into the application.
Insert a blank CD into your disc burner, then click "Burn." When the burn is complete, insert the disc into a computer to view the CDA files. Put it in a CD player and it will play like any other audio disc.