Edit | Preferences. Click Edit Button on 'Preferred Format'.
Click New. Enter 'CD Quality, Raw' and click Create.
Edit 'CD Quality, Raw' and put
audio/x-raw-int,rate=44100,channels=2 ! wavenc name=enc
in the Gstreamer pipeline and click 'active'.
Close down the Preference Windows and Rhythmbox then restart it.
You can now select 'CD Quality, Raw' as the menu type.
Why do this? You get the WAV files in your Music directory with the correct titles and they transfer across to Windows a bit easier than FLAC.