I think you would need to save your .cda files to your hard disk as .wav files and then convert from there. I use a programme from WIS technologies called MP3 converter to do just that but they have to be .wav files first.
Samsung Galaxy S8 review
1995-2015: How technology has changed the world in 20 years
What’s happening in VR right now: From psychedelic art to combat therapy
Siri not working? Try these troubleshooting fixes
Synology invites you to visit them at Insomnia on 26th – 29th August. Book your tickets now and visit Synology.