A copy of a copy; making an mp3 of an mp3

[Doughnuts]

Years back I had some mp3s on my cpu which I burned as a music CD. I just tried making mp3s using the mp3s on the music CD, and the sound is faint and clips like an old phonograph.

Would it work to convert the mp3 music to wave, and then mp3 again?

Or should I just download the music again from a fresh source?

Thanks

[dodecahedron]

Or should I just download the music again from a fresh source?

much better.
mp3 is a lossy compression format, whenever you make an mp3 you lose some of the original sound = degraded quality.
if you use an mp3 as a source (convert it to wav and then reencode a new mp3) it's going to be much worse.