a minute is a minute,
What changes is the ammount of bits the different digital formats take up on disc space.
When you convert LP to uncompressed "Date" Microsoft PCM/WAV format a CD will hold 702Mb of "data" or music in CDDA format which has a play time of 79min52seconds.
On the other hand if you burn the music to a CD-R as mp3 at a data rate of 320Kbits/sec the CD-R will hold 4.5times as much music (in terms of play time) compared to CDDA format.
If you convert your music to 160Kbit/sec mp3's the CD-R will hold nine times as much music.
This is the effect of "compression"