Connect your turntable to the pre-amplifier to boost its audio signal. Then, connect the pre-amplifier to your PC's sound card. If you connect a standard turntable directly into your sound card, the audio signal may be too low for the recording software and will result in poor or silent recordings.
Start your audio recording software and open a new sound file. Start playing your record on the turntable and check the software's level indicators. Adjust the volume until the indicators light up the green section but not the red section to avoid distorted recordings. Stop the record and place the needle at the beginning of a track.
Press "Record" in the audio software and start playing the record. Stop the audio software recording when the track has finished playing and review the sound file that has been created. If the quality is satisfactory, continue to record one track at a time. This way you will have more flexibility when it comes to choosing which tracks you wish to listen to in MP3 format.
Save each file you have recorded as a Waveform Audio File Format (WAV) file. These files can be large but retain the audio quality of the original recording. Convert the WAV files to MP3 by choosing "Save as" from the audio software's file menu and choose "MP3" as the file type.