When recording from a line input, the content is stored as a WAV file on a partitioned section of the hard drive. This partition is 1.5 GB. When the recording finishes, the file can be tagged/named, and added to the main music database. The maximum size WAV file that can fit in a 1.5 GB partition is 2 hours. Therefore, the maximum length of any single line input recording is 2 hours.
It is, of course, possible to stop and save the recording, and then start another line in recording.