When playing a record, I hear a faint audio signal before the song starts? Is there something wrong with the stylus or cartridge?
The stylus is not defective; the cartridge is not defective. They are working properly.
On a vinyl record, the groove has ridges cut deep into the vinyl wall. The other side of the vinyl wall will have faint impressions of these deep cuts. During a silent passage, or before a song starts, these faint impressions are picked up by the stylus. This is especially noticeable if the following groove contains loud sounds.
This is known as pre-echo, i.e., the song is heard before it starts. When a heavier vinyl is used for the record, pre-echo is reduced.