Cartridge Break-In

It will vary by cartridge and manufacturer, but at least 25-40 hours for most moving coils, some will be longer. I really don't have any experience with moving magnets, but I would guess about the same with them. What is breaking in, is mostly mechanical.

A cartridge can deteriorate if unused for very long periods of time, and again will vary from manufacturer and cartridge.

Hope this is of some help.
Mike

Here's a tip from the Psychic:

Buy a cheap (99 cents) 12 inch rap or club music single, 45 RPM if possible. Use it to break in the cartridge (make sure the volume is way down!). I play it about 4-5 times per side each day for the first few days and that really shakes them loose...

I don't understand this cartridge break-in process. Why would the cartridge need to be broken in?

Is the tip manufactured with small spikes on it that eventually wear down with use?

If you try and rationalize this I just don't see how time would make the needle play any better. Also what causes the tip to wear? I though it was made of a harder surface then the LP.

Perhaps I misunderstand what you mean by break-in.