It's a combination of a very powerful magnet and that the voice coice and gap are exposed to the elements. If you look between the phase plug and the whizzer you can see the small size of the gap. Even a tiny piece of debris will get jammed causing unpleasant sounds. That said, I used a PM6A with no covers since the early nineties with no problems.
Posting Rules
Members
Search
Help
Register
Login
Get a T-Shirt!
