"Arny Krueger" wrote in message
...
"UnsteadyKen" wrote in
message
m

He was writing about tonearm bearings "chattering".

This seems improbable. To chatter a tonearm bearing the
bearing has to have free play, and there has to be a
source of force that is so great that the tone arm is
being lifted free of the sloppy bearing.

Drag + resonance, like wet finger on glass, perhaps. It
wouldn't chatter if the force were great enough to sustain a
lift, but would if there's a mechanism that stores and
periodically releases energy, such as a spring.

Knife edge pivots, even those in good working order, can
have considerable vertical free play. So the free play can
exist in a properly operating tone arm of a certain kind.

However, lifting an entire tone arm free of its bearing by
applying force to a cartridges stylus seems to be
physically impossible. Doing this with a vinyl record
would seem to require such a force that the record would
be grotesquely physically damaged.

And
they do, back when the world was young, and for a short
time, I used a Decca London Gold cartridge mounted in an
Infinity Black Widow tonearm.
http://www.vinylengine.com/library/i...ck-widow.shtml

Decca London Gold = high mass, low compliance cartridge.

Infinity Black Widow = low mass tone arm designed for high
compliance cartridges.

Is there a mismatch? Highly agreed!

The probable outcome would be a strong LF resonance. If
somone told me that the resonance would be so great that
the cartridge would bottom out, I might believe it.

If one tries to tell me that the tone arm was lifted free
of its bearing, my ******** meter is headed off the scale.
But I would accept good proof that such a thing actually
happened. An audiophile anecdote would not suffice.

Maybe a standing wave along the arm, with a node at the
counterweight, could chatter the bearing without needing to
move much mass.

Also, sideways play could result in chatter that wouldn't
need to lift the mass.

Ian