[Trevor]

On 9/08/2018 10:25 PM, Scott Dorsey wrote:
In article , Trevor wrote:
On 9/08/2018 9:04 AM, Pamela wrote:
I've never understood this properly but on a linear arm turntable,
wouldn't there still be a lateral force experienced by the stylus
(which some sensor then picks up and activates the arm servo)?

Of course. Should be no more than with any other turntable/arm combo though.

My arm has an anti-skate mechanism that adds adjustable amount of lateral
force to keep the stylus centered perfectly in the groove.

You do realise the arm *HAS* to have some force from the groove wall in
order for it to follow the groove and move toward the centre of the
record right? It's NOT telepathic with an alien external force doing the
job for it! :-) The anti-skating mechanism is just to make sure the
forces are of the correct magnitude to provide the desired result.


You can't do
that with a linear-tracking arm... the inner edge of the groove -has- to
have more force on it in order to push the arm down the support rod. (The
servo control reduces the amount of force needed but it just helps what is
already there).

Yep, SAME as with a normal arm except there is NO servo to help. In fact
the air bearing linear tracking arms with no servo are very similar to a
standard pivoted arm in that respect.



Isn't that lateral force going to introduce at least some audio
distortion?

The lateral force by itself should not introduce very much distortion,
and no more than any other turntable (probably less). It's an
unavoidable consequence of dragging a rock through vinyl. What you do
gain is the stylus is always at the proper angle to the groove, or so
close as makes no difference. Whether you introduce other problems
though is another matter. Funny though that some people forget the lathe
cutter head suffers from these same problems and is already embedded on
the disc. :-)

The lathe cutter is driven mechanically by a leadscrew. It is always
centered in the groove because it's making the groove.

Right, and that leadscrew causes no jitter, no "rumble" or any other
groove anomolies right? :-) There are *always* problems, just different
ones, or ones people simply choose to ignore! :-(