In article , Johny B Good
wrote:
On Fri, 14 Dec 2012 13:54:30 +0000,
(D.M. Procida) wrote:

RJH wrote:


It seems to me that it may be something wedged around the tone arm
pivot (you mentioned a cartridge change in your later posting). If you
can, take a closer look at the cartridge lead wires where they exit the
tone arm and verify whether or not they are misrouted in such a fashion
as to create the effect of springy 'end stop'.

Yes, that is quite a plausible cause of a rise in sideways force.

Regarding cartridge tracking downforce, it's usually best to choose the
upper end of the recommended range, rather than the lower end. A 1.4
gramme downforce equates to a 1 gramme groove wall force which, with an
effective tip mass of 1mg (typical for most quality cartridges) yields a
maximum acceleration of 1,000G. Loud passages on some heavily modulated
pressings can easilly exceed the 1,000G mark.

[snip]

Regarding the issue of sideforce bias compensation, the word
"anti-skating" should never grace any discussion involving record decks
and tone arm setup.

Erm... if you wish to be picky about that, you may also need to be so about
calling "grammes" as "tracking downforce". :-)


There was a period (mercifully brief, afaicr) where you could buy a
blank grooveless record to calibrate your "anti-skate" compensation. The
(bogus) idea being that you could immediately see the effect of the
adjustments as a veering away from the halfway point either inwards or
outwards. Sadly, the condition that pertained with a blank grooveless
disk was so radically different to 'real life' that any such adjustments
became totally inappropriate when playing an actual vynil disk recording.

The best way (apart from using the tone arm or cartridge manufacturer's
guidelines) was to use a test record with a range of fixed frequency
tones specially chosen for the task at varying levels and points along
the groove where you could carefully audition for mis-tracking
distortion or (for those more technically dedicated) use a distortion
meter or oscilloscope.

Again, I'd agree with that! The old 'blank disc' approach for this is
likely to be useless.

When I was doing this, some 30 odd years ago, I was staggered by how
much of the highest level of 300Hz test tone energy was reaching the
pivot of the SME3009 (detected by the vibration that could be detected
by a finger tip pressed to the junction of the arm's pivot bearing
mounting and the baseboard.

I have long felt that the growth in anxiety about 'tone arm resonances'
stemmed from the MC carts that grew popular having much lower compliance
and tip mass than the Shure/Empire/etc MMs. Thus injecting much higher
vibrational force into the arm.

Slainte,

Jim

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