NEED HELP on my Kenwood KD-500 and the Infinity Black Widow Tone Arm

[EJCUSA1]

Hello. I have the Kenwood KD-500 turntable with an Infinity Black Widow tone arm
on it. I just put a new cartridge on it, the Ortofon OM 10. The bad thing about
this is, I don't have the overhang adjusting template to align the cartridge. I
have the manual on the tone arm, but thats about it. The cartridge alignment tools I do have will not set this up right. In the Black Widows manual, I see that there is a template that came with the tone arm. Is there a way of getting a copy of it? Or a way of getting one.... Thanks... Eric

[BrianL]

There are a number of phono alignment gizmos available
on the market. I'm sure you can find an alignment gauge
to download and print off the web if you look. Overhang,
per se is not what you need to worry about. You want to
align the cartridge so that it is perpendicular to the grooves
at two different radii. There were two schools of thoughts
on the particular mathematical weighting to use when
calculating these optimum radii, but that is a rather fine
point.

If you want to buy one, a Google search just brought up
the turntable basics and "DB Systems" units. See:

http://www.audiophilia.com/features/cartridge_setup.htm

here's one to print yourself:

http://mkjnovak.homestead.com/files/align.PDF

There, a couple simple Google searches. Isn't it amazing
what you can find on the Web.

[EJCUSA1]

Thx Bel. The overhang template for the Black Widow tone arm is a cartridge alignment tool that came with the tone arm. I have some bought tools that don't work right with the set up... It has to be the one that came with the paper work with the tone arm, but thank you anyways....

[BrianL]

The point is that you don't need any arm-specific overhang or
alignment template. Correct alignment can be done with
one of these templates (purchased commercial unit or downloaded
and printed one). Any pivoted arm can be aligned this way.

ASSUMING that the arm designer did their thing correctly AND
assuming that the arm pivot is mounted at the correct radius
from the spindle, a cartridge installed with sides parallel to the
headshell axis and overhang set per spec, WILL produce the
correct alignment. If any of the above factors are in error, the
alignment will not be correct.

That's reason why the 2-point alignment gauge is very handy.
It eliminates all those factors and gives you the minimum RMS
tracking error (assuming Baerwald's calculations) across the record.

Consulting one of the definitive articles on the topic (Tonearm
Geometry and Setup by Martin D. Kessler and B.V. Pisha, Audio,
January, 1980) the following is given for the Infinity Black Widow GF:

(specs)
. Effective length: 220 mm
. Offset angle: 21.017 deg
. Overhang: 14.359 mm
(calculated per this)
. null radius R1: 60 mm (optimum is 2.6" or 66.04 mm)
. null radius R2: 110 mm (optimum is 4.76" or 120.9 mm)

To give optimum geometry they recommend:
. overhang: 17.477 mm
. offset angle: 23.221 deg
NOTE: this assumes spindle-to-pivot distance exactly as
specified by the arm's maker.

See why the two-point alignment gauge is so handy -- you can
optimize the alignment of any pivoted arm without any
manufacturer-supplied gizmos and even if the manufacturer
did it wrong (as cited in the article, only 3 of 22 "high end"
arms tested were correct when done per the manufacturer's
spec)