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Everyone who has to
mount cartridges frequently understands the importance of precisely adjusting
an arm/cartridge combination to release it’s full potential.
Overhang, azimuth,
VTA, tracking force and, if featured, variable damping of the arm movement are
all important parameters.
The overhang
adjustment was described already, nevertheless let me add that a single
"perfect“ overhang setting
does not exist. Should you own a lot of records that are cut close to the inner
groove you might consider using 63mm instead of 66mm as your inner
"zero point“ – many
crescendo finales of symphonic works could be tracked with reduced distortion
this way.
On the other hand
exist a lot of
"pop“-records with no modulation
but leadout groove already where the
"inner“ zero point is
located. One doesn’t even benefit from this second distortion
minimum..
Correct overhang adjustment
results in tracing-error-related tracking distortion
of barely more than 0.1%.
Next, the azimuth should be adjusted so that crosstalk is the
same for both channels. This can be done by using a mono record played back via
an X-adaptor or through your preamp switched to mono.
Reverse the
headshell clips on one channel only
(switch red and green i.e.)
and adjust for the weakest signal coming from your speakers.
The proper way to
adjust azimuth is by turning the counterweight set screw loose enough to allow
turning the counterweight clock-or anticlockwise until the headshell plate
appears to be parallel with the record surface
(as a starting point). If
the resulting image stability leaves something to be desired, turn the
counterweight in small increments clock-or anti-clockwise. This will allow you
to compensate for minor misalignments of the stylus/cantilever assembly.
Once you’ve
"hit it on the nail“ a
centrally recorded female voice should be precisely located in space with no
difference in the decay characteristics
between channels.
Starting with the
armwand parallel to the record surface, VTA adjustment should be carried out in
small steps until the best separation between individual instrument in space,
the least amount of
"grain“ audible and the best
integration of fundamentals and upper harmonics is achieved
(see above)
There is no
"perfect“ position, varying
record thicknesses and a different cutting angle used for most records made
before 1965 necessitate
a new setting for every other record
(if you want to get the
absolute “best” out of each record). Stylus shapes are also more or less
susceptible to changes in the VTA – generally speaking, the
"sharper“ the stylus, the
more sensitive to changes..) The more time you spend on adjusting the VTA the
less you’ll get to actually enjoy your records.
The tracking force
determines the tracking ability and also the position of the coils in the
magnetic generator. Follow the manufacturer’s recommendation and try increasing
or lowering the tracking force by increments of 0.1gr. Low frequency tracking
ability shouldn’t be lower than 70my. Sound-wise
more relevant is the high frequency tracking ability. The appropriate tracks on
the Shure TT115 test record are helpful to get closer to the optimal tracking
force.
The damping is , as
already mentioned, a function of the distance between the magnets, or, more
precisely, the flux density in the gap between the magnets.
It is to be
adjusted so that the lower registers will be reproduced with control and heft
without loosing the resolution of high frequency fine detail and
"air“.
Overdamping this
arm is close to impossible
(often the case with silicone
fluid damped arms) but rarely does the smallest gap result in the most
satisfying sound.
The amount of
tightening of any of the arm’s screws has an influence on the energy
transmission and therefore dissipation and should be experimented with.
Generally speaking,
only screws b and f should be tightened well. Screws g, i and j
require some experimentation.
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Should you have
any questions regarding mounting/adjusting or technical details of this
tonearm, feel free to contact me via phone or email.
Equally welcome
is any sort of criticism or suggestions for improvements.
Yours truly,
Frank Schröder |
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