There seems to be alot of mis understanding and mis information about
the TD-1200 fluid damping system for the Technics 1200 tonearm lately. This is
likely because many seem to think that dynamic fluid damping is the same as hi
static friction. It is not.
A little background and data.
The
paddle is oriented such that the predominant damping effect is in the vertical
plane- a direction in which the stylus is very strong to begin with. In other
words, there is more vertical damping than lateral damping. It is important to
note that this is how it should be. Arms that damp equally in both planes
cannot be optimized.
The mechanical advantage of a 9" lever arm means
the stylus cantilever sees very little stress. And unlike an arm with high
bearing friction, the effect of fluid damping is dynamic and mostly seen at
higher frequencies. It is a fluid Below 5 Hz, the effect of the fluid is
transparent. In otherwords, it offers very little resistance as the stylus
follows a warp. but prevents the arm from over reacting as it normally would
from the shock of the warp. The fact that fluid damping reduces woofer cone
pumping suggests that the stylus is moving less, not more. If the stylus was
seeing greater resistance, it would move more and produce more woofer
excurssion, not less.
It is easy to confuse friction with dynamic
fluid damping, They are not the same however. Friction is ever present and the
stylus needs to work against that at all frequencies of motion. The resistance
of dynamic fluid damping all but dissapears at slow motion.
Clearly,
there is alot of mis understanding at how this enhancement really works.
The product was developed for audiophiles. The fluid viscosity was
chosen to show a marked reduction in resonant amplitude using a Stanton CS-100
which has a compliance of 30 and resonates at 9 Hz in the 1200 arm.
60,000 CST is the highest viscosity that is still classified by Union Carbide
as a fluid. It flows quite easily as anyone who has spilled it will attest to.
The measure of the mechanical advantage of the 9" arm is revealed by
the fact that viscosities less than 60,000 CST showed very little change in the
peak amplitude at resonance.
In summary fluid damping does the
following:
1. Attenuates peak amplitude at resonance.
2. Actually
reduces the stress the cantiliver sees riding up and down a warp.
3.
Eliminates que skipping at the beginning of the disc.
4. Reduces the
senstivity of the tonearm to external vibration.
5. Subjectively increases
detail retrieval.
Damping has no effect on the Arm/Cartridge resonant
frequency. It does not change the effective mass of the tonearm.
A good
electrical analogy would be the onset of oscillation in a crystal oscillator.
Study this and you can understand how damping merely changes the "Q" of the
tuned circuit. Since damped resonance has a wider, less pronounced peak, it's
frequency may appear to move slightly when compared to the before damping
measurement, but it really has not changed at all.
The resonance
issues are less of a problem with stiff cantilever suspensions becuase the
stiffer the suspension, the lower the peak output at resonance. But the
advantages gained from #2-#5 above are still beneficial to any cartidge design.
Fluid damping offers benefits that cannot be acheived any other way.
It is a neccessary component of a hi quality tonearm design.
Key
components to good arm design include:
Low friction gimbal bearing
assured lateral and vertical stability without damping.
fluid damping
good quality wire.
those are my requirments for a hi quality tonearm
system.
The tonearm should not dictate the cartridge you must use.
Rather, A good tonearm will allow you to get the best performance from any
cartridge you choose.
I hope this helps alittle.