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Plinth mass vs. Foundation mass

In pursuing my analog education, I perused an old thread
on here, a long thread, about Panzerholz plinths.

This thread, along with numerous others, got me to
formulate the following question:

In the general attempt to isolate the platter & cartridge
from vibrations in the rest of the universe, where is the
added mass more/most effective, in the plinth or in the
mounting base ?

I suppose a 100-lb wood plinth sitting upon a 500-lb stone
table would be fairly effective. But what might be a more
"compact" solution ? Is it too subjective to ask where
is the point of diminishing returns ?

Thank you in advance for insights & ruminations.
noslepums
ptmconsulting
1,000 posts
 
In my mind (totally un-scientifically validated though) there needs to be mass it the interface of the stylus and the record (e.g. the platter) to minimize any micro resonances that could distort that tiny signal.

Next, mass or non-resonant chacteristics in the plinth and suspension are needed to minimize larger vibrations affecting the signal.

Thirdly, mass in the stand is needed to minimize air-born and floor transmitted vibrations.

You are correct, that ideally you need all 3 to be optimal if you are using a mass loaded design.

There is of course the other camp, using rigid and light designs.
mapman's avatar
mapman
22,095 posts
 
I don't see how mass itself has any effect on how well a stylus tracks since the stylus is coupled to the cart and the cart to the arm which is designed to pivot in order to track a record properly.

It does make a difference in terms of isolation from external vibrations. No doubt there! A plinth alone cannot accomplish that. You also need a solid foundation. The plinth can also help isolate from motor vibrations but there are other ways to decouple a motor effectively to limit vibrations. Belt drives with separate motor components for example is one design I would tend to favor.

Also, I do not doubt that the plinth can affect the sound, but my goal would be to use it isolate the arm, cart and stylus from all vibrations, external or motor as best as possible. That would be the ideal scenario. Use the plinth as an isolation device, not as a tuning device that affects the sound in some desirable way other than its role to help isolate things (and also look nice perhaps as well while doing that). To do that effectively, mass/weight is typically required, both in teh foundation and in the plinth in order to isolate from all undesired vibrations best.

Mass can never hurt IMHO and a solid foundation is always needed for best results.

The need for mass in the plinth might vary somewhat though I would think depending on what other mechanisms might be in place to help isolate from motor noise and vibrations.
mmakshak
589 posts
 
Isn't there a correlation between high mass and acoustic breakthrough, or resonance, at the low frequencies. Wouldn't that tend to thicken the sound?
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