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Single plinth for multiple table/motors

I recently saw a picture in another thread about a Sony TTS-8000 which got me thinking. Would it be possible and/or reasonable to build a single plinth (in the manner of CLD a la Lenco "Home Despot" tables or similar to the construct of Alberporter's recent Technics SP-10 Mk2 and Mk3 efforts) which would accept a "top plate", to which the table/motor was affixed, similar to the way some of these tables have armboards to switch arms.

I have a couple of table/motors that I would like to re-plinth, and a couple of arms which I would like to use. If I could affix the table to the "plinth top plate", and then seat the "plinth top plate" within a larger "outer plinth", my thought is that a slight change in material construction between the top plate and the larger outer plinth would have the effect of reducing overall plinth resonance. It would also allow me to build a single large "outer plinth" and cheaper sub-plinths for each table so that I could play around with several others. Theoretically, once I build a basic plinth, I could add more TTs/motors, or simply change from one TT to another at some point in the future, building only the sub-plinth in order to make it work. I would not need to build (or get built) a whole new plinth with sets of armboards each time I wanted to change things.

Any thoughts as to whether this is a stupid idea? Or any thoughts about methods of attaching the sub-plinth (the one carrying the table) to a larger "outer plinth" would be helpful. I was almost thinking that using something like bicycle wheel quick-release assemblies which would clamp on the bottom would be one way to be able to change them quickly and efficiently, and to allow a little bit of flexibility in how hard one clamps down (when I tested headshell screw tightness, I was surprised to discover some changes are audible).
t_bone
mosin
410 posts
 
T-Bone said, "Mosin, assuming different mechanisms require different sorts of tuning, how does one acquire the knowledge to know without a huge amount of experimentation what the best starting point is for a particular mechanism?"

This is a good question, and I do not have a ready answer for it, except to say that each material used should be with purpose, and not simply a guess. It is experimentation really. That, and research of the materials present and those you plan to add. If you look at a turntable as an entity unto itself, that is the only way to reach any sort of meaningful conclusion. Otherwise, you won't have a clue about what you did right, or what you may have done wrong. In the end, it may look as if it was easy, but that won't necessarily be true.
pryso
1,501 posts
 
T-bone, I cannot speak from the experience of trying your idea but I foresee many downfalls -

* Consider the variations in cutouts required for SP-10, 301, 124, etc. Your idea would require the largest cutout of these for your donut, something that might not allow as much support or mass as a custom cut out for one of the smaller footprints.

* Different mechanisms generate different resonances and vibrations, thus requiring different materials. For example, the famous Lenco site began recommending layered MDF, although later a sandwich of ply and MDF has been favored. At least one SP-10 site recommends against MDF. So, what materials do you use?

* Considering the potential mass of your plinth and some of the motor units (plus the top board), switching back and forth like armboards is hardly comparable.

* From all my reading on plinth design and building, one point is consistent - the need to securely couple the motor unit, plinth, and arm. Some folks use both screws and glue in constructing plinths. Designing for a removable top board might require 20 or more screws to truly secure it to the base (donut) plinth. How interchangeable would that be?

So to close with your own words, my thought is this would be a stupid idea.
hiho
451 posts
 
I think it easy to design a plinth or multiple plinths that allows for interchanging tonearms, that is, to make all the plinths to be able to accept the same armboard or mounting mechanism. And that is a better idea to experiment or to play with different sound than to have a fixed plinth. A plinth might work well for one table but not for a different one. But keeping the tonearm and cartridge the constant can tell you a lot about turntable genres. People like to mess with plinths and platters, I prefer to swap out motors - in a belt-drive (or to a lesser extend, idler drive) turntable of course.

Have fun!

t_bone OP
1,182 posts
 
Hiho,
I thought about that, but frankly, figured that was more of a hassle, and more expense than what I am thinking of. That said, I am still wondering what the right way to do this is. The idea is still more for fun than anything else. It is of dubious utility unless one has multiple tables to plinth and one only wants to use one motor at a time. It is a tinkerer's toy, not a music machine.

johnbrown
195 posts
 
Your idea would not allow each table to sound it's best due to compromises in design necessary for it to work, but even if it were practical, it would be more work for only two decks than simply building two plinths. i.e., if you had ten TT's to plinth, maybe (though I wouldn't), but for two, why bother?

Not to be unkind, but this seems like one of those ideas that might deserve a moment or two of internal dialogue, and then immediately dropped.
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