The necessity of a plinth

We still have a nomenclature problem here. A "plinth" is simply any type of base or pedestal. All turntables have a base of some sort. The Simon Yorke's plinth is its' round base. The LP12's plinth is the wood-trimed case that supports the suspension, and the Rega plinth is he rectangular board to which the bearing, motor and arm are mounted. The Technics has a plinth too, it is the plastic case to which all of the guts are mounted. I think the original question really applies the the need for some type of mechanical isolation device for a turntable.

Thsalmon: what I mean with a plinth is the often rectangular box (= base) that accommodate both the spindle encasing for the platter and the tonearm. For example the "nude" Technics SP-10 without the dedicated obsidian base already comes with an encasing (as you mentioned) made from plastic (I didn't know that, I thought it was made from some sort of metal). I've read here at Audiogon that a custom made plinth is a necessity to bring the best out of the SP-10. My question is: why does the SP-10 without this custom plinth sound that bad? You can use some of the graphite feet or the Walker Valid Points for under the "nude" turntable for decoupling purposes.

Chris

Ultimately, you're talking about draining energy from the bearing/platter interface in this discussion. In this regard, the materials chosen are as important as the actual mass.

There are different ways to solve the problem, or alternatively, to screw things up.

For example, high mass with ineffective energy transmission (stores energy) is going to have a resonant signature at some frequency. It will be the mechanical equivalent of a capacitor having a high dielectric coefficient with resulting blurring and resonance. Low mass done poorly can be equally compromised.

As is typical in audio, it's the design/implementation of a particular architecture rather than the chosen architecture that makes the most difference.

All of my experiments have shown me that in a non-suspended design, high mass done right has an inherent advantage, but it needs to be noted that this is the path I've been led down, so I have a bias in making this statement.

The unfortunate reality (in terms of arriving at shared, transferable, reproducible results) is that you need to consider the experiences of SP-10 owners in the context of their entire system, their setup, and of course, their turntable shelf/stand.

I like to think a of the shelf/stand combo as a part of the turntable and try to be very careful in drawing conclusions because of this.

Context is everything, but you all knew that ;-)

Cheers,
Thom @ Galibier

Your analogy between a turntable plynth (water down the drain) and enclosure-less loudspeakers is faulty. A loudspeaker is a transducer, a turntable is not. The cartridge is the transducer. So, maybe the question should be "does a cartridge need a body?" I have no experience with nude cartridges, but I know they have their proponents.

Dear Chris: +++++ " why does the SP-10 without this custom plinth sound that bad? " +++++

I don't know where do you read that statement. I'm using one of my SP-10s with out that custom plinth ( only three pneumatic AT footers/isolators ). I heard it with at least two different plinths and IMHO and in my system sounds better with out that plinth. I already heard too some other SP-10 ( on other auduio systems ) with custom plinth and with the Technics plinth and " sounds " good but I prefer mine. Now, the SP-10 with out plinth looks not very good but works fine.

Regards and enjoy the music.
Raul.