The necessity of a plinth

Mark, yes I mean the spring suspension. A turntable with spring suspension needs a plinth to accommodate the springs of course. turntable without a spring suspension don't need a plinth theoretically --> just look at the Simon Yorke designs. You can make a dedicated plinth for the Yorke turntable but I think that would not improve it's sound. In theory the Technics SP-10 also doesn't need a plinth because the motor/drive unit is already encased in a metal cage. You only need to use three decoupling feet for mechanical isolation, that's all. Of course you should make a separate tonearm base to accommodate the tonearm.

Chris

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

Hi Raul, I didn't know that. I thought a custom made plinth is a necessity with the SP-10 to sound great. Stock SP-10 is very good, but SP-10 + custom plinth = great. But now you are saying a bit the contrary and it's an eye opener for me. Do you also concur with the hypothesis that a plinth can actually add coloration (or drain away the life out of the music)? In this regard Thom Mackris is quite right: it takes a lot of expertise to design a dedicated plinth/base that brings out the best of the turntable without the draw backs (there are many variables to deal with: mass, dimensions, materials, structural design, attachment of the turntable to the plinth, etc.).

Chris

Hi Lewm, the idea of dampening of spurious vibrations is a nice one, but you actually don't need high mass to accomplish this! What you need is a low impedance path for the redundant kinetic energy, which should have a constraint layer construction. Such a construction is not by definition high mass --> look at the theory behind the Symposium Ultra Platforms.

Chris

Cones have the shape of the electrical symbol for a diode but this doesn't mean they act as (mechanical) diodes. Btw, why should mechanical devices act like electric devices and vice versa? Personally I think the mechanical diode theory is not a scientific one.

Chris