A Copernican View of the Turntable System

Thuchan,
The Toho base is an excellent, heavy base. The issue is not so much one of moving by hundredths of a millimeter as the fact that it may flex or resonate at a different frequency or 'offset' (the timing of the when the wave crosses the zero point) than the table does. Thebase (and its footers) may react differently to flexion or resonance of the platform that it shares with the Continuum than the Continuum does. The plastic thing - whatever it is - between them will not link them so that they share whatever internal resonance they have.

At least that would be the theory of the downside to separates which were nonetheless supremely stable in their own right - the problem which Micro Seikis and the Kenwood L-07D, to some extent the Exclusive P3, and other tables sought to address.

Lew, when it comes to choice of material rather than choice of processing, it is harder to say what is better, and what is less so.

While audio design is predominately about engineering (or should be, IMHO), there is also an element which is similar to cooking, or matching clothes.

You pick a design direction which you think is technically correct, decide on a building method (including materials) which you think is likely to bring you the benefits in a cost-effective manner, listen to the results, then assess what needs to be added, subtracted, or changed. If you make a wrong decision at any stage, chances are that the resulting product won't do particularly well in the market. Build it, and they will laugh (grin).

What the above also means is that, the design direction affects the choice of materials, and vice versa. My preferred material choices are affected by my design direcions, and undoubtedly the same is true for other designers. There are some materials which, when used as structural materials, don't particularly sound good for my ears and my designs or operating environments. But these same materials seem to work fine for other designers and how they operate these materials.

When it comes to subjective choices, there is no "right" or "wrong", in the same way that chocolate isn't "better" than tomato, nor the reverse. You may listen to a material or component and like it, I may disagree. But if it produces the sound that you are aspiring to, that is what should matter the most to you.

FWIW, I also agree fully with Daniel and Travis regarding outboard arm pods. When you play a record, what you are actually doing is measuring it against the platter and spindle. Mounting the tonearm on a separate pod allows relative movement to occur between the tonearm pivot and the platter / spindle, and this will interfere with the accuracy of measurements.

I acknowledge that in some situations the tonearm may be picking up environment vibration, which will affect the sound, and some listeners may be reacting to that. However, what this strongly suggests is that the plinth design offers inadequate environmental isolation. I suggest that a more elegant, and technically correct solution is to mount the tonearm pivot and platter / spindle onto a single rigid structure that allows everything to move together at the same rate and same distance (and phase), then isolate the complete system from the environment by means of an isolation platform (not footers). Even better would be to add an acoustic shield around the turntable so that it doesn't get affected by the sound pressure from the speakers.

Lastly, you may find it interesting to study grounding theory in amplifier designing. There are strong parallels to what is being discussed here.

hth, jonathan carr

Thanks Jonathan - I was searching for that word "phase" in my head, when noting the possibility of similar resonances having an "offset" through different coupling or whatnot. I think it got lost rattling around in there - probably a "just-ate-a-Ku'a-Aina-burger-on-a-Friday-afternoon-after-a-long-week-so-brain-is-not-all-there" kind of thing... decent burger though...

I agree the right way to do it is to make the armpod/mount as rigidly associated with the spindle as possible, and then isolate (preferably a magnetic floating platform loaded on the heavy end (grin)) the whole.

Jcarr,

I appreciate your comments as usual and recognise the logic (indeed a Japanese technician who used to produce tonearms in the 80s has pressed the same logic on me for some time) but can only say that my experience of isolated tonearm and turntable does not accord with the theory. Whatever the reason, the results really do speak for themselves.

Lewm,

Thanks and its machinability and aesthetics are key reasons why I am considering using brass for my arm towers. This will be important as I intend to do all the work myself. The other reasons are its relative price to bronze and its decent mass.

Now I just need the time and opportunity to try this out