A Copernican View of the Turntable System

In general, I try to avoid commenting on things that I have no hands-on experience with, or at the very least, have never discussed with another designer who has had hands-on experiences with the topic in question.

This thread is no exception to my policies. I have tried and listened to independent arm-pods on multiple occasions, spanning from the early 1980s to earlier this year.

Any dissent that I may have voiced for independent armpods or other design particulars espoused in this thread, is based on a combination of personal experience (including listening), engineering training, and study and analyses of other turntable manufacturer's design efforts.

Everything that I have learned and experienced about turntable design (particularly regarding DD) suggests that the plinth should have very high moment of inertia but with as few structural or cavity resonances as possible, and as small diaphragmatic area as possible, while the tonearm mount should be non-resonant and completely rigid in relation to the platter so that there is no possibility for relative movement between the LP and tonearm pivot. The reason is that if any relative movement occurs between the LP and tonearm pivot, the cartridge has no way of distinguishing whether the relative motion comes from noise or vibration in the environment, or is part of the LP groove.

This should be accompanied by full isolation from structure-borne noise and vibrations from the environment, and preferably full isolation from air-borne noise and disturbances from the environment.

Some of the posts in this thread very clearly suggest that the poster isn't hearing distortions that should be quite measurable and audible, or that the sound of their system is deemed to be preferable with those distortions present.

cheers, jonathan carr (hugging a pneumatic isolation platform - grin)

BTW, if you place equipment between the speakers, you create an acoustic problem for the speakers, not only a vibration problem for the turntable, CD transport or electronics. IME, if you must place equipment between your speakers, it should present as small of an acoustic profile to the speakers as possible, and should be placed as far away from the speaker's radiating pattern as possible.

Dear T_bone, For someone who is refering to the 'original marketing material' as a 'argument' for his church you should understand how important the right words are. To me
the pedestal also sounds much nicer than a'pod'.I am alas not familiar with the church furnishing but for our church we (should) prefer 'pedestal' above a 'pod'. Ie you and other members of your church are free to pray before a plinth we have, I think, a much more sacral object in our church: the pedestal. Besides our religion is the true and the right one.

Regards,

Pedestals, plinths, and pods oh my! LOL Nandric! You are right. 'Marketing material' perhaps does not have the 'gravity' that one might wish for, though the research behind the concept seemed to be well done.

T-Bone, Nikola,

Pods, Plinths, Pedestals.......? No, I don't think so.

I recommend using a Podium, as the winner always ends up there....

John

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Dear Jonathan,
We all, I believe, value your contributions to these forums.......I know I certainly do.
And I recognise that you must have vast experience in listening to audio systems of all types.
You should appreciate that most of to us here, also have many years of experience in listening to various systems belonging to other audiophiles as well as those in dealer's listening rooms and also hi-Fi shows so that our 'hearing' is conditioned by all those experiences and also more importantly, live music performances.
It is thus a little puzzling to think that you actually believe we are perhaps listening to distortions without somehow knowing it?
I have listened during a period of 2 years to a Rockport Sirius III turntable with your own quite good Olympos cartridge :^) and over the last 4 years, have regularly listened to a Continuum Caliburn with Cobra and again.....your modest Olympos.
I have heard hundreds of systems in rooms far far better than mine and have continually monitored my sound against all of these.
My room is not ideally designed with regard to equipment placement as you quite rightly point out but some of us have no other choices without a dedicated listening room.
One thing my room does have......is a wonderful acoustic volume with a ceiling raking up to a height of 18 feet. If you've ever heard what room 'volume' can do for your sound, you'd select that over most other parameters I believe.
My point is that the sound emanating from my system is compared to that of the finest sources, amplification and speakers commercially available and I believe that I can detect 'distortions' as well as you or anyone else.
The greatest changes I've heard to my sound over the last 2 years is in fact in the reduction of distortions from the turntable.
Some of this results from the isolated armpods (I do still play the Raven AC-3 for comparison) but the major reduction in analogue distortions to my ears, has been the switch to MM cartridges over LOMCs.
I can hear high frequency distortion in most of the LOMCs regardless of the arm, turntable or set-up.
Now you obviously do not hear these distortions so I'm not sure that a meaningful discussion between us on that topic is achievable :^(
Having said all that......there are those who prefer DD to Belt Drive and others who prefer Idlers. As I've said before.......I find far greater differences in cartridges than in drive type and I admire those who claim to hear those differences.
I can't stand the distortions I hear in digital reproduction yet most here, can happily live with them?
We all are different and all our experiences are valid.
I've also learnt that 'blanket' statements regarding audio are commonly wrong?
This is a 'discussion' Forum and the more we have.....the more we can possibly learn.