A Copernican View of the Turntable System

Dear Raul,
You're lucky...........But as Syntax says........intelligent design and precision should eliminate the need for 'luck' in our systems?....don't you think?
Regards
Henry

03-06-13: Peterayer
Syntax, I presume that digital level also reads 0.0, 0.0 while it rests on the platter.

click me softly

Like Halcro wisely wrote, we do not need luck, we need someone who does something right.....btw. did you ever check the Pulleys from the super-duper VPI TNT motor .... but I think, the unlevel Armboards from the Raven are the compensation for the unstable motor management.....it is a design feature

Dear Halcro: Agree. Btw, the problem with the MS 5000/8000 is that the cantilevered arm boards came with a screw to fix it and there there is a " play/loose " between the arm board hold hole and the tube where the arm board be fix it and if the owner don't check how the arm board was fix it chances are that is out of platter level. Micro Seiki is IMHO a bad TT design, I don't use it any more but other people " die for it ". Such is life.

Regards and enjoy the music,
R.

Dear Henry, I just stumbled upon this revival of your interesting thread. I think in your post of March 6 you have accomplished a well known rhetorical ploy; you've raised a "red herring". My argument (and Dover's) was never primarily about plane parallel mounting of tonearm with respect to the platter surface, although I would never argue that this is not important. My argument for a fixed relationship and a physical connection between the tonearm base and the turntable bearing assembly had mostly to do with preventing motion of one relative to the other in response to external or internal sources of vibrational energy. One wants the combined structure to dissipate mechanical energy as a unit. My metaphor about trying to cut a diamond resting in a rowboat whilst sitting in a second rowboat vs performing the same task while having the whole operation in one boat (easier, obviously) was meant to illustrate the point. That's the "bad thing" that I fear could come into play when a tonearm is mounted on an entirely separate support system and dissociated from the platter/bearing. Disparate vibrations of the platter vs the tonearm generate spurious signals from the cartridge.

I would also posit that the problem of "parallelism" (for want of a better single phrase) exists for both types of systems. A less than astute user of an outboard arm pod could screw up the parallel relationship between tonearm bearings and LP surface even moreso than could a poorly executed turntable design. As someone else with a lot of experience in tonearm design once remarked regarding azimuth adjustable tonearms, having the capacity to adjust azimuth endows one with the capacity to really mess up azimuth adjustment, as well as to get it right.

Dear Lew,
For a ‘man of science’…..I am surprised by you?
You posit a phantom condition……and then proceed to create an argument and case around it.
Nikola would be less than impressed with your logic?

My argument for a fixed relationship and a physical connection between the tonearm base and the turntable bearing assembly had mostly to do with preventing motion of one relative to the other in response to external or internal sources of vibrational energy.

Preventing “motion” of one relative to the other”??
What “motion” is this exactly?
Other than a fully suspended deck (which is outside the Copernican view of this thread)…..can you please explain this “motion” and present some evidence of its existence?

You appear to equate “vibrational energy” with “relative motion”?
The most fundamental aspect of supporting a turntable system IMO…..is to create a base for it as free from “vibration” and structure-borne feedback as is possible?
If “relative motion” exists…..all bets are off….unless you are playing one on a moving vessel such as a ship, yacht, train or plane….in which case……gulp!?

If one is successful in creating a ‘mounting shelf’ free of structure-borne feedback……there should be no “vibrational energy” transmitted to the turntable system.
Air-borne feedback is rarely an issue in an audio system unless one’s cartridge is ‘microphonic’. Cartridges work by translating ‘motion’ into electrical energy whereas microphones work by translating ‘airwaves’ into electrical energy.
Many listeners assume that when they detect ‘feedback’ in their systems…..it is the result of air-borne feedback whereas it is usually existing structure-borne feedback which is amplified when the volume is turned up.
If air-borne feedback was a problem in audio……the plinth would be the least of the problem areas?
The platter would be directly affected as well as the tonearm and particularly the cartridge and stylus.
Oh….and did I mention the vinyl disc itself??
If air-borne feedback were a problem……the sound of everyone’s system would….by definition….deteriorate as the volume increased?
My system’s quality IMPROVES as the volume increases.
As I listen comfortably in my home at 90-95dB SPLs and Raul claims he can approach 100-110dB!!!….air-borne feedback is a myth propagated by sheep following sheep.
The primary source of “vibrational energy” sadly……is created by the turntable itself….or rather…the motor, belts, pulleys, bearings, coils and transformers.
A ‘happy carrier’ of all these demons….is in fact the plinth which you unselfishly wish to connect with the tonearm. The tonearm! The very heart of the Copernican view of the turntable system?!

So now your ‘a priori’ proposition (devoid of any facts or evidence) has been questioned….you are left with the claim that the advantage of a plinth is that a separate tonearm base is likely to be adjusted ‘out-of-level’?
I can’t believe that you wrote this with a straight face? :-)
So let me get this straight……you are quite happy for people to get their platters AND tonearms ‘out-of-level’ by being connected on a plinth……but you draw the line at a tonearm pod being messed up?

Disparate vibrations of the platter vs the tonearm generate spurious signals from the cartridge.

So you prefer the platter and tonearm to ‘vibrate’ homogeneously?
In my system….I prefer them not to vibrate at all?

No Lew….the plinth is not a necessity.
It is a hangover from the early days of marketing a complete ‘turntable system’ as a package and few have questioned the premise of the turntable platter as the centre of this universe?
The ‘plinth’ is about as useful as tits on a bull and is the cause of many more problems than it solves.
The turntable/platter is the ‘slave’ of the cartridge/tonearm…..and the anchor of the ‘king’ tonearm must be as heavy, solid rigid and level as a rock.