A Copernican View of the Turntable System

Wow - there are a lot of discussion points here - my points :
Sota - used to import these and my Sota Star Vacuum is still one of my favourite decks. It was far more speed stable than the Linn, Roksan etc. We use to rebuild the power supplies for the motors, knocking out the on board regulation of the papst motor and replacing it with better regulators. The improvement was massive, speed accuracy, organic wholeness of sound, but SOME CUSTOMERS DID NOT LIKE THE MODS BECAUSE THEY LOST THEIR WOBBLY BOTTOM END.
Raul - speaking from personal experience on my Final Audio ( 40kg platter ) I recently installed a wall hung shelf. Whilst the deck was in pieces, I cannot lift the tt in 1 piece ) I pulled the inverted bearing apart to check, clean and relube. The tt is 30+ years old and believe me I have seen more bearing wear on a 2-3 year old Rega, Linn, Roksan, Pink Triangle etc. There is virtually no wear, the oil is clean as a whistle. I use Motul V300 Power Racing oil which is very unctuous. I have seen it prevent a racing porsche which boiled the oil from seizing. The Final had Sine/Cosine wave generation for the AC motor along with infinitely adjustable speed AND adjustable torque 30 years ago.
I think the sad thing in audio is that the megabuck decks in many cases have been built to look different and the engineering is no better than decks costing a 1/3 their price. I think you nailed the importance of power supplies - I cringe when when I see puny power supplies on megabuck decks. Pure marketing rules these days.
Another great example is the L07D - look at the plinth design - many top end decks go nowhere towards approaching the level of detail in this plinth.
Notwithstanding that we cannot ignore the high frequency purity of a low mass tt - the best example in terms of high frequency extension for me was the Pink Triangle - woeful performance on speed accuracy but high frequency purity and extension to die for.
I prefer non suspended decks for speed stability - but the context is "within a reasonable budget". The Rega P9 is a great example of a low mass non suspended deck at a modest price.
The SME I still recommend to many friends and colleagues on the basis that it is a very good deck, a complete solution - tt/arm - and SME have been around forever. It is a lifetime purchase and an easy solution for a non audiophile who wants excellence.
Arm pods ( ugh ) - Halcro, why not use a decent engineers vice as a temporary solution for experiments. You can then have a nude rigidly mounted arm.

Dear Ecir (Brad, I think), Thanks for that URL but which feet on that page are you using? There are at least 6 or 7 different products shown. (This kind of troubles me because it makes me wonder whether the manufacturer has a real "philosophy" or does he just want to have something for everyone to buy, no matter what are the buyers preconceived notions.) For my Lenco, I needed rather tall feet, because I have an aftermarket bearing that sticks down well below the underside of the slate plinth, and tall feet are needed for proper clearance. Since I am allergic to spending on megabuck footers, interconnects, spkr cables, AC cords, discs, weights, etc, etc, I seized upon the idea of canned goods as footers.

Dear Raul, I think I understand what you are saying as regards your preference for lighter platters, which is that high mass objects might have trouble letting go of energy that is delivered into them, and heavy platters might therefore continue to accumulate vibrational energy that can leak into the LP and cartridge, rather than to dissipate it internally. This is a reasonable theoretical consideration, but what evidence do we have that it is operative in the world of turntable platters? Moreover, if the platter is made of layers of dissimilar materials, and/or a proper platter mat is employed, I believe the issue could be ameliorated. Please correct me if I have misstated your thesis. I am not a "big-platter" guy myself, as you know.

We can all agree without rancor that power supplies for turntable motors are a critical determinant of the performance, regardless of the drive system. I have demonstrated this for myself in my system many times.

Finally, I don't understand why it is necessary for your and Thuchan's interchange to be so caustic (not to mention the back and forth between you and Dertonearm). You are both good and sincere guys and this is all fun and games, as Thuchan likes to remind us. I've never heard an SME, but I have heard from others that it is either fantastic or dry and analytical sounding.

Brad,

Halcro, your a tough cookie when an idea is presented that is not yours.

Sorry you feel that way. I thought this Forum was an exchange of ideas and information?
I studied structural engineering for 5 years as part of the Architecture course and for 40 years worked on a daily basis with some of the best structural engineers in the country including Arup Assoc who did the Sydney Opera House.
Structural design involves physics, mechanics, material proerties, geometry, maths, trigonometry and even algebra.
Advanced structural design is not often 'intuitive' and can rarely be interpreted by lay people.
When you present a design which I see has obvious structural flaws.....I am attempting to prevent those who might see this solution as viable....from making a mistake? Nothing more....nothing less.
And the added lead ballast to the lower section of the pod actually does little to increase the mass of the pod at the arm connection point. But I won't rain on your parade by explaining the reasons :-)
And c'mon......the asparagus tin jibe?
But just for interest's sake.....there is more structural integrity in an unopened asparagus tin than in that armpod.

Lew, rigidity (aka-stability) does not assure transmission of vibrations from the shelf into the pod. A constrained layer pod can be rigid and stable yet repel vibrations.
However I think it best to decouple vibration from the shelf via the footers or spikes under the pod.

Henry, Agreed. Dissimilar materials. Spikes only work as diodes if one takes care to place them over vibrational nodes in the shelf material. These can be identified by tapping the shelf whilst moving a stethoscope bell across it so as to find places where the tapping sound is least well transmitted, i.e., a node, a point where the shelf is not in motion. I have done this, and it's really quite obvious when you have found the sweet spot. Otherwise, spikes will move energy in both directions albeit with different efficiency depending upon direction.

Lew, I'm looking at the the V2D series ball contact, have not purchase them yet. Open the pdf and eBay listing to get a better look. Their description is contradicting in some areas to me so a call to them will be done before purchasing. I like the concept and the price isn't out the box.

Brad