VPI HW-19 Upgrade question SAMA or SDS?

Stringreen, I always welcome spirited discourse about the finer points of music making and playback. My comments are not intended to offend in any way. Having said that, I think I can prove my point to you:

It is true that if a turntable's speed accuracy is off by a very small amount, one may not necessarily be aware of a problem during playback, unless one has perfect pitch. My contention is that the performance may simply not be experienced as originally intended by the performers, because the music may now be just a bit under or over the intended tempo. Additionally, the pitch distortion (and it is just that) will void the emotional effect of the chosen pitch center. This, I hope we can agree, is a problem.
We agree that orchestras and/or their conductors choose the "A" that they tune to, and that this choice has an emotional effect. Here are some numbers that I think prove my point, as it relates to vinyl playback:

-A 3.3% deviation in rotational speed of a turntable's platter results in a change of one half step in pitch.

-The difference between "A" 440 and "A" 441 represents a mere .23% change in pitch.

-If you do the math you will see that a mere .13% deviation from perfect rotational speed results in the aforementioned .23% change in pitch. A not unlikely scenario with many turntables. Amazing, when you consider that the "broadcast standard" has been .3% speed accuracy.

We agree that the difference between "A" 440 and "A" 441 is significant. When you consider that the error is oftentimes much greater, you can see the importance of it all. I am sure that as a performer yourself, you have oftentimes experienced playing situations where the pitch center is off by an even smaller amount than the statistical difference between "A" 440 and "A" 441; where the difference is simply an almost subliminal feeling that the pitch center is just "leaning" one way or the other. In analog playback, a change in pitch also means a change in tempo (unlike with digital). However subtle that change may be, it will most certainly create a different emtional effect from what the performers intended. Again, as a performer, I am sure you and your colleagues have often remarked during a rehearsal or performance that the chosen tempo is the perfect tempo (or the wrong tempo) for a particular piece. That chosen tempo may be, in actuality, only a fraction of the difference between two adjacent markings on a metronome.

Clearly, vinyl playback can be enjoyed, and be quite good, in spite of small deviations from perfect platter speed. But is it more accurate, more enjoyable, and potentially more exciting when the speed is right? Without question. When you consider how much effort we put into getting other aspects of playback right, or as right as possible, why not do what we can to get the speed accuracy correct?

Thank you, thank you, thank you all for the great information.

I've sure learned a lot from this thread.

Frogman... My point was that short term speed deviations can be/are very distracting/annoying, and that long term speed difference aren't important. Going back to the original posts that said things like lubrication, dynamic contrast friction, etc. are critical... no. I agree that if the table doesn't spin at the exact speed it is distortion, and naturally our goal is to eliminate/mollify distortions, yet, it is not necessary to constantly adjust the speed for acceptable/pleasurable vinyl reproduction. Regas typically run fast, and yet, they are valued and praised with justification.

Siramazing, I recently bought a TNT MK5 (23 lb, acrylic, steel, lead) platter and bearing, and compared the platter only, to the original TNT platter (also known as the HW19 MK4). I say platter only because the wider diameter bearing is not usable on a HW19, and it is really intended for the TNT turntable that I am in the process of "assembling" from parts of various vintages that I have been buying from owners who have upgraded. Anyway, the MK5 platter is a definite improvemnet over the original 15lb all acrylic and lead platter, with better bass extension, and better overall clarity, if perhaps a little bit less warm. I can only surmise that using it with the correct bearing makes it even better. I mention this because in a conversation with Mike at VPI, he remarked that this platter is "as good as anything we make today". These platters show up for sale occasionally for a lot less money than the superplatter.

As far as the sorbothane goes: Listen first! Don't assume that the sorbothane is going to be better. I have switched back and forth between springs, tiptoes, and sorbothane suspension, over the many years that I have owned my HW19. All depending on which tonearm I had on the table, and wether the table was on the rack, or the wall shelf. Overall, I would say my favorite has been sorbothane pucks with short tiptoes on top. Cut the sorbothane as thick as will allow the top plate/armboard to be just below the top edge of the plinth.

A wee bit off topic here, but I have a factory built MKIV. Over the years the springs have compressed and finding it difficult to replace them. VPI no longer has replacements or the sorbothene replacements. I know can insert neoprene tubing into the center of the springs to correct. But would like to get other ideas on a remedy. Anyone have suggestions?