VPI acrylic vs. aluminum

I am wondering what is the biggest difference between acrylic and aluminum platters. I have the acrylic and I really like the midrange.  The heavier aluminum platter ime has a little more heft in the bass and a little quieter background.  Not sure the instruments sound better though.  Tradeoffs I guess. What are your opinions?
Generally, the heavier aluminum platter is more musical.  However, the cartridge is often the key, not the platter. I have an Aries II.  I tried the acrylic, but in my system the aluminum was more musical, so I switched back and sold off the acrylic. 

A final word.  Harry is a marketing genius, for years he pushed acrylic, now he is back to aluminum.  You can be sure Harry will return in a few years with acrylic.  Hey, it is not about better sound, it is about profit.  
Actually, the original VPI platters were of aluminum with a lead ring insert.  When VPI moved to acrylic, also with a lead ring insert, it was hailed in TAS (then a credible mag) as a major improvement.  I went through that transition and agreed.  My near to original (but updated) TNT has the acrylic/lead combo at about 20 lbs.

VPI then gave up on lead (for environmental reasons, they say) and provided other acrylic sandwich platters for a while, including the super platter.  Then for a while it offered acrylic alone; these were clear and not black.  Then it gave these up for aluminum with a steel plate, probably for the weight and for any dampening it might offer.  VPI claims good acrylic is hard to find (expensive), and maybe hard to machine.

I'm not going to get in a debate about what's the best, but I have never been willing to give up my acrylic/lead platter for anything that came later.

MY final word: I have been dealing with VPI for many years and do not believe Harry is the cynic you claim.  I believe he combines his personal interest as a hobbyist (just like us) with a need to keep a serious business in the black.  If you don't agree with changes being made, keep the old stuff, it will outlast you and your kids.  Or, if you are just beginning and favor the older designs, you can buy on the used market with the assurance that VPI will offer you the same customer service as if you bought new.

To me its not a tradeoff.   The Classic platter is a "WOW" definite improvement to the accrylic.   I had both and I tell it how I hear it.  You might also want to give the mag/lev platter a try.

What do you mean by "more musical?"

coolhunter and stringreen,

Do you mean the pure (clear) acrylic platter?
What people miss by saying acrylic or aluminum platter (depending on the era) is the latest platters are offered with an inverted bearing that has a substantial impact on it's own. By just referring to either of these platters without including whether or not it's an inverted or non-inverted bearing is missing part of the equation, IMO.

I've have personal experience with a Mk.III platter/non-inverted bearing (TNT 3.5) on my highly modded HW-19 MkIV and in blew away my TNTII platter/ non-inverted bearing combo. (quieter, more bass expression/ impact, more musically involving).

My Classic 3 Sig. SE has the new platter/inverted bearing. A comparison between these two tables is not fair. I will say that one noticeable improvement on the metal platter is there is no static charge and the presentation is much quieter.
IMO you are exaggerating the effects of the bearing types. Notwithstanding some theoretical advantage of the inverted bearing, the non-inverted bearing has the clear advantage of a continuous lubrication bath top to bottom. Also the bearing pivot, which is the part that tends to wear, is closer to the stylus in the inverted type. By and large, though, I think the two types are indistinguishable in normal usage. VPI must agree as it has returned to the non-inverted bearing as the main bearing in its most sophisticated platter, the magnetic one.

What you may have heard is the simple advantage of a better bearing, just as I did when I replaced my original bearing with the Mark V bearing, both non-inverted.

There is no static charge that I am aware of on my acrylic/lead platter and it’s about as quiet as it can be. I don’t understand how a platter can be the origin of noise. Years ago, when I went from aluminum/lead to acrylic/lead (with everything else exactly the same) I heard a clear advantage. So did the TAS critic.
melm, I do have an advantage of actually owning/hearing both types. According to you previous post, you've never been willing to give up your old combo for anything that came later.

FWIW: (When I did my above comparision, I didn't use the beefier bearing that came with the 3.5 platter. They are both interchangeable with regards to being able to use both platters). So the platter WAS the difference I heard!

The non-inverted bearing is subject to more things being in absolute alignment, and also that alignment needs to be accurate on much more "bearing shaft surface area". Additionally, there is the superlative machining of the Classic platter and the fact that it is self leveling.

The static charge on any acrylic latter is evident when removing an lp from an acrylic platter. It is not a factor in this regard on a metal platter.

You seem to make a lot of final conclusions without the benefit of actually hearing/experiencing them for yourself.
To be clear, maybe when I said "the presentation is much quieter", I should have said the presentation has a quieter background.

Slaw....correct....and in listening to the Classic, the acrylic seems slow and laboring.  In light of that statement, some say the Classic is bright..but I find the Classic portraying much more music, dynamics, color, and whatever we audiophiles value.
This is getting a bit personal. I’ll try to explain without returning the favor.

At one point in my hobby I traded a VPI aluminum/lead platter for a virtually identical acrylic/lead platter. The improved performance of the table was clear for me to hear, also a reviewer. This was a perfect and controlled experiment for nothing else was changed. Once having done that I never saw a reason to go back to aluminum.

My platter does not carry a static charge. I brush each disk with an AQ carbon fiber brush. Perhaps that discharges static; it is supposed to. Or perhaps it is the ground wire from the TT. Just never has been an issue.

It has been claimed that the acrylic/lead platter was the best performing one VPI ever made. I am not a machinist, but my platter seems superlatively machined to me. I notice that many who use aluminum platters seek some kind of platter mat, just as was the practice with the original aluminum platters. People with acrylic platters do not. The acrylic only clear platter made for a long while by VPI was inferior to what I have as acrylic is relatively light weight. That platter was too light IMO, and many replaced it, first with the super platter, and later with the 20 lb. aluminum platter. My acrylic/lead platter weighs the same 20 pounds. Lead is an almost perfect dampening substance. You can make a bell out of aluminum. But then try making one out of acrylic. Finally, try making one out of lead!

The job of the platter should be to dampen the disk. But some people like the distortions given by platters that don’t do that. Some feel it gives the sound more life, or even PRaT. I don’t believe that the platter should add anything.

At one point I traded my bearing for the TNT Mark V bearing. I believe it was the last, or one of the last, non-inverted bearings VPI made. It was said at the time that the Mark V was released that it was the best they ever made, and by a very wide margin, and was perhaps the principal reason for the Mark V version. I was certainly able to hear the improvement. An improved bearing provides a quieter background and a more stable speed.  I’ve stuck with the non-inverted bearing for that allowed me to stick with the acrylic/lead platter.

"The non-inverted bearing is subject to more things being in absolute alignment, and also that alignment needs to be accurate on much more ’bearing shaft surface area’". Perhaps. What that means is that for equal quality, the non-inverted bearing is more expensive to produce. That is another way of stating that the inverted bearing is LESS expensive to produce. In the world of business that is often the controlling factor. That is also certainly a factor in the return to aluminum.

In any event, many of the best ($$$) turntables in the world use non-inverted bearings. And the best belt driven TT that VPI makes uses a non-inverted bearing as its principal bearing. Properly made, the two types of bearings are indistinguishable in their performance IMO.

If my re-stating your previous point to make my opposing point seems like a personal attack, I apologize.

It may be true that your particular platter/TT/non-inverted bearing works best for you and your tastes. I have no reason to contest this.

The fact that a non-inverted bearing is more expensive to produce, (on that one merit), surely doesn't mean that it is superior in every application. I've found through the years with many things, simplicity in design and execution is more often than not, superior in most ways. In a non-inverted bearing, the more surface area of the bearing shaft = more surface area contact which causes friction/vibration/resonance.

The Classic platter... in addition to being self-leveling, is also self-centering.

Happy Listening.
"The Classic platter... in addition to being self-leveling, is also self-centering." Which means what exactly? And why would I care?

So far as I know, my platter is level and centered and has no play whatever that I can discern.  Is there play in the Classic bearing?
I can only speak to my experience with the platters that work with non-inverted bearings where the platter sits on top of the bearing supported be three set-screws where the spindle has rubber o-ring/s to off-set (some) of the play that is inherent in this design.

I use a square or something that I know is square (sometimes a business card works if checked for square, or you could invest in a dial indicator) to set on the plinth close to the platter as it spins. I've always seen the need to adjust the platter on the bearing by sliding it slightly in one direction in order to get close to no wobble or "out-of round" as possible. (With the Classic platter/bearing design, the only way for it to be off-center would be for a machining error, otherwise, there is no play there). (I find it hard to believe that anyone who's ever checked this, hasn't experienced the same thing.) This is why when I say the Classic platter is "self-centering" it makes a big difference. The only other possible measurement left to deal with is the precision of the machining of the run-out tolerances for the platter to run true, therefore have correct, consistent speed leading to more musical satisfaction. I believe, according to VPI, the Classic platter has closer machining tolerances that most older platter designs. (This is why I care.)

When one obtains more expensive, more closely machined devices... this is where a lot of the improvement in sound quality originates and separates good sounding components from great sounding components. (Another reason why I care.)
One more point: in anything mechanical, in the case of this forum post, (turntable, tonearms, cartidges,) machining tolerances are extremely important in overall end musical satisfaction. Take some cartridge lines for instance, the only difference in some models are the closer tolerances that were found after the manufacturing/machining process was completed for a specific model, and only, after final testing of these parts, found to be much better sounding, therefore the manufacturer creates a new model that sounds better/costs the end user more (costs the manufacturer no more) from the batch of original cartridge parts for one specific model.
melm: With all due respect, I've read through this discussion a few times. Even though I've tried to explain my personal experiences with these differing platters/bearings, you have, (without as much personal experience, as you stated), have again & again asked questions that show that lack of experience or thoughtfull reasoning that should be considered here. The questions you've continued to ask, show this. It seems you have either an unwillingness to accept others' personal experience without careful thought or the fact that ongoing improvements in mechanical design/machining tolerances, just may be an improvement to your listening experience. For these reasons, I will not post here again.

I only hope the OP has gained some insight here.

I hope you all have a good day.
What is a mag/level platter?
Here's the platter: http://www.avsforum.com/forum/imagehosting/75530955554817eb537e.jpg

There is a gap between the top and bottom platters. A belt-drive motor spins the lower segment while magnets link the top and bottom.
I like this
Just a word for the OP who may feel neglected in all of this.  

I think in his original question you hit the nail on the head.  The acrylic platter (by which I assume meant the acrylic ONLY platter) has real sonic advantages.  The heavy aluminum platter has the principal advantage IMO of being heavy; it weighs 20 lbs; the acrylic weighs only a fraction of that.  The acrylic/lead or the acrylic/steel (super) platters offer the best of both worlds IMO.

As I have written above I don't think the type of bearing matters, only the quality.

If I had a VPI acrylic platter, which I think has almost no value on the used market, I would try to find some way of adding weight to it.  If there's enough clearance one might find a thick 12" diameter steel plate and glue to the underside of the platter.  Or one could try to emulate platters like on the Teres and drill holes in the platter, perhaps from the bottom, and fill with them with lead.  Or rout out a deep and wide circle in the bottom of the platter to fill with lead.  Or something like that.