VPI acrylic vs. aluminum

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.

coolhunter, 

What do you mean by "more musical?"

coolhunter and stringreen,

Do you mean the pure (clear) acrylic platter?

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.

"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?

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.

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.

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.