VPI TNT Turntables

What you are asking is for someone to write a book because you don’t want to do the research yourself. The information is all out there for you.

There were differences in each generation and differences within generations. Here are the topics, each of which has several variants:

1. Suspensions
2. Bearings
3. Platters
4. Plinths
5. Motors
6. Flywheels
7. Speed controllers
8. Belt tripods
9. Arm size*
10. Arm base*
11. Arm tube*
12. Arm wiring*

To which we can add VPI accessories (stands, clamps, weights, etc.) and third party products and services.

*You say you have chosen an arm, but when you find a TNT for sale it will likely come with an arm.

Did I leave anything out?

So how many combinations are out there? Too many to count and write about without writing a book.

"What was the biggest improvement you perceived when using a flywheel?"

Quite similar to the improvement gained by using a speed controller. More of the same.

luca58,

Just two additional points.  Another source of information, if you have not found it yet, is the VPI forum:  http://vpiindustries.com/forum/index.php

The VPI TNT you will find is probably going to be a used unit since they are no longer being manufactured, though there is a bit of new old stock around.  Therefore it may be useful to seek forum advice about a specific unit offered, its playing potential and its upgrade potential.

Also, since most advertised VPI turntables come with an arm, perhaps you should give that arm a careful listen before replacing it.  VPI arms are generally well thought of and the newer 3D arms are the best yet.

Finally there are many disagreements regarding the best platters, the best bearings, weights, etc.  You will get may different and opposing opinions

analogluvr,

I went from the spring suspension directly to the squash ball one and it was a noticeable and trouble free improvement.  (Though HW says that the squash balls give only 95% of the benefit of the air bladders.)

Flywheel speed?

I'm not an engineer.  Why don't you buy or borrow a VPI flywheel and try it yourself?  I'm not the only one to observe this; see analogluvr above.  As all TNTs (I think) came with a speed controller of some sort, anyone who has added a flywheel has done it for a reason.  If it didn't add additional audible stability and benefit we would have heard complaints well before now.

I have always thought that the flywheel, like a heavy (and rim-weighted) platter, is the more important component as instantaneous speed accuracy is more important (to me) than average speed stability over one or a small number of revolutions.

Like I said, I’m no engineer, but:

Lets assume that the platter speed is affected by the stylus drag, which itself varies according to the music being played. As there is no equivalent drag on the flywheel, small as it may be, it can contribute to a more stable platter speed.

Also, my flywheel has a diameter of 5".  

"a properly designed speed controller will provide excellent instantaneous speed stability" Yes, perhaps, but not excellent enough, since the instantaneous speed stability is clearly improved by adding a flywheel or a periphery ring.

"I do find you have to be careful with vpi, a lot of their changes were made to lower manufacturing costs and marketed as "better"

Though you may consider this a distinction without a difference, a number of changes may have been made to keep prices form rising,  HW has maintained that it has become far more difficult (translation: expensive) to obtain the quality acrylic that was used to machine what were probably some of VPI's very best platters.  Thus the return to aluminum.  Yes, the original VPI platters were aluminum and lead and the movement from those platters to acrylic and lead so was widely praised that the aluminum was dropped for many, many years.  Then, as now, many who used the aluminum platters sought all sorts of mats for them.

Lead was discontinued as well, though it had very favorable audible advantages: heavy weight and great damping properties.  The shift here was attributed to health effects during manufacture.

And yes, marketing masters that they are, every change was promoted as improving the sound and they had the published reviews to second their promotions.  And along the way they were making improvements in other ways, such as with their bearings, flywheels and speed controllers.