DIY TT

@holmz , The new Sota bearing is just like the Clearadio. It has a magnetic thrust mechanism. The female section of the bearing is an integral part of the platter so what you are talking about is a new platter assembly which is heavier than what you currently have and the suspension will sag and it's resonance frequency drop.

You are best off sending the table back to Sota and let them upgrade it for you or just trade it in on a new Sapphire Eclipse. You might as well add vacuum clamping while you are at it. As far as multiple arms are concerned if you get additional; tonearm boards weighted for any specific arm you can have several arms mounted up and fully aligned then changing arms is a snap. Three Allen cap screws is all you have to undo. I can change arms in less than five minutes. I am contemplating getting a wood CB directly from Frank Schroder and doing just that. 

@lewm , it is interesting that the DP80 and Sota both read a trigger under the platter to gauge speed. In the Sota's case it is a small magnet. The controller's response is different. The Denon makes an immediate adjustment while the Sota makes its speed changes very slowly. The MinusK is full of springs by the way.

It has also proved useful that the DP-80 Platter is a Two-Piece Assembly, as the Lower Section interfaces with the Speed Control System and the Top Section is able to be produced from different materials.

I have a substantial Phosphor Bronze Top Section. The design enables it to be used as a Platter on other TT's.

I also have purchased a few Spare SP10 MkII and DP-80 Platters for the future and for some usage on a few trial ideas I have come across and had brought to the table for discussion with an engineer, who will qualify as a TT specialist, if a title were to be given.  

The TTS 8000 has a similar magnet speed control via a Magnet Strip but is a much harder to discover platter for sale, a few years of searching has not shown a platter on offer only from the usual search sites. The engineer I use has this TT and has had to consider using the only Patter available for this model to produce the modifications that have been under discussion.

It is a difficult call to work out how far Mod's should be introduced to Vintage TT's especially when a selection of models is at hand.

The Aurex SR 510 is the one that is begging to be given a full attention.

The Aurex has a different Speed Control, being that it is a concealed under platter incremental marked disc that is read to control speed, which is observed through a Periscope Type Lens for the stability.   

Mijostyn , I am well aware of the difference in the method for speed control between the SOTA eclipse system, and the Denon Dp80, because I have both, as you may know. Of course, I do not own a Sota TT, but I have the phoenix engineering prequel to it, controlling the speed of my Lenco. Now as to which is the better way to control speed, you are just making up a story that fits an argument that the Sota method (or the phoenix engineering method) is superior to that of the Denon. I could make up an equally compelling argument in favor of the Denon, but since we have no head to head data, I won’t bother. The Denon is extremely good at it, and so is the eclipse system, and I defy you to hear a particle of difference between them . Denon did publish specifications, showing speed stability over time when they marketed the Dp80. If you search for their promotional material from that era, you will find it. Data are shown in their owners manual, I think. I might also add that the Kenwood L07D from 30 years ago used a magnetic elevated bearing. You could also say that the Verdier TT which is entirely based on magnetic elevation, in the vertical plane, is now vintage material. Several other makers use full or partially magnetic vertical bearings too. So the SOTA mag lev bearing is not earth shattering or groundbreaking, but I am sure it is an improvement over the previous bearing.

As to springs, what I object to is internally, sprung turntables, where the motor on one hand and the platter and bearing on the other are treated differently, which is to say the motor is usually unsprung whereas the platter and bearing are sprung. I have reiterated this argument and my feeling about it many times over. That arrangement makes it impossible to avoid some speed variation Whenever the suspension is activated, because activation of the spring suspension will inevitably stretch or contract the belt which will change the speed momentarily. I could hear this effect quite plainly with my SOTA star sapphire vacuum hold down turntable that I owned for 10 years. This has little to do with the Minus K.

 

@holmz , The new Sota bearing is just like the Clearadio. It has a magnetic thrust mechanism. The female section of the bearing is an integral part of the platter so what you are talking about is a new platter assembly which is heavier than what you currently have and the suspension will sag and it’s resonance frequency drop.

The old platter goes on the existing table.

I was thinking I could recycle the old arm, motor and cart into a table for my daughter, or to use in the shed outside.
To do that I would need a plinth, bearing and platter. I have access to a lathe and would likely use acrylic and maybe stuff in some copper plugs towards the outer edge to make the intertia a bit higher without making it heavier.

And since that would be a second table it would not have the Sota springs, but maybe some anti vibration feet to hold the plinth up.

You are best off sending the table back to Sota and let them upgrade it for you or just trade it in on a new Sapphire Eclipse. You might as well add vacuum clamping while you are at it.

SOTA have been good, and I have rebuild stuff for the existing table from them.

I was more than just a little bit reticent in sending back the whole table, but I did send back the platter Friday.
In hindsight, I could have sent the platter assembly, separate from the table, and kept the cover here.
And then reassembled it back here.

As far as multiple arms are concerned if you get additional; tonearm boards weighted for any specific arm you can have several arms mounted up and fully aligned then changing arms is a snap. Three Allen cap screws is all you have to undo. I can change arms in less than five minutes. I am contemplating getting a wood CB directly from Frank Schroder and doing just that.

I made my first arm board about 1988 I think.
And two more a month or three ago.

The CB-9 is going on one of those two arm boards. Basically I had enough alloy for two, and if I jacked up the drilling I would have a spare.

I would be a bit apprehensive changing an arm board with the CB-9 and cart attached. It would be easier/safer if it had a removable head shell.

The drilling went easier than I expected and the spindle to hole was bang on 222mm. It took a bit of futzing around with a calculator, calipers, center drills etc.

Since I did not have a 10” caliper, I took a scrap of alloy and measured from its edge.

I am dropping off the alloy arm board to get a black anodise.
The Pythagorean math was left on the alloy disc.

With the CB-9 fully lowered, it is pretty flat and makes it easier to measure. But when doing the arm board scribing, there is a drop between the table and the arm board. Nothing too difficult, just time consuming to check, recheck, check 4 more times.