'Bearing Base Plate' Upgrade for SL1200

[Mike_New]

Base Plate.jpg

Hi Folks,

I have not been to proactive of recent weeks on this forum, mainly because I have been flat out producing bearings and platters. Interestingly, a larger percentage of users are from the US, but I guess this reflects the very large uptake of SL1200s in that country. However I guess it’s time for me to come out from under my rock and let you all into the secret. I sincerely hope this does not cut across the edicts of the commercial rules, the problem is, anything to do with the SL1200 is really a bit special and dare I say, boutique.

I have for some time been pondering the problem of the SL1200 chassis mechanics and had come to the conclusion some many months ago, that using my new 6Kg Alluminium platter was one thing; however, does the existing chassis do optimal justice to it?? A study of the ‘mechanical system’ using CAD analysis showed me otherwise. With the added weight, the SL1200 chassis will tend to act like a diaphragm, since it is cast from very thin metal and has little ‘real’ positive mechanical support. Studying the situation prompted me to evaluate the idea of stiffening the chassis with a steel plate of suitable size.

At this time I would like to acknowledge the contribution that Yves, Pete, Mark, Martin and a number of others who have contributed their thoughts on the subject, to bring this upgrade to a point where the average Audio/DIY person can implement the upgrade successfully. It is not rocket science (although others would have you believe it is) and rather quite exciting, when you complete the project and listen to the results of your efforts.

I guess what I am trying to say, is that anyone who is contemplating using a heavier platter, from whoever, is really not going to get the real maximum benefit from it, in terms of the money they may be asked to spend, unless they do something about enhancing the platform on which the much heavier load has to be supported!!!

Accordingly, I have manufactured a “Bearing Base Plate” which has been specifically designed to accommodate my High Precision Bearing so as to provide the optimum rigidity to the Chassis, under the much heavier load of a 6Kg. Platter.

Additionally, the added height of 6mm, allows much more flexibility for those people who have Jelco, SME, Dynavector, Rega, or other arms which require more height for effective VTA adjustment, than is allowed by the restricted envelope of the standard SL1200 configuration.

I have included a few Pics, so as to show what I am trying to achieve.

I have accordingly, offered all users of my new Alluminium Platter the ‘Bearing Base Plate’ upgrade, for a nominal cost. All future users will receive the Bearing Base Plate as part of the Platter upgrade. They do not have to implement the upgrade, if they do not desire to do so. Others can of course, use it independently of my Platter if they are using the standard Technics platter with my High Precision Bearing.

Specification:--

a) Lazer cut from 6mm Milled-Flat-Plate, (not un-coiled sheet)

b) Holes threaded for 1/8” Whit, Tensile Allen Head bolts to more effectively clamp the bearing/coil/motor assembly to the Bearing Base Plate. (The bolts are threaded into 6mm of steel, not self- tapped into soft die-cast-alluminium!!!

c) Five, 5mm holes for clamping to the chassis (bolts & nuts supplied)

d) Three 4mm holes provided to additionally positively clamp my Bearing to the Base Plate, for those people who require the optimum engineering rigidity and sonic integrity.
Note: For those people who opt to obtain the Bearing/Platter upgrade at the one time, then the Bearing will be supplied already secured and locked to the Bearing Base Plate.

e) The ‘Bearing Base Plate’ affords an increase of VTA adjustment of 6mm and allows for a much more substantial arm board than is commonly available from suppliers.




e) This ‘Bearing Base Plate’ upgrade will be compatible with my shortly-to-be-released Bottom Plate. Which is designed to far more effectively clamp the three SL1200 components together as an integral assembly.

f) The diameter of the Base Plate, 125mm ( 5”) is maximized to fit within the floor of the SL1200 chassis, so as to provide the maximum support to the much heavier weight of the Platter, and commensurate with ease of installation.

In summary, it is my considered judgment that the use of a substantially heavier platter, (than was envisaged by the designers of the SL1200); is to an extent, an invalid option unless one considers the engineering /sonic constraints represented by the chassis, and accepts that the chassis must be upgraded to accommodate the extra loading.
I have recently added the upgrades to my own personal SL1200
(I couldn’t use my development unit, as it has more holes that a Swiss cheese!!) It would be rasical of me to make esoteric claims for radical improvements across the sonic spectrum, however I am always impressed with the perceived improvements, which I believe I have achieved.

I am now using a SME-V and have ordered a Benz Micro Wood MC to hopefully improve the sound!!! and have just received a SME cable set from John Miller in the UK.

I posted my production version of the ‘Bearing Base Plate’ to Martin last Monday, so hopefully he will be able to comment on it’s validity in the next few days.

I have updated the design of my Platter to accomodate the new 'Bearing Base Plate' so that cosmetically there is no discernable gap between the Chassis and the new Platter.

[Ammonite Audio]

Mike

This seems like totally sensible engineering. Are there any issues with the now elevated brass bearing shell making contact with the underside of the control PCB? With your own upgrade bearing it is necessary to trim a few wires off the bottom of the PCB to prevent short-circuits, so raising the bearing can only make matters more tricky, unless you are raising the entire PCB as well.

[chris@panteg]

I think it looks like sound engineering to me ' Dale ' i see your point but lets see what the results are ? Martin ' has ordered one and i am sure will post his thoughts accurately and honestly.

Is it a step too far ? maybe it is to some but give Mike some credit for all his efforts , he must be doing something right .

[Mike_New]

Hi Marco,
Unfortunately down here in Sydney town we are opposite the UK in the time zone sphere of things, as you all well know, so I cannot catch up on all the postings until about 8 hours later.
After the posting by ‘dale kid’, you said you would leave it to me whether to request that his observations and comments be moved to a more appropriate location. I normally would have no objection to leaving it here; however the conversation will always get hijacked, as in this instance, when people try to become negatively controversial for their own sake

Dale makes the cynical observation that the “amusement continues”, for him maybe! so be it from his point of view.
However, as I slide down the banister of life, I tend to find that there are many people who are only to enthusiastic to espouse negative views. There are always those who will provide a thousand reasons for why something cannot be done, or was not worth the effort when it has been achieved, and provide not one reason why it can!!. The ranks of would be managers in technology and development, are full of these people.

If Dale as he indicates, has some exposure to the operations at Matsushita and is familiar with their general design philosophy. Then one would perhaps think that he would show as much enthusiasm for a positive critique of my work, as he displays in dismissing it!!! But I guess there will always be a surplus of armchair ramblers who become enthused at seeing their words in print. For my part, as a former group technical director for a multinational high technology corp. I have long since ceased to become excited over such experiences!!

He later posts “More Ramblings’. It was not my intension to waste peoples time rambling, rather to inform those folks who have an ongoing interest in upgrading their Turntables, and would like to be informed of what I am doing. To this extent the thread has indeed become somewhat hijacked. To wit, Reid Malenfant’s observations about Hornby locomotives and V8 engines, the mind boggles!!


To answer a very valid question from “Shuggi” about the Bearing Base Plate upgrade.

The whole bearing and motor/coil assembly is raised by the height of the Bearing Base Plate.
Since the main control circuit board is permanently attached to the coil assembly, it is also raised by the same amount, so there is no problem. To this end, three brass spacers and longer self-tap screws are supplied so that the PCB can be secured in it’s now, elevated position.
On the subject of clipping the wires, when installing my Bearing. I have been asked by some folks why I do not machine off the thick bottom flange, like the original. The simple reason is that I am achieving the utmost rigidity where it is needed most, by retaining the full area of the flange. That is why the Bearing works so well. In most cases the wires do not poke through by very much, however on some boards they do. With my new Base Plate, the Bearing now has the full flange area to seat on, rather than being perched on the three raised lugs which are cast into the chassis and which are not machined flat! Albeit they do form a three point support.

As Chis has observed, ‘is it a step to far?’ It is not for me to wax lyrical about how fantastic the sonics become as a result of these upgrades, rather let the people who are willing to try these things and who in part have become involved in their development. voice their opinions.

In short what I am trying to do, is to produce as good a ‘mechanical support system’ for the excellent direct drive system as is possible within the given envelope of the existing design, and commensurate with the cost and complexity of installing the resultant upgrades.

It could be argued, why not produce a new chassis/plinth. I have in fact designed one, but I personally believe that it will not be an economic proposition, for most of us. Further the constraints of the existing motor design, whilst excellent for the price, do not I believe justify the much higher cost of a new chassis.
For instance the Bearing I have designed is about as large as can be accommodated within the present motor/coil assembly. The bearing could indeed be made somewhat longer, which would require cutting out the bottom of the bearing well so that it pokes through the bottom. However there are certain mathematical constraints on the ratio of length to diameter, in regard to the engineering physics of the problem, which in my judgment, would make this exercise somewhat pointless, except to increase the cost!

I have recently, as a result of discussions with Pete, modified my platter design to allow for the new height of the Bearing Base Plate.

[Marco]

Hi Mike,

I have moved the 'off-topic' content to the other relevant thread:

http://theartofsound.net/forum/showt...167#post148167

Therefore if Dale (or others) would like to indulge you in discussion regarding the 'Bearing Base Plate', or anything else relating to your SL-1200 upgrades, it can be done there.

This thread will remain solely for discussion of your new products by potential customers

Marco.

P.S Dale, feel free to quote from here, if necessary, and refer to it on the other thread.

[Mike_New]

This post is in response to Ian's request for prices.

SL1200 UPGRADE PRICES as of Sept 10th 2010

Prices are in USD
Bearing Base Plate: $180.00 Inc del
High Precision Bearing: $580.00 Inc Del
Bearing and Base Plate together: $720.00 Inc del
Solid Alluminium Platter: $850.00 Inc shipping by FedEx

If the Platter together with Bearing and Base Plate are ordered together then all can be shipped in the one 10KG FedEx box for $1,570.00 less 10% == $1,413.00

For those who already have My Bearing and require to purchase the Platter and Base Plate then this will come to $980.00 By FedEx

If the Bearing & Base Plate are ordered together then they will come assembled as a unit with the Bearing bolted to the Base Plate by three 4mm tensile bolts.

Full Installation Instructions are provided for each upgrade, which have been editted and improved on, by existing users.

I have attempted to provide a scaled upgrade path so that users are not locked into having to purchase everything at once. The Bearing can be purchased first and used with the existing SL1200 platter. The other components can then be obtained later as funds permit. I would however strongly reccomend that the Bearing Base Plate be obtained if you are considering getting the new Alluminium Platter.