Thoughts On Turntable Clamps And Weights

The Stator Bowl, is one area of a design that has been severely scrimped on.

I have witnessed the gauge for metal used for pressing/casting that is close to a range of 1/64 - 1/8.

I have done work on rigidly bracing the base of the bearing housing and have encouraged others to adopt methods to achieve the same end.

The improvements discovered are worthy of mentioning and the reports from those that have adopted this as a method are again not to be overlooked.

As I own a 3" (75mm) Thick Board of Permali, I am in a position to have the Bowl formed as a recess in the chassis, which will not be a thin flimsy add on, prone to flexion and deflection, the Stator and other parts for the drive will be directly attached to the Permali Wood, the original bowl will be redundant.

What really matters is how the new bearing housing interfaces with the Permali Bowl and how the Platter Spindle is catered for as it passes through the Bowl and Stator and other parts of the drive.

This is to be my design for the Kaneta, as an alternative to the original motor drive being bedded into a substantial chassis.

At present there are two Kaneta designs at hand, one as a thick laminated wood chassis and the other a single P'holz Board chassis.

There is at present one electronically modified TT, at hand to the used with the two mounting methods.

Another TT will need to be a donor model to produce my Permali Chassis version, where the modified electronics can be shared to have the experience of both types. 

As an aside, I was yesterday involved in what I will refer to as a healthy conversation with my Engineer friend about Air Bearings 😎, I do like the general expressed ideas being made known.

You might want to investigate the modifications made by Richard Krebs for Technics SP10 Mk2 and Mk3.  He spent a lot of time investigating the stators and how to stabilize them.  I have had my own Mk3 modified according to Richard's Ideas, by a local tech who learned the procedure from Krebs himself and is one of a few persons in the USA qualified to perform the modification.  The idea being that these motors have enough torque such that the stators are subject to movement in a direction opposite to that of the platter, when torque is required.  This causes the servo to "read" a speed instability where there may be none, and thus a kind of oscillation is possible where the servo is calling for unnecessary speed correction.  This in theory can cause an audible coloration. Unfortunately, the actual modifications are shrouded in mystery; I can only say the changes seem to involve the stators.  I can also say that even though I heard no real "problem" with the Mk3 a priori, the Krebs mod really did rmake the Mk3 sound more like real music.  I did hear, and have so stated in this Forum, a slight "gray-ish" coloration in the SP10 Mk2, when I owned one.  I assume the Krebs mod would be beneficial to reduce or eliminate that issue in the Mk2.  The good news is that the Krebs mod on the Mk2 is less expensive than on the Mk3  I am quite sure the Krebs mod(s) do not include the introduction of Panzerholz or the like.

@lewm  The Engineer I use, is an individual renowned for their knowledge and their unique modification works carried out on the SP10 MkII, my own SP10 MkII is modified by this person.

I can assure you that others, that are renowned in their own Countries (yes even the US)  for their works done on Japanese Vintage TT's, have picked my engineer friends brain at some point.  

I have had many a discussion about the ideas behind the engineers practices and how the practices of others are said to impact on the SP10 MkII.

I don't believe there is much that can be done to my own TT, that will improve on it electronically, or for speed control.

The next frontier is the attempts to improve the mechanical interface for the seating of the drive gear and the Platter Spindle Bearing being a complete overhaul and not the already put in place upgrade for the assembly on  the one I have in use.

As stated previously, I am keen to learn, if the rethink for the Platter Spindle Bearing, can be one that is able to be transferred onto other Brands models, if the Stator Bowls are remade using a CNC to accommodate the new bearing housing design. 

The CNC owner has access to substantial thicknesses of Thermoplastics, and has the programming skills which can produce items to low microns as a tolerance.

Alternatively for the individual like myself, the Bowl replacement can be a simple affair to, where there is a Top Flange plate fastened to a thick walled cylinder of the ideal ID/OD, that has a base fastened to the side wall as well.    

The world of modifying these vintage turntables is such a tiny one, I can only wonder why you cannot include the name(s) of these "renowned" engineers so others might benefit.  And the engineer might also benefit in terms of increased earnings. In any case, the Krebs modification is worthwhile based on my listening to the Mk3 before vs after, if that interests anyone.  Richard Krebs resides in New Zealand.  I have never met him. He is lately known for the K3 turntable which is his build, now sold by Oswald Mills Audio for huge bucks.

I'm running a Rega Planar 10.  They recommend no weight or clamp.  Of course the Rega strategy is about the lack of mass.  I have an HRS center weight with which I might try a listing test.  It's currently holding down my Eight Switch which tends to move with all the ethernet cables pulling in it.  An expensive paper weight.