Richardkrebs,
From your lack of answers to the questions I raised, I can only assume that you agree that the issues are valid.
05-12-14: Richardkrebs
Does Artisan Fidelity provide before and after resonance plots for their plinth and bearing drain?
Artisan Fidelity's website gives a very clear description of the work done.
The turntable is not modified with magic oil and other remedies. Clearly they strip and check the turntable to ensure it is operating correctly, including overhauling the power supply and recalibrating it. Considering the age of the Technics now, it would seem prudent to do this work before considering mods. They also give a description of their plinth design adequate enough for customers to make an informed decision.
I note that your own SP10 power supply had to go back to Bill Thalman for repair. Can I assume from this that you do not have the capability to overhaul and troubleshoot the power supply in NZ ?
I also note from your website that you claim to have dismantled the SP10mk3 motor hundreds of times. In the ET2 thread you stated that the only SP10mk3 in NZ that has had the full mod is your own one. It would appear that you have had your SP10 motor in bits 100's of times ? If so, could you tell us why ?
05-12-14: Richardkrebs
To supply any more detail on my upgrade would risk divulging sensitive IP.
This assumes you have sensitive IP to protect. Most owners of sensitive IP, if it is of any value, patent it.
I recall you recommending the use of Slick 50 teflon oil additive to turntable bearings many years ago. The result was increased bearing wear. Discussion with Roksan designer Touraj Moghaddam, a fully qualified engineer, a graduate of the University of London, Imperial College London & Queen Mary College, confirmed that the use of this oil can accelerate wear because small metal particles can stick in the teflon, resulting in increased bearing wear. This is an example of damage that can be caused using a product designed for a different application when it is untested and misapplied.
In my view the cost of the krebs mod is relatively modest. It is clear that given the well known structural issues that Richardkrebs outlines above, that rather than applying stone age remedies by adding oil gunk and glue, one would be better off eliminating the motor chassis or building a new one that eliminates the structural weaknesses rather than bandaids them.
If we examine the structure of the Pioneer P3, Kenwood L07D and look at the Kaneda and Mitch Cotter solutions, is it very easy to design a more rigid motor & platter mounting.
Furthermore a review of the error correction logic and parameters should be part of the target for improvement as one of the primary goals of the TT was instant start up and stop times for DJ's. This is not normally a requirement for domestic audio systems. There is much information on this on the web.
There is much discussion on this forum about replacing electrolytic caps on old DD turntables. The reality is that electrolytics sitting on the shelf dry up and resistors drift. My own experience with recalibrating power supplies is that even mill spec metal film resistors can drift after only 10 years in the field. So a proper restoration of the SP10 should include a complete rebuild and calibration of the TT motor control boards and power supply, not just cap replacements.
