SP10 Mk II vs Mk III


A couple of guys here were planning to do listening comparisons of the Technics SP10 Mk II vs the Mk III, in their own homes and systems. Has anyone actually completed such a comparison? I am wondering whether the "upgrade" to the Mk III is actually worth it in terms of audible differences between the two tables. Possibly mounting either table in a well done wooden or slate plinth mitigates any sonic differences that would otherwise be heard. I am thinking of Albert Porter and Mike Lavigne in particular, who were going to do the comparison. Thanks for any response.
lewm
Lonestar, Your sentiments are commendable. The Walker Audio Proscenium is built out of lead too, but at that price, not many of them are going to end up in landfills, ever.

As far as tubes for the SP10 power supply, I quite agree that that sounds impractical. Perhaps Albert has heard the optional tube power supply available for the Brinkmann table. (That's the only tube tt ps I know of.) But that PS only has to supply sine waves to run the Brinkmann motor and to control its speed. There is no servo mechanism, etc, to worry about. It would be nice enough if any of the known ongoing projects to build modern outboard supplies for the SP10 would finally come to fruition. I refer to Mark Kelly's project and to that of "Steerpike" over on diyaudio. Either of those devices, like the Kaneta, would enable one to remove the electronics from the chassis and sink the motor directly into a plinth, thereby dramatically improving the coupling of the motor to a high mass.
I think lead would be a bad move (toxic and its not very strong, certainly not rigid)- if it were me, I would design a plinth from solid machined aluminum (like we did for the old Empire 208), and then create a sandwich of dissimilar materials- an extensional damping compound, and maybe machined steel, so that you have rigidity and absolute deadness.

I get people joking that I should make an all-tube digital watch or GPS, I have to assume any comments about the Technics power supply come with the same friendly smiles :)
Robyatt, What cartridges work well in the RS-A1? I've got one too, largely because it is so easy to move between tts, it will facilitate my ability to compare one tt to another. But the darn thing is so unorthodox in construction and implementation that it is difficult to know what cartridge to use with it, except by experimentation perhaps. For example, what is the effective mass of that crazy arm tube with the swinging counter-weight? (It's a rhetorical question, unless 47 Labs have given the into in the manual, which I don't have.) I heard it sound great on a Lenco with a simple Pickering MM.
Anybody aware of the SAEC SBX-7 plinth for the SP-10 mkII? http://yasshin.hp.infoseek.co.jp/saecsbx7.htm

Atmasphere, you've got a point though. Lead is not optimal - its got high mass but is 'unstable'.

I would rather go for a fiber-loaded (incl aggregates) compound that is pour-cast and then CNCd.
What do the SP10 experts think of this Teak plinth for sale on ebay??

http://cgi.ebay.com.au/Teak-Plinth-for-Technics-SP-10-SP-10MK2-SL-1000_W0QQitemZ390014496088QQcmdZViewItemQQptZTurntables?hash=item390014496088&_trksid=p3286.c0.m14&_trkparms=66%3A2%7C65%3A1%7C39%3A1%7C240%3A1318