SP10 Mk II vs Mk III

Jloveys,

Making a single plinth from lead surely is not a catastrophe. The designer of such a plinth should also think of ways to seal the lead to prevent oxidization and lead poisoning. You only have to start worry about lead contamination when someone dumps a used car battery on a dumpsite or in a eco-sensitive area. There is much more worse things to worry about such as the thousands of people dying in Zimbabwe of cholera due to an incompetent government. Walker Audio turntables are made of lead but the structures are sealed with specialist materials to protect the environment and the lead itself. There is also still people on this planet living with lead fillings in their teeth!!

Please dont get me wrong, I care for the environment a great deal but I would rather channel my rage and energy towards mega-factories the churns out thousands of gallons of toxic gasses rather than get upset with a chap in the US who wants to make a lead plinth for his turntable.

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.