SP10 Mk II vs Mk III

Guys!

I have to be honest and say that a tube-based power supply for a turntable such as a SP-10 mkII or III will not be worth the effort at all. The incoming DC power from the PSU is regulated and modulated in a complex manner that will void any "tube-iness". The SP-10 motors are precision devices that operates in a different way than amplifiers. One should not treat it electrically as a piece of audio gear but rather a precision instrument. As long as the stock PSU are operating within specs then it will be the best partner for the motor unit.

Anyway, the stock PSU is much more better designed and constructed than most other audio related PSUs. If only half the worlds audiophile amplifier PSUs were so well designed and regulated then this would have been a much more sane place. This is why I am working on a SE tube amp with a super-regulated PSU. Its not over-kill, it just makes sense.

I am frightened by the materials used on this thread. A plinth made of lead ? Please we also have to be eco/planet friendly on our hobby. One of the reasons I use VPI for turntable, it is an ecological minded industry.

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 :)