SP10 Mk II vs Mk III

Hiho, Are you saying that for the SP10 MKII you just lengthen the wires from the chassis-bound electronics to the motor, when you install the motor only into a dedicated plinth? How long are the leads between the motor and its electronics when you get done with this mod? If it works, I am all for it. I just wonder whether it is dramatically better than just installing the whole assembly in a big piece of slate, as I and others have done. This says nothing about Mike Lavigne's MkIII set-up, of course. Despite what I wrote, I am tempted to try this with my second MkII, but I would also re-install the electronics into a cosmetically nice chassis. Six inches diameter for both the MkII and the MkIII?

The stock 12-strand wires come out of the motor assembly to the connector is about 8" long. I would extend the wires by at least three feet. I have three SP10's so I plan to do this soon. The important thing is that in the stock form, the motor is bolted to an 1/8" cast aluminum and the motor just hangs there. Now, imagine the motor mount directly to a thick slab of slate or wood or whatever material you like to use, don't you think that's better than the stock form? If you use the stock chassis, I don't care how wonderful your plinth will be your motor is still bolted to a thin sheet of aluminum hanging there. Just spend the time one day and carefully take the motor out of the stock chassis and then examine it yourself and you will know exactly what I am talking about. It's not rocket science. Almost ALL direct-drive can be improved this way. And for whatever reason, if you don't like the sound, just put it back to stock form - it's all reversible. The reason I haven't done it sooner is that I don't have the tools to cut slate! I would suggest keeping the stock chassis to house all the electronics because everything is all there with the buttons and switches, why re-invent the wheel? Unless it's an aesthetic issue and you just want to play around, go right ahead!

I plan to have two SP10 set up this way so I can have one tape-driving the other platter so it can be used as direct-drive and belt-drive. Fun!

I fully agree that nearly all production dd tables can be improved by improving their plinths. And I take your point about the suspension of the motor in the SP10. Albert addresses this issue by supporting the motor/bearing assembly via a brass rod that is imbedded in a dense metal block. I am using Albert's support system underneath my slate plinth. What do you do about the on/off switch when you take the electronics away? Also, can you answer my question; is a 6-inch diameter hole correct? I have a remaining blank slate plinth, a company with a waterjet machine, and a second MkII, so I may try it too.

By the way, how do you get a belt around the SP10 platter in order to use it to drive a second platter? The SP10 platter has a beveled edge.

You do NOT have to take the electronics away. You are doing absolutely NOTHING to the electronics nor the switches. The motor is mounted to the stock chassis and there is a bundle of 12 wires soldered to a 12-pin connector connected to one of the circuit boards. All you're doing is to extend the wires by a few feet and mount the motor to something more solid like a slate, plywood, or butcher block or whatever. The stock chassis is acting as housing for the electronics and switches, so for the Start/Stop and speed change functions you still need to use stock chassis.

Apparently you never removed the platter out of the SP10. The platter has about 1/4" flat area below the beveled edge. If I install two SP10 motors outside of the stock chassis then I can have one platter driving the next one without any speed adjustment because they are one to one ratio in diameter and I will use 1/4" magnetic tape, something thin to have no effect on speed. I have done this experiment with two Pioneer turntables before and I prefer the sound in this arrangement than in DD mode. But DD is usually a little more dynamic though. If I have the budget when I win the lottery, I would use a SP10mk3 to tape-drive a Micro-Seiki platter, since the Mk3 has speed adjustment.

Here are some pictures from a Japanese website applying the Kaneta mod so ignore the DIY electronics but the images give you a better idea of the motor and chassis.
http://homepage2.nifty.com/~mhitaste/audiotop/audio_apparatus_page/sp-10mk2.html

The cut out hole can be between 5-7/8" to 6".

FWIW, I have removed and replaced the platters from two different SP10s, a MkII and a Mk2A, in order to lubricate their bearings and in order to replace electrolytic caps in the electonic module. (In medical training the aphorism regarding procedures is "see one, do one, teach one".) I simply forgot about the flat area on the edge of the platter because it is not visible when the tt is put back together. However, as I recall, it is pretty narrow with no ridges to prevent a belt or tape from wandering off course. But if it works for you, that's all that counts.

I know all about the Kaneta modification, but he re-designed the electronics (as far as I can tell without being able to read any of the Japanese text), so his work is (probably) not relevant to the question of whether lengthening the leads will negatively affect function of the stock servo mechanism. Again, if it works for you, then I may be wrong to worry about it.

So I now finally get the picture that you use the stock chassis intact as a housing for the electronics that don't go into the plinth. Do you do anything cosmetically to cover the hole left by the motor/platter et al?

Thanks for the idea.