Vintage DD turntables. Are we living dangerously?

A belated response to Henry's question about the complexity of the SP10 Mk3 vs the TT101: There are no on-board electronics in the Mk3 save for the on/off and speed selector switches and wiring thereto and the brake solenoid. All the electronics are housed in the outboard power supply, which is much larger and heavier than that of an SP10 Mk2, for that reason. This arrangement allowed Technics to build the chassis proper such that resonances are minimized. (No hollow cavity or thin-walled structures, etc) And I reckon it also allowed more room on board for the humongous motor. As to what's inside the Mk3 power supply, I deemed it to be so "special" that I did not want to mess around inside it. (As you may know, my Mk3 was acquired in NOS condition.) I simply handed it to Bill Thalmann and let him do the work. Ergo, I don't know what it looks like inside. But the schematic is available on VE.

Thanks for that information Hiho.
I didn't appreciate that the TT-81 didn't have a coreless motor?
Can anyone explain the advantages of one over the other?
Are there still 24 poles so that there are 24 impulses every revolution?

Its worth the risk IMO. Firstly, the depreciation on a vintage TT is way, way less than on a new belt drive TT. You also get a piece of history as well as a functional HiFi component .

Going through life in fear of something breaking down is no way to exist. Look at the stats - chances are things won't go wrong anyway, so why choose to fret about it? You can always buy a spare if you really cant sleep at night.

Long term the vintage DD will be cheaper. Many high end belt drive TT's I can think of have an uber expensive upgrade path that give you the feeling you are missing out unless you keep spending. Not so with some of the substantial and dare I say majestic DD turntables ( in terms of engineering and appearance).

This may not be an advantage for everyone but chances are the wife can probably handle a vintage DD TT more so than the less ergonomic belt drives. And both of you don't need to go cross-eyed every night trying to take a reading from a strobe disc........

Halcro,
I am using a thin sorbothane sheet against the platter, topped with a thick achromat and a brass center weight. How are you dressing the platter?

Also, I am considering an outer ring, but am worried about how the extra weight will effect the motor and speed control.

I am picking up the TT101 tomorrow, fingers crossed.

Dear Henry,
The question you raise has also interested me from time to time. The internet is full of information on motors. However, much of it is written using jargon that is unfamiliar to me and therefore quite dense. But here goes my current understanding: (1) Not all cored motors have 24 poles. A cored motor can have as few as 2 poles, but such a motor would exhibit a pronounced cogging effect. Cogging is the tendency of a motor to want to stop when the magnets are aligned such that the distance to the attractive element is minimal. Obviously, in turntable motors, we do not want cogging. In general for cored motors, the more poles, the less cogging effect. A 24-pole motor is likely to exhibit markedly reduced cogging compared to a 12-pole motor. The SP10 Mk3 has a 24 pole motor. If the Victor TT81 does, that's good. (2) Coreless motors either have zero cogging, because there is no iron in the windings, or they have very little cogging. (I have trouble with this issue, since I see contradictory statements on the internet, but it seems to make sense that coreless motors would not "cog"..) As far as I can tell, coreless motors do not have "poles" per se, so the question is irrelevant. I have also seen the statement that "slotless" motors have zero cogging. Whether coreless and slotless are synonyms in motor jargon world I have not yet figured out. In any case, the L07D and TT101 motors would have zero cogging, most likely. I think this gives rise to the "fluidity" that Hiho and I hear. Did you notice such a thing as regards the difference between TT81 and TT101? If anyone has a clearer understanding of the consequences of coreless motor design, please jump in here.