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.
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.