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01-26-12
Dear dev, your question was: "don't you think it's stra ... Lewm
01-26-12
Hi lewm, thanks for the reply but if i'm paying top dollar ... Dev
01-26-12
Dear halcro: a friend of mine brought his timeline with him ... Rauliruegas
01-27-12
Dear raul, it's good to get your feedback. it appears that y ... Halcro
01-27-12
Ummm..., dev, i think you took what i wrote and ran away wit ... Lewm
01-27-12
Lew, you both 'heard' it :^) i think our descriptive languag ... Halcro
01-27-12
Here is a link: go back up the thread two or three posts of ... Lewm
01-27-12
Hi lewm, thanks for the reply back and clarification. i ha ... Dev
01-27-12
Dev, as i wrote, i used the walker because (1) the exact fin ... Lewm
01-27-12
Lewm, thx that's great info. Dev
01-27-12
One more thing. i realized whilst taking my evening stroll ... Lewm
01-27-12
i agree. all lenco tables in stock form have speed issue. ... Hiho
01-27-12
Hiho, thats crazy and thanks for sharing. that's exactly wha ... Dev
01-27-12
dev, i hope i did not discourage you to pursue the lenco. ... Hiho
01-28-12
Hiho, fwiw, i use a 2nd generation ptp. as you know, it has ... Lewm
01-28-12
Lewm, which of the 3 tt's the lenco l75, technics sp10mk3, ... Dover
01-29-12
Dover, cannot fairly answer any of those questions yet. i l ... Lewm
01-30-12
it is, indeed, a head game. sometimes i wonder if we make r ... Hiho
01-30-12
for a lot of audiophiles everything is more or less a fasci ... Syntax
01-30-12
"a turntable needs the right speed, knowledge to make t ... Lewm
01-30-12
No doubt repeating a point someone else has made. if the spe ... Lrsky
01-30-12
What turntable? Lewm
01-30-12
The argument between measured performance and audible perfor ... Pryso
01-30-12: Dfhaleycko
This is an interesting discussion! Thanks all who have participated. I'm particularly interested in the role of the type of motor as it relates to speed stability. It seems that DC motors require a lot of fancy/expensive control mechanisms to achieve speed stability, many with a feedback loop of some sort for control. And as with any feedback loop, there is an opportunity for oscillation, which is certainly a problem.
On the AC motor front, you have synchronous motors, but perhaps the best performance came from the 3-phase motors, like the old Papst pancake motors that a number of high-end turntable makers used to use. I think technically they are eddy-current motors, and hugely inefficient. But their design with the spinning outer rotor and inner coils gave the motor a bit of flywheel effect regardless of the type of platter being used. It seems to me that the Papst motor is what is in the turntable that Atmasphere was raving about earlier.
Are there other 3-phase eddy-current turntable motors still in use today? I know that Papst ceased production of theirs, and it was problematic in several areas (the vanes make a whirring sound, for instance, and the bearing technology is 1950's era).
What other types of motors are best for speed stability?
Dfhaleycko (System | Threads | Answers | This Thread)
01-30-12
I think you have it a bit backwards. generally the motor ch ... Lewm
01-30-12
How do tt bearings in motors from the 50s differ from those ... Ketchup
01-30-12
Ketchup, tt bearings of the 50is are bigger, more stable and ... Thuchan
01-31-12
There are also crappy bearings in turntables both old and ne ... Lewm
01-31-12
"you would not use a pabst motor in a direct-drive turn ... Lespier
01-31-12
I meant to say that thorens offered an external rotor papst ... Lespier
01-31-12
Lewm asked, 'what turntable', i'm thinking that he was askin ... Lrsky
01-31-12
I owned a sota star sapphire iii with vacuum for many years. ... Lewm
01-31-12
Hi lewm. papst made a huge variety of motors. i think the c ... Lespier
01-31-12
Pabst is indeed a company name and does not refer to a type ... Atmasphere
01-31-12
Hi lewm. papst made a huge variety of motors. i think the c ... Lespier
01-31-12
I found a website where the owner installed a papst motor in ... Lewm
01-31-12
I found a review posted by 'grimagog'? for a mark kelly cont ... Dfhaleycko
02-01-12
i share that sentiment. lewm: " i actually thought ... Hiho
02-01-12
Dear lewm, yes it is exactly as you described. modern manufa ... Thuchan
02-01-12
Dear thuchan, i just this past month ordered the bearings fo ... Dertonarm
02-01-12
Hi dertonarm, how in the heck can a bearing for a table cost ... Dev
02-01-12
Dev, just read what dertonearm is asking that bearing to do. ... Lewm
02-01-12
that's very zen. i need to do that myself. bill belichick ... Hiho
02-01-12
Hi dev, the bi-planar air bearing for my turntable in the 19 ... Dertonarm
02-01-12
hi lew, if the motor was noisy then its likely that there w ... Atmasphere
02-01-12
Dertonarm fascinating and of course your table would be some ... In_shore
02-01-12
Lewm, been thinking about your 'what turntable' question... ... Lrsky
02-01-12
Ralph, by all accounts, a really accurate subdivision of the ... Lewm
02-01-12
Lrsky/lewm - my money on an 80's demonstration by magnepan w ... Dover
02-01-12
Atmasphere - i think you are too optimistic on the quality o ... Dover
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