Click title to read one, or click date to read all below it.
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
This is an interesting discussion! thanks all who have part ... Dfhaleycko
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: Dfhaleycko
I found a review posted by 'grimagog'? for a Mark Kelly controller applied to a Papst 3-phase motor. His claim was that having the ability to "tune" the current via the conroller leads to a quieter motor and (back on topic) improved speed stability.
Mark Kelly posts over at the DIYaudio forum occasionally and appears to be extremely motor-knowledgable. Jim Hagerman was toying with the idea of a new 3-phase motor controller as well.
I've got to believe that a multi-phase AC motor should be easier to design for speed stability compared to a 2-phase or single phase motor. More continuity of pulse per revolution, for sure. Certainly much of heavy industrial motors are 3-phase, so I think the math is pretty well-understood. But since most of us live where the power coming in over the wires is not 3-phase, some kind of controller is needed.
The Papst motors discussed above use a 4uF cap to provide the appropriate phase delay, to "trick" the motor into sync. I wonder if atmasphere has any tricks for improving the motor performance on his tables?
I've had good success with some of those grand old tables by micro-polishing the bearing balls, and improving the sleeve's ability to retain oil via fine cross-hatching at 1500 grit. The Rabco tables were interesting in that they had a spiral groove to "pump" oil back up the sleeve to keep a nice continuous lubrication film. With the right lube viscosity, these things would spin for several minutes down from 78rpm. I think the Empires were the same way.
So a nice even motor and nearly frictionless bearing = speed stability? (carefully avoiding the drive question here)
Dfhaleycko (System | Threads | Answers | This Thread)
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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