Idler wheel "magic"...

[Daniel Walte]

http://www.reliance.com/pdf/motors/whitepapers/B7100.pdf

For Rayw: this is taken from the link here on poles of motors:This results in a motor configuration which
allows a larger rotor and shaft diameter to be
used for designs with a higher number of
poles. This tends to improve the “torque
density” or rating per frame size which can be
achieved with a higher number of poles. As
will be seen later, a degradation of motor
power factor which occurs with an increased
number of poles is a key effect which works
against the desirability of a higher number of
poles. (Figure 1)

 

[Pio1980]

There are still record lathes in operation that use gear driven motors.

Can't find specific examples re Scully or Neumann for pro/commercial cutting lathes, can you direct me?

 

[Pio1980]

"Smearing" and blurring of detail seems to me amongst other factors primarily a resonance management issue, micro/macro timing errors from BD stylus drag pitch droop and poor-performance DD correction timing/pitch jitter/wow is something else IMO. The cogging criticism came IIRC from improper testing of the DD motors with the platter off, screwing up the correction time constant factor without the flywheel effect of the platter. Dirty dealing by the perp.

 

[gusten]

Personally I have no experience at all with an idler drive TT. I have read though that many owning one are very happy with their performance, especially with transient responce, resolution and pitch stability.

I`m not a believer in resistance to stylus drag as a reason for this, as I´m not a believer in transient drag per se. So if there is some truth in that by many stated performance of idlers, a more plausible explanation could be a more stable platter and at the same time a supported bearing by idler wheel forces.

This can of course, if it is so, be perfectly addressed on a BD or DD, which I´m sure is the case with some top of the line TTs.
gusten

 

[RayW]

http://www.reliance.com/pdf/motors/whitepapers/B7100.pdf

For Rayw: this is taken from the link here on poles of motors:This results in a motor configuration which
allows a larger rotor and shaft diameter to be
used for designs with a higher number of
poles. This tends to improve the “torque
density” or rating per frame size which can be
achieved with a higher number of poles. As
will be seen later, a degradation of motor
power factor which occurs with an increased
number of poles is a key effect which works
against the desirability of a higher number of
poles. (Figure 1)

We're talking about different things now. The part I was addressing was when you stated that a 4 pole motor would have less wow and flutter than a 16 pole. We weren't talking about power factor. I simply wanted to point out that more poles means improved "torque density", as stated in your quoted paragraph, which will mean inherently less wow and flutter.

Of course this is just one detail of the motor design that will affect it's suitability or superiority as a drive system for an audio turntable.

Also please note that the article linked is about industrial variable speed motors where inertia tends to be a bad thing.

 

[Daniel Walte]

Ray whatever after all I can`t argue with a minor authority figure LMAO I`ll just pick on the major ones, no kidding aside I`m not here to argue with anyone and their beliefs. cheers to ya

 

[dnewma04]

So we'd be trading idler smear for motor cogging. Lovely. Wasn't cogging supposed to be the cardinal sin of direct-drive systems?

I was hoping that it would be clear that I was being facetious. If belts "smear" the signal, clearly, idlers would smear the signal compared to a less lossy mechanical connection. It just so happens that there are a fair number of cutters floating around in operation that use gear driven motors.

 

[dnewma04]

Basically, it works like this:

more poles = lower rpm = more torque
less poles = higher rpm = less torque

 

[marc mc]

I`m not a believer in resistance to stylus drag as a reason for this, as I´m not a believer in transient drag per se. So if there is some truth in that by many stated performance of idlers, a more plausible explanation could be a more stable platter and at the same time a supported bearing by idler wheel forces.

This can of course, if it is so, be perfectly addressed on a BD or DD, which I´m sure is the case with some top of the line TTs.
gusten

Years ago I went to TT set up event. They had a computer that gave a printout of your TT while it played a test record. The printout gave specs for speed as it tracked through various sections of low and high frequency combinations.

By itself I can't say that it was very useful but I do remember looking at all the printouts from a variety of tables and side by side they revealed variances. I now feel that what I saw all those years ago was revealing more than I thought.

Marc mc

 

[marc mc]

Audio stores used to settle debates like this in minutes. We would play one piece of gear. Then play the other one! Case closed.



Marc mc

 

[dnewma04]

Marc, once you get to upper end equipment, it takes far more than minutes to make those sort of decisions unless there are drastic differences. My experience with the best of each technology is that they are far more similar than different.

 

[Dr Tinear]

I was hoping that it would be clear that I was being facetious. If belts "smear" the signal, clearly, idlers would smear the signal compared to a less lossy mechanical connection. It just so happens that there are a fair number of cutters floating around in operation that use gear driven motors.

If this forum weren't so good at serving up the audiophile version of Poe's Law, I probably would have caught the tongue-in-cheek note you intended in your post. As it is, though, it's often hard to distinguish facetious suggestions from crazy suggestions that are offered in all seriousness.

 

[Daniel Walte]

I personally don`t care about facts and figures . Well at least my ears don`t.

 

[dnewma04]

The problem is, you were trying to use facts and figures to show why idlers might be better. If the only important thing to you is your subjective impression, so be it. There is nothing wrong with that approach just like there is nothing inherently wrong with going with facts/figures over subjective assessment. It's your money and your system.

This thread is proof that when faced with situations that we don't quite understand, our nature is to figure it out. Many things presented as fact in this thread would have a tough time being proven as such with objective measurements or subjective assessments.

 

[marc mc]

Marc, once you get to upper end equipment, it takes far more than minutes to make those sort of decisions unless there are drastic differences. My experience with the best of each technology is that they are far more similar than different.

Upper end? Who's talking about the upper end?

I don't think anyone here is at the upper end of anything. I don't feel that we are trying to discover what is the best, that's impossible with far too many variables. But what is being discussed is the utilization of potential.

Marc mc

 

[dnewma04]

I think most people have been comparing things like modded Lencos to upper end? Maybe I'm reading a different thread? One poster essentially dismissed the entire upper end turntable market as being inherently flawed.

 

[marc mc]

I think most people have been comparing things like modded Lencos to upper end? Maybe I'm reading a different thread? One poster essentially dismissed the entire upper end turntable market as being inherently flawed.

I don't think many on AK have heard the upper end Newman. For the most part a 2k TT with arm,cart and all is out of range.

I don't fly with all the assertions I have read on this threa. But I love people trying things out and learning. I mean what else is the gear side of this hobby about.

Marc mc

 

[Daniel Walte]

found this on the internet about tonearms:So what happens to all that energy transmitted into the arm wand? Some of it gets dissipated into the material of the arm wand, some lost in the coupling between the metal and whatever it touches such as the counterweight, the cable and so on. Most of the energy though will travel up the arm wand (which is normally a tube just like a woodwind or brass instrument) at a resonant frequency and the harmonics of that frequency till it meets a point of resistance, which will normally be the bearing where it will bounce and reflect or refract back again. So again, under our microscope imagine what is happening to the arm wand and the bearing. The waves are both traveling through the material of the wand and over its surfaces. At the same time the entire arm wand is shaking, that is moving back and forth and side to side. When it meets the balls in the bearing it will bounce off them and cause them to bounce against their bearing race. This is known as bearing chatter. In theory and with many caveats, the tighter the fit and the tolerances in the bearing, the less it will chatter.

 

[Daniel Walte]

so the whole turntable surely influences the end outcome of sound.
So our arms and their bearings alter the sound is my question and I think Arkay although won`t say it and keeps turning everything into a qeustion. This question above is for you Arkay! You answer it and we will know you have some real knowledge of turntables:thmbsp:

 

[dnewma04]

I don't fly with all the assertions I have read on this threa. But I love people trying things out and learning. I mean what else is the gear side of this hobby about.

Marc mc

This I can appreciate. As you know, I like this about the hobby almost as much as I like the music itself.