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04-28-2011 Post does not mapped to Knowledge Tree
Serge


Russia
Posts 51
Joined on 09-21-2009

Post #: 1
Post ID: 16173
Reply to: 16173
Rim drive?
fiogf49gjkf0d
Stumbled upon a company in North America which makes 'rim drive' turntables, which I presume are idler-wheel type of drive, is this right?

GEM_V2_All_033.JPG

May be someone had experience with that? www.ttweights.com? NB: I do not know anything about how those TTs sound, nor do I recommend them. It's just refreshing to see that someone does go off the beaten paths here. I can't chek the results unfortunately but would be glad to hear your comments.





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04-28-2011 Post does not mapped to Knowledge Tree
N-set
Gdansk, Poland
Posts 439
Joined on 01-07-2006

Post #: 2
Post ID: 16174
Reply to: 16173
Idler inside out?
fiogf49gjkf0d
Sergei, I'm not sure how far off the beaten paths that is as the ideal is very similar to the idler drive.



Cheers,
Jarek
04-28-2011 Post does not mapped to Knowledge Tree
Serge


Russia
Posts 51
Joined on 09-21-2009

Post #: 3
Post ID: 16176
Reply to: 16174
Burned rubber
fiogf49gjkf0d
Wow, N-set, I've got it, thanks. It's indeed idler inside out. So they need to change this rubber O-ring outside the platter from time to time?



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04-28-2011 Post does not mapped to Knowledge Tree
N-set
Gdansk, Poland
Posts 439
Joined on 01-07-2006

Post #: 4
Post ID: 16177
Reply to: 16176
Big rim=big trouble
fiogf49gjkf0d
Sergei, it does not burn but it gets hard and slightly deforms due to the stresses during the operation.
Contact with greases is even more degrading. That why it's
absolutely prohibited touching the rubber surfaces of idlers OR ANYTHING THAT HAS CONTACT WITH IT with bare fingers!  
Another point is that the rubber surface must be ideally flat, otherwise pizdets polnyi and your
wow&flutter goes to hell due to bump...bump...bump.... Looking at e.g. EMT new idlers, the surface seems like
machined in some way. In the design you've shown,
I cannot imagine how they are able to get ideally flat and even surface on such a huge rim!



 



Cheers,
Jarek
04-28-2011 Post does not mapped to Knowledge Tree
IslandPink
Posts 18
Joined on 02-08-2005

Post #: 5
Post ID: 16178
Reply to: 16177
Verus
fiogf49gjkf0d
I've been using the Teres 'Verus' rim-drive motor on a Nottingham 'Hyperspace' deck for about 6 months. The Verus was a major upgrade . The bass and timing got a lot better , that was obvious from a few seconds of listening. The midrange also got cleaner and more tonally pure as well .
The deck is a fine unit to begin with, it has very good tone and refinement in the mids and highs - I think due to the platter construction. With the 13kG platter weight, you'd think it would have very solid bass, but it's only driven by a little AC motor , and when you swap to the big rim-drive motor it sounds like it's running 10% faster, with much better 'togetherness' of the bass and midrange .
You have to remember to move the motor pod off the platter after playing each time ( to avoid getting a flat-spot on the O-ring ) but otherwise I've had not problems of any sort with it .
Bit expensive, but you certainly get some results for the money - not a 'snake-oil' product .
04-28-2011 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,369
Joined on 05-28-2004

Post #: 6
Post ID: 16179
Reply to: 16173
Rim drive turntables and the rest of them.
fiogf49gjkf0d
 Serge wrote:

GEM_V2_All_033.JPG
I do not have any opinion about rim drive, idler drive, belt of whatever. Sure we can extend out theories but in reality we still do not know what truly is responsible for Sound. I am very sure that if to have purely sonic objectives then any type of the driver might be good. How many people drive own TT to the level of perfection of given selected capacity? Not many. Unfortunately TT manufactures “perfect” the TT only up to the moment when industry’s former TT marketing campaign do not generate sales and the industry whores invent a new campaign around a new TT idea. If you look the history of popular TT for the last let say 20 years tan you will observe designs that were pulley driven by marketing BS and as soon any TT idea hit run time then any farther concerns about perfection of design ideas and implementation directions were abandoned.

Anyhow, I have no problem with Rim drive turntables but I do have problem with what I see in the picture. It looks like rotation stop by shutting down the motor and the axis of motor does not get removed from a rubber rim. This is horrible as with a few days the rubber where the motor touched the rim will sag and form a microscopic indentation, similar to the capstan and pinch roller in reel to reel machines. I see absolutely no mechanism to remove motor from the rim in the depicted TT.

The Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
04-29-2011 Post does not mapped to Knowledge Tree
Serge


Russia
Posts 51
Joined on 09-21-2009

Post #: 7
Post ID: 16181
Reply to: 16179
List of Idiocies
fiogf49gjkf0d
Oh, yes. there was a plenty of absolutely stupid ideas implemented and copied incessantly in turntable manufacturing.
The gross one is of course the magnetic suspension to ease up the work of the platter bearing. Not mentioning that it is a very unlinear suspension at best but the sane designers immediately argued that it is equal to throwing stones in a galsshouse. Why on earth would you need a magnetic field strong enought to hold a (part of) platter weight near a (MC) cartridge which actually relies on alternating magnetic field to produce useful signal?
I think the idea first was realised in high end by Gabriel Turntables (probably a rip-off of some Japanese company's technology exercises which they were fond of then) then JC Verdier tried it out but abandoned soon. Then some German company, probably Clearuaudio, picked it up again and now you have Transrotor doing the same and all copycats following. True case of blind leading the blind.



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04-29-2011 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,369
Joined on 05-28-2004

Post #: 8
Post ID: 16182
Reply to: 16181
I do like the idea of magnetic suspension
fiogf49gjkf0d
I do like the idea of magnetic suspension; I do not know why you feel that it is a stupid idea. As you built up the mass of your platter then very soon will not be able to hold the heavy platter at a single point bearing. The 20 point still cap sit on vertical bearing but 50 or 70 pound will not as the contact surface per mass ration will be too great. So, to use magnetic suspension in this scenario I fell is very cool idea. Pretend you have 100 pound platter but only 10 of them is being handled by bearing, the rest is elevated by magnet. I think it is an elegant solution as you would have high moment inertia combined with hard path to ground (important in my view).

Rgs, Romy the Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
04-29-2011 Post does not mapped to Knowledge Tree
Stitch


Behind The Sun
Posts 222
Joined on 01-15-2009

Post #: 9
Post ID: 16183
Reply to: 16181
History & Tomorrow
fiogf49gjkf0d

Today every Design (even the most stupid ones) will have - or have - a Fan group. High End Audio actually used to have a goal:

Perfect reproduction of the sound of real music performed in a real space. That was found difficult to achieve, and it was abandoned when most music lovers, who almost never heard anything except amplified music anyway, forgot what "the real thing" had sounded like. Today, "good" sound is whatever one likes. 

Now we have a lot of manufactures in analog, not because they are clever, no, because making a "Turntable" is no big task and the profit is high.

Digital for example is expensive, when you want a good one, you NEED the latest and fastest processors, or a top Transport, here you have to pay the high prices from the suppliers. No way out.

In analog you simply find the most simple „Design“ but covered with a nice finish Design all over, only cables and Speakers are in the same league.

The customer wants something "new", because he wants something outstanding (whatever this is).

Back to the good old times when real brain was behind a Design, a lot of Parts were used and when looking inside, the customer sees a lot of unknown but impressive parts. No idea what they do, but they look serious. 

Idler drive is going back to 1920's, more primitive Design simply does not exist (maybe rim drive, I am not really sure about the rating).

When we multiply a regular Tonearm by Factor 100, the Arm is about 27.34yd (25m) long, the Cartridge System is about 1.09 yd (1m) high with a Length of the cantilever in the area of 0.55 yd (0.5m) and the contact area from the Diamond is only 0.020 in. (0,5mm) ! Similar is the Mass in comparison.

A simple example to show what analog reproduction really is. Mechanic. Precision. Tolerances. Material mixes, suspension...Removal of all distortions which can influence the diamond (motor, bearing, spindle...)

This old Design was used as long as nothing better was available. It was replaced immediately even from Radio Stations when Direct Drives were available. But even this is sonically not the holy grail. Stations never had any importance for maximum Performance. They wanted speed to start the record, reliability and that was enough. Bass or high frequencies were never important, they couldn't send it out anyway.


These turntable were dirt cheap to buy in the 90's and now we can go back to the blood which moves the market: Marketing

See these companies who offer these vibrating units with expensive plinths, even when completely useless (some of the main units are suspends with springs, but nobody cares...). And then we have Listeners who have no idea from anything but they want to live their hobby and this is something "different", to show others "I go a different route, I am more clever than you.."

Listening with such units can make fun. Each his own. But real Performance is something different.

Colorations, vibrations can create something which some call PRAT.

A good turntable does nothing, he spins a record and isolates everything which influences the area of diamond when it is in the groove.

But when someone writes, this or that design is completely BS (you need no big intelligence, just some thinking how something works) you will get immediately flames from hurt owners, who are so happy with it. And paid a lot of money for that crap.

And they fear negative comments, because this ruins the value of their unit when they want to sell it. But - slightly - intelligent audiophiles are a minority anyway, so who cares...

Modern times :-)    




Kind Regards
Stitch
04-29-2011 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,369
Joined on 05-28-2004

Post #: 10
Post ID: 16184
Reply to: 16183
The Fan groups!
fiogf49gjkf0d
 Stitch wrote:
Today every Design (even the most stupid ones) will have - or have - a Fan group.

Actually I think the subject of forming those fan groups around some brainless ideas and inadequate results is a very interesting topic.  That “family”, communion audio and the buildup of a communion, fake empathy in audio is something that I absolutely abhor. Interesting that marketing in audio is structured to seed those warm feelings of communion successes. In most of the fields BTW it does not work this way. If you go to doctor and he proposes you to implant some kind of metal rod into you bone then you most likely will ask about the material and technology.  Most likely you will not be satisfied by a comment “do not worry, it is titanium alloy. Probably you will ask your doctor why this alloy use, want benefit for your implant it will have and how it compete with other type of alloys.  Most like you will ask 5 other doctors and read a lot about it wherever you can.

In audio it is different.  People tell to each other – it is good because it has silver foil or acrylic platter or aluminum former or gold amalgam cathode. Ironically this expansion itself serves as some kind assurance of wide audio success. I use to annoy audio Morons by asking them “why”. Do not ask them why one “why” but follow up with 3-4 times, asking “why” each of their answer. The point is that most of their “answers” are not based on reasons but are based upon correlation between fan group they chose to be and the literature that the industry pre-develop for them to enable them to join the fan groups. Thos people do not talk but just subconsciously recite the adopted “vows”. The good part is that the “quotations” were prepared to them by industry marketing whores, who in borderline between idiots and lightweight simpletons. So, the digging 2-3 layer “why” usually exceeds the depth of the “conviction”.

The Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
04-29-2011 Post does not mapped to Knowledge Tree
Serge


Russia
Posts 51
Joined on 09-21-2009

Post #: 11
Post ID: 16185
Reply to: 16182
Keep the magnetism in the cartridge
fiogf49gjkf0d
 Romy the Cat wrote:
I do like the idea of magnetic suspension; I do not know why you feel that it is a stupid idea. As you built up the mass of your platter then very soon will not be able to hold the heavy platter at a single point bearing. The 20 point still cap sit on vertical bearing but 50 or 70 pound will not as the contact surface per mass ration will be too great. So, to use magnetic suspension in this scenario I fell is very cool idea. Pretend you have 100 pound platter but only 10 of them is being handled by bearing, the rest is elevated by magnet. I think it is an elegant solution as you would have high moment inertia combined with hard path to ground (important in my view).

Rgs, Romy the Cat


It's silly because the minuses outweight the pluses. In order to suspend the heavy disc constant magnetic field should be strong. This field will easily travel through the platter, since the platter is by definition non-magnetic. MC-cart will be actually moving across this constant magnetic field which will generate current in the coils, law of physics. This current will be uncorrelated to the audio signal generated by groove modulation. This is obviously bad.
Consider also that the 'constant' field from a permanent magnet is non linear (related to distance) in practice and will also cause some resonances between its 'springiness' (inductance in electronics) and platter 'mass' (capacitance).
So IMHO outwardly the magnetic suspension is nice but does not hold to further examination.



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04-29-2011 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,369
Joined on 05-28-2004

Post #: 12
Post ID: 16186
Reply to: 16185
Not necessarily.
fiogf49gjkf0d

 Serge wrote:
It's silly because the minuses outweight the pluses. In order to suspend the heavy disc constant magnetic field should be strong. This field will easily travel through the platter, since the platter is by definition non-magnetic. MC-cart will be actually moving across this constant magnetic field which will generate current in the coils, law of physics. This current will be uncorrelated to the audio signal generated by groove modulation. This is obviously bad.
Consider also that the 'constant' field from a permanent magnet is non linear (related to distance) in practice and will also cause some resonances between its 'springiness' (inductance in electronics) and platter 'mass' (capacitance).
So IMHO outwardly the magnetic suspension is nice but does not hold to further examination.

It is not necessarily true. Of cause no one wants to inflict cartridge by a stray magnetic flux but do you insist that it will?

The field from a permanent magnet is linear. It varies with distance but distance varies with mass. So, as platter sit on an array of magnates then it will self level itself and if there is no further vertical movement then it will be in very stable magnetic condition.

Now, let see what we have with magnetic field affecting cartridge. Your feeling that magnetic field should be strong I think is incorrect. The magnetic field shall be very week. My relatively heavy Micro 8000 platter is suspended by air but my compressor that pumps the suspension air is EVRY week (very small aquarium pump). Since the air is distributed across large surface of platter then there is no need for high pressure. The very same is with magnets. I see the magnets to be VERY week, not to mention that they might be focused with not a lot of stray magnetic fields. Do not forget that you do not need to levitate the platter 10” in air but just rise it for 1mm or juts unload the mass of the platter for let say 80%. So, I think that leaked magnetic forces, if any leek even takes please, will be so week that when it reaches cats if will be at the level of background magnetic noise.

I think it is very simple to measure the influence of the platter magnates to the cartridge. I never had magnetic TT but I am sure the people who do it measure it and take actions that the stray fields are not a problem at all. What I am saying is that if the magnetic fields would affect the cartridge and tonarms in any meaningful ways then no one would make the magnetic suspension on TT as the negative impact is VERY simple to detect. BTW, I do have magnetic suspended tonearm, I did not see any magnetic related problems with it. The tonearm sound like shit but not due to the magnets…

The Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
05-11-2011 Post does not mapped to Knowledge Tree
Serge


Russia
Posts 51
Joined on 09-21-2009

Post #: 13
Post ID: 16239
Reply to: 16186
Let's look at direct drive then
fiogf49gjkf0d
Okay, I see your point, though I feel there is something wrong about magnets in the MC catridge's vicinity. I will have arguments later, probably.
Now we can look at it differently. Remember direct drive? A motor sits right below the platter and emits a lot of electromagnetic garbage through it. Could it be one of the reasons that direct drive sounds incoherent and muddy?



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05-11-2011 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,369
Joined on 05-28-2004

Post #: 14
Post ID: 16242
Reply to: 16239
What is relevant.
fiogf49gjkf0d
 Serge wrote:
Okay, I see your point, though I feel there is something wrong about magnets in the MC catridge's vicinity. I will have arguments later, probably.
Now we can look at it differently. Remember direct drive? A motor sits right below the platter and emits a lot of electromagnetic garbage through it. Could it be one of the reasons that direct drive sounds incoherent and muddy?

Serge, a motor that sits right below the platter is enclosed in a metal can, why would it emits a electromagnetic garbage. BTW, years back when I was running non-shielded bare wises directly from the cartridge to a postage I did asked myself this question: does Motor enclosure of my TT affect anything electromagnetically. I had actually two turns of non-shielded and non-twisted wires to wind around my motor. There was absolutely no auditable effect or any kind. The only noise that I was able to pick up was nose that was coming from power cable to motor. So, I do feel that your preoccupation with “electromagnetic garbage” is a bit overstuffed. It is not that I insist that it is imposable – there are plenty foolish TT out there. However, if a TT was designed by a person with understanding of what she/he is doing then I do not think that electromagnetic from motion is a factor.

I do not know if direct drive sounds incoherent and muddy. They might, I did not experimented with them a lot. I had only one good direct drive TT (Micro Seiki) but I did not pay too much attention to it sound.  There are some direct drive TTs that claim that direct drive is more superiors then anything else. I do not buy it but I would also admit that we do not deal with topology general but with the specific implementation of the given topology. So, it is possible that a given specific TT, with the way HOW the things are done in this TT might have some problem but it will be no topological problem, but a result of specific blinders of this given design.

I personally tend to use TT with heavy platters and I feel that if a platter is substantially heavy then there is no different how you would drive the platter. Put a platter of 100kG then you will never recognize HOW the platter was pushed. So, all of these conversation about platters and way to drive them are for light platters, for heavy platter it is all become less and less relevant, up to the point of being irrelevant.

The Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
05-11-2011 Post does not mapped to Knowledge Tree
IslandPink
Posts 18
Joined on 02-08-2005

Post #: 15
Post ID: 16245
Reply to: 16239
Direct
fiogf49gjkf0d
 Serge wrote:
that direct drive sounds incoherent and muddy?


Oh yeh, the Technics SP10 sounds really incoherent and muddy .
05-11-2011 Post does not mapped to Knowledge Tree
IslandPink
Posts 18
Joined on 02-08-2005

Post #: 16
Post ID: 16246
Reply to: 16242
Motors for big platters
fiogf49gjkf0d
 Romy the Cat wrote:

I personally tend to use TT with heavy platters and I feel that if a platter is substantially heavy then there is no different how you would drive the platter. Put a platter of 100kG then you will never recognize HOW the platter was pushed. So, all of these conversation about platters and way to drive them are for light platters, for heavy platter it is all become less and less relevant, up to the point of being irrelevant.

The Cat


Like you, Romy, I did (intellectually) believe that the drive method on a heavy platter would make little difference.
I did however decide to spend a fair amount of money ( based on one or two reports from trustworthy contacts ) to try a rim-drive ( and more powerful ) motor on my Nottingham Hyperspace.
The Hyperspace has a 13kG platter made as a two-piece combo of aluminium alloy topped with carbon-ceramic.
It's normally driven by a small and weak AC motor and belt drive, aim being to make the motor noise as low as possible.

As I mentioned above it was really obvious within a few seconds that the rim-drive motor had improved the sound substantially .
Improvements were greatest in the bass but extended through to the midrange .
It's still quite hard to believe that the stylus drag can affect the speed of a platter this size, in any audible way, but it must be true .

I haven't had the option to hear this effect on a 100kG platter , but I guess it would be less.
However, I dont think many platters out there are really 100kG , or whether any of them are any good .

MJ
05-12-2011 Post does not mapped to Knowledge Tree
T3GGG
Posts 9
Joined on 02-06-2011

Post #: 17
Post ID: 16251
Reply to: 16246
Rim drive, ill try it and let you know my thoughts
fiogf49gjkf0d
My recently finished TT has the option of silk thread or rim drive. I will on the weekend when I have some quality time make a few small changes and see if I can add anything useful to the rim drive debate.
06-17-2011 Post does not mapped to Knowledge Tree
Serge


Russia
Posts 51
Joined on 09-21-2009

Post #: 18
Post ID: 16483
Reply to: 16251
Another one from TransFi
fiogf49gjkf0d
 
http://www.trans-fi.com/salvation.htm

Unknown (to me) manufacturer. Uk based? Seem to have some kind of lever to remove the idler from the O-ring after stopping the rotation.






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06-18-2011 Post does not mapped to Knowledge Tree
IslandPink
Posts 18
Joined on 02-08-2005

Post #: 19
Post ID: 16488
Reply to: 16483
Vic
fiogf49gjkf0d
He is UK based, somewhere down South near London. I bought one of his early Ladegaard arms , sort-of the Mk.1 version of the latest ones, and gave him some advice on areas like the counterweight etc. He is a very genuine and interesting chap who is selling some fantastic gear at really 'generous' prices, hardly any mark-up from cost.
Even on the early air-arms the performance was extremely good, with just a bit of 'greying' from the carbon-fibre wand , which was longer on the early ones. The latest design seems much improved in various areas.
It's still a bit messy to run an air-arm like this - more tubes, boxes ( pump, accumulator ) and difficult to get the pump quiet or far-enough removed, but I would consider trying the arm again in the future once I have the speaker and amp set-up finalised.
The deck looks like a great bargain too , if the motor is reliable and everything lasts OK .
04-26-2012 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,369
Joined on 05-28-2004

Post #: 20
Post ID: 18093
Reply to: 16173
I wonder if constitute Rim Drive TT?
fiogf49gjkf0d

RimDriveTT.jpg




"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
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