Hello Dertonarm,
>The "air-pulse" drive (no pulse would exclude a problem) has some considerable problems while looking close to a theoretical ideal first. It not only will require considerably (really serious...) periphery, but indeed a "assist"-motor to bring the (high mass) platter to requested speed first and than de-coupling.<
Weren't you asking about "all out",no compromise, no commercial consideration approaches? Did I not explain some of the caveats? Yes, the periphery would be expensive, but maybe not as expensive as it appears(remember, this is not about a commercially viable project).
The Onkyo PX-100M eddy current drive turntable does feature an idler drive just to bring it up to speed within half a revolution, then the eddy current drive takes over(and it has a break too). It can be done...
Platter speed needs to be monitored, which in turn can govern the force of the air(or any other driving) "pulse". It will have a VERY slow recovery time, but(that is where my chronometer analogy comes in) the disturbing influence of the drive system could be minimized.
To assess which principle is superior, we'd have to build two(or more) otherwise identical turntables that can be driven by more than one means. I have done this several times many years ago, Chris Brady has done this more recently, so his assesment holds merit, even if some may not agree with all of his peripheral design choices.
I suggest opening another thread to discuss that there is VASTLY more to building an excellent turntable then the drive principle, even though nothing else matters if the record doesn't spin at (as close to)constant speed to begin with.
Dertonarm, I didn't ask you any questions, I just showed that your approach is just as far from or as close to being perfect as some other approaches, at least from a conceptual/theoretical point of view. But that part of the discussion was doomed from the start... and yes, it's not neccessary to repeat yourself yet again.
Nevertheless, have an enjoyable and relaxing Easter weekend!
Frank |
Dear dertonarm: Good to hear it, happy holidays.
regards and enjoy the music.
Raul. |
I believe some models of Jeep/Chrysler used hydraulic cooling fan motors powered by the P/S pump due to the fact they are quieter. I would speculate that the main reason for using a hydraulic motor is more to do with the high-temperature environment in which the fan motor must operate, especially if used on the back side of the radiator. At these temperatures, copper conductors get pretty lossy, and when running a 12V motor (drawing 20-30 amps), they start to really add up . . . in windings, commutators, brush leads, wiring, relay contacts, etc. And then you've got make up for those losses in power generation . . . and when a cooling fan is most important is when the vehicle isn't moving, hence engine speeds are low, and the alternator suffers from poor effeciency. In this application . . . hydraulic makes lots of sense. But for a turntable, both air-vane and fluid-vane motors are far from vibration-free and cogless (go to an auto-body shop and listen to their air-vane-powered tools) . . . so there will be similar challanges as electric magnetic motors. Maybe an expanding-chamber screw-type armature fed by high-pressure hydraulic fluid? Then the problem is that you've got NO speed feedback, not even the fixed-frequency rotating magnetic field in an electric motor, and there's been disapproval voiced for a feedback speed control system. Believe me, I'm not completely poo-poo'ing the idea, but rather will be extremely impressed if these challanges (and all of the others that I've not thought of) are able to be solved. And of course I'll want to read all about it, so do keep us posted. |
Dear friends: IMHO the subject on speed accuracy/stability in TTs are almost addressed and solve by almost all the TT designers and manufacturers. We can take examples like Technics, Denon, Rockport, Walker, Kenwood, Basis, Pionner, SME, Monaco, Sota, Raven, etc, etc, where we find very good numbers on the subject that goes as low as 0.001% ( speed subject ) and figures on SN of 92db or WF of 0.015%.
So one way or the other ( different TT design approaches ) the spedd accuracy and speed stability are already achieved by commercial TTs.
Where I think there are a non-definitive solutions are ( like other people point out ) in self TT isolation and neutral build materials on each commercial TT design out there.
As Dertonarm poin out, the TT must does not have any " sound "/signature by it self that can add some kind of distortions/colorations that affect the cartridge quality sound reproduction, the TT must be " dead neutral ".
If we read any TT subject thread in this forum or in any other one we are reading things like this: the bass in this TT has a better bass that the other TT, it is warmer that the other ones, it is more alive that the others, the high frequencies sounds better, everything sounds lower in record noise, etc, etc, etc.
There is always a TT sound, so these TT are faraway to be neutral ( that is our target like customers. We are full of distortions/colorations to continue to accepting more. )
IMHO two main factors that contribute to those each commercial design TT " sounds/signature " are due to a poor isolation and what were the choose on build materials ( including the arm board ).
I think that is here where the commercial TT designers/builders have the greatest " room " to improve and achieve " neutrality ": for to have a TT running with speed accuracy and stability with out adding/removing almost nothing.
I think that the challenge is a big one but with a lot of rewards when solve for everyone.
The build material issue is critical, you can take how important is when you try different TT mats in your own TT: you have different sound quality level as different are each one mat and its build material.
This build material challenge is enormous if we take in count that exist hundred/thousands of build materials that can be use in the TT manufacture and million of blend/combination materials that could be use it, so not an easy task to have the " answer " but IMHO if we want to have better TTs ( any kind of TT. ) then we have to ask for to the commercial TT builders. I think that the " ball " is in their hands and I hope we can see in the near future ( and can buy ) that " neutral " TTs in favor of the analog music-sound home reproduction.
I know it can do it because I already experienced and " solve " something similar with our tonearm design.
Regards and enjoy the music.
Raul. |
Other subject that I would like that the commercial TT designers/builders could address and solve is to have a record " perfect center " mechanism.
This out-off center record hole is a " cancer " in the analog quality performance ( due to an extremely poor build quality of the record industry. ), we need a solution. I think on the TT builders because I don't think that the records industry can " hear " our needs.
There are other " desirable " characteristics that will be welcome in a TT design but for now I think these ones are enough.
Regards and enjoy the music.
Raul. |
out-off center record hole is a " cancer " in the analog quality performance ( due to an extremely poor build quality of the record industry. ), we need a solution. I think on the TT builders because I don't think that the records industry can " hear " our needs. This was made 25 years ago from a Nakamichi Turntable. It centered the record automatically. Too expensive for our days I guess.:) |
Yes, I know: the Dragon and TX1000. A friend of mine in San Diego and other one here own these units.
Raul. |
The build material subject could grow-up in complexity if we add that we must take in count that maybe we need different build materials for different TT parts and that each one of those build materials have to have a constant " behavior " under any " normal " TT operation condition forming a " synergy TT system ".
Regards and enjoy the music.
Raul. |
Dear friends: We are in a so imperfect home analog sound reproduction world with so low know-how that instead to use our main each day time to hear and enjoy music we are " loosing " our precious life time trying to correct that imperfect world that is full of imperfect hardware.
That's why exist so many forums everywhere. Take how many are here in Agon: more than ten!!!! and in almost everyone we are talking/asking to a better hardware, to a better up-dates in hardware, to a better tweaks, to a better, to a better....etc, etc and what about the main target: music sound reproduction and the " emotion " to enjoy it.
In a perfect world all those audio forums will change for a one and only: the music forum.
It is so imperfect that for some of us don't pass any single day where we don't " touch " the system hardware trying to improve even for some of us don't pass a single hour where we stay " calm/in-active ", name it like you want: changing VTA, VTF, load impedance, cables, speaker position, room treatment, new mat, rolling tubes, changing caps/resistors/inductors, new record cleaning solutions, DIY items, new clamping system, new belts, new or different something everywhere at each link in the whole audio chain.
A lot of fun but a misery on the time hearing music where we are not thinking how to improve but only enjoying that music sound reproduction.
Well such is world: nothing is perfect.
Regards and enjoy the music.
Raul. |
Dear friends: We are in a so imperfect home analog sound reproduction world with so low know-how that instead to use our main each day time to hear and enjoy music we are " loosing " our precious life time trying to correct that imperfect world that is full of imperfect hardware.
Rauliruegas (System | Threads | Answers) Well said, now if you'll excuse me, I'm going to listen to some music for a few hours. Thanks for the inspiration Raul. |
Out-of-center record hole. An important point. Still on holiday, but just a short note:
I solved that problem in my earlier design in 1992. Not with a complex motorized approach as Nakamichi did, but with a total mechanic approach - very simple and very effective. Everybody will find the solution himself following one simple hint:
- do decrease the diameter of the center spindle from approx. 7 mm to say 3-4 mm.
Now you have the option to adapt, with a small set of very simple - you can most likely even make it yourself at home - devices, to any excentricity of any given LP.
I will leave it to our "professional" TT designers to pick up the idea. Maybe the "german fraction" will find the solution in older reports about my old design. It was featured there. |
Dear Dertonarm: I'm thinking in an automatic solution ( like the Nakamichi one, I don't mean the same. ) but I can see that will be not only complex/expensive but with some trade-offs on the whole TT performance so the manual/mechanic one could/can be a good alternative in the mid-time ( maybe the one that works with almost no compromise other that the customer has to do it, but the customer ( through a jig ) has to make too in manual way the tonearm instalation so that will be not " big deal ". ) waiting for an automatic self-design TT ( we have the right to dream about. ): it is an interesting challenge.
Regards and enjoy the music.
Raul. |
Dear friends: I want to return a little about our analog imperfect world. It is imperfect because the " medium " is an imperfect one but the imperfections growing-up to fast on each link in the whole analog chain starting/begining with the recording sessions: choice of micros, choice of micro recording positions, choice of cables on those micros, choice of tape recording machine and the tape it self, reconding console, enginner whole priorities, choice of vynil material, choose of head-cutters, choice..., choice, choice, etc, etc
We don't have any control on the recording process and as you imagine in each link on that recording process the signal suffer a different kind of degradation, so when we " receive " that heavy degraded signal the best we can do ( in theory ) is to mantain it with no additional degradation ( impossible that this can happen. ).
There are so many places where the signal goes worst and worst due to its native imperfect " world " and it is not only that those different links made/makes a constant signal degradation but you can take the RIAA double process ( first one at the recording and the inverse one in the phono stage ) where the signal manipulation is to heavy.
Why I point out these facts ( and many other that exist. )?
Well, I think that we can do better if the designers/builder of audio items put on the market products that through an analisis of the real analog medium/customers needs can " cope " some of those imperfections, I mean that those audio items could help to the whole reproduction process trying not only add the less and lose the less but " understanding " things like : why we need that " perfect center " mechanism in TT? why we need neutral product quality performnce? why we need flat speaker electrical impedance? why we need extremly lower distortion figures on electronics? why we need lower output impedance on amplifiers?, why..., why... and why's.
We can take an example that almost no one cares about ( the why's ), today the LP industry are growing-up through new realeases and re-issues with several small manufacturers ( that live from the customers. ) where I think they can/could put a little care to the LP process will assured that LP perfect center hole: well no one of them cares about!!!!!
Almost all audio items out there I think were designed with out take in count real several Why's, so that's one reason why we always are on the tweacks: we need FINISHED audio items, not an easy task but we all ( customers an audio industry ) have to try about.
Things are hard for we customers to achieve good quality performance in our home audio systems: it is a " long long road to home ".
One way to make things " easy " and better is through the designers/builders of audio items. Of course that like I post it is not easy and not because they are not good enough to do it ( I honest think that they can do it ) but because we have to be ready to pay for those " great " and useful audio items.
Many of us already made/making audio items with that " philosophy " in mind and I'm sure that we follow making in the future but what we need is that the " full commercial " audio items industry take this kind of " road ".
I always say that we need to grow-up ( real grow-up in the right direction. ) but IMHO this is almost impossible if the whole audio industry ( recording, designers, builders, reviewers, dealers and customers. ) does not grow-up.
Regards and enjoy the music.
Raul. |
IMHO the fun in our " hobby " must be the MUSIC enjoy and not the endless quest of tweaks.
Raul. |
As I can see there are none that want to share his thoughts on the different subjects, maybe is not important for other than me.
Anyway I will follow " alone ".
Mybe I'm wrong but I think that things ould and can be better if each ( any ) link audio item in the audio chain will be more " friendly " against the other links, I mean that the audio item manufacturers could take in count the environment ( audio chain ) where its product will work and how that product can works in better synergy with that audio chain environment.
This " friendly " attitude help to perform better to each audio item in the audio chain: each audio item will be more " strong" as the other ones are " strong " in that audio chain.
Sometimes seems to me that some audio items were designed and manufactured like if them goes to work in an aisle environment taking no care of what surrounded it. I think that this un-friendly " attitude " goes against the whole quality performance.
Maybe could help if in someway some " institution/audio industry association " could define a minimum audio industry "sandards " in the more critical areas/stages/links to warranty a minimum synergy/friendly between audio components.
Today is almost an anarchy that don't help to anyone in the audio industry, IMHO we need a minimum of " order ".
Which are the " subjects/factors" that can impede that happen? do you think that could help us? am I totally wrong?
Your thoughts ( any ) are appreciated.
Regards and enjoy the music.
Raul. |
the fun in our " hobby " must be the MUSIC enjoy and not the endless quest of tweaks. Of course. But you can enjoy music via MP3, too The normal Audiophile wants to have a "better" reproduction and is willing to pay for it. Unfortunately, money alone is not enough today. Marketing and"I can hear better than you" or the "...he has money, but no idea about music ..." influences every decision...not easy. Would a electronic Standard help? Don't know, when I listen to Denon or Kenwood or Accuphase, I can say, all got the Standards but I am not in the reproduction.... 25 years ago, there was an audiophile community which was able to afford anything (was not part of it, I was too young) and they really knew what was good or not. They created a High End Magazine, knew all Manufacturers and wanted to give a Demo in the High End show to show the customers how they listen to Music and how they rate the "reproduction". Long Story short, they were ready to give a demo with their own components... Before this was done they made a Pre-Demo and invited some top Manufacturers to listen... the result was depressing....they have been asked not to do that, when customers will "hear" that, they can't sell their units.... It was cancelled. The customer wants not "only good sound", he wants more, a good "test", a "Hype", something "exclusive", something"expensive, no more expensive" etc. etc. etc. And then we should not forget those, who are not among the Genius in this world, but they want to survive too. And to make a little money (or a bit more :)) Sometimes I am a bit sad, because I think, the Know How is existing, but this is not enough today. Having success is not based on this, it is based on Marketing mechanism (Profit, Sales, Ads, Promotion....) On the other side, what would happen, when a Designer would be able to create a definitive unit for 8K consumer price? For a few this would be too cheap to be good....or a piece of wood on a string for 6k, yes, this would work.... |
Syntax, I think the electronic standard is probably best simplified, at a minimum, to mean making input and output impedances fall within a certain range for every component downstream of the amp's inputs, and making source component output voltages within a certain range. Trying to get speaker mfrs to all provide a flat frequency response curve and impedance curve, and to all jump on the 'power paradigm' is kind of a lost cause.
As to your other point that customers want more than just 'good sound' (they want a certain look, cachet, convenience, hype, or exclusivity), I am convinced it is true, which is why having a designer create a "definitive" component is effectively a lost cause too.
OTOH, I have some really great pieces of wood on a string (limited edition (exlusivity), coming in their own signed paulownia box (cachet - looks), which I am certain will be popular (hyped) after the first few people buy them, which I can sell for even less than $6k, shipping included (convenience). Inquire within :^) |
Dear T_bone, I totally agree with Syntax and you. For the love of music - we do not need high end gear at all to appreciate music.
Beethoven string quartet op 132 will have its impact via an MP3 player or the car stereo as well as via a million dollar high-end set-up.
High-end is a nice playground to satisfy the longing of man for something absolute and gives us a microcosmos where each and everyone can produce his/(seldom...) her own dogma of something "best" in every subjective way possible. Today high-end is sold not only via sound - it is sold much more via the price tag (ask any high-end dealer in HongKong or some of the manufacturers of rather elusive components that they do not sell less when the lift up the price, but more) and the image related to it.
This is a very strange part of the luxury market.
Its not about quality - its about image, "face" and "show off".
All we need to simplify high-end is adapting some of the standards from the professional audio segment or PA. Matching impedance (600 Ohms for instance..) would make most super high-end cables and their effect null and void. But honestly - none of you would like to listen to a speaker with flat frequency response curve ..........
Flat impedance curve and easy load would eliminate in one moment 85% of all high-end speakers. Expect low power consumption and the next 10% will be gone for good.
We should accept High-end audio the way it is - a childrens playground.
The difference between the boys and the men??
The price tag on the toys.
Nothing else. |
There are some little " things " that can help if we take it like " standards ".
If we take the phono cartridge like an example we could ask for: same horizontal distance between stylus and center cartridge mount holes, this simple " standard " could permit to mount the cartridge and forget about overhang ( with different cartridges ) because the tonearm manufacturers with that distance " standard " their tonearm headshell holes ( no slots. ) will comes at exactly the right position to set up in automatic way the overhang in any cartridge, this seems to me a " friendly " standard.
Other could be that the cartridge connection pins always be at the same position in relation to left/right ,+/- . One more that the stylus angle always be at the same angle, example: 20 degrees, not 17 or 23 degrees.
We can/ould take each audio item and think ( analize its relationship with the others. ) on " simple " things that can/could help in many ways.
It can help for example that the CDP's comes with the same output level.
It could help too if the tonearm arm board shape be the same/similar for all pivot tonearms.
For the people that own more than one TT ( different ones )it could help that the height position of the arm board in relation with the top of the platter will be a " standard " height.
T-bone " touch " the impedance subject that is very important and exist other" technical " areas where is important to fix standards. Btw, I think that all kind on " ideas " are welcome on the " standards " subject.
I think that are many subjects/factors where we can fix/define " standards " that will be help to anyone it does not matters what we customers/manufacturers have on " mind "/attitude: the " standards " serve to help to the whole audio industry, we are part of that audio industry.
The main subject is not only to make things more easy/friendly but to obtain better audio system each link synergy in favor of better quality performance.
With that kind of minimum " standards " the off-center record hole cancer will disappear and all of us will be really " happy " on it and we don't need to think in a mechanism to fix it.
IMHO there is no reasons why everything has to be so complicated when/where this complexity goes almost always against the quality performance of our home system reproduction.
Regards and enjoy the music.
Raul. |
It is a nicer challenge to build a wonderful sounding system with a minimal budjet than buying the most expensive items. I learned alot with the Lenco threads, the MM/ MC thread , Quad 57 thread to apreciate the "downgrading" pathway , maybe I find my "kid" pleasure again ! |
This is the sign of a BAD design Bearing Friction a good table should have very very little. |
Dear Ebm, it depends - bearing friction doesn't necessarily means increased noise. In some of the smarter designs bearing friction is introduced by oil bath, eddy current and the like to increase speed stability and damping of platter. But some of the other semi-pro's here on Audiogon will (and have already during this thread) tell you more about this. If bearing friction goes with increased noise (= low quality bearing) however I do agree with you - thats a bad design. |
To fix standards on the audio industry can help to the " new " people in our high-end world while they achieve experience with.
That " standards " does not have to be " extremes " one but only at " minimum ", so the toy-play will be " respected ". The record perfect-center hole can't go against almost no one but persons that can say: " hey I want to fix it ( toy-play ) please leave in that way... ".
The whole idea on the standards subject is for more positive, serious and open mind in favor of our hobby.
Other desirable subject on the high-end industry could be " quality standards " where an audio item/device must pass some test steps where it show that meets ( or not ) those " quality standards " and when achieve it then that audio item will show a official certification about, something like the ISO standards. This could help that we can buy better products with better quality and stop to find out that " three " days from the day we buy and audio item it has some failure: this happen every day even products that goes to a reviewer comes with defects in its operation.
IMHO if we want to be better ( overall ) we have to ask for be better, don't you think?
Oh yes we can enjoy music through a walkman either, but this is not the issue.
Regards and enjoy the music.
Raul. |
I think the correct term is "bearing drag", not bearing "friction". Friction would implicate 2 surfaces contacting each other and if that was the case there would be no place for oil, and as such, you would have a very noisy bearing.
Furthermore, a well made bearing would have a hardened shaft, be cylinderically ground, and the bearing housing would be honed to accept the rotating shaft with perhaps 0.0001"-0.0002" clearance at most. |
Dear Frank_sm, if you look real close, you will find that almost ALL bearings in turntables ( not just the old Well Tempered Turntable ...) AND gimbal bearing tonearms as well as ALL pivot tonearms do indeed consist of two surfaces contacting each other. Most of these do feature oil to lubricate the bearing and to decrease wear and noise - but in the end (aside from magnet bearings, pure air pressure and oil pressure bearings ( and all of these have to be horizontal AND vertical )) almost all (NOT all.....) bearings in use in audio components do indeed feature surfaces ( 2 or more..) contacting each other. |
Dertonarm, magnet and air bearings also have their own drawbacks. Magnet bearing a'la Verdier bears the platter weight with no friction but features conventinal journal bearing, which is more loaded, and most importantly less evenly loaded due to inherent instability of magnetic repulsion system: magnets are trying to slip sideways with the side force increasing as the deviation from perfect concentricity of the two toroidal magnetic fields increases. I'm not familiar with any other magnets arrangement addressing lateral instability, do you?
High pressure double air bearing (vertical and lateral) is near close to perfection, providing compressor noise, water condensation, air contaminations and pressure fluctuations problems solved. In addition, it shall provide possibility to safely "land" the platter in case of sudden pressure loss, otherwise axial bearing may be easily ruined. This is the first rate engineering problem by itself, bearing in mind very small air gap.
What do you think about hybrid bearing: magnet axial bearing combined with air journal bearing for lateral stability? Sounds crazy complicated, but who cares? |
Dear Livemusic, I have been involved in lateral/vertical air bearing for 5 years and given an air bearing with a large number of individual "openings" - a sintered material for instance - there is no problem with "safe landing" in case the air supply breaks down. Water, dust and micro particles, fluctuation and pump frequence are problems all solved long ago in todays high-end air-supply applications with the approbiate technical applications (3-way filters, surge tanks, air dryer etc. etc.). The vertial magnet bearing is applicated in the Verdier for several reasons.
That it still do feature a conventional lateral bearing - well, why not?
Today I see the most potential of improvement for high-end turntable bearings in oil-pressure conical bearings. |
