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  »  New  Michael Fremer Continuums…..  Pre-manufactured box speaker...  Audio News Forum     54  431964  01-21-2006
  »  New  The Foolishness of Analog People..  Late to the discussion but cannot resist...  Analog Playback Forum     56  404505  01-30-2006
  »  New   A longer turntable belt...  SP10 and the Japanese contribution to audio...  Analog Playback Forum     60  367425  02-02-2006
  »  New  My Analog Playback: the fat lady has sung..  My analog setup update....  Analog Playback Forum     9  83974  04-04-2006
  »  New  Micro Seiki SZ-1T..  I guess it's my own fault....  Analog Playback Forum     2  25209  06-10-2008
  »  New  Dynamic viscose stabilization of turntable’s platter...  Will not work...  Analog Playback Forum     14  72911  11-26-2008
  »  New  Active Tonearm Monitoring System...  The most idiotic idea I’ve ever seen...  Analog Playback Forum     2  24853  07-14-2009
  »  New  The HoroMusic turnable...  And the 27" long tonearm might be a Moronic as thi...  Analog Playback Forum     6  46787  08-05-2009
  »  New  Audio Note new turntable and inflation..  When I see the crap like this thing…...  Analog Playback Forum     13  102141  01-03-2010
  »  New  How much does it cost to stabilize a turntable speed?..  How much does it cost to stabilize a turntable speed?...  Analog Playback Forum     0  12292  03-13-2010
  »  New  A turntable platter as a turbine?..  A turntable platter as a turbine?...  Analog Playback Forum     0  9744  10-27-2010
03-17-2008 Post does not mapped to Knowledge Tree
hagtech


Hawaii
Posts 117
Joined on 02-13-2006

Post #: 51
Post ID: 6933
Reply to: 6931
Rotating Discs

Sounds like a Tesla turbine.

jh

03-17-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,545
Joined on 05-28-2004

Post #: 52
Post ID: 6934
Reply to: 6933
Tesla?! OK, I’m in a good company! :-)

Actually I was more thinking about skin friction drag. Did you throw the stones to slide off the water? All that is necessary is speed of rotation of this thing…

http://en.wikipedia.org/wiki/Skin_friction

In fact if this thing reaches own cruse high-speed rotation then the vertical bearing might be even dropped as it would hold itself strictly vertically under the principles of angular momentum. It is similar to the old sea navigation systems that maintained orientation in gimbals…

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
03-17-2008 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,157
Joined on 10-12-2006

Post #: 53
Post ID: 6935
Reply to: 6934
A recent patent and keeping it reel
I was actually looking for something else when I ran across this:  http://www.patentstorm.us/patents/6955469-description.html                          I'd need to see the drawings to figure out if/how this idea relates.

Of course Romy's idea has to be closely retained in its axes in order that the arm/cartridge could do its job well.  But at the same time it should stay +/- decoupled to keep its other advantages.  Combined fluid drive/suspension might still allow for a small captureDrinks bearing of some sort that would serve as a 3-D control point.  If the height and vertical center could be controlled this might yet beat the usual motor/belt/levitation idea.

The idea of slots and/or grooves for fluids cut into captured shafts is old, AFIK, but it is also tried and true.  I have no idea how far this idea has been taken, though.

Best regards,
Paul S
03-27-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,545
Joined on 05-28-2004

Post #: 54
Post ID: 7019
Reply to: 40
The Da-Vinci Audio push ups.

The Swiss company Da-Vinci Audio that use to make very interesting LC phonocorrector it looks like trying to hit the jackpot with TT design. I look at all the TT that are being made I never stop wondering what the ultimate from my point of view shape of Micro Seiki 8000 never was embraced by other companies. The way how Micro did the bases was the simples possible and that allow putting in the same footprint max among of arms with unlimited design, since the arm-boards allowed spinning on their pivots. Well, it looks like the Da-Vinci has gone there:

http://www.da-vinci-audio.com/Turntable/reference_turntable.htm

They use a heavy platter with vertical magnetic bearing. The same design only with this older model according to them was 100kg – it already a solid mass. I hated their older design - it is what people do for stupid visual appeal instead of the best implementation of the functionality. The new design, it looks like it is a prototype right now is very good and it should make a TT that is very convenient to deal with. I hope then will make it with a reasonable price and I hope it will sound well. Yep, the reasonable price it is exactly what should be expected from Swiss manufactures and this US distributors!

The only criticism that I would express about the new Da-Vinci TT idea is that they allow only 2 pivots for armbords – it should be 3 as there is one extra space that is not being used. In the rest I applaud the direction the Da-Vinci Audio has gone with this new TT objectives.

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
03-27-2008 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,157
Joined on 10-12-2006

Post #: 55
Post ID: 7020
Reply to: 7019
Back to the disc/platter interface
It appears that in most cases like the DaVinci, the gigantic platter is used only as rotational mass.  And in most other cases where the manufacturer does speak of the platter as an impedance sink, either the platter material seems ill suited to the task or the disc is none-the-less poorly coupled to the platter.

I have recently seen two designs that attempt to seriously address the disc/platter interface without a vacuum holddown, namely the Townshend Rock V and the Walker.  Both of these designs use an adjustable spacer at the spindle that is said to give purchase to a wide screw-down clamp that in turn is said to do a uniform job of coupling an avaerage disc to a platter that is designed to be a sink.

The Townshend eschews the vacuum because of the cost and because of ruumors of record damage caused by particle embedment caused by the vacuum's force.  I have noticed no such damage in 20 years of using the (low pressure)vacuum, by the way, and I have never used the thin, soft mat Sota offers as a sop, either, since I prefer the sonic results when my records rest directly on the hard "interface" mat itself.  Anyway, no "embedment" issues in my case.

The most  interesting thoughts on "no vacuum", IMO, come from Lloyd Walker.  He likens the sound/effect of the vacuum holddown to the sound/effect of driving along in a modern car with the window just slightly cracked open, where whatever "it" is  "goes away" when you hit the button and the window closes tight.  Walker insists that there is always noise from even the slightest leakage along the disc/platter/stylus interface, and he insists he eschews the vacuum because his system "sounds better".

Well, I have never seen a clamp that actually creates uniform pressure across a disc the way even a low pressure vacuum can do it.  But I have not seen or tried Townshend's or Walker's systems, either.  Townshend must be re-thinking his own system, however, since he has mentioned trying a rim weight to aid the center clamp.  Again, the idea is more about the "impedance drain" than about just flattening the record, although that is a good idea, also, IMO.

Sad to say, neither of these otherwise-interesting TTs have provisions for multiple cartridges, although I suppose it would be possible to fit a multi-wand type arm onto the Townshend.  I have to say I would really like to be able to easily use a mono cartridge and also I would like to have the option to play 10" discs and 78s, as well, and I can't do any of these things at present.

C'est la Vie.

Paul S
03-28-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,545
Joined on 05-28-2004

Post #: 56
Post ID: 7028
Reply to: 7020
The negative curve as disc/platter interface solution.

I still feel that there was nothing more elegant in the disc/platter interface invented then the negative curve and all those vacuum or “no-vacuum” solutions are half-ass solutions. The negative curving is longer to engage but it takes time until vacuum builds up as well….

I would personally discard the whole subject, as I do now, and would play the records without forcing them to do anything then just freely lay atom of platter. But I am a freak in it as I do not like even the records camps. I have camp but I hardly ever use it….

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
03-28-2008 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,157
Joined on 10-12-2006

Post #: 57
Post ID: 7029
Reply to: 7028
Playing Taps

Romy, what do you mean by "the negative curving is longer to engage"?  I picture a platter that has been machined to the negative trace of the LP face but without any means to "engage" the LP unless there are further stipultions, such as weights, clamps or vacuum; in other words, the negative trace itself is just a "mirror" resting place where the disc sits +/- , according to how flat it happens to be, unless and until the disc is made to conform and sit perfectly tight by other means.  Of course Micro did have high-tech vaccuum TTs available, too, although I know nothing about them, nor do I know anything about their propritary clamps, if they had them.

It appears however that I am the oddball, with the vacuum, since the vast bulk of TTs are sold and used without any means, let alone any effective means, to couple the LP to the platter, negative curve or no, and most people who use the clamps believe they are just flattening the warped LP with them.  While many people want to think they are coupled, most of that lot basically does nothing active to ensure that it happens.

If anyone following along has used low-pressure vacuum for a while and then gone away from it, please speak up and offer some intelligent reasons for your switch.  Although Lloyd Walker makes some very interesting observations during his clamp versus vacuum arguments, the "tap test" and subsequent listening comparisons have convinced me of the generic fact that well-done coupling is very beneficial.  In my comparisons I hear no advantages in loose discs.  Needless to say I am curious to hear the Walker, although it could be pretty scary, given the ancillary equipment they all seem to use.  Even so, as I laid out in my "Balls to Shop" thread, there might still be some There there.

Best regards,
Paul S

03-28-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,545
Joined on 05-28-2004

Post #: 58
Post ID: 7031
Reply to: 7029
I hate vinyl records ceremonies

 Paul S wrote:
Romy, what do you mean by "the negative curving is longer to engage"? 
The negative curving works only with very heavy clamp and it takes time/efforts to put the clamps on and to press it strongly.  It makes playing records as too much ceremony. The negative curving platters do not do well without clamping. It I possible to use an insert but it defeat all purposes
 Paul S wrote:
Although Lloyd Walker makes some very interesting observations during his clamp versus vacuum arguments, the "tap test" and subsequent listening comparisons have convinced me of the generic fact that well-done coupling is very beneficial.  In my comparisons I hear no advantages in loose discs.  Needless to say I am curious to hear the Walker, although it could be pretty scary, given the ancillary equipment they all seem to use. 

I am NOT a big fan of Lloyd Walker, I do not pay a lot of attention to what he says and I genially am not happy with what he does or willing to do.

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
03-28-2008 Post does not mapped to Knowledge Tree
enjoy_the_music
Strasbourg, France
Posts 12
Joined on 02-21-2007

Post #: 59
Post ID: 7032
Reply to: 7031
Walker turntables and Technics sp-10mk3
Funny thing is that recently I had 4 Walker Proscuitto owners buy Technics SP-10mk3 motor units from me in a matter of 2 weeks. I think a guy in the states, who had said Walker TT, also created a plinth for the Technics and it happily put the Proscuitto to the carving knife...and that was using an SP-10mk2!

Regards

Richard
03-28-2008 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,157
Joined on 10-12-2006

Post #: 60
Post ID: 7033
Reply to: 7032
How likely is that?
Richard, by "Proscuitto" may I assume you mean, "Proscenium", or whatever name the Walker thing actually goes by?

Yes, the "Tech-ies" are a rabid bunch.  I love their AA threads!

Given that Walker's TTs are so dear, and anyone who buys in is thereby deeply invested, the wave of negative sentiment you describe must have generated a lot of buzz in the Walker Camp.

Certainly Walker's ideas have to be taken out of the context he himself has established for them in order to even begin thinking about them clearly.

I also dislike the extra work involved with vinyl, but I do it for the sound quality.

What happened with the Versa?


Best regards,
Paul S

03-28-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,545
Joined on 05-28-2004

Post #: 61
Post ID: 7034
Reply to: 7032
The “critical” motors for heavy belt turntables

That is a whole another subject all together. I truly have no strong opinion on the subject but I do hear a lot of talking noise about the “quality” of motors for heavy belt driver turntables. My idea is that with a sufficiently heavy platter and proper tension of belt the influence of motor should not be issues for sound. Some people disagree and invest a lot of efforts, or at least talk into the motors. Go figure….

AC motors, DC motors, synchronous, asynchronous, brushed, brushless, big and powerful motors, under-powered motors, and motors with heavy flywheel… whatever people use. A friend of my a few years ago wanted to manufacture extremely advanced TT and he invested months of searching and huge financial efforts into founding of a “perfect motor” for TT. He calmed that it is virtually imposable to found a “right” motor for TT. Eventually he found some in Austria I believe some old new stock motors that he claimed “are the only one type of TT he have seen that could do the job”.  I have no idea what his problems with motor were, as well I am not exactly compostable with his technical justification but he did invested a LOT into the notions of “perfects” TT motor.

Interesting that I have purchased from him one of those outragesly expensive “unique and perfect” TT motor, more expensive then the cost of some turntables in many hi-fi installations. I made that “unique” motor to drive my Micro 8000 TT and… I heard nothing different. There was literally no impact if it was a different motor, so the “unique” motor is sitting in my storage….

I think that all fantasies about motors in case of use of heavy TT are not warranted...


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
06-15-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,545
Joined on 05-28-2004

Post #: 62
Post ID: 7580
Reply to: 40
The 47Lab’s ways.
I stopped yesterday at Borders and looked through current Stereophille magazine. It looks like 47Lab came up with their turntables. In the magazine there was an article about the TT by Mike Framer. Framer is the dirty Pampers of audio and I routinely ignore his writings but flipping the pager further I found an interesting note from 47Lab owner of designer (I have no idea who it is) about the 47Lab’s turntable objective. Basically he proposed to make TT very live from the viewpoint of isolations, damping and vibrations and to put a disk and a needle inside of the “live” and vibrant environment.

The idea is not as bogus as it sound but I do not believe that this might be accomplish on production series model as there are so many “on location” variables involved. So, I fell that commercial initiative itself is faulty but the idea as an inspiration I think is very valid.

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
06-20-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,545
Joined on 05-28-2004

Post #: 63
Post ID: 7613
Reply to: 40
The TW-Acoustic turntable.

Actually it is surprisingly interesting. It is a German company and they do a fascinating and it appears to be appealing turntable

http://www.soundscapehifi.com/tw-acustic-raven-ac-pics1.htm (you can click the images to enlarge them)

I like the configuration: simple and with no-nonsense. The base looks like polymer presumably with solid mass. The platter is steel-type, presumable non-magnetic. The TT has not too overlay sophisticated bearing but the top layer of platter – the brose layer is decoupled from the bottom steel layer with polymer layers. I am sure that if the density and mass of that polymer layer to tune properly then the design might yield very interesting results. I like the idea quite a lot.

The same company does the 3-motor version that I believe is foolishness…

http://www.soundscapehifi.com/tw-acustic.htm

…but the initials direction of the TW-Acoustic I found quite fascinating. I never seen it or heard it but it looks like it is $10K turntable - very much worth attention.

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
06-20-2008 Post does not mapped to Knowledge Tree
coops
London, United Kingdom
Posts 115
Joined on 02-16-2007

Post #: 64
Post ID: 7614
Reply to: 7613
TW
Romy, Thomas  Woschnick makes superb turntables, I bought one with my own money, I don't sell them! It has the pitch stability of a DD but with far superior dynamics, it is a no nonsense design, superbly engineered and manufactured. Keith.
06-20-2008 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,157
Joined on 10-12-2006

Post #: 65
Post ID: 7616
Reply to: 7613
Interesting because presumed +/- simple (for a change)?
Tough to find anything without a gimmick or three these days, for sure.

Well, I wonder about a few things, like the 1/8" "round" drive "belt", the copper surface (why copper, other than exclusivity?), and I also wonder if there is a provision on either bearing face to retain and redistriubute displaced lubricant, because I didn't notice anything like this.  Additionally, if they are on the right track with their approach, then why do they think their top model needs 3 motors?  This MIGHT put this particular model into the "Accidental Success" catagory, right along with most other decent audio "products".

Also, still griding the same old axe, are TT manufacturers really saying vacuum HD does not help, or are they just avoiding  it to keep costs "in line"; or are they just not dealing with it?

Still, I think materials choice here is better than the "carbon fiber" for this application, although if polymer, then I think sintered material is best, at least according to tap tests.

But it is likely better than solid acrylic (also according to "tap" tests).

Nice arm mounts...

Still looking for the Ultimate Turntable...

Paul S
06-21-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,545
Joined on 05-28-2004

Post #: 66
Post ID: 7625
Reply to: 7616
The TW’s idea of making active turntables.
Paul,

What attracts me to the TW TT is the idea that it is possible to discard anything that we might consider important but to make the platter as a sandwich what the bottom of the platter care bearing but the top of the platter is decupled from the bottom by some kind of anti-resonance layer. The concept I think is superbly powerful. It to plug into the game some very serious materiallogists then I think it might be possible to make an collection of the insertion rings with different level of viscosity and energy-transfers characteristics that might be placed between the bottom and top of a platter and tune the sound of turntable to what is necessary. Very cool idea of making active turntable instead of staticly-made design. Pretend that you get a TT base with a collection of 10-20 insertion rings and you in your own room ( considering how your TT install, what arm, cartridges, and zillion other criteria that influence your sound) is able to tune the TT to sound neutral in your specific circumstances. After you done you return the leftover rings to the manufactures. I think it is incredibly powerful concept, Very liberating concept!

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
06-21-2008 Post does not mapped to Knowledge Tree
Paul Costa
Posts 11
Joined on 04-30-2006

Post #: 67
Post ID: 7632
Reply to: 7625
TW
TW Acustic latest website here only in German though.  http://www.tw-acustic.de/00000198640aab305/000001985b0e5e29a/index.html

I have had the AC single motor for almost two years now.  Coming from an SME 30 I personally enjoy the TW more and find its pitch stability superior to the SME.  It can handle long or short tonearms and more than one as well.  Once set up not much to check other than speed which has never drifted for me.  Nothing else to touch once level it stays there etc...

Aparently the new powersupply for the motor makes it sound even better, but I have not heard it or the three motor.  I would like to hear the three motor but really do not have any interest in owning it.  Much debate on the synchronization of the three motor tables, some folks say it deos more harm than good.  But TW uses only one belt and the belt has minimal surface contact with the platter perimeter.  How it makes any sense I do not know.  They say it has a bigger sound and better pitch stability and more torque with less belt contact.
06-21-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,545
Joined on 05-28-2004

Post #: 68
Post ID: 7634
Reply to: 7632
The wickedness of ‘smart’ TT’s power supplies
 Paul Costa wrote:
Aparently the new powersupply for the motor makes it sound even better, but I have not heard it or the three motor.  I would like to hear the three motor but really do not have any interest in owning it.  Much debate on the synchronization of the three motor tables, some folks say it deos more harm than good.  But TW uses only one belt and the belt has minimal surface contact with the platter perimeter.  How it makes any sense I do not know.  They say it has a bigger sound and better pitch stability and more torque with less belt contact.

Paul, I have a lot of attitude toward it and I believe that 3 motors, 5 motors, 543 motors is very idiotic direction. Why a minimal surface contact with the platter shell be better? A belt applies moment to platter only in the area of initial attack of platter. The rest of the belt juts lay on plate with no effect at all. Why we need more torque in belt moment? We need opposite - as soon the platter hit it;s cruise speed we need less torque. I also do not know how all that PS paranoia for TT motors makes any sense. You see: those types of the tables, with platter of over 10kg have absolutely enough stability from a passive, regulated low-torque motor. They are stable and do not worry about the stability. Then the designers introduce the sophisticated systems of the motor management, with servo, with sensors, with feedbacks… you name it… all those extra intelligence in motor make a bad damage to sound of TT. When a single belt drives a relatively heavy platter with low BUT CONSTANT torque then the micro-beating in the bearing is stressed on one side and the TT is in a perfect dynamic equilibrium. As soon the torque begin to fluctuate then the TT’s bearing jumps out cruise beating and all hell get loose. The CONSTANT torque in a way biases the platter bearing. So, I see all conversations about better PS in TT as marketing BS the has absolutely no relation to actual sound

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
06-21-2008 Post does not mapped to Knowledge Tree
hagtech


Hawaii
Posts 117
Joined on 02-13-2006

Post #: 69
Post ID: 7635
Reply to: 7634
Belt torque
Wow, I never thought of that before.  But you could be right.  Perhaps the only section of belt contact that matters is that last inch or two before it leaves platter.  Clearly the belt does not push, it can only pull.  And if belt has some elasticity, then you are right, and only the last few inches.  Then again, too little contact and the belt may slip.

The concern about pulling the platter off bearing axis has always been an issue for me.  That is why the two motor system that has pulleys on both sides of platter can help.  It does not add an extra lateral force on bearing.

I've seen and heard the Raven tables, met the designer.  He puts everything he can into them.  I believe the copper was chosen for sonics, not because it looked different or had good thermal or conductivity parameters.  The tables are extremely well built, and appear to be machined to extraordinary tolerances.  If I had the cash, I would not hesitate to buy one of them.  They deliver a lot of dynamic range.

jh
06-21-2008 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,157
Joined on 10-12-2006

Post #: 70
Post ID: 7636
Reply to: 7635
Anticipating "problems"
Jim, isn't the idea is to do the bearing so the nominal (and constant) side load is OK, versus trying to "control" all speed and balance parameters with tricky electronics and/or multiple drives?  As near as I can tell, platter inertia makes nominal errors of a decent low torque motor +/- a non-factor, as opposed to manic attempts to elevate motor function to "perfect speed control", let alone adding "balance" issues.

It just seems like lead or some type of heavy sintered plastic/resin/composite have got to sink vinyl (and resist other sound) better than copper, which last I checked rings like a bell.  And Romy's "tune-able" platter/interface is genius, the only way to fly, now that I think about it.

But then,  I have never yet spoken with or read a blurb by a TT designer who couldn't "explain everything".  And of course the smart ones explain everything better ;>Wink

I grant that it looks expensive, all right; a real piece of work...

Best regards,
Paul S
06-21-2008 Post does not mapped to Knowledge Tree
hagtech


Hawaii
Posts 117
Joined on 02-13-2006

Post #: 71
Post ID: 7637
Reply to: 7636
Copper

I'm not convinced a constant side load on bearing is good.  It causes assymetrical wear.  Just seems to me a center balanced bearing with no lateral loads would be better.  Merely an intuitive hunch.

As for the copper, yes, it will ring all by itself.  But reaction is much different when sandwiched or clad.  I think what the designer is trying to do is an impedance match or translation.  We go from soft vinyl to a hard and damped sink.  Putting the vinyl directly onto the mechanical sink is not right.  The idea is to convert from one impedance to another in a broadband manner.  Same as with a horn!  That is what rubber or felt mats do on most tables.  The copper on the Raven replaces the mat.

jh

06-21-2008 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,157
Joined on 10-12-2006

Post #: 72
Post ID: 7639
Reply to: 7637
"No lateral loads"
And what, really, is the "wear factor" for a TT side load?  At least you can +/- "trap" the bearing that way, and certainly it can be engineered to accomodate?  'Just the Ockham in me talkin'...

I like the sandwiches for certain types of damping/isolation, but someone is going to have to show me how the "impedance conversion" here actually works with purely disparate materials, especially right at the point of disc/platter interface, without leaving something to get back (to the stylus), particularly with the usual/typical "loose" disc.  I have seen/heard everything from glass to "dots" to wood, cork, paper, rubber, felt, etc., etc., and I think my main problem with copper is that it just seems like it was basically "intuited" and/or pulled out of a hat as it may/may not relate to vinyl compounds.

Since I've already bought into sintered materials, I hope it's clear that I like the idea of "broad band" and "sink"; but wouldn't the path at least begin with a closer match to vinyl?  In any case, I have never seen anything rigorous on this, TTs being at least 50% snake oil; more expensive = better art/longer blurb...

Best regards,
Paul S
06-21-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,545
Joined on 05-28-2004

Post #: 73
Post ID: 7640
Reply to: 7637
Copper, assymetrical wearing and the theories.

 hagtech wrote:
I'm not convinced a constant side load on bearing is good.  It causes assymetrical wear.  Just seems to me a center balanced bearing with no lateral loads would be better.  Merely an intuitive hunch.

Yep, the center balanced bearing is certainly better but dues it exists in a real word. I would say it never exists. The assymetrical wear is night not be good but… it is where the bias of a platter with a belt of constant torque makes the wearing irrelevant.  If cause they are all hypothetic theories and how it all works in a real word I have no idea.

 hagtech wrote:
As for the copper, yes, it will ring all by itself.  But reaction is much different when sandwiched or clad.  I think what the designer is trying to do is an impedance match or translation.  We go from soft vinyl to a hard and damped sink.  Putting the vinyl directly onto the mechanical sink is not right.  The idea is to convert from one impedance to another in a broadband manner.  Same as with a horn!  That is what rubber or felt mats do on most tables.  The copper on the Raven replaces the mat.

I agree that it is not advisable to use copper without a mat. When I was in Japans I had a dinner with Micro-Seiki designer and I ask him why some of the identical Micro TT have copper or steel platters. He explained to me that copper platter by nature have idiosyncratic colorations that he felt was it a offset for SS electronics of 70s and 80s. I used Micro a few 1500, 3000, few 5000 and 8000. The 1500 had steel and I was able even to lay the record on the platter. Other 1500 with copper platter were too colored. I never was able to play the 5000 and 8000 with any heavy platters, in fact the 5000 need a special platter.

So, I think that TW’s copper top is not a big deal. The most important is how the TW’s people made and tuned the middle insert of the platter – here is where all hart of this TT lives in my view. If they “voiced” it interestingly then it shell be an interesting turntable. How much elections they stuffed in PS and how many motors they made their customers to buy is irrelevant and serve only the objectives of Framer-level BS literature.

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
06-22-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,545
Joined on 05-28-2004

Post #: 74
Post ID: 7643
Reply to: 7625
How to take the TW’s idea of active platter further.

 Romy the Cat wrote:
What attracts me to the TW TT is the idea that it is possible to discard anything that we might consider important but to make the platter as a sandwich what the bottom of the platter care bearing but the top of the platter is decupled from the bottom by some kind of anti-resonance layer. The concept I think is superbly powerful. It to plug into the game some very serious materiallogists then I think it might be possible to make an collection of the insertion rings with different level of viscosity and energy-transfers characteristics that might be placed between the bottom and top of a platter and tune the sound of turntable to what is necessary. Very cool idea of making active turntable instead of staticly-made design. Pretend that you get a TT base with a collection of 10-20 insertion rings and you in your own room ( considering how your TT install, what arm, cartridges, and zillion other criteria that influence your sound) is able to tune the TT to sound neutral in your specific circumstances. After you done you return the leftover rings to the manufactures. I think it is incredibly powerful concept, Very liberating concept!

I would like to take the idea of the TW company further - just a pure fantasy.

pretend we have the same platter at Tw has with mass-loaded bottom, light top and middle anti-resonance section. The anti-resonance section is not the polymer that TW uses but a two sandwidges of light multilayer mater similar to what Kevin Tellekamp uses - a chemical saturated foam that resonates ant temporary hardening at given frequency. Those two sandwidges are divided by air bubble. Now, we install the TT, set up and then we attach to the platter a bicycle air pump and begin to pump air into the air bubble inside the platter. The air bubble with the raise of pressure presses the side of the sandwidges, changing the frequencies where the sandwidges operate. So, we effectively implement a situation where a platter might be fine-tined for the specific ant-vibration characteristic that might take place in a given TT situation. BTW, the same sandwidges-air-sandwidges decupling might be used between a TT’s base and the tonearms….

If it works then would you like to take it further: be my guest. Let the fantasy to fry and let call the concept as Active Suspension.  Pretend a TT with Active Suspension, eclectic compressor and high precision manometer shadowing psi in the platter bubble. Then pretend an electromagnet at the bottom of the base with an anchor making a mechanical ping to the body of TT. Then a phonostage has a scope hat allows read from the cartridge the bottom base ping. By modifying the pressure of the bubble and changing the ant-vibration and damping characteristics we monitor on the scope a regular impulse response of the entire TT suspension. We can even set a desirable pressure for a given records thickness, pressing type, type of music… whatever….

Rgs, 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
07-07-2008 Post does not mapped to Knowledge Tree
ducatirider
Posts 3
Joined on 07-07-2008

Post #: 75
Post ID: 7756
Reply to: 7643
Vibration Control - too much of a "good" thing?

newbie here but this interests me as i have the baby raven one.  the platter of the ac is hollowed out and filled with a gel and then topped with the copper "mat".  why is this important?  because vibrations exists is 2 forms, s-waves or rolling waves and p-waves or compression waves.  in a fluid, s-waves do not exist (think about it, how can a fluid roll?).  this leaves just the p-waves.  as the p-wave passes through the different materials, some will be refracted and trapped in the boundary layer, some will be attenuated and continue on it's path and some will be reflected.  reflection is what we want to control.  this design eliminates much of the vibration propagation but one needs to be careful not to make the table sound too dead or there will be lifeless sound with no dynamics.  so voicing becomes as much an art as a science.

the raven one platter is homogenous, made of one like material.  it still sounds great though.

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