| Search | Login/Register
   Home » Analog Playback» Copper Mat on a Micro Seiki Gun Metal Platter (39 posts, 2 pages)
  Print Thread | 1st Post |  
Page 1 of 2 (39 items) Select Pages:  1 2 »
   Target    Threads for related reading   Most recent post in related threads   Forum  Replies   Views   Started 
  »  New  The Foolishness of Analog People..  Late to the discussion but cannot resist...  Analog Playback Forum     56  321447  01-30-2006
  »  New  Micro RX 5000..  Do not worry....  Analog Playback Forum     8  29336  11-09-2008
  »  New  Micro RX5000: is that bearing spins normally?..  How many turns do the good bearing......  Analog Playback Forum     7  10725  02-03-2014
10-07-2015 Post does not mapped to Knowledge Tree
Wellington


South Florida
Posts 11
Joined on 10-03-2011

Post #: 1
Post ID: 22028
Reply to: 22028
Copper Mat on a Micro Seiki Gun Metal Platter
fiogf49gjkf0d

My first post here, although I have read some of the discussions on this site over the years.

I wanted to share my experience with my Micro Seiki RX-5000 and resonance control of its heavy platter. I have seen posts here before about the bronze platter ringing. Romy suggested that a simple hard rubber mat would be the answer. I tend to agree, but I found another approach that I do not see explicitly written about here. Forgive me if my search failed to turn up this topic already addressed.

The concern is, of course, is that these resonances will color the mechanical pickup of groove modulations by the cartridge. The stylus, which is forced into motion by the music being played imparts opposing forces back into the vinyl and then into the platter. If the platter “answers back” with ringing at specific musical pitches and not at others, the cartridge will pick up these resonances too. You may not hear anything obviously amiss, since all transducers impart resonances, but they are there. Perhaps the best test is to play well-recorded piano which runs up and down the scales. Notes exciting resonances may sound slightly louder, with more smearing and sustain. When resonances are vanquished, the music flows with more ease and naturalness, all music, not only piano. Of course resonance control is valid for more than just platters - tonearms, cartridges, speakers and rooms matter too.

I have heard an argument that the forces imparted into the platter by the stylus must be so weak that they can’t possibly excite the heavy platter. Large heavy objects are moved by tiny forces. The motion is just correspondingly tiny. It’s all about relative proportionality. True, the excitations and resonant responses are very small, but then the cartridge is designed to pick up tiny groove modulations that can be measured in the Angstroms. And we follow that transducer with huge amounts of preamp gain. So, as weak as the excitations are, a phonograph system is equally sensitive in picking up their responses.

If you gently rap a turntable platter (even with a record on top) you can get a sense of its resonant properties. A sharp rap (perhaps with a plastic-tipped object like the handle of a screw driver) can impart a pretty good approximation of an impulse excitation into the object being tested. This impulse (an approximation of the "Dirac delta" function) excites the object equally at all frequencies and therefore excites resonances without having to perform a sine-wave sweep as excitation. With a microphone or an accelerometer and an FFT spectrum analyzer, you can see discrete frequencies representing resonances at the various modes of vibration.

The original gun metal bronze 5000 platter exhibits a primary bell-like resonance at 855 Hz. I’m guessing that this mode is due to the comparatively thin horizontal deck (just under the groove area) acting as a spring and the heavy peripheral ring as the mass. There are other modes too, but they are down much farther in level. The next most significant resonance is a damped one at 2258 Hz. There is nothing unusual here. All platters will exhibit resonances; it’s just the physics of things.

Micro Seiki offered a “copper” mat called the CU-180, which some of you may know about. This 1.8kg device is very popular with the Panasonic SP-10 crowd, but it can be useful with heavyweights like the RX-5000 too. Suspended by itself with something like a screwdriver shaft through its hole so that it is free to move (like a cymbal), it exhibits numerous resonances, at 51, 132, 312, 549, 844, 1182 and 1569 Hz and several spread higher in frequency. Think of it as a flat and thick cymbal. It might not seem promising, but it is.

The magic comes when you place a CU-180 on top of the RX-5000’s gunmetal platter. The pairing is completely devoid of readily measurable resonances. Together they comprise a constrained layer mechanism. The CU-180 must be perfectly flat so that is sits on the 5000 platter with no gaps or rocking. Never drop or bend a CU-180 because you’ll never get it perfectly flat again!

The improvement can be demonstrated easily. If you rap on the bare platter, you’ll clearly hear the pitch of the 855 Hz mode. When you rap on a suspended CU-180, you’ll hear the multiple pitches combining into a sound roughly reminiscent of a cymbal. Now combine the two pieces, and rap on the copper mat. A dead thud. It sounds like knocking on a concrete wall. The two devices have constrained each other from exhibiting their natural resonances.

Next, remove the CU-180, and then place a rubber mat of your choice back onto the patter. Rap again, and you’ll hear the muted, but still quite audible, 855 Hz mode. I have used a Fulton Kinetic Barrier mat, a very thick and well damped rubbery mat. It does reduce the ringing (shortening its duration), but the CU-180 quenches it completely.

Lately I have been playing with a sandwich. First the CU-180 is placed on the platter, then the Fulton mat (or a Micro Seiki leather mat) is placed on top of the CU-180 (minding the VTA adjustments). I have also experimented with the record sitting directly on the CU-180, and weighted down by the 1kg Micro Seiki ST-10 gun metal disc stabilizer . This weight forces the LP to sit on the copper mat’s surface tightly, with no air gaps that could cause buzzing or unchecked resonances. I have not yet formed hard conclusions about which configuration I prefer sound-wise, but I’m leaning toward the CU-180 without any compliant mat at all, in terms of pace and rhythm. One risk of any rubber mat or other compliant mat is that its top surface can shift in the shear mode relative to its bottom surface (without actually sliding) as stylus drag changes with groove modulation. Thus speed is thus slightly modulated by groove modulation, more like in a light platter table. I believe that if the record is held tightly and directly against the heavy platter surface with its high inertial momentum, the speed is less perturbed. More listening needed.

So, I can recommend that other 5000 owners experiment with the CU-180. As always, though, YMMV.

*******************************  

Chapter Two: Recently I had machinist Mirko Djordjevik make me a new 5000 platter out of 316L stainless steel. As most of you know, the platters on the last mega tables from Micro Seiki were made from stainless steel. The exterior dimensions and appearance are the same as the original 5000, but I had him bevel the inside edge of the peripheral ring to reduce the cantilevering compliance, and also we thickened the horizontal deck (just below the groove area). Mass went from about 16kg in the gunmetal platter to about 22.4kg in the new stainless platter. That’s roughly going from 36 to 49 pounds. We both believe that the spindle bearing can handle the higher mass. The new platter is a beautiful thing to behold, and tarnishing will no longer be a concern. The only resonance I could pick up was a well-damped one at 1667 Hz, which is about one octave higher than in the original platter, but lower in magnitude with little sustain. With the CU-180 on top, even that resonance was squelched entirely, and once again the sandwich is quite quiet. I have yet to spend time auditioning the new platter. > >




______________
Brian
10-07-2015 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,327
Joined on 05-28-2004

Post #: 2
Post ID: 22029
Reply to: 22028
That is very nice.
fiogf49gjkf0d
 Wellington wrote:
Perhaps the best test is to play well-recorded piano which runs up and down the scales. Notes exciting resonances may sound slightly louder, with more smearing and sustain. When resonances are vanquished, the music flows with more ease and naturalness, all music, not only piano. Of course resonance control is valid for more than just platters - tonearms, cartridges, speakers and rooms matter too.

It might be a valuable test but in most of the instances the “slightly louder” in this case would be a fraction DB that is not easy to get. There is “simpler” test but it would require to do recording as the test hardly exist in normal music. Take any key on a VERY good piano with no damper or with holding the key. Do it for let say 60 second and observe the wobbling of tone as it will be decaying. Not any piano would do it as most of them do wobble a lot. However, if you get access to a VERY good piano or allocate in your piano a key/note that happen does not wobble then record it, put in on LP somehow and you will have a VERY good tool to test anything you imagine. Do not use for this purpose a recording of decaying generator. You would need a complex cultural note, not just a fundamental pitch.
 Wellington wrote:
Lately I have been playing with a sandwich. First the CU-180 is placed on the platter, then the Fulton mat (or a Micro Seiki leather mat) is placed on top of the CU-180 (minding the VTA adjustments). I have also experimented with the record sitting directly on the CU-180, and weighted down by the 1kg Micro Seiki ST-10 gun metal disc stabilizer . This weight forces the LP to sit on the copper mat’s surface tightly, with no air gaps that could cause buzzing or unchecked resonances. I have not yet formed hard conclusions about which configuration I prefer sound-wise, but I’m leaning toward the CU-180 without any compliant mat at all, in terms of pace and rhythm. One risk of any rubber mat or other compliant mat is that its top surface can shift in the shear mode relative to its bottom surface (without actually sliding) as stylus drag changes with groove modulation. Thus speed is thus slightly modulated by groove modulation, more like in a light platter table. I believe that if the record is held tightly and directly against the heavy platter surface with its high inertial momentum, the speed is less perturbed. More listening needed.

Very interesting indeed. I never played with it as I had only bronze platter on my 5000s.
 Wellington wrote:
Chapter Two: Recently I had machinist Mirko Djordjevik make me a new 5000 platter out of 316L stainless steel. As most of you know, the platters on the last mega tables from Micro Seiki were made from stainless steel. The exterior dimensions and appearance are the same as the original 5000, but I had him bevel the inside edge of the peripheral ring to reduce the cantilevering compliance, and also we thickened the horizontal deck (just below the groove area). Mass went from about 16kg in the gunmetal platter to about 22.4kg in the new stainless platter. That’s roughly going from 36 to 49 pounds. We both believe that the spindle bearing can handle the higher mass. The new platter is a beautiful thing to behold, and tarnishing will no longer be a concern. The only resonance I could pick up was a well-damped one at 1667 Hz, which is about one octave higher than in the original platter, but lower in magnitude with little sustain. With the CU-180 on top, even that resonance was squelched entirely, and once again the sandwich is quite quiet. I have yet to spend time auditioning the new platter. 

Hm, if I had someone to make me a custom platter then I would probably go for curved platter, or a platter that has not plat but parabolic top surface with lockable center weight. This way a record would be kind of indented into the platter with a center let say one inch lower than the peripheral. Then I would set the azimuth of the arm (not needle) with a little angle (to be perpendicular to the record) and run an arm with no anti skating. The presumption is that mass of the arm that will be “continue falling” to the middle or the record should theoretically balance out the circumference force of the needle. How it would be in practice only God knows…
 


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
10-07-2015 Post does not mapped to Knowledge Tree
Wellington


South Florida
Posts 11
Joined on 10-03-2011

Post #: 3
Post ID: 22031
Reply to: 22029
Salad bowls
fiogf49gjkf0d

Interesting, but I have to say that does sound a bit problematic in several ways. For one, I’m guessing you meant to say “one mm”, or even “one quarter of an inch”, but not “one inch”. One inch is quite a soup bowl! For another, anti-skating force compensation must pull the arm toward the outside, because skating forces pull it inward toward the spindle. So you’d need an inverted bowl, higher in the center, to use gravity for anti-skating.>>

Perhaps you’re also trying to achieve a tight intimacy between LP and platter, without relying on vacuum clamping (which won’t allow the use of a CU-180 anyway). This reminds me of a simple idea. Decades ago, I bought a SOTA reflex clamp. It included a small rubber washer, which miraculously I still have after all these years. First you slip the washer over the spindle, then the LP and finally the clamp. When you tighten the clamp’s lever, the spindle is gripped and a clamping forced is exerted. So, before the force is applied, the LP is raised slightly higher in the middle by the washer, maybe 1 or 2 mm, with the LP edges drooping down toward the outer edge of the platter (barely visibly). When the clamp is tightened, it pushes down on the outer edges of the label area only, which is between the high spindle washer and the outer edge. The LP is forced to make contact with the platter first at the edges, but then all the way to the label, if you have a washer of the right thickness and the correct clamping force is applied. The idea here is to avoid the cupping problem that can occur with heavy record weights and some soft mats, where the heavy center force causes the outer edges to lift up into a shallow bowl. The SOTA clamp pre-biases the forces with the center lifting washer. BTW, the SOTA clamp works with Micro tables just as well. A simple test is, you guessed it, another rap test, only this time it’s a tap. With a (clean) fingertip, tap around the record’s playing surface while it’s clamped. You can hear any air gaps as “ticks” because the record will momentarily slap the platter when you tap over a void. After a while, I can pretty much determine how much force to exert with having to mishandle my records!>>




______________
Brian
10-08-2015 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,327
Joined on 05-28-2004

Post #: 4
Post ID: 22033
Reply to: 22031
How I kill my “what if” frustrations.
fiogf49gjkf0d
 Wellington wrote:
Interesting, but I have to say that does sound a bit problematic in several ways. For one, I’m guessing you meant to say “one mm”, or even “one quarter of an inch”, but not “one inch”. One inch is quite a soup bowl! For another, anti-skating force compensation must pull the arm toward the outside, because skating forces pull it inward toward the spindle. So you’d need an inverted bowl, higher in the center, to use gravity for anti-skating.

Hm, perhaps we imagine the process differently. In my view the anti-skating force compensation must pull the arm not toward the outside but rather toward to inside. The skating forces pull arm not inward toward the spindle but toward to peripheral. 
 
Regarding the tight intimacy between LP and platter. This is complicated subject. In some cases the tight intimacy LP and platter is great in some not. I have no idea what the rule is. I have seen the TT with LP were literally floating in air on 3 contact points and I have seen some crazy platter binding solutions. It is very hard to make a generalization between different TTs considering that they all produce different results and they never sit in the same room, setup by the same person.  My general feeling, based on extrapolation rather than empirical practice, advise me that as soon  LP and platter are bound and develop intimacy then many uncontrolled conditions begin impact sound: like own sound of platter. If it happens that your platter for instance “sound good” then it might be not a bad thing but I feel that to cancel out as much as possible variables is more stable way to go. It is like some people build SETs with 4-8uF last capacitor in B+. Then they go over the pain to choose the transformer, chokes, rectifier tubes and zillion other elements to make the output channel to sound good. I prefer to rise the volume of the last cap with would diminish or cancel the “sounds” of the preceding PS elements and “use” only sound of the output tube with  good but “default” PS. I feel the very same with LP and platter. I would like do not know about the platter sound this why I have think but hard robber mat on the top of my platter. I for sure do not insist that this is the only way to do but this approach make me to be at peace with my “what if” frustrations.


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
10-08-2015 Post does not mapped to Knowledge Tree
Wellington


South Florida
Posts 11
Joined on 10-03-2011

Post #: 5
Post ID: 22035
Reply to: 22033
Skating around the issue
fiogf49gjkf0d
Sorry, but I have to tell you that you do have it backwards on the skating forces. Just Google for a force diagram. Another way to know is to look at how the anti-skating force is applied in arms using the weight, pulley and monofilament line approach. In the classic SME arms, for example, the weight is on the record side of the arm, but it pulls on a point which is BEHIND the arm's pivot axis; so that the weight pulls the stylus-end of the arm outward. In my Triplanar, the weight is on the opposite side of the arm, away from the record, and is attached to a point on the arm in FRONT of the pivot axis. So it also pulls the arm outward, away from the spindle. Easy to confirm.
I think the notion of NOT having the LP in intimate contact with a well-damped and heavy platter is misguided, in fact terribly misguided. If the LP is forced into contact with a lively, resonant platter (as many are), that's not good either, of course, but it's the platter's problems that need to be fixed. The answer is not to lift the LP free from the platter. Perhaps starting with the Transcriptors turntable of decades past, to the odd Meitner Platterless table, several have tried a platter-less approach, and none have succeeded. Hold a LP freely in your hand in the usual way, and tap the surface. You will hear that plasticy sound. It's a characteristic sound, not neutral at all, not like tapping a concrete wall. Spectrum analysis shows a number of resonant modes especially at lower frequencies, depending on the LP's weight. Those are the sounds that will be underpinning your music if the LP is not forced onto a neutral platter surface. Look at how records are made: Scully and Neumann lathes used massive turntables with vacuum hold down for the lacquer. Early Neumann lathes had 65-pound platters, later ones went as high as 130 pounds, if I recall correctly. No mats, just hard vacuum pull down. Similar to...Micro Seiki!


______________
Brian
10-08-2015 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,327
Joined on 05-28-2004

Post #: 6
Post ID: 22036
Reply to: 22035
Everything is possible....
fiogf49gjkf0d
 Wellington wrote:
Sorry, but I have to tell you that you do have it backwards on the skating forces. Just Google for a force diagram. Another way to know is to look at how the anti-skating force is applied in arms using the weight, pulley and monofilament line approach. In the classic SME arms, for example, the weight is on the record side of the arm, but it pulls on a point which is BEHIND the arm's pivot axis; so that the weight pulls the stylus-end of the arm outward. In my Triplanar, the weight is on the opposite side of the arm, away from the record, and is attached to a point on the arm in FRONT of the pivot axis. So it also pulls the arm outward, away from the spindle. Easy to confirm.
The anti-skating force pulls arm outward? Sorry, I very much degree. In any arm that I have seen and that makes any sense, including the classic SME arms the anti-skating force pushes arms toward to middle. I think it is not even debatable and I am very surprise that we even talk about it.
 Wellington wrote:
I think the notion of NOT having the LP in intimate contact with a well-damped and heavy platter is misguided, in fact terribly misguided. If the LP is forced into contact with a lively, resonant platter (as many are), that's not good either, of course, but it's the platter's problems that need to be fixed. The answer is not to lift the LP free from the platter. Perhaps starting with the Transcriptors turntable of decades past, to the odd Meitner Platterless table, several have tried a platter-less approach, and none have succeeded. Hold a LP freely in your hand in the usual way, and tap the surface. You will hear that plasticy sound. It's a characteristic sound, not neutral at all, not like tapping a concrete wall. Spectrum analysis shows a number of resonant modes especially at lower frequencies, depending on the LP's weight. Those are the sounds that will be underpinning your music if the LP is not forced onto a neutral platter surface. Look at how records are made: Scully and Neumann lathes used massive turntables with vacuum hold down for the lacquer. Early Neumann lathes had 65-pound platters, later ones went as high as 130 pounds, if I recall correctly. No mats, just hard vacuum pull down. Similar to...Micro Seiki!

Possible that it is misguided. I do not have reason to stick to one or another side of the argument. I do feel that there are multiple options and it is not that one is clearly better but rather it has to do how any given topology is implemented. I am peaty sure that with any LP/platter topology (if a TT is well done otherwise) it is possible to get good result if to perfect this given topology and use proper empirical listening techniques.  


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
10-09-2015 Post does not mapped to Knowledge Tree
Wellington


South Florida
Posts 11
Joined on 10-03-2011

Post #: 7
Post ID: 22038
Reply to: 22036
Skating on thin ice
fiogf49gjkf0d
 Romy the Cat wrote:
 The anti-skating force pulls arm outward? Sorry, I very much degree. In any arm that I have seen and that makes any sense, including the classic SME arms the anti-skating force pushes arms toward to middle. I think it is not even debatable and I am very surprise that we even talk about

Well, I guess we talk about it until we agree! Do me a favor: I think we both have SME 3012 tonearms. Look down at the anti-skating weight hanging on a thread. The weight pulls down, which pulls on the rod extending over the back of the arm. This tends to rotate the arm COUNTER-CLOCKWISE. Therefore the stylus is pulled outward to compensate for the inward force of skating. I don't think SME got it wrong! I don't have time this morning to research and post links on the topic, but here's a somewhat silly video that does show skating forces acting on a tonearm: https://www.youtube.com/watch?v=YAPhIp8U9uA




______________
Brian
10-09-2015 Post does not mapped to Knowledge Tree
JJ Triode
Posts 75
Joined on 09-12-2007

Post #: 8
Post ID: 22042
Reply to: 22038
Direction of the skating force
fiogf49gjkf0d
I agree with Brian: the anti skating mechanism on my Grace 707 also works to rotate the arm outward, towards the edge of the record.  So the skating force (actually torque) it is fighting must be the other way.  It can be explained this way: the friction on the stylus is tangent to the record groove and tends to pull the stylus forward, in the direction the record is turning.  The vector component of this force along the arm is cancelled by the rigid constraint that the arm doesn't stretch, and the remaining component is clearly inward.
10-09-2015 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,327
Joined on 05-28-2004

Post #: 9
Post ID: 22043
Reply to: 22042
Enough please.
fiogf49gjkf0d
Are you guys catapulted from another planet or you are exposed to some kind of mass-hallucination? None of your arms have anti skating mechanism that rotate the arm outward, towards the edge of the record. NONE OF THEM. The anti-skating force is force that pushes arm toward to middle of the record


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
10-09-2015 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,327
Joined on 05-28-2004

Post #: 10
Post ID: 22044
Reply to: 22043
You are all wrong.
fiogf49gjkf0d
I got a number emails informing that I am fool and that skating force is so called because it causes the tonearm to push over the record from the outside to the inside. I went online and looks at all imaginary references. Yes, you are right that is what you and perhaps entire world call it… but I find that YOU all are wrong. 
 
What I experience is that an arm with no anti-skating tend to move from center of record to the peripheral and anti-skating force acts in opposite direction – toward to the mid of the record. Ironically my vision perfectly consistent with circumference force and the fact that a needle on the arm with not enough anti-skating has outside side worn more than inside. I have witnessed it multiple times under scope and I am a bit surprised how wrong you people get it.

Me


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
10-10-2015 Post does not mapped to Knowledge Tree
Wellington


South Florida
Posts 11
Joined on 10-03-2011

Post #: 11
Post ID: 22045
Reply to: 22044
Moving on...
fiogf49gjkf0d
Wow. What can I say? My intention here was simply to propose good news to owners of heavy Micro Seikis - to consider trying a CU-180 on top of their big platters. Somewhere along the line I had to gently correct Romy on a point has been common knowledge in the phono world for decades. The directions of the skating and anti-skating vectors are well known, logically explained, easily observed and incontrovertible. So, indeed, enough on that point.


______________
Brian
10-10-2015 Post does not mapped to Knowledge Tree
rowuk


Germany
Posts 212
Joined on 07-05-2012

Post #: 12
Post ID: 22046
Reply to: 22045
Common knowledge?
fiogf49gjkf0d
Who says that a myth told a thousand times becomes more real? Who has actually measured the wear on the stylus instead of just "trusting" the industry?
Romy may not be infallible, but he does only post first hand and for sure backs up his posts with facts.
Can I imagine the cartridge industry being not interested in reducing wear? YesCan I believe that very few people in the press really know what they are talking about? YesCan I believe that where a little bit of truth is, that the rest does not line up? Yes
It has not been an issue for me since 25 years due to use of various linear trackers.


Whenever I feel blue, I start breathing again.
10-10-2015 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,067
Joined on 10-12-2006

Post #: 13
Post ID: 22048
Reply to: 22046
Not Being One to Trust
fiogf49gjkf0d
what others say, I have used the following procedures to set my own "anti-skate" on my own pivoted tonearm: 1) level TT/platter 2) set-up arm/cartridge for minimal tracking error, including proper VTA/SRA and VTF 3) use ""blank" sections of (test) LP to see if the arm drifts (without compensation) 4) use "anti-skate" compensation to correct drift 5) use test record and ears to fine tune arm in/out balance, and verify over time with actual Music.

I don't need anyone to tell me that my own Well Tempered Reference arm tends toward the spindle without compensation, However, my present arm has a pretty unique "pivot", as well. I wish I could remember what I did with my old SME 3009, but I can't!, really. I had a Rega RB300 for a while, but any anti-skating issues were swamped by the "wiggling counterweight", at least until I invented the "Plastic Milk Jug Fix". But I think I remember the Rega tended inward, too.


Paul S
10-12-2015 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,327
Joined on 05-28-2004

Post #: 14
Post ID: 22054
Reply to: 22048
A confusion.
fiogf49gjkf0d
This weekend I played some records and was kind of confused. In my mind I went to this conversation and was sickened with the fact that “people do not understand obvious”. Then took my SME arms and pulled the anti-skating wait down with my head. The arm went toward to the side of the record. “What the hell” - I said. 
 
For the new couple of housrs I examined the issues for all possible sides and read a few paper on the subject: 
 
www.audiomods.co.uk/papers/alexandrovich_AES.PDF
www.audiomods.co.uk/papers/Oakley_skatingforce.PDF 
 
From what they say and from what how my arms are made Wellington for sure is correct: the skating force moved an arm toward to the mid of the record. It was for years my believe of very opposite, well it looks like I was wrong. 
 
However, for all intenede porpoise my analog setup functions poorly and all geometrical and sonic issues are worked up. I for years been operated under look like wrong perception of skating and my understanding of reasoning of skating have very direct relation with sonic practicality of arm setup. Despite that it might be wrong but I am still a believer that skating is a circumference force or the force of rotating subject applied to the tangent of circle drawing the subject away from the axis. In English it frequently call centrifugal force but I think the circumference force is more accurate.  The circumference force explains why different amount of anti-skating is necessary at beginning and in the end of the record: the local speed of the needle in the grove is higher and therefore the circumference tangent is higher in the end of the record. 
 
So, even there are very objective reason to presume that I am wrong but I still chose to believe that anti-skating force pushes the needle toward to the edge of record. If for whatever reason it does not then it would be a clear evidence that Nietzsche was right and God is dead.


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
10-13-2015 Post does not mapped to Knowledge Tree
be
Copenhagen, Denmark
Posts 86
Joined on 02-12-2007

Post #: 15
Post ID: 22058
Reply to: 22054
Skating force
fiogf49gjkf0d
Your circumference force is right, but when viewed from above it work clocwise around the lateral bearing of the arm, therefore the arm wil tend to move inwards :-)
10-13-2015 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,327
Joined on 05-28-2004

Post #: 16
Post ID: 22060
Reply to: 22058
My circumference force
fiogf49gjkf0d
 be wrote:
Your circumference force is right, but when viewed from above it work clocwise around the lateral bearing of the arm, therefore the arm wil tend to move inwards :-)

 Soory, Be, no matter how I look into it I can’t understand why circumference force would make the arm to move inward. If you spin your platter not at 33 but at let say 45 and pule some light subjects on the platter then they will be thrown off the platter. A needle and a tonearm are the subject of the very same forces and this is why LEFT side of the needle worn more if anticaking is not enough. The platter spins clockwise, so the needle left (the external) side pushed by circumference force press harder to the left side of the groove. It is not a surprise that the left side her more distortions and trucking problem when anti-skating is not enough. When you make a left turn at high spin then your car rolls over it’s right side- or outside of your driving trajectory…. Right?



"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
10-13-2015 Post does not mapped to Knowledge Tree
Wellington


South Florida
Posts 11
Joined on 10-03-2011

Post #: 17
Post ID: 22061
Reply to: 22060
The "C" words
fiogf49gjkf0d
 Romy the Cat wrote:

Soory, Be, no matter how I look into it I can’t understand why circumference force would make the arm to move inward. If you spin your platter not at 33 but at let say 45 and pule some light subjects on the platter then they will be thrown off the platter. A needle and a tonearm are the subject of the very same forces and this is why LEFT side of the needle worn more if anticaking is not enough. The platter spins clockwise, so the needle left (the external) side pushed by circumference force press harder to the left side of the groove. It is not a surprise that the left side her more distortions and trucking problem when anti-skating is not enough. When you make a left turn at high spin then your car rolls over it’s right side- or outside of your driving trajectory…. Right?

I think that the "C" words, centripetal, centrifugal and circumferential are causing you confusion. If a loose object is placed on a rotating platter so that it too rotates, and the centripetal force requirement is NOT met (which would be a constraint that would pull it toward the spindle. Imagine a string.), then the object will roll off the edge of the platter, because it has momentum and it seeks to travel in a straight line, not in a curve. In order for the tonearm to share the same motion as this object it would have to be rotating around with the platter. But the tonearm only pivots; it doesn't rotate with the platter. The skating force is not about those "C" words. Skating is simply caused by the friction of the groove walls passing by the stylus at an offset angle. Uncompensated skating force increases groove wall forces on the inner groove which is the left-channel side. The outer side, the right channel, sees a reduced force. If tracking force is high enough the stylus will stay in contact on both sides most of the time and distortion might be acceptable. In that case you'd expect more wear on the inner stylus surface. But if the tracking force is too low to overcome the skating force's reducing the force on the outer groove wall, the stylus will mistrack frequently on the outer right-channel wall with the stylus leaving the groove surface and then slamming back again. In this case the outer groove wall and the outer stylus edge will wear prematurely.


______________
Brian
10-13-2015 Post does not mapped to Knowledge Tree
alex
Posts 3
Joined on 09-13-2010

Post #: 18
Post ID: 22064
Reply to: 22060
.
fiogf49gjkf0d
 Romy the Cat wrote:
 be wrote:
Your circumference force is right, but when viewed from above it work clocwise around the lateral bearing of the arm, therefore the arm wil tend to move inwards :-)
Soory, Be, no matter how I look into it I can’t understand why circumference force would make the arm to move inward. If you spin your platter not at 33 but at let say 45 and pule some light subjects on the platter then they will be thrown off the platter. A needle and a tonearm are the subject of the very same forces and this is why LEFT side of the needle worn more if anticaking is not enough. The platter spins clockwise, so the needle left (the external) side pushed by circumference force press harder to the left side of the groove. It is not a surprise that the left side her more distortions and trucking problem when anti-skating is not enough. When you make a left turn at high spin then your car rolls over it’s right side- or outside of your driving trajectory…. Right?

Sorry Romy,We are talking about pivoted tonearm with overhang. That is the geometry  that creates force to pull the cartridge toward the centre of the record. If you take a moment to observe how anti-scate weight is attached to SME3012 ...you may find that it pools cartridge toward the edge of the record to compensate  force  toward the centre. Right  ?  When we are done with the anti-scate, as a free bonus I can also help you understand how NF EQ works in  EAR834P.
10-13-2015 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,327
Joined on 05-28-2004

Post #: 19
Post ID: 22065
Reply to: 22064
What can I say?
fiogf49gjkf0d

 alex wrote:
Sorry Romy,We are talking about pivoted tonearm with overhang. That is the geometry  that creates force to pull the cartridge toward the centre of the record. If you take a moment to observe how anti-scate weight is attached to SME3012 ...you may find that it pools cartridge toward the edge of the record to compensate  force  toward the centre. Right  ?  When we are done with the anti-scate, as a free bonus I can also help you understand how NF EQ works in  EAR834P.
 
Yes, Alex. The overhang’s parallelogram is how the technical papers above explain the “wrong” direction of skating. As I said above I chose to stay with my simplistic circumferential  force, my life with it is more comfortable, pleasurable  and I do not need to admit to myself that I was a Moron for years believing in opposite. I will not take your free bonus. S ince people like you expressed their interest to study EAR834P NF after I pointed to them out that the circuit sounds interesting then I will let other people, the people of my choosing, who explaine to me how EAR834P works.


Affectionaly,
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
10-13-2015 Post does not mapped to Knowledge Tree
alex
Posts 3
Joined on 09-13-2010

Post #: 20
Post ID: 22066
Reply to: 22065
..
fiogf49gjkf0d
 Romy the Cat wrote:

 alex wrote:
Sorry Romy,We are talking about pivoted tonearm with overhang. That is the geometry  that creates force to pull the cartridge toward the centre of the record. If you take a moment to observe how anti-scate weight is attached to SME3012 ...you may find that it pools cartridge toward the edge of the record to compensate  force  toward the centre. Right  ?  When we are done with the anti-scate, as a free bonus I can also help you understand how NF EQ works in  EAR834P.
 
Yes, Alex. The overhang’s parallelogram is how the technical papers above explain the “wrong” direction of skating. As I said above I chose to stay with my simplistic circumferential  force, my life with it is more comfortable, pleasurable  and I do not need to admit to myself that I was a Moron for years believing in opposite. I will not take your free bonus. S ince people like you expressed their interest to study EAR834P NF after I pointed to them out that the circuit sounds interesting then I will let other people, the people of my choosing, who explaine to me how EAR834P works.


Affectionaly,
Romy the Cat



" ....Since people like you...  "   Bravo !

Page 1 of 2 (39 items) Select Pages:  1 2 »
   Target    Threads for related reading   Most recent post in related threads   Forum  Replies   Views   Started 
  »  New  The Foolishness of Analog People..  Late to the discussion but cannot resist...  Analog Playback Forum     56  321447  01-30-2006
  »  New  Micro RX 5000..  Do not worry....  Analog Playback Forum     8  29336  11-09-2008
  »  New  Micro RX5000: is that bearing spins normally?..  How many turns do the good bearing......  Analog Playback Forum     7  10725  02-03-2014
Home Page  |  Last 24Hours  | Search  |  SiteMap  | Questions or Problems | Copyright Note
The content of all messages within the Forums Copyright © by authors of the posts