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Guest Hensa

Innovative Headshell - The Nasotec Swing

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The turntable with the best speed stability and control is direct drive.    Once heard done well, DD is quite intoxicating with its continuousness.

 

sorry - off topic  :D

Edited by metal beat

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I always wonder why companies who make headshells don't allow longer cutout lengths in them or more toward the front.

Thinking of past turntables and pics online, the majority are mounted right towards the end or it does not quite fit as they run out of room. I don't think I have seen one right back in a headshell.

The one right now, just fits but might try another(Jelco one) to see if it makes any difference.

 

How is the Swing?

 

 

Mine

 

attachicon.gifIMG_3582.jpg

 

You can swap it out for the Orsonic AV1 --it moves on the two Axi's 

post-107838-0-51559300-1459151758_thumb.

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If your measurements are not faulty, then something else is causing it, not the variation in (pulley diameter plus half belt thickness), which has no effect, as Owen mentioneD

 

Nearly, but not quite correct, belt thickness makes no difference if the two pulleys are the same diameter, but is only an approximation if the two pulleys are different sizes.

 

There is in fact always one and sometimes two mechanical effects that cause the effective diameter of a turntable drive pulley to be larger when a thicker belt is used.

 

1. The belt has a finite width or thickness. When it rolls around the pulley, the inside half of the belt is compressed, and the outside half is elongated; if this did not occur the belt would break. More length of 'straight' belt contacts the pulley than there is length of pulley contacted. This makes the pulley "appear" larger in diameter than it actually is, by a function related to the the diameter of the pulley and the thickness of the belt, and hence the amount of compression of the belt inner contact surface. The effect is greatest when the belt dimension are close in size to the pulley dimensions, which in the case of a turntable is the drive pulley.

 

2. In the case of Rega turntables and some other turntables, the belt runs in a 'v' groove in the drive pulley. The larger the diameter of the belt, the higher it rides in the 'v'. The higher in the 'v' the belt rides, the larger the *effective* diameter of the pulley.

 

In the case of my Rega turntable, the sub-platter has a diameter of 101.25mm, the motor has a rotational speed of 250 rpm, the desired speed of the turntable is 33⅓ rpm. Therefore the diameter of the drive pulley required is 33⅓ ÷ 250 x 101.25 = 13.5mm exactly. The contact radius where the belt (an 'O' ring) sits in the 90 degree 'v' can be calculated using trigonometry and the diameter at the bottom of the groove (12.0mm) and the diameter of the belt (1.80mm) to be being 13.27mm (disregarding of course any tension that pulls the belt in). If this was the effective diameter of the drive fully, the platter would run ½ rpm slow.

Edited by johnmath

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Does the device have a spring in its joint? It looked that way in the video, and I'm trying to think what would be its purpose.

 

The pivot does not specifically have a spring, but the headshell wires do act as springs and it is important that they are dressed symmetrically side to side to prevent introducing a bias that would also introduce a tracking angle error. The importance of this is stressed in the Nasotec user manual.

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Nearly, but not quite correct, belt thickness makes no difference if the two pulleys are the same diameter, but is only an approximation if the two pulleys are different sizes.

 

There is in fact always one and sometimes two mechanical effects that cause the effective diameter of a turntable drive pulley to be larger when a thicker belt is used.

 

1. The belt has a finite width or thickness. When it rolls around the pulley, the inside half of the belt is compressed, and the outside half is elongated; if this did not occur the belt would break. More length of 'straight' belt contacts the pulley than there is length of pulley contacted. This makes the pulley "appear" larger in diameter than it actually is, by a function related to the the diameter of the pulley and the thickness of the belt, and hence the amount of compression of the belt inner contact surface.

 

Not with rubber, though: the middle of the thickness stretches just as easily as any other part, and so only the pulleys' diameters matter.

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Not with rubber, though: the middle of the thickness stretches just as easily as any other part, and so only the pulleys' diameters matter.

 

 

Sorry, that is an approximation only unless the pulleys have the same diameter.

 

Draw a rubber belt going around a circle in sections - where the belt is straight the inner and outer sides are the same length, when it is curved they are not. The dimension that does not change is (approximately) the centre line through the belt. The effect has to be taken into account or the turntable speed would be wrong with the pulley diameters alone, as I have shown above. Even when taking into account the riding height of the belt in the 'v' groove, the effective diameter of the pulley is too small to run the turntable to speed. If you add the thickness of the belt measured from the contact surface to the centre of the belt x 2, the speed works out to three significant figures, namely effective pulley diameter of 14.508 versus a 'required' diameter of 14.500. The 'contact' diameter of the pulley is 13.272. Believe me I have been measuring the effect of belt thickness on turntable speed for the last few months and have bought around 20 different 'standard' and 'upgrade' Rega belts to test. In all cases if there is a speed error it is proportional to average belt thickness 'error' with thicker belts running faster.

 

I just checked the output frequency of the Rega TT-PSU which is crystal locked and it is correct to 6 figures on my HP counter, hence the motor is running at a fixed and correct speed. The only variable between measurements is the belt.

Edited by johnmath

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Don't know what happened there... 

Edited by johnmath

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Guest Muon

Anyone still testing this head shell in the real world?

 

Just curious..

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Guest Hensa

Anyone still testing this head shell in the real world?

 

Just curious..

 

I'm assuming it's on its way to Tassie and @@125dBmonster at this point... :thumb:

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Guest Muon

@@Hensa

 

Cool, with all the hypothetical I wasn't sure if that had taken over from real world results.. or not.

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Guest

Hello @henza, yes believe so, some time this week.

Looking forward to setting it up and giving it a run, on the old Micro, belt drive  ;)

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with all the hypothetical I wasn't sure if that had taken over from real world results.. or not.

 

Have you seen some of the 'real world results' from exotic cables? Or even cheap cables reversed so the music 'flows backwards through them'? The 'real world results' for these products are highly persuasive and should be enough to convince anyone to part from vast sums of money. I mean, if 'real world results' are in fact 'really real' and 'the ultimate test', then that's that: every cockamamy BS con job and made up nonsense explanation, and every thicker piece of wire, every thinner piece of wire, every better-shielded wire, every shielding-removed wire, every thicker faceplate, every metal-less cabinet, every spike added, every spike removed, every homeopathic medicine, every crystal, every pyramid, they all work fantastically well if we are to base everything on 'real world results'.

 

So, if you are saying what I think you are saying, namely that a critical mass of testimonials is a 'real world result', then every vacuum cleaner is the best in the world, every real estate agent is the worlds best at getting the highest price for sellers and the lowest price for buyers, and every solid-state amp with a disconnected-but-glowing valve on its top plate has 'organic analog sound', guaranteed, just read the testimonials!

 

Are you sure this assessment method works?

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Guest Muon

Newman, I said what I meant, don't over analyse things, or read into things further than needed to discover what does not exist.

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The next step thinking scientifically is after it has been established that those who have tried it have found the technology beneficial is to ask the question of why it has a positive effect to the sound and try to understand more extensively how it works.

 

 

Marty makes an important point... 'science' is always only a set of hypotheses formulated to explain what we firstly observe.

Not the other way around.

 

Cheers, Owen

Dark Lantern blog - http://darklanternforowen.wordpress.com/

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Marty makes an important point... 'science' is always only a set of hypotheses formulated to explain what we firstly observe.

Not the other way around.

 

If that were true, there would be no record players or CD players, or transistors or computers. It is the application of science that allowed these inventions to be first imagined, and then realised.

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I think science uses both theoretical ideas and observations. Isn't science about studying the world around us, testing theories, and proving or disproving the theory, and in the process learning something. What came first. The chicken or the egg?

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Guest Muon

In Physics you have Theoretical and Experimental.

 

A Theoretical Physicist  has no need to experiment. A Experimental Physicist applies the theory through experimentation.

 

Edit: Both these guys need each other.

 

 

 

Hehe...I like this..

 

Psychologists think they're experimental psychologists.
Experimental psychologists think they're biologists.
Biologists think they're biochemists.
Biochemists think they're chemists.
Chemists think they're physical chemists.
Physical chemists think they're physicists.
Physicists think they're theoretical physicists.
Theoretical physicists think they're mathematicians.
Mathematicians think they're metamathematicians.
Metamathematicians think they're philosophers.
Philosophers think they're gods.

Edited by Muon

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First we use our senses - to observe, to see, hear.

Then we attempt to understand.

 

I think it was Lynn Olson who said.... 

You can measure all you want, but a mass spectrometer isn't going to find a lot of difference between lunch at a high school cafeteria & the best dinner at a four-star restaurant.

 

;)

Cheers, Owen

Dark Lantern blog - http://darklanternforowen.wordpress.com/

Edited by Owen Y

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Yeah but the hifi system is more like the plate you eat it off of, not the food itself. Lynno's comparo was more relevant to listening to The Kinks at a sleazy 60's joint vs the Berlin Philharmonic at the beast theatre in town.

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In Physics you have Theoretical and Experimental.

 

A Theoretical Physicist  has no need to experiment. A Experimental Physicist applies the theory through experimentation.

 

Edit: Both these guys need each other.

 

 

 

Hehe...I like this..

 

Psychologists think they're experimental psychologists.

Experimental psychologists think they're biologists.

Biologists think they're biochemists.

Biochemists think they're chemists.

Chemists think they're physical chemists.

Physical chemists think they're physicists.

Physicists think they're theoretical physicists.

Theoretical physicists think they're mathematicians.

Mathematicians think they're metamathematicians.

Metamathematicians think they're philosophers.

Philosophers think they're gods.

 

Sensational!  :thumb:

 

Andy

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If set up correctly most conventional arms have very low tracking angle errors, as my mate says in an email today

< Yes there are many good articles in Wireless World of the 70's analyzing these low errors, they even designed an articulated arm (like a windscreen wiper) to eliminate tracking error -but the lack of mechanical stiffness more than offset the minor tracking errors -and tracking error mostly affects parabolic/elliptical stylii rather than traditional conical ones >

 

 a bit of looking around, found them, good reading

 

Pickup Arm Design - 1: JK Stevenson (Wireless World May 1966)

http://www.helices.org/auDio/turnTable/stevenson.pdf

http://www.hi-fiworld.co.uk/vinyl-lp/37-technology/71-arm-geometry.html

 

Pickup - arm Design Techniques: Teijinder Singh Randhawa (Wireless World March 1978)

http://www.audiomods.co.uk/papers/randhawa_pickupdesign.PDF

 

here's another good reference:

Tonearm Geometry and Setup: MD Kessler and BV Pisha (Audio Jan 1980)

http://www.melbourneaudioclub.org.au/pdf/tonearm.pdf

excellent article on practical setup, includes a table of popular 1980's arms' effictive lengths, overhang etc

 

Tangential arms are better, in theory...... in practice, very problematic engineering wise:

servo motors, air bearings, parallelogram (and associated bearings) they've all met with difficulty in execution

 

regards Ian

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If set up correctly most conventional arms have very low tracking angle errors, as my mate says in an email today

< Yes there are many good articles in Wireless World of the 70's analyzing these low errors, they even designed an articulated arm (like a windscreen wiper) to eliminate tracking error -but the lack of mechanical stiffness more than offset the minor tracking errors -and tracking error mostly affects parabolic/elliptical stylii rather than traditional conical ones >

 

Ian makes a good point.....with tonearms, many technical inaccuracies & compromises are less significant than major flaws design/construction - eg. bearing/armtube resonances, etc.

However, we have come a long way....many older high end tonearms would now be considered 'characterful', coloured & in-accurate.

 

When using (good) Linear Trackers, it becomes clear that the significance of Tracking error, whilst noticeable in it's absence, is really not the biggest bonus IMHO - we under-estimate the elimination of Skating forces IMO.  The degree of dynamic tracking instability wrought by this & Anti-skating devices, is brought home by the amount of additional energy, power, scale & dynamic range that LTs can dig out of the groove - when the stylus does not have to contend with constant & varying Skating & AS side-forces.

 

(Air bearings, incidentally, are not necessarily the big problem that they are peceived to be.....because horiz Effective Mass is so high with most LTs, that the tonearm appears massively rigid down to very LFs, as 'seen' by the stylus ;-) )

 

(Sorry about the digression again.)

 

Cheers, Owen

Dark Lantern blog - http://darklanternforowen.wordpress.com/

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here's another good reference:

Tonearm Geometry and Setup: MD Kessler and BV Pisha (Audio Jan 1980)

http://www.melbourneaudioclub.org.au/pdf/tonearm.pdf

excellent article on practical setup, includes a table of popular 1980's arms' effictive lengths, overhang etc

 

 

PS. This Kessler/Pisha article from 1980 esp, is an important piece - even if, like me, you don't go deep with the maths, it summarises what you need to know about pivoted tonearm geometry - ie. Mounting Distance, Overhang & Offset Angle.

 

Cheers, Owen

Dark Lantern blog - http://darklanternforowen.wordpress.com/

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