[neobop]

I think many vinyl spinners might find this interview interesting:

http://www.tnt-audio.com/intervis/lurne_arms_e.html

neo

[BaMorin]

Not a bad article. Some things aren't explained, but that is I guess do to speaking to the masses. Regarding speed changes, or variations due to material......as the velocity of the sound wave  goes up, the amplitude goes down. When going from hard fast material to soft slow material the velocity drops but amplitude increases. You cannot make energy from nothing. The wave form at the boundry will either reflect back at same phase, or reflect at opposite phase. It will not always be 50% reflection. Boundary is always the key.
This even includes electricity running through a wire. At each grain there is a boundary. Gold (pure) does not have grain boundaries.
 The math number he gives for stylus movement shows that stylus talk (actually hearing a stylus make noise) is impossible. If one can hear "stylus talk" is because the energy is not being terminated at the boundaries and all is running back to original source of energy.

[neobop]

The physical vibrations of the stylus/cantilever propagate in all directions, including the air around it. That's why we hear needle talk. Most of the vibrations though, either go back in the record or into the cartridge where they excite the generator.

The numbers were interjected by the author of the article. I don't see any problem. Pierre Lurne studied physics extensively and many of his ideas are copied by other designers.

Here's a previous interview:
http://www.tnt-audio.com/intervis/lurne_e.html

neo

[BaMorin]

The physical vibrations of the stylus/cantilever propagate in all directions, including the air around it. That's why we hear needle talk. Most of the vibrations though, either go back in the record or into the cartridge where they excite the generator.

The numbers were interjected by the author of the article. I don't see any problem. Pierre Lurne studied physics extensively and many of his ideas are copied by other designers.

Here's a previous interview:
http://www.tnt-audio.com/intervis/lurne_e.html

neo

AH, but the cantilever should not be vibrating.......it should only follow the grooves. The amount it moves right and left, the maximum amount at the diamond end is too small an area to produce enough amplitude (air movement) for the human ear to hear

[neobop]

Obviously needle talk is a common phenomena. Following the grooves is vibrating. A 15KHz signal will have the cantilever vibrating at 15,000 times per second. The cantilever is the transmission line for stylus tracking a modulated groove. It's the movement of the cantilever that excites the generator. I don't see how needle talk could be anything other than audible cantilever movement.
neo

[doug s.]

i found the tnt article interesting.  i was wondering what the proposed "solution" to headshell/cartridge coupling would be, even before i opened the link. the "mod-squad" folks, one of the first folks to introduce spikes for stereo equipment, also came out with "tip-toes" for headshell/cartridge coupling; i have been using them for >25 years.  two small shims with 3 tiny spikes on one of them, to be inserted between cartridge and headshell...

you can barely see the cartridge tiptoe plates between headshell & cartridge.  (also note my "longhorne" tweak - the lead outrigger weights blu-tacked at the tonearm pivot to reduce lateral movement.)


doug s.

[neobop]

I think Joe Grado made one of those even before the Mod Squad. I tried the cartridge coupler a couple of times and found no improvement, so I sent them on (I had 2) for someone else to try. The one proposed in the article is a little different. It's a single point with a damper. I never tried that. I guess like any other tweak, YMMV.

The 2nd article I linked to is an earlier interview with Lurne. He talks about his concept of "pure mass". Further down in the article he says that the horizontal compliance of a cartridge should be the same as the vertical. Otherwise resistance to movement will be different in one plane from the other. [Ortofon specs their carts cu in both planes.] I guess this presupposes that the arm has the same friction or eff mass in both planes. I think his unipivots do. Maybe some of the great classic combos are realized when horizontal and vertical cu/mass match up on both arm and cart, among other things.
neo

[Wayner]

I read the whole thing and IMHO, it's going into the land of diminishing returns. In other words, lots of tweaking with little improvement. The big disappointment will be the hours of futzing around and little (if any) improvement in the end. All resulting in the gasp of "why did I bother".

Mapleshady offers the 3 point cartridge sandwich (between cartridge and headshell), so The idea is nothing new. The guy knew lots of techno-babble, but offered nothing really new.

Wayner

[glrickaby]

An interesting article, apparently about isolating the cartridge from the
headshell etc., Interestingly, I have had a couple of Grados laying around
which have not been used much because of the "veiled" and generally
lackluster sound.  I've kept them because of various reviews on the
Prestige series as I've thought the problem was with my set up rather
than the cartridge i.e. Blue, red, silver. Been trying them on Duals
lately, a 1225 and 1237 with the shorter arms and 10 inch platters.
Just tried a couple of 2mm spacers between the headshell and Dual
holder to bring it out to a full 24mm from diamond to top of the holder
which was recommended at another site, and about 8mm from diamond
to front holder edge. My what a difference! i.e. the Grado sound talked
about by others... Now is this because of the 2mm increased distance
top to bottom or is it because of the isolation of the cartridge from the
Dual holder-Sled caused by the 2mm sleeve spacers? Clearly, the unit
only has contact with the holder now via the screw and spacer and is
otherwise isolated from the headshell. Bearing in mind the Dual head
shell on the 1200 series is somewhat a mickey mouse arrangement,
what am I hearing here? Is the original article correct?

[BaMorin]

An interesting article, apparently about isolating the cartridge from the
headshell etc., Interestingly, I have had a couple of Grados laying around
which have not been used much because of the "veiled" and generally
lackluster sound.  I've kept them because of various reviews on the
Prestige series as I've thought the problem was with my set up rather
than the cartridge i.e. Blue, red, silver. Been trying them on Duals
lately, a 1225 and 1237 with the shorter arms and 10 inch platters.
Just tried a couple of 2mm spacers between the headshell and Dual
holder to bring it out to a full 24mm from diamond to top of the holder
which was recommended at another site, and about 8mm from diamond
to front holder edge. My what a difference! i.e. the Grado sound talked
about by others... Now is this because of the 2mm increased distance
top to bottom or is it because of the isolation of the cartridge from the
Dual holder-Sled caused by the 2mm sleeve spacers? Clearly, the unit
only has contact with the holder now via the screw and spacer and is
otherwise isolated from the headshell. Bearing in mind the Dual head
shell on the 1200 series is somewhat a mickey mouse arrangement,
what am I hearing here? Is the original article correct?

Another satisfied customer..............I keeps sayin I says.......if it don't sound right
sumpthin else is wrong.

Ba(...and my shoes shined black...)Morin

[neobop]

LOL, that Morin kid,
The first interview is limited in scope, as they all are. I'm fascinated with these aspects of record player design. I think the "right" application of this stuff can make the difference between just playing a record and the magic that sometimes happens with good equipment. Lots of these things can be applied to your own set up or in choosing replacements. Vibration considerations, propagation and dissipation or damping can make a hugh difference IMO. Even if it only comes down to whether or not you use the rubber washer between the headshell and arm coupler, or how you mount your cart, sometimes it can make a significant difference.

Lurne designed or was instrumental in the design of the Goldmund T3 linear tracker. That was the arm that came with the Reference TT. Lurne made and sold the arm for awhile. He has since abandoned linear trackers. The philosophical reasons are spelled out in the 2nd link, an earlier interview. There have been threads right here about linear tracking and horizontal mass considerations. Even if you don't take this to its logical conclusion, everyone can learn something about horizontal vs vertical compliance and mass. It will open your eyes to just how much an oversimplification our vertical cu/arm mass calculators are. BTW, the T3 is a great sounding arm with the right cartridge. They were usually med/low cu MCs. My friend had a VDH Grasshopper on his. The T3 also was available on the Studio and lots of great carts were used successfully. That being the case, I'm even more interested in the theory about what's wrong with it. After all, this guy designed it.

If you're interested in this design application stuff, here's some meat and potatoes:
http://www.enjoythemusic.com/magazine/manufacture/0208/index.html

neo

[BaMorin]

LOL, that Morin kid,
The first interview is limited in scope, as they all are. I'm fascinated with these aspects of record player design. I think the "right" application of this stuff can make the difference between just playing a record and the magic that sometimes happens with good equipment. Lots of these things can be applied to your own set up or in choosing replacements. Vibration considerations, propagation and dissipation or damping can make a hugh difference IMO. Even if it only comes down to whether or not you use the rubber washer between the headshell and arm coupler, or how you mount your cart, sometimes it can make a significant difference.

Lurne designed or was instrumental in the design of the Goldmund T3 linear tracker. That was the arm that came with the Reference TT. Lurne made and sold the arm for awhile. He has since abandoned linear trackers. The philosophical reasons are spelled out in the 2nd link, an earlier interview. There have been threads right here about linear tracking and horizontal mass considerations. Even if you don't take this to its logical conclusion, everyone can learn something about horizontal vs vertical compliance and mass. It will open your eyes to just how much an oversimplification our vertical cu/arm mass calculators are. BTW, the T3 is a great sounding arm with the right cartridge. They were usually med/low cu MCs. My friend had a VDH Grasshopper on his. The T3 also was available on the Studio and lots of great carts were used successfully. That being the case, I'm even more interested in the theory about what's wrong with it. After all, this guy designed it.

If you're interested in this design application stuff, here's some meat and potatoes:
http://www.enjoythemusic.com/magazine/manufacture/0208/index.html

neo

Did you ever see how Joe built his platter and bearing assembly back in the 50's?

His mass was well below the platter, with a single bearing collar at the top. Looks like an inverted design of this paper.

Unfortunatly I can't access that from the Library on the VE

[neobop]

Back in the heyday I never heard of people building their own tables. Not like today, at least. Sometimes people would substitute a platter or something like that, but often it was an upgrade from the same manufacturer. Now, I read about guys building their own. I plan on using a platter/bearing combo that's already worked out, but if you're designing an inverted bearing to use with a different platter, this stuff is good to know. The manufacturing practice of raising the  bearing 1mm above center of gravity can really help out. Finding the center of gravity isn't always straightforward, especially if you have a weighted platter.

Lurne talked a lot about energy (vibration) dissipation. This applies to plinths as well as arms. Over the years this has been one of my guiding principals in setting up tables. Sometimes you have to experiment to figure out whether to damp or dissipate, cause it isn't always straightforward. Dissimilar materials can wreck havoc with assumptions but it's hard to argue with results.

Here is an interview in Stereophile. Every one adds some little tidbits, maybe some history.
http://www.stereophile.com/interviews/pierre_lurne_audiomecas_turntable_designer/index.html

neo

[rollo]

 Guys please check out Mapleshades nano mounts for cartridge and arm. You will be glad you did. For me another one of the no brainers. They have transformed my Linn. Very affective.


charles

[neobop]

Wow, Mapleshades charges $95 for a set of them with one pr of brass mounting screws and bolts. They don't even give you an assortment of different length screws. You have to tell them what length you need.

Whether or not this will make a difference really depends on the particular cart and arm. Sometimes, obviously it will. But you might want to try it out first. The suggestion in the article uses a damper and a pin head held in place with some tack. You could do the same sort of thing with ball bearings. I think the damper was just some rolled up paper. Experimenting might be a PIA with realigning you cart each time, but it might be worth it.

I'm not into skimping on something that will make a difference. But I'd cut the tips off a few brass wood screws and file the bottom flat to do the same thing. Even if you want some brass screws and nuts, you could probably get them at a home improvement store. Just get 2.5mm, standard thread. If they don't have it you can get #3-48. Aluminum is lighter and stainless steel is strong, but magnetic in varying amounts depending on the type of steel.

Turntable Basics has some stainless screw sets and a lot of other stuff like silicone. This is a good place to get some of this:
http://www.turntablebasics.com/hardware.html

These people sell hardware and you can see what a box of screws really costs.
http://www.mcmaster.com/#metric-screws/=bv0c9c

neo

[neobop]

Maybe I shouldn't rag about Mapleshade. When you consider the R&D and all the hard work that went into the development of these couplers    I get a little peeved with some of the seemingly outrageous prices charged to audiophiles. On the other hand with charge card expenses and returns, they have to have some incentive to offer it. I'm surprised Herbies doesn't have them. We have 2 testimonials about the possible benefits and it might be worth checking out. This thread has only been going a few days.

I'm sure not everyone is interested in all these articles. But for those into DIY tables or arms, there's design considerations here that can point you in the right direction. I haven't seen expert info like this offered elsewhere. I've seen some cool looking DIY tables. Most look like they'd be inferior sonically to commercial offerings even if they look beautiful. In the Stereophile interview he talked about the use of a counter pulley located on the opposite side of the motor pulley with a belt drive. This is unique and worth considering IMO. The only thing remotely like this is the VPI Classic locating the pulley at 7:00, opposite the arm pivots, like a Pink Triangle. My plan for using a Teres outer rim drive will locate the wheel like this. This addresses vibrations effecting the plane of the cart as it tracks the arc, but falls short of applying equal pressure on either side of the platter. I don't think you could do both and locate a counter pulley near the arm. There's no possibility of a counter pulley with a rim drive anyway, but it's something to consider with a belt drive.

Some of the subject touched on, are tonearm/headshell vibrations, counterweight coupling, cart vibration dissipation, arm mass/inertia - vertical vs horizontal, platter/bearing design, platter construction, suspension considerations and the use of a counter pulley. Any comments or ideas are welcome. Here's another link:
http://www.tnt-audio.com/sorgenti/belladonna1_e.html

neo

[aln]

Has anyone done a before and after using the tiptoe or mapleshade device?  There is a lot of techno-babble in the article but his advice is cheap and easy to try.  The proof is in the listening.

[BaMorin]

Has anyone done a before and after using the tiptoe or mapleshade device?  There is a lot of techno-babble in the article but his advice is cheap and easy to try.  The proof is in the listening.

  .    My good man..........are you aware you have landed dead square in the DMZ of audiophiledom?     Well at least you've found a forum where you can express your oppinion without the wrath of the "purist physicists" ...........of course the proof is always in the listening. The greek alphabet might say different.......but the machines can't hear. I'm always a fan of the cheap/easy........usually because they more often than not work better than the expensive and complicated. Provided that the cheap and easy was thought out and not just a whim.

[jmpiwonka]

seems like the screws would provide the needed coupling.

i have a thin and quite firm strip of cork (cut from sheet of gasket material) between my headshell and the tonearm.
not because i think it helps with sound, i don't think i noticed a difference with or without, but because the spacer gets my tonearm in a good sweet spot for me to adjust the VTA.
if i had a plane that i could run my armboad through i'd just do that a few times and lose that cork spacer...

[neobop]

Ha!  Lurne happens to have a degree in physics. All that stuff about the center of gravity an ellipsoid of inertia, is the real deal.

From Glrickaby's description I'm not sure exactly if he is using regular spacers or the Grado ones with little spikes. It seems like a more desirable alignment was achieved also. Rollo says he got a significant improvement with his Linn Ittock and unnamed cartridge. I think the particular cart might be important. The spike coupling thing addresses the cart/headshell interface and the transfer of vibrations to the arm, away from the cart. It is not decoupling, it's coupling. Improvement should be or not be realized on that basis. It is possible to get other benefits like VTA or alignment correction on some arms, but then it isn't clear exactly what's responsible for the improvement.

Over the years a few people told me that these things worked for them. That's the best I can tell you. I think you'll have to try it on your particular arm/cart to find out. I was just thinking that you could try a shortened thumbtack, at least in the back. I tried it yrs ago with a Genesis 1000 and a Zeta. It didn't seem to do anything. Maybe the cart didn't need any coupling help. The cart body is physically small. 
neo