Tonearm recommendation

Raul,

Sorry, I gave you credit for being a little smarter than that, but you've proven me wrong. I wasn't planning to return to this thread and now I'm teaching remedial geometry.

**Dear fleib: Not really. Let that I try to explain all that. As you I 'm talking of standards alignments as both Loefgren A and B solutions ( Baerwald/Loefgren. **

I wasn't talking about Loefgren alignments.

**In those Loefgren equations the main target is to find out the precise offset angle and overhang with foundation/knowing the tonearm effective lenght ( L in the equtions. ) and radius of the Lp grooved  surface ( most inner and outer LP groove recorded area. ). For difference between that L and the overhang the Loefgren solutions achieve the distance between tonearm pivot to TT spindle. The L does not change in those Loefgren standard solutions, WHAT CHANGED IS OFFSET ANGLE, PIVOT TO SPINDLE, AND OVERHANG VALUES.**

What don't you understand? Effective length = pivot to spindle (mounting distance) + overhang (spindle to stylus).  If mounting distance remains constant, then effective length (L) must change with a different alignment.

The rest is nonsense. The Loefgren alignments are close in headshell length and angle, especially for arms longer than 235mm.

As long as we're talking alignments, here's a post from Audio Circle:

**Not sure if we talked about this on this forum - UNIDIN alignment is a legit alternate alignment. Nulls - 66.3, 112.5mm
Here are more conventional nulls:
Stevenson - 60.325, 117.42mm
Baerwald - 66.0, 117.42mm
Loefgren(B) - 70.3, 116.6mm

You can read something about this in Stereophile or Analog Planet and see the alignment error curves. It looks pretty good.  I was playing with the numbers and what you won't read is that the alignment is nearly identical to Loefgren, but moved inward about 5mm. The distance between Loefgren nulls is 46.3mm. UNIDIN is 46.2mm.

Nice to get away from Agon. What'shisname is really a block head. Guess every forum has one.
neo**

I wanted to have the 3 standard alignments posted so no one would have to look them up.  Here's another:

**According to VE the nulls for the 507 II are 60.1 and 116.6mm.  That puts the inner null next to Stevenson at the lead out, and the outer null is Loefgren. This should optimize the middle and end of the record.**

Many people dislike Stevenson alignment, but you have to admit it's the best at the end where the grooves are crowded and the tip gets pinched. Some people prefer it. That would include Peter Pritchard (ADC/Sonus). He also recommended a low frequency resonance of 6.5Hz. That would put the resonance as far away from the audio band as possible, just above warps. If someone has a big fat spherical stylus or inner groove problems, Stevenson comes to the rescue, especially with a cart that emphasizes "musicality" over detail.

No, this isn't about taste or practicality. This is about distortion. People use the terms alignment error and distortion interchangeably. That comes from Loefgren - his description. There's no denying the cantilever excites the generator and lack of tangency is undesirable, but what's the exact correlation? Does 2° of error correspond to 2% distortion, and what kind of distortion? 

The reason some people find those zero offset arms sound good, is reduction of torsional forces on the cantilever. Do linear arms solve these problems? If and only if, they can maintain tangency at all times and otherwise behave as a proper tonearm Re: mass, friction, etc.

Something to think about.

Someone is not paying attention. Dynavector nulls were just posted and they are not Stevenson.  The inner null is close to it, but outer null is Loefgren B.  How does this change tangency and alignment error?

http://www.vinylengine.com/tonearm_database.php?make=Dynavector&mdl=&sort=2&eflo=&ef...=

Click on the nulls to find out.  Scroll down to the columns headed with the stock and standard alignments. Notice the odd relationships between various alignments with regard to eff length, offset, and overhang.

What remains constant?  Pivot to spindle = mounting distance. 

The equation is L = MD + OH. Where MD is mounting distance and OH is overhang. If L remains constant, then the values of MD and OH change for different alignments, but still total to equal L. 

Forget about Loefgren's papers, it's all right there. You're confusing yourself trying to reinvent the tonearm. If you start doing the math for different nulls, your arm will be released around the year 2127, or the 2nd of never.

What interests me is the DV total alignment error - looks pretty good. They say "Distortion figures are calculated from samples of tracking error in the modulated groove area." Samples?   Sounds like smoke and eyewash. Distortion analyzer?

Raul, My job is being a consultant to you? This is news to me, am I on the payroll? Maybe a flat fee for consultation, or maybe I misunderstand. I thought this thread is about high quality arms around $6K or less. It looks like all the DV arms have the same geometry and the 507 may look a little weird, but I don't care about that.

I thought I was your geometry teacher - remedial 101. I guess not because you're assigning the curriculum.  This is confusing, and to be honest, Griffithds would be a better consultant/teacher. He comes highly recommended and has experience in the aerospace industry. He's practically a rocket scientist. I'm quite sure he's forgotten more than I know about math, the problem is how much does he remember?  Remember his post admitting to brain flatulence? Not much to worry about on that score though, he can consult from home.

You know the bit about feeding the hungry - teach someone to farm and he can grow his own, or something like that?  That was my teaching plan.  Know any algebra? You're supposed to pass algebra before you take geometry. How can you solve an equation without algebra? I think you just push buttons without understanding and want someone to tell you which buttons to push?  Know what an equivalency is - 2 sides of an equation? L = MD + OH   L = 10" = 254mm.

254mm = pivot to spindle + overhang. L is your constant and you need 2 numbers that add to 254 for the other side of the equation. To find those numbers for any standard alignment go back to VE calculator and put in 254 for effective length. If that doesn't work find a 254mm arm in the database and click on the nulls. That will give the other numbers.

That's the best I can do. My specialty is solid geometry and my brain is farting like crazy. They told me I was filling in for Professor Timeltel. I thought he was an English Lit prof. I think I was conned. Did Timeltel retire? I don't know what's going on, but Griffithds is your man.

Regards,

Dear Raul, You wound me deeply. I was the greatest tutor in all of the Americas, and look what I have become. I have failed you. Now I am just a hollow shell of a tutor, like an empty tortoise shell in the sand, I'm a dead tortoise tutor, not to say I tutor dead tortoises, but my tutoring, he is very sick. I thought I answered all your questions, but usted no entiende.  Si me lo permite.

Yes, the Loefgren calculations are correct. They are the basis of all the others. The spreadsheets, VE calculators are the same thing in different formats. Your answers should be the same. If you start out with L the spreadsheet or calculator will show you M distance, offset, error, etc. for each alignment.  I don't have your spreadsheet. I told you how to access the calculator. You don't need to log in.  Follow my instructions and it's all there. If you can't use the spreadsheet or calculator I suggest you build something else. How about a nice headshell holder display block? 

Regards,

Dover, Interesting comment. The straight zero offset arms available today address lateral torsional forces.  The ViV Rigid Float requires little or no antiskate as a result of this. Skating force is increased by cart offset, that is lateral cantilever angular difference between pointing at the pivot and pointing at offset angle. There is still skating because the cantilever is tangent to the groove at only one null point on an underhung arm, but it's said to be insignificant.

The only arm I've heard of that addressed lateral and vertical torsion is RS Labs. That one had the pivot elevated so the zero lateral offset cantilever would also approximately be vertical zero offset.

The trade off with alignment error is significant, but reviewers say it's worth the trade. Ironically, they also say the shorter version sounds better. This is supposed to be because reduction of length also reduces arm resonances, or something like that. It's conjecture but makes sense. 

My skepticism with distortion figures and alignment error correlations isn't based on these arms. There is necessarily a phase difference between channels with lack of tangency, but it seems to me any other distortion would be cantilever and tip dependent.

Regards,

Dover,

**Result is effective length of 254.97 and overhang of 16.158.
This is impossible with the Dynavector unless you extend the length of the arm or headshell.**

The arm has 2 non-coincidental pivots, an ingenious design.

Regards,

Pryso, Dennesen made another device to accurately locate the arm mounting hole. It was like a 2 sided ruler with a long slot in the middle. One end tightened over the spindle while staying at zero. The other end had a clamp where you could insert a pencil or stylus to subscribe an arc on the armboard. The clamp could be tightened anywhere along the slot to accurately locate mounting hole.

I believe the SoundTractor was the first device of its kind, and the prototype for the ones like it - pivot pointers. A GeoDisk works on the same principle but with a different kind of pointer. With some of these newer ones you have more options for alignments and they might be easier to see.

There is an inexpensive magnifier you can pick up. It's called a linen magnifier. They come in various powers and stand at an angle - could be helpful. Get low power though, like 5X ?  Stronger lens is hairier, has a shorter focal length and is more liable to optical/user error. I use reading glasses of various strengths. Magnifiers and uneven lighting can mess up a careful alignment and I always double check with a conventional protractor. Depending on your arm sometimes the pointer goes off center pivot, you misalign, and the pointer goes back and looks okay when you put it back in the arm rest.  30 years ago a metal SoundTractor was $100 and the tonearm hole locator was $200.To answer your question, no reason to upgrade with your situation.

An arc protractor is predicated on the proposition that your arm is perfectly mounted - factory. Otherwise it's not only useless, you'll wind up misaligned. Not recommended for DIY tonearm mounts.

Regards,

The Mint is an arc, custom made for each arm?  If you want an arc check this out:

http://conradhoffman.com/chsw.htm

I can only reiterate my caveat about arcs.  If you're swapping arms and using an arc your alignment is most likely off.  It should be obvious as to why.

I must say Harry was right. We're on page 7 now and precious little about different arms, but lots on care and feeding the Kraken.

**Actually, the full name is Crazy Bill The Eel Killer. Interesting story, if anyone cares.**

I'd be interested.

Regards,

Now that I think about it, I asked a dumb question. Of course a single set up protractor can have any 2 nulls drawn or etched on it.  I was thinking from the standpoint of protractor with a single standard alignment, hence the question.

Is that Audio Beat a review or a marketing business? Probably both.   Gregory did a nice sales job with only a deception or two, but the only thing that really interests me is the UNI-P2S, and he only mentioned it. Follow the link and you have to download. It's probably a fancy Dennesen tonearm locator, just as all these alignment grid/pivot pointer protractors are based on the SoundTractor, only they're better.

Thanks for the link Folkfreak. Those Dertonearms look interesting. A little pricey maybe.

Regards, 

Lewm,
**I use the UNI for the DV505.  Dertonearm's design is complex and a bit cumbersome to use, but it is also ingenious and permits very accurate alignment because of the ancillary tools he provides.  However, I cannot quote distances in fractions of a mm; I'm just a slave to the UNI. Life is short**

Is this UNI like using 2 protractors?  Seems to me no individual protractor can align for both Stevenson on the inner and Loefgren on the outer.

Regards,

Pryso, Dennesen sold a separate device for dealers. I couldn't remember the name. I searched for a photo, but couldn't find one. It was called the Pivotram and used for locating arm mount holes.  I do the same thing as you - reverse the SoundTractor bar and use a ruler to measure distance. It's easy for me to correct for the offset of the bar and get a pretty accurate mount hole. There is usually a little play in the fit of the arm pillar into the hole, especially with DIY drilling.

When using a pivot pointer device like this to align, it doesn't matter if your mounting distance is off a hair or two, as long as you can align to the grid with the pointer in correct position, your alignment is good. A SoundTractor or Feikert works where the pivot is actually located, not where it theoretically should be. If your arm mounting distance is off a bit , and you get a good alignment, then your offset angle will also be off a hair.  Here's an old discussion about it. My user name was lfleib.

http://www.vinylengine.com/turntable_forum/viewtopic.php?t=10827

With most pivoting arms the cantilever is not pointing to a pivot, due to offset. The discussion of maintaining mfg. offset is arm specific, and should be limited to that IMO.

RE: the quote - I tend to think the Brits should be blamed for most things, but I don't know about the Japanese use of the Stevenson alignment. That seems a bit of a stretch. The use of Stevenson was a very sensible thing at the time, but became a sort of default standard along with 15mm overhang.  If you have an arm designed for Stevenson, there are some options.

Part of the quote was linking Dynavector to Stevenson.  It is not.

Regards,

Thanks Crazy Bill, Eel Killer.

nice story

Chakster, If dreams were wishes, beggars would ride. 

Go back a few pages and look for Griffithds on 801, 7045.

The rest is all gobbledygook and purloined poser poison.  

Regards,

What are the factory nulls for Dynavector?

Anyone ??

Dover,

Stevenson - 60.325, 117.42mm
Baerwald - 66.0, 117.42mm
Loefgren(B) - 70.3, 116.6mm

Dynavector - 60.1, 116.5  Notice anything unusual?

Alignment is defined by a standard, not a test record. Inner null is standard lead-out groove. Even if you use IEC (or whatever it is) the numbers are very close and the relationship between inner and outer null is the same, only moved slightly, just as UNI nulls are Loefgren B moved in 5mm, with a variance of 0.1mm.between the nulls.

It seems to me, the suggestion to align to Stevenson is ill conceived. Further demands to change to one of the Loefgren alignments by changing mounting distance, is bizarre.

I've already posted this information and I have to agree with Lewm, life is too short.

Regards,

Dover, I meant to say, Stevenson inner null is standard lead-out groove.

That might help understand  a particular alignment's relationship with the various parts of a record.  I'm sure you know the design goals of each alignment, but any 2 null points are a "good" alignment. If you ask why Loefgren B is lowest total error, and why A is lowest average, then you can figure what is traded off.  Maybe a graph helps see it.

Raul, you made some basic assumptions that are not necessarily true. I didn't discuss it with you because it seems fruitless and I'm under no obligation to do so. It's good you gave opinions on some arms.

Raul,

You must be kidding. I'm beginning to wonder if in fact, you have a brain cell. You go back to '13 to quote Dover?

dover: """  do you have right now on hand the 505?

If yes just try Baerwald or Löfgren alignment changing the P2S distance from Stevenson. Then listen and listen in between ( B, L and S alignments. ) and return here to share your experiences there.

If not, your post is useless and futile this time. """

There's only one reason you'd write something so stupid.

I agree with Soundsmith.  You're an undeclared manufacturer using this forum to promote your private sales.  I wonder how many of your preamp sales and used cartridges exchanges paid a fee to AudioGon.  I suspect you dine in luxury and fail to leave a tip.

I was going to explain where I think you went wrong in your basic assumptions, but upon further reflection, I think not.

If yes just try Baerwald or Löfgren alignment changing the P2S distance from Stevenson. Then listen and listen in between ( B, L and S alignments. ) and return here to share your experiences there.""

You left out the stupid part (above). Your ignorance is only exceeded by your arrogance.  DV is none of those alignments.  I posted that at least twice.

Remember when you came on VE  years ago and we had a running battle? You're just as ignorant now, as then. Every MC was hopelessly distorted and you heard them all.  You're ridiculous. 

Using a forum for private sales and not paying a fee is a separate issue.  I wonder what the new owners of this site will think of such behavior?

fleib, neobop, lfleib

Lew,

What are you a champion for the mongoloids?  I don't expect Raul to be anything other than what he is, not anymore.  My intent is to get him booted from this forum for unethical behavior.  I think he should pack up his stories of scientists and electron microscopes and sell them elsewhere. 

 For a number of years I wouldn't post on this forum because of Kraken. When I asked Dlaloum why he came here when a horrible kraken is afoot, he said because you were talking about the carts interesting to him. I relented and joined the legion of the kowtow, the kraken kowtow club, if you will.

I see by your comical alignment solution you desire his retention here. I have done nothing as of yet regarding this matter, other than give some perspective. It's early and the cat is settling in and I need some coffee, a much more important matter. I have misgivings.

fleib

All right Ladies, calm down. 

Lew, I had no idea you drank tea out of Waterford china with your pinky in the air.

Aceman, I assume you're familiar with the fallacy of quoting out of context, in order to let me preach. Smart move, but I'm not a preacher. For those unfamiliar, read the rest of my post and see how much I've done and the importance I give this matter.

Interesting post Kirkus. I used to have a Miles record on Columbia that came within about 5mm of the label. I say used to, because I lost it in a storage place flood in '95 which I refer to as the Great Flood - 1400 records approx. Shit happens. I have/had a few more which went beyond the lead out groove, but nothing like that one.

Like I said, I'll be moving on, but I might be reading.  Titanium or Boron?

Lewm, Point missed. That's an affirmative anyway.

ghost writer out.

Dear Raul,

I found an email, quite old, in an address used for other matters and one I almost never check.  I was wrong and should have taken your touching greeting at face value.

Enjoy the music,

The arm and cart work as a team and for the Rosewood and 103r you probably can't better the FR66s. If you want a mono cart, I suspect the same goes for the Miyajima Zero.  With a removable headshell it would be relatively easy to switch carts.

I was under the impression the Blackbird could accommodate 2 arms. I don't know what's involved, but that might be an option to add a lighter arm?

Raul,

"Dear fleib: why is the best team those cartridges with that 66?, maybe I'm missing something and always is time to learn so some " light " from you can help all of us."

Sorry, I didn't see your post. Those carts are very low compliance. A low compliance cart needs high effective mass arm to control the cart and be a stable platform. Put a stiff, heavy tracking cart on a low mass arm and the resonant frequency approaches or goes into the audio band. The amplitude of the resonance can be quite high, producing colorations.

On another forum someone mentioned that a "guru" advocated a resonant frequency of 18Hz for a particular cart. I can only assume this was to augment the deep bass on his records or system.  

We often deal with the opposite situation - a cart with compliance too high for a particular arm. In that case the resonant frequency goes low - easier to live with if SQ doesn't suffer from poor low frequency tracking and/or sluggish sound. Peter Pritchard (designer of 50cu carts), advocated a resonant frequency of 6.5Hz.  This is above the warp region yet the arm will have enough mass to be stable. Arm damping (fluid) acts to limit the amplitude of the resonance peak and spread it across a wider frequency band, mitigating the affects.

Regards,

Raul,

> "Mantain frequency resonance value, between tonearm/cartridge, in the range of 8- hz to 10 hz is something that many of us always are looking and is something all of us want it."

The recommended range is 8 to 12 or 13Hz.

> "Now, what happen during playing because the theory is on static way where the cartridge is not ridding the LP grooves."

No, it's not about static. There is no resonance with static as the name implies. We're talking about dynamic compliance, arm mass, and resultant resonance or affect on performance.

> "The theory of that cartridge/resonance frequency is that to low frequency like 4-6 hz cabn be exited and coincide with vibrations/resonances generated by the TT/cartridge and then can make that in some areas of the LP surface the cartridge/tonearm " jump "/mistracking."

No one is talking about that. This situation is the opposite - a low compliance cart. No theory was proposed, especially about high compliance carts on a heavy arm. Arm/cart resonance is a measurable phenomena. It occurs. If it occurs close to, or in the audio band it will cause intermodulation.

> "As I said the all metal FRs are because of that metal a natural/self resonace/vibrations generator device but along that is a NON DAMPED DESIGN!!!! go figure."

Miss science class when you were a kid?  Self resonance vibration generator? Would that be static or dynamic self resonance?

That's a cute anecdote about the MC2000, Unfortunately, it has nothing to do with the situation at hand.

Regards,

Raul,

You're looking for subjective proof?  How bizarre.  Crazy Bill has 2 low compliance carts and you start talking about one that resonates at a very low frequency, a high compliance cart on a heavy arm.  This is supposed to refute some unstated theory.  Apparently you don't know what you're talking about. You're the one who brought up recommended  frequency range, so you can refute it as a theory?

FACT - When a low compliance cart is mated with a light arm the resonant frequency goes up.  If that resonance approaches or goes into the audio band it will produce intermodulation distortion.

OPINION - The Rosewood and FR66s sound excellent together.  Crazy Bill said it sounds better than his 12" Jelco, a fluid damped arm.  IMO this is a great combination. I haven't heard the Rosewood sound better, maybe you have, but your lack of knowledge and vested interest makes you suspect.

Are you selling arms now Raul? If so, I hope your partner knows more about this stuff than you.

Sincerely,

Raul, I think your patronizing attitude about others' knowledge on this and other subjects, is not appreciated, at least not by me. Mine is not a general recommendation. It is specific to Crazy Bill's two low compliance carts, and possibly a third, the Miyajima Zero.  I admit the Zero recommendation is guesswork on my part.  I think I stated as much on my initial post.

I don't think the FR64s and 66s are a good choice for general use and cartridge swapping as some other people might, but in this case, mated w/Rosewood or a modified 103, it can sound quite good.  In certain circumstances the arm is prone to ringing, but this is not one of those circumstances IMO.  Ringing can be alleviated by damping the arm tube. Having a replaceable headshell allows finding a synergistic combination and adjusting mass somewhat.

It was you who challenged my recommendation and started talking about ideal resonance range theory, yet you made no recommendation. Waiting for your arm to be introduced, or is that not imminent?

This forum happens to be in English. If you can't understand what's being said or can't express yourself so you can be understood, whose fault is it? You're obviously remedial in some of these tech subjects, but I don't think challenging others is a good strategy to learn. 

Sincerely,

Hi Nandric,

In a literal sense the arm does not follow the groove, or only as much as the cartridge body. I agree, it's the stylus that tracks/traces, the groove.

Considering different aspects of record player functions, it's usually simpler to reduce to two dimensions like horizontal and vertical, but tracking is in four dimensions in-groove (don't forget time). 

Rather than add dimensions with other functions, in reality the other functions also operate within those four dimensions. If you consider the movements of the stylus as being within an imaginary sphere of tracking, the movement of the arm across the record can be seen as a separate function operating in the same dimensions of time/space. The same would go for vertical movement - tracking a warp. Neither of those functions is completely horizontal or vertical. 

A record player is a bizarre device. Maybe that's part of why we love them. "They" used to say it's like a bumble bee, by the laws of aerodynamics it should not fly. It turns out they greatly underestimated the speed of the bee's wings flapping.

Regards,

Raul,

You're trying to win an argument instead of making a recommendation or two.  That was the request of OP. It's all right to support what you say with technical information, but if the only way you can do that is by insulting others, you're not going to win the argument you started.

You seem to assume you're the only one who can hear (discern audio differences).  You assume too much. If I may suggest, discuss something like the amplitude of resonance and ways it can intermodulate and affect the sound, and refrain from saying you can hear it and someone else can't.  That last part is implied and saying it will only alienate others.

You seem all wound up and out to prove something. Why don't you give that TEA BS a rest, and lighten up?

Regards,

Dover, Sorry I didn't see this sooner. You accept this nonsense as correct, or just the part about a noisy mechanism?

>>additional we have to remember that the 64/66 are dynamic balanced designs  and all dynamic balanced designs always generate ringing ( noise/distortions. ) through the dynamic mechanism but two tonearm design: the MAX 237/282 and Luste GST-801. Adding to that problem the micro and macro waves in the LP recorded surface makes that in a dynamic balanced tonearm design the " normal " continuous changes in VTA/SRA/VTF  that always exist in any tonearm ( static balanced included. ) been more pronounced do that when there is a crest in the LP surface the deflection in the cartridge cantilever is higher in a dynamic balanced design that in the static balanced one that works with natural gravity where in the dynamic the mechanis always force to mantain the VTF but when is against a crest the cantilever is pushed up making a higher cantilever deflection.
In both kind of tonearm designs exist the problem but in the dynamic one is bigger. Normally when the human been goes against the mother nature fall down.<<

These are the ravings of someone who makes things up, or doesn't understand what he reads.  When a static balanced cart is riding up a warp VTF is substantially reduced. The cart/arm is accelerating upwards.  What happens when VTF is reduced? VTA is steeper angle.

At the crest VTF/VTA are more affected with a static balanced cart and it's much more likely to mistrack.  Due to the constant spring action a dynamically balanced cart will maintain a more even VTF. Back in the '80s we were setting up dynamically balanced arms by splitting the force.

Regards,

Raul, you're quite long winded and you bring a novel aspect to technical matters.  Thought you might like to know, on another forum you're referred to as the 32 bit Bandito.  Due to the length and number of your posts, I think Kraken might be more appropriate.

To address your last post, did J. Carr say that all metal arms must be damped?  I doubt it, but it doesn't matter. You use that as justification for:

*IMHO no one can " to suck life out of the sound or smear it "" by damping a tonearm. You can't overdamp a tonearm.*

With all your ear training I'm surprised you can't hear the affect of over-damping a tonearm. One can MEASURE a negative affect on transient response by over-damping.  It also tends to kill the natural sustain of acoustic instruments.  I agree with Dover, arms are easily over-damped. If it was Dgarretson who said that about vacuum hold down, I tend to agree with him. It's easy to suck the life out of the music by over-damping.  

I think you might be surprised by the number of people who add fluid damping to their arms. KAB sells a trough and paddle device that is popular, and it's very easy to DIY.

Too many words Mr. Kraken, too many words.

Sincerely,

Raul,

I didn't call you stupid.  It was long winded, which I think is accurate. If you object to your nicknames I won't use them.

It might interest you to know that the lower the compliance of a suspension, the lower the amplitude of arm/cart resonance.  We happen to be talking about 2 very low compliance stereo carts.

You previously talked about the metal arm generating resonance and distortion. That's impossible. The arm is not a generator. I assume you meant propagating or amplifying. There are many mistakes like that in your posts. I don't have the time or inclination to correct them.

You've been posting on this forum in English for many years. I've long thought you use language to disguise lack of specific knowledge. If you look over this thread I think you'll see that you are the predominant responder. You say the same thing over and over. We heard you the first time. Why don't you give us a break? 

Sincerely, 

Raul,

*I said " over and over " because almost no one post the right answer explain it why I’m totally wrong or why they are recomended " this or that ". *

Because it doesn't work like that.  You made a case for damping. Damping is one factor, not the main consideration. In the initial post we read that the Jelco arm is inferior. I think you would agree, yet the Jelco is fluid damped at the pivot. Clearly, there are other factors.

You talk about ringing and amplifying vibrations. In my experience with these FR arms, the right headshell combined with a suitable low compliance cartridge, negates this consideration.  I've heard them with a small amount of armtube damping and less than perfect match with cart compliance and still nice results.

Maybe the 4 point would be better, I don't know, but I don't think it falls within the price constraints. This is a matter of opinion not a case of right/wrong. 

Sincerely,

Raul,

Did something upsetting happen in your life? To be honest, your posts seem irrational.  Sometimes when life throws us a curve we react in strange ways. To avoid a negative situation it would be natural to go to something that gives us pleasure, like audio.  

I'm not being condescending, your bit about pure musical information going through the wires is bizarre. Of course you can overdamp an arm. Look at the output on a scope. 

In the past you've made some great contributions to our hobby.  If something else is bothering you now, it might be better worked out with a friend or family.

Regards,

Raul,

Still doesn't make sense:

**What I’m talking is what in a non-existen " perfect audio world " we have in those internal wires: ideally a pure non-contaminated signal information.

I posted that we can’t have it never ever because we have many distortions/noise/vibrations/resonances surrounded the ridding of the cartridge LP grooves modulations as: TT/arm board/Tonearm//air pollution/LP anomalies and that’s why we need to overdamp those audio chain links to be nearer to that " ideally non contaminated pure signal music information ".**

Overdamping is not going to cure the ills from the source.  In fact, overdamping will take you further away from your "ideal signal". Specifically, overdamping a tone arm will negatively effect cartridge transient response - rise/slew.
. Overdamping prevents the arm from responding in a timely manner. Functionally, in some ways it mimics high bearing friction.

I think you call me dogmatic because I won't agree with the nonsense you post.  All the BS about your ear training and you seem incapable of correlating what you hear, with what's going on with the record player.

Dover,

*I have also made a metal jig to ensure that the FR64S's that I use are installed with a 231.5mm pivot to spindle distance. It is accurate to 0.1mm and this pivot to stylus distance recommended by Dertonam makes for a considerable audible improvement over the factory recommended 230mm.*

Any further explanation?  Factory alignment nulls are 59.2 and 120.4mm?   Somewhat unusual, inner null is close to Stevenson and outer is close to Baerwald. What alignment do you use?

Regards,

Lewm, Dover, I assume this is the UNI-DIN alignment I read about (Fremer?). Nulls at 66.3 and 112.5mm. If you hunt down the article you'll see the curves for alignment error. It looks pretty good. I'm reluctant to call alignment error, distortion. Unless/until someone correlates alignment error with a master type source and a distortion analyzer, I think the use of the term distortion is misleading. Some people throw this word around who clearly don't know what they're talking about.

I don't have an FR arm and I haven't read the past threads.  It's a little hard to imagine how or why increasing mounting distance 1.5mm would make a significant difference. The only thing I could come up with is a miniscule reduction in offset angle. I believe perception of differences is sometimes fueled by anticipation and expectations, although I'm not saying that is the case here. It could be that Jupiter aligned with Mars and Dertonearm is the 7th son of a 7th son born on a blood moon (whatever that is).  Don't take offense here, I'm a sarcastic type.

It's interesting to note, the factory nulls minimize inner groove problems with that null being close to the run out groove. The outer null is close to Baerwald.  UNI-DIN moves the inner null out near Baerwald, and 112.5 puts the outer null in closer than Loefgren(B). I think this minimizes error in the center of the grooves where error is highest.

Dover, VE has a free protractor called Chpratz. It's just a calibrated straight line. With it, you could experiment with different alignments, although it's not easy to set up like a Dennesen.

Regards,

Sorry Raul, You can't lump all types of vibrations into a pile and deal with them by damping. It doesn't work that way. Damping doe not kill vibrations, it mitigates the affects.  In this case fluid damping an arm pivot can reduce the amplitude of resonance by approx. 50% depending on compliance, mass etc. Damping does not stop the resonance, it redistributes it over a wider frequency range with a less severe peak.

Overdamp the pivot, and as the name implies it's too much, it impedes motion. That's why Stingreen and Crazy Bill experienced negative affects with overdamping. There are other ways to deal with vibration depending on type and situation.

The use of mass is a way to convert vibrations to heat. Consider Mosin's Saskia table. It has a 200 lb. plinth made of slate. Even though slate is good at transmitting vibrations the mass converts them to heat. Another way is to dissipate vibrations and convert to heat or direct them out of the table.  Some coupling should be rigid, not damped. Overdamp everything on a table and the sound turns to mush (opposite of live music).

Regards,

The simple definition of damping is to reduce oscillation. If we use a broader definition as in physics, it would be to reduce or dissipate vibration.  I was making a distinction between different types of vibration control, but it does not matter. Critical damping is just enough to prevent vibration or enough to allow something to return to its rest position.  Overdamping is a state where vibration is prevented to the extent that a moving part is prevented from movement.

A fluid damped tonearm does not have to have the fluid located at the pivot, for the pivot to be damped. Attach a paddle to the base of an armtube and have it dipped in a fluid trough when tracking a record, and you're damping the pivot.  Overdamp the pivot and you're restricting arm movement. 

Yo Lewm,

WTF ? 

Tonearm recommendations? 

Atmasphere,

**I suspected that was the case and so made sure that I clarified my position, which is that there are two forms of damping- one of which cannot be overdone as I had previously stated, and the other (which I never use) which most definitely can!**

You never used the fluid damping trough on the Triplanar?  

There are many kinds of damping schemes and it can certainly be overdone and/or misapplied.  Try some rubber washers between cart and headshell and hear how it sounds.

Raul,

What's wrong with you?  Why did you post that digital crap in a thread about tonearms?  Apparently science, reason and logic have no affect on your opinion, but you're off topic and way out of line.

If you're having emotional problems, please get help.

The unipivot  has some advantages which are undeniable. Those advantages are reflected in the number of top performing unipivot designs.  One advantage is damping, a feature so highly touted in this thread. When SME came out with the model V, many design features were to control resonance. That included the tapered armtube and the fixed headshell. High end "contenders" in the '80s were Zeta and Alphason 100S - fixed headshells.  The advantage of a fixed headshell is to eliminate the physical boundary and its tendency to reflect vibrations back to the cartridge. This might not be an insurmountable advantage, but an advantage nonetheless.

By its nature, a fluid damped unipivot can easily be critically damped.  The potential to over or under damp a unipivot should not be considered a fault. Any arm can be set up improperly.

Most of the mechanical energy from the cartridge does not get converted to electricity. That's why top cart designs today use exotic materials and design features to dissipate energy. An elegant solution for excess mechanical vibrations from the cartridge is to dissipate down the armtube and convert to heat by the mass of the arm or plinth, or run it out of a foot.  The contention is, this is more easily accomplished by a unipivot; one clear path for vibrations to exit, while conventional bearings are a two way street.

The task of a tonearm seems impossible and contradictory, to be a stable platform while completely free to move laterally and vertically. Two dimensions of movement is an oversimplification. If an arm is moving laterally and vertically at the same time, the movement is angular or three dimensional. Are conventionally pivoted arms necessarily more detailed and exact?  I think performance defies that generalization.

Our Mexican friend likes to use the word distortion.  This is meaningless without supporting evidence. The Dynavector 507 II is a bi-axis design with intentionally high inertia laterally, and low vertically. This type of  inertia scheme is used by the DP8, apparently to good effect.

I'm not writing this in support of arms I haven't heard, but an arm designer shouldn't be expected to answer ignorant, unintelligible assertions.

Regards,

Raul,

**Unipivots works during playing in continuous desequilibrium, its bearing damping is not to really damp the whole tonearm but, mainly, trying to put at minimum that unstability during playing and that’s all.**

A unipivot maintains stability by the distribution of mass and the center of gravity in relation to the pivot. It's like a platter on the bearing. A well designed table will have the mass of the platter distributed so it does not have a tendency to wobble.  If the center of gravity is too low or high, it will be unstable.

Some unipivots use no fluid. How would they work if they relied on fluid?  A unipivot feels unstable with manual cueing because there's no weight on the stylus. The system isn't loaded. As soon as you let it go, the cart straightens.  If the bearing was in a constant state of disequilibrium (good one), you would not be able to listen to it. A fluid damped unipivot is damped, any way you cut it. There might be suggestions for the amount and viscosity of the fluid.

Neither the DP8 or 507 II are unipivots.  They both use high mass (inertia) in the horizontal plane to optimize tracking and bass response. The difference between bearing friction and high inertia is in the type of resistance to movement. Effective mass and inertia are the same.

The 507 is designed to have high inertia (mass) laterally. You call it friction, but it's part of the design.  Less than 50mg lateral sensitivity and less than 40mg vertically - also part of the design. The little vertical arm is so light, that pivot is damped to keep it from flying away.  With all the damping going on, I would think you would be enthusiastic.

You're innocent until proven guilty?  You keep saying the same thing over and over as if that makes you right.  As soon as the thread gets interesting you start up again.  You're the only one trying to prove something.  Lighten up, life's too short.

Regards,

Raul, Nice story, but it's a little hard to believe.  You and your scientist friend are in a lab playing records and watching the stylus with an electron microscope?  This was at normal speed and slow motion.

You can't see a record groove with an electron microscope unless it's painted with conductive coating.  Vinyl is an insulator.  Must have been a pretty big scope to fit the record player. Check this out:

www.youtube.com/watch?v=GuCdsyCWmt8

Even if your story is true, it's an anecdote about one particular unnamed pair of tonearms. You think there are better arms than the 507 II. Okay we get it, but not everyone agrees with you. I read 2 reviews of the arm and the reviewers bought it from Dynavector.  Probably a decent arm?

What don't you understand about bearing friction and inertia? 

Regards,