View Full Version : '2 gram' cartridges.


catman
10-21-2011, 05:31 AM
G'day all, well I'm getting used to my AT95E since the demise of my M97xE and the AT95E is a very fine cartridge except possibly for one thing, 2 grams tracking weight!

I'm not bothered by a 2 gram tracking weight to the extent that I used to be, but lifting the tonearm with a 2 gram tracking weight sure feels a lot heavier than 1.25 grams! Is 2 grams really 'that' heavy!? :scratch2: Regards, Felix aka catman.

gillsev
10-21-2011, 06:48 AM
I'm using 4 grams with my Shure M7D on my Garrard Type A for my 78's. Sure is twice as heavy than yours. :yes:
Yes, I feel a significant difference from the 1.25 VTF I'm using on my Dual 1229Q sporting a Shure M91ED.

guiller
10-21-2011, 07:01 AM
Hi Felix, is your question pointing out to the effects on record wearing?

dlaloum
10-21-2011, 08:00 AM
There has been an extended discussion on VE about VTF...

There is evidence that higher VTF does increase wear over the longer term.

There is however debate over the audibility of that wear, and whether the fact that a record might have audible wear after 50 or 100 plays is relevant when most of us might only play it 10 or 20 times....

The audibility of the wear discussion needs to also take into account that much of the wear is at higher frequencies.... some of the frequencies where many of us may lack the hearing acuity we once had!

So for many of us, there may be additional wear (or not) but we can't tell anyway....

Part of that discussion also revolves around the fact that many radio stations played records over and over, using cartridges like the DL103 in Japan, with relatively high VTF's an conical styli....

But most of these Radio stations were also bandwidth constrained (15kHz max for FM, less than 10kHz for AM...) - so was that wear of any relevance? - Same problem as with "ageing" hearing .... your acuity in the range most at risk from wear is likely to be shot anyway.... so how can you tell!!

Current fashion is for MC's with higher VTF's... and a tendency for a rise in the high end.... (does the rise in the high end make up for the loss of acuity in the hearing of the well heeled and mostly mature buyers of expensive MC kit?)

So many interesting interlinked and hard to disassociate parameters...

In any case there is a clear link in terms of low frequency (subsonic) matching between arm mass, VTF and compliance.... And without getting these right you get mistracking and other issues....
So there is definitely a link between mid to high mass arms and VTF of 2g and higher...

Various Shure publications have Data from their research into wear with different styli profiles and different VTF's....
And this data was clearly one of the drivers behind the efforts made by so many manufacturers to develop very high compliance low VTF cartridges and the matching ultra low mass arms.

Like anything, where you set your chosen level of compromise between convenience and wear, this is very individual.

Conceptually I am 100% behind the High Compliance cartridge/stylus, low VTF, Low mass arm school of thought.
To date I have not heard really convincing arguments in the opposing direction...

Most of the arguments for high VTF solutions (low compliance, high mass) tend to go along the lines of:
1) various cartridges run at high VTF and sound good. (ergo high VTF is good)
2) I cannot hear any wear and I have played my records many times. (associated argument is the example of broadcast use)
and
3) The data published was all marketing and therefore cannot be trusted... (by extension, all data published by a manufacturer is suspect?!)

To which my take is
1) Various cartridge run at very low VTF and sound good (ie high or low VTF is not an indicator of quality of sound, but a design choice)
2) Like the frog in a pot of water being heated, the listener can often be deceived by something that changes slowly over time - without a comparison to a new pristine record it is hard to tell whether there is audible wear or not, and that assumes hearing acuity within the frequencies at risk. (by no means a given)
3) Perhaps I am Naive, but I tend to lend higher credence to manufacturer data... although still reading it with some caution and a pinch of skepticism - There seems to have been a lot of work done on vinyl wear in the 60's 70's and early 80's - all of which pointed to low VTF with high tracking capability being the key to low wear. (and also high sound quality)

So far nothing has shaken my conviction that the latter approach is correct....

I don't think high VTF is "wrong" - but I do think low VTF is "better"

bye for now

David

grooveman
10-21-2011, 08:06 AM
G'day all, well I'm getting used to my AT95E since the demise of my M97xE and the AT95E is a very fine cartridge except possibly for one thing, 2 grams tracking weight!

I'm not bothered by a 2 gram tracking weight to the extent that I used to be, but lifting the tonearm with a 2 gram tracking weight sure feels a lot heavier than 1.25 grams! Is 2 grams really 'that' heavy!? :scratch2: Regards, Felix aka catman.


Are you using the AT95E with a medium to heavy mass tonearm? Cartridges that track at 2 or more grams are generally lower compliance and are usually intended for tonearms that are medium-heavy mass. Maybe the AT95E is more compliant?

I recently replaced the Empire 200E(which tracks at 2-4g) in my Empire 980 tonearm, with a Stanton 500 V.3 and it sounds very nice. It'll have to do till funds permit a phono-preamp upgrade with MC capabilities and a Denon 103R cartridge.

Looks like dlaloum in the previous post went into detail on this topic.....great info!

dlaloum
10-21-2011, 08:19 AM
I forgot to mention...

The AT92 is the same core generator in a p-mount body...

With a little trimming of the plastic "wings" you can fit an AT92 stylus to an AT95 body...

The AT92 styli are higher compliance and lower VTF.... (and they are economical too...)

So if you arm prefers a higher compliance stylus - maybe some judicious ATN92 stylus surgery might be of interest?

KentTeffeteller
10-21-2011, 08:54 AM
My present Stanton 681 A tracks around 1.8 grams optimally. No record wear problems and it plays Styrene 45 singles without damage to boot. Rugged, reliable, and superb sounding. Tracks like a demon.

JHS2RT
10-21-2011, 09:05 AM
Yes-Felix --what type of turntable or arm are you using.
And have you tryed to lighten it up to say 1.5 or even less?

2 grams sounds heavy to me.

empirelvr
10-21-2011, 09:20 AM
I think a lot of the bad rap with higher tracking cartridges have regarding record wear has to do with the trend back in the 60's of using as light a VTF as possible, even if the cartridge really wasn't comfortable with it.

If you look at old ads or catalogs from say...1960 to 1967, you'll see tracking force ranges for many cartridges that are extremely unrealistic. For example Empire touted their 888 cartridge as being capable of tracking from 3/4 to 4 grams! And they weren't the only company to do that.

Naturally, what was meant by that was you COULD track at 3/4 of a gram IF your tonearm was capable of it, and IF the disc wasn't heavily modulated and wasn't that challenging in terms of content. But really, it was a 3 gram tracking cartridge. Sadly though, I think most people took that to mean they could track ALL of their records at 3/4 of a gram and did it in arms that weren't meant to track that light and caused a lot more damage from tracking too lightly than if they tracked heavier. I know my uncle insisted on tracking his Pickering 380 at one gram because in his mind, if it wasn't skipping or jumping the groove, it was fine. But then, he blamed the blatant mistracking from tracking too light on the mics used by the engineers. I think a lot of people thought like him back then. Strange...

My personal experiences with heavy tracking cartridges seems to prove the thought that, if you have basically okay equipment, keep your records clean and treated with care, and change styli frequently, even if you're tracking with a 4 gram cartridge, you won't be causing *undue* wear. I have records that I've owned since I was in single digits and played with a six gram tracking Pickering PAC-1 and because I was so anal-retentive about my records and record player even as an adolescent, those discs sound fine. Not perfect, but you'd never guess they were used on something as "crude" as a Garrard 40B for as long as they were.

marcmorin
10-21-2011, 09:56 AM
G'day all, well I'm getting used to my AT95E since the demise of my M97xE and the AT95E is a very fine cartridge except possibly for one thing, 2 grams tracking weight!

I'm not bothered by a 2 gram tracking weight to the extent that I used to be, but lifting the tonearm with a 2 gram tracking weight sure feels a lot heavier than 1.25 grams! Is 2 grams really 'that' heavy!? :scratch2: Regards, Felix aka catman.

The manufacturer lists the tracking weight to be 1.5-2.5, with 2.0 recommended. I'm assuming you've tried this at the various VTFs between 1.5 and 2.5? There is more wear (quicker) with a mistracking cart than with a cart that isn't mistracking but at what people would consider a high tracking force. The vinyl should be able to support 2 grams without any problems.

ChairSpud
10-21-2011, 10:08 AM
There were actual reports with evidence and photos to back up claims that tracking forces in excess of 3/4 Gram caused noticeable wear over time on LPs. As I recall the articles precipitated the drive for manufacturers to produce cartridges and turntables that could track 3/4 Gram and even 1/2 Gram, remember Duals ULM tonearms? My best recollection is the article(s) appeared in Stereo Review and maybe other HiFi publications in the 70s or very early 80s.

Anyone else remember the articles or have a copy?

Dave/ChairSpud

Celt
10-21-2011, 10:13 AM
2 grams isn't going to hurt anything...vinyl, styrene or even acetate...just as long as the stylus is good.

Ed in Tx
10-21-2011, 10:31 AM
There were actual reports with evidence and photos to back up claims that tracking forces in excess of 3/4 Gram caused noticeable wear over time on LPs. As I recall the articles precipitated the drive for manufacturers to produce cartridges and turntables that could track 3/4 Gram and even 1/2 Gram, remember Duals ULM tonearms? My best recollection is the article(s) appeared in Stereo Review and maybe other HiFi publications in the 70s or very early 80s.

Anyone else remember the articles or have a copy?

Dave/ChairSpud

I remember an article like that. Might have been in Audio magazine

flavio81
10-21-2011, 10:34 AM
G'day all, well I'm getting used to my AT95E since the demise of my M97xE and the AT95E is a very fine cartridge except possibly for one thing, 2 grams tracking weight!

I'm not bothered by a 2 gram tracking weight to the extent that I used to be, but lifting the tonearm with a 2 gram tracking weight sure feels a lot heavier than 1.25 grams! Is 2 grams really 'that' heavy!? :scratch2: Regards, Felix aka catman.

Felix, i am currently using a 4gram cartridge. You shouldn't worry at all. As long as the tip mass is low (say, less than 1mg) and the needle is well polished, and the surfaces are clean, then record wear is non-existent, unless you want to play your record more than 1000 times. More on that later.

As far as i've "researched", all record 'wear' reported is actually record damage caused by mistracking. Assuming the cartridge setup is OK and the arm is OK, the surfaces are clean and the needle is well polished, this is very ultimately depending on effective tip mass. And now, my friends:

From my other thread at VE:

Effective mass at the tip -- the smaller, the better.

6.000mg ELAC STS-200 (1958, first stereo MM pickup?? 4-6g VTF)
6.000mg GE VR-II (1955, mono, variable reluctance, 4-7g VTF)
4.500mg Sonotone 9T (1960, stereo, ceramic)
3.000mg Philips GP316 (1958, crystal, mono, 5-7g VTF)
1.400mg Philips GP380/GP390 (1968, high fidelity ceramic cartridge)
1.200mg Shure V15 first generation (MM)
1.000mg Ortofon SPU (all classic and 'mono' models)
0.970mg Shure "bi-radial" (0.4x0.7mil, MM)
0.800mg (less than) Philips GP400, 401 1st gen (MM)
0.750mg Ortofon X1-MCP (p-mount, high output MC)
0.600mg Nagaoka JT-555 (pseudo "carbon fiber" cantilever)
0.600mg (less than) Philips GP412 1st gen (MM)
0.500mg Ortofon OM10 stylus (bushed elliptical, MI)
0.500mg Philips GP922 (high end MC)
0.450mg Shure V15-II (MM)
0.400mg Ortofon OM20 stylus (nude elliptical, MI)
0.400mg Ortofon X5-MC (HOMC, nude FG)
0.370mg Shure Elliptical (0.2x0.7mil, MM)
0.330mg Shure bi-radial on V15-III (MM) (berillium control rod)
0.300mg Ortofon OM30 stylus (nude Fine Line), OM40 (nude FG), MI
0.290mg Technics EPC-P202C (p-mount, MM, boron cant)
0.290mg Shure HE on V15-IV (MM) ("telescopic shank")
0.270mg Denon DL-301 (MC)
0.250mg Denon DL-207 (MC)
0.240mg Van den Hul Colibri (MC)
0.230mg Technics EPC-P310MC (p-mount, MC, boron cant)
0.220mg Ortofon Jubilee (MC)
0.180mg Denon DL-303 (MC)
0.170mg Shure Micro-Ridge (0.15x3.00mil, MM, beryllium cant)
0.168mg Denon DL-305
0.109mg Technics EPC-P205CMK4 (p-mount, 0.2x0.7mil, MM, boron cant.)
0.098mg Technics EPC-100CMK3 (MM, boron cant.)
0.077mg Denon DL1000 (MC, boron cant.)
0.055mg Technics EPC-P100CMK4 (p-mount, MM, boron cant.)

The SPU is reported to be OK with records (1mg effective tip mass). Anyway, what i want to show is how drastically the effective tip mas has been reduced over times. In my view, most of the damage that could be caused by 1950s and 1960s cartridges wasn't fault of the heavy VTFs of the time but because of the effective tip mass... Even the Sonotone 9T, one of the best ceramics of its era, was too massive in this regard.

flavio81
10-21-2011, 10:43 AM
There is evidence that higher VTF does increase wear over the longer term.

"wear", "longer term". Too subjective.

AES papers show that indeed there is a visible "wear" mark left on the groove, even at 2gm with a conical after some plays, when looking at the microscope... yet this "wear" isn't audible. So it deserves to be called "wear"?

"Longer term". Loescher, inventor of the Lencoclean gizmo, tests a Shure M91E (a very good tracking cartridge with a low mass stylus assembly) tracking with a conical at 2.5gram. The same level of audio quality was mantained for 1200 repeated plays, with the record dry. With lencoclean (wet play), 2000 plays.

With stylus forces of 1.0-1.5 gram, 1500 repeated plays dry, 2500 plays wet.

So well, records do wear and higher VTF gives "higher wear" in the strict sense. That's what a scientist would say. But an engineer would say:

"As long as the cartridge has perfect tracking, records don't wear for practical purposes. Higher VTFs are still safe."

flavio81
10-21-2011, 11:02 AM
(post deleted by me)

Clean&Tight
10-21-2011, 01:45 PM
G'day all, well I'm getting used to my AT95E since the demise of my M97xE and the AT95E is a very fine cartridge except possibly for one thing, 2 grams tracking weight!

I'm not bothered by a 2 gram tracking weight to the extent that I used to be, but lifting the tonearm with a 2 gram tracking weight sure feels a lot heavier than 1.25 grams! Is 2 grams really 'that' heavy!? :scratch2: Regards, Felix aka catman.

Do/did you use the brush down when you had your Shure going? Then VTF would have been very close to 2 grams.

I'd have a tendency to think you're pulling my leg if you're telling me you can feel 3/4 of a gram in your fingers when you lift your tonearm.

I think you still haven't gotten over the loss of your old friend :no:

I'm sorry, it stinks when you have to make uninvited changes.

Multiplex
10-21-2011, 01:52 PM
Do/did you use the brush down when you had your Shure going? Then VTF would have been very close to 2 grams.

I'd have a tendency to think you're pulling my leg if you're telling me you can feel 3/4 of a gram in your fingers when you lift your tonearm.

I think you still haven't gotten over the loss of your old friend :no:

I'm sorry, it stinks when you have to make uninvited changes.

You can indeed. :yes: When I handle my tonearm with my M97xE at 1.25g, it feels considerably lighter than my Grado F-1+ at 1.6g.

jhaan92
10-21-2011, 02:27 PM
2 grams? Wow, my AT cart tracks at .8 grams...

catman
10-21-2011, 02:43 PM
G'day all, interesting coments. Personally I certainly can feel the difference between 1.25 and 2 grams tracking weight. :yes: It certainly does feel much heavier to me!

I would also think that generally correct overhang/ alignment would be a big factor here too would increased tracking weight. I am using my AT95E on the moderate/medium mass tonearm of my Kenwood KD-1500 and actually this turntanble came factory preinstalled with an AT95E (but a different headshell).

Perhaps memories of my childhood still haunt me as our family had a record changer with a horribly high tracking mass ceramic cartridge. Many of the records that were frequently played then back were totally destroyed by the high tracking weight of that cartridge. That was an entirely different situation though!

As an aside though, I notice that some of the ultra high end cartridges from Ortofon for example, track at somewhat higher than 2 grams. I wonder why? :scratch2: Regards, Felix aka catman.

Clean&Tight
10-21-2011, 03:03 PM
You can indeed. :yes: When I handle my tonearm with my M97xE at 1.25g, it feels considerably lighter than my Grado F-1+ at 1.6g.

.35 of a gram difference and you can feel it with your hand.

That's amazing.

Thomas

flavio81
10-21-2011, 03:05 PM
Perhaps memories of my childhood still haunt me as our family had a record changer with a horribly high tracking mass ceramic cartridge. Many of the records that were frequently played then back were totally destroyed by the high tracking weigtht of that crtridge. That was an entirely different situation though!

They were probably damaged because of intrinsically bad tracking of that cartridge, not precisely because of the heavy tracking force per se.

If it was, for example, an Ortofon SPU at 4.0g, your records would have stayed like brand new.

persil
10-21-2011, 03:54 PM
G'day all, interesting coments. Personally I certainly can feel the difference between 1.25 and 2 grams tracking weight. :yes: It certainly does feel much heavier to me!

I would also think that generally correct overhang/ alignment would be a big factor here too would increased tracking weight. I am using my AT95E on the moderate/medium mass tonearm of my Kenwood KD-1500 and actually this turntanble came factory preinstalled with an AT95E (but a different headshell).

Perhaps memories of my childhood still haunt me as our family had a record changer with a horribly high tracking mass ceramic cartridge. Many of the records that were frequently played then back were totally destroyed by the high tracking weigtht of that crtridge. That was an entirely different situation though!

As an aside though, I notice that some of the ultra high end cartridges from Ortofon for example, track at somewhat higher than 2 grams. I wonder why? :scratch2: Regards, Felix aka catman.

Possibly that record damage was more due to the actual TT and a very rough cut diamond?
I would guess that if you are used to tracking at very low vtfs 2 gram probably feels heavy, but to many of us its about right. I use high end MCs and have done so for longer than I care to remember! I have never noticed any record wear. Though I do make sure that everything is set up perfectly and I check for that regularly!
An MC usually is required to track at around 2 gram because of the higher mass connected to the cantilever that it has to move.
When you think about it a high end cart such as an Ortofon jubilee or spu has been built to the highest of standards with a diamond cut perfectly, The equipment its associated with it should also be near perfect as well? I never think twice of a vtf of up to 2.5 gram, After all the cartridge demands it! I am using a Benz Glider at this moment and it worries me that its ideal vtf is low at only 1.9 gram! And, as they say, "the proof is in the pudding", and I doubt if ANY cart tracking at, say 1.25 gram could produce music anywhere near the quality of that Glider?
Lots of us guys use a vtf around or above 2 gram and believe me if that caused record wear the cartridge would go out of the window!
I will say though that I do believe that at the higher tracking weights any damage on the diamond will certainly cause damage to the record?
I also "feel" the difference between 1.5 and 2 gram on the arm.
I remember in the early 70s how the cartridge manufacturers all used really low vtfs to sell the things! some as light as 0.75 gram! The lighter it tracked the better it had to be? I would think that more record damage was caused by the punters trying to achieve those unrealistic low tracking weights?

Well catman, now you are using higher vtfs its possibly time for thinking of moving up to a decent cart? and that will have to be an MC!:D

Clean&Tight
10-21-2011, 03:58 PM
They were probably damaged because of intrinsically bad tracking of that cartridge, not precisely because of the heavy tracking force per se.

If it was, for example, an Ortofon SPU at 4.0g, your records would have stayed like brand new.

You said a mouthful there brother! :yes:

Still going strong at 4 Grams after all these years:
http://www.needledoctor.com/Ortofon-SPU-Meister-Silver-GM-MKII

They say that my M3D which I still haven't mounted on a real deck yet, is the poor man's SPU. I sure am hoping that's true. If you've ever heard an SPU on a nice system don't miss the opportunity. Many concerns will evaporate!

BrocLuno
10-21-2011, 05:05 PM
Where are you tracking your other cartridges? Say Red Ed and the JT-555?

I track as light as I can until I hear something like distortion though headphones, then go back up at least 0.2 gram - sometimes more. Most of my AT cartridges run at around 1.5 grams as they seem to get noisy around 1.1 or so. If I had my O-Scope hooked up, I might be able to see distortion earlier (?), but the headphone method seems to work well enough.

I do this because aftermarket styli have little or no relationship to the OEM design and MFG parameters. Each aftermarket styli has to be tested to find it's sweet spot anyway, so why not do it for all :)

Multiplex
10-21-2011, 07:13 PM
I'm no expert, but I have heard it said time after time that more weight is ALWAYS better than mistracking. It sounds logical to me. As long your as records are kept clean, and your stylus is of good quality, there is merely a very tiny, and constantly moving contact point at which friction occurs between your stylus and the groove walls. The friction generates a tiny amount of heat that can slightly melt the surface of the vinyl. Over hundreds of plays, this may eventually deform the grooves, but hundreds of plays is what it would take at 2g. After all, the stylus passes over the surface of the groove so quickly that heat never has a chance to build up and cause real damage.

When mistracking, the stylus is violently bouncing around in the groove walls, chipping and gouging the fragile surface. Wear won't take long to become audible under these conditions.

I still prefer to only use cartridges that can successfully track at or under 2 grams, but when in doubt, add more weight! Nothing is worse than mistracking!

melofelo
10-22-2011, 01:30 AM
on this side of the pond it was often suggested that around the 1.85 gm mark was where the at95e sounded and tracked best...its only in the last few years that i've noticed a higher recommended tracking force being suggested online.
I've used mine for years between 1.8-1.9gm depending on how warm the room is and i think thats where it sounds most detailed ,spacious and balanced...
It is a versatile cartridge in that respect so do experiment and listen at a couple of tenths below 2.0gm in your arm

too low a tracking force is just as bad as too high...or so the theory goes anyway...

gusten
10-22-2011, 03:30 AM
VTF must be corrolated to suspension´s spring, damping and tonearm eff. mass. VTF on its own doesn´t mean much and is of little interest per se. 1,5g can only be better than 2,5g if it better suits spring, damping and eff. mass.

If 2g feels heavier than 1.25g does only mean that, it feels heavier.
gusten

jancumps
10-22-2011, 03:39 AM
.35 of a gram difference and you can feel it with your hand.

That's amazing.

Thomas

The arm lift operates close near the mount point of the arm. If I remember my mechanics lessons correctly, that means that the effect of that .35 grams is higher than .35 in the arm lift

http://www.audiokarma.org/forums/attachment.php?attachmentid=305816&stc=1&d=1319272646

I am open for any attacks on this theorema, as I had low marks on mechanics.

BrocLuno
10-22-2011, 05:41 PM
Windex good :)

jrtrent
10-22-2011, 08:17 PM
Years ago, someone on another forum posted lots of data from Shure and other sources on tracking force, stylus shape, and record wear. One conclusion was that a .7 mil conical stylus tracking at 3 grams would wear a record at the same rate as a .2 X .7 mil elliptical tracking at 1.5 grams, and in both cases the wear, though observable with a microscope, was not detectable in the sound. The .4 X .7 mil elliptical of the AT95E should be fine at its recommended vtf range.

markd51
10-22-2011, 08:37 PM
Years ago, someone on another forum posted lots of data from Shure and other sources on tracking force, stylus shape, and record wear. One conclusion was that a .7 mil conical stylus tracking at 3 grams would wear a record at the same rate as a .2 X .7 mil elliptical tracking at 1.5 grams, and in both cases the wear, though observable with a microscope, was not detectable in the sound. The .4 X .7 mil elliptical of the AT95E should be fine at its recommended vtf range.

No disrespect to you, but I call BS on this theory. How can a conical stylus, at a heavier weight, have less weight distributed to the groove wall sides, versus an elliptical stylus at a lower weight?

Shure was a lot of times full of shit though, I always especially thought so, with their "famous" stylus microscope, which its basic goal was to push another new cartridge on you, when there was absolutely nothing wrong with the one you had. Mark

dlaloum
10-22-2011, 09:13 PM
No disrespect to you, but I call BS on this theory. How can a conical stylus, at a heavier weight, have less weight distributed to the groove wall sides, versus an elliptical stylus at a lower weight?

Shure was a lot of times full of shit though, I always especially thought so, with their "famous" stylus microscope, which its basic goal was to push another new cartridge on you, when there was absolutely nothing wrong with the one you had. Mark

How do you measure "something wrong"?

Assuming the stylus is wearing evenly - as it wears down, the contact patch will change in shape and grow... as it grows the level of distortion will rise.

If you objective is to maintain "as new" distortion performance... then a couple of hundred hours is the best you can hope for (more if using a Line contact stylus)

If your target "acceptable" performance allows for 10% distortion, then a couple of 1000 hours is not out of the question.

What is your target?

Once you know your quantifiable target.. (so if your target is "it sounds good" you would need to determine the quantifiable parameters of it sounding good) - you can then measure where and when a stylus falls outside that range.

After all, many people were perfectly happy with the sound from their steel needled Victrola's.... if that is your performance target - no need to change the stylus short of destructive collapse...

The Shure stylus microscope works... I use a much more basic USB microscope, but base the method on the Shure microscope manual - and you can indeed see the difference as a stylus wears down.

Numerous people have noted audible improvements when replacing styli (same stylus type, same cartridge).

Some people have noted that an audible improvement on replacement occured when the worn stylus was insufficiently worn to be visible using the shure microscope.... - this appears to imply that by the time the Shure wear pattern is visible, sound quality would be substantively/measurably degraded.

One of the discussions over the years, and some of the experiments relate to the fact that an eliptical, at the same VTF, applies more pressure per surface area than a conical/spherical - this is due to its contact patch being smaller.
Also a Line contact, provides a lower pressure per surface area due to the larger contact area.... So high VTF setups are safer when using a line contact stylus.... and even less safe when using an eliptical. (theoretically... )

bye for now

David

markd51
10-22-2011, 09:37 PM
http://www.vinylengine.com/turntable_forum/viewtopic.php?t=22894

flavio81
10-23-2011, 01:26 AM
No disrespect to you, but I call BS on this theory. How can a conical stylus, at a heavier weight, have less weight distributed to the groove wall sides, versus an elliptical stylus at a lower weight?

Because the .7mil conical has greater contact area compared to the .2x.7mil elliptical. Pressure = Force / area. The greater the area, the less the pressure in the vinyl walls. You can't call BS on this particular theory, it is proven science.

Bob_in_OKC
10-23-2011, 01:35 AM
Sounds backward to me. The narrower profile would seem to have a longer line of contact, therefore more A in the P = F/A equation.

dlaloum
10-23-2011, 01:51 AM
Eliptical and conical/spherical contact on a "spot", as the spherical tip in fact is a semicircle/sphere in the groove zone - the geometry is such that if it were not for the deformation of the vinyl, the contact patch would be infinitely small....
(They make them by grinding down a diamond tip to make the tip round... so it is not in fact a "needle" but a half ball tip on a cone)

flavio81
10-23-2011, 01:56 AM
Sounds backward to me. The narrower profile would seem to have a longer line of contact, therefore more A in the F= P/A equation.

It is more evident when you look at the pictures of elliptical vs. conical. In theory both contact the groove in an infinitely small point. That would only be true if the groove was totally hard. But since the groove deforms, it "hugs" the diamond 'sphere' in the case of a conical stylus. An elliptical is a conical stylus with one cut at the front and another at the back, so the sphere is 'truncated'. Thus, the vinyl groove has less sphere to "hug". Result is less contact area.

The theory predicts it and the experiments confirm it.

Bob_in_OKC
10-23-2011, 02:02 AM
It is more evident when you look at the pictures of elliptical vs. conical. In theory both contact the groove in an infinitely small point. That would only be true if the groove was totally hard. But since the groove deforms, it "hugs" the diamond 'sphere' in the case of a conical stylus. An elliptical is a conical stylus with one cut at the front and another at the back, so the sphere is 'truncated'. Thus, the vinyl groove has less sphere to "hug". Result is less contact area.

The theory predicts it and the experiments confirm it.

That contradicts the information here, which I've seen at more than one site.

http://www.turntablebasics.com/cartridges.html

Do you have objective documents you can refer us to?

DENNYDOG
10-23-2011, 02:18 AM
It seems to me they don't want to believe the manufacturers specs.

jrtrent
10-23-2011, 03:07 AM
No disrespect to you, but I call BS on this theory.

As flavio81 mentioned, it was not just theory; it was experimental research, where records were actually played, record grooves microscopically examined, frequency response measurements made, and listening tests performed.

The link you provided in another post to the thread at Vinyl Engine includes a chart from JICO which is mostly information from Namiki. Jonathan Carr of Lyra also quoted the Namiki data when answering questions about contact area. The .7 mil conical has 30.5 micrometres of contact area on each groove wall, while the .3 X .7 mil elliptical has just 20.6; an elliptical with a .2 mil tracing radius as used in the Shure study (Kogen, 1964) would have even less contact area, thus needing lighter tracking forces to reduce wear. I know there is also a chart from Audio Technica that seems to contradict it, but even AT in their "A Guide to Phono Cartridges" states, "For a given tracking force, pressure on the groove wall will be highest for a small elliptical tip (say 0.2 X 0.7 mil) and lowest with a MicroLine stylus."

gusten
10-23-2011, 03:12 AM
Most styli´s footprint are to a rather great extent depending on vinyl compression. Personally I believe that instantaneously this compression is very small, and the contact is very similar regardless of shape, and in a little longer term the contact point is moving when playing.
Commonly explained footprints are very hard to visualize and believe.
gusten

flavio81
10-23-2011, 10:50 AM
That contradicts the information here, which I've seen at more than one site.

http://www.turntablebasics.com/cartridges.html

Do you have objective documents you can refer us to?

Where's the contradiction? Please point it out.

As for objective documents, go to the "Advanced stylus tip shapes" on Vinylengine, it was linked above. I collated that information.

Bob_in_OKC
10-23-2011, 10:55 AM
Where's the contradiction? Please point it out.

As for objective documents, go to the "Advanced stylus tip shapes" on Vinylengine, it was linked above. I collated that information.

I need to go back and see what everyone said. I thought there was a contention here that the linear contact caused more pressure than elliptical.

Ed in Tx
10-23-2011, 11:25 AM
Where's the contradiction? Please point it out.

As for objective documents, go to the "Advanced stylus tip shapes" on Vinylengine, it was linked above. I collated that information.

Ha! I got down to the Stanton Pickering Stereohedron pictorial diagrams, yep that looks like the stereohedron all right... and a little lower and there is my old 881S avatar!

Here's the big version...

http://i125.photobucket.com/albums/p72/tblazed/stanton-d81s-big.jpg

I took over 50 shots to get one or two this good with a toy Eyeclops camera.

Great collection of information btw!

jrtrent
10-23-2011, 11:38 AM
I need to go back and see what everyone said. I thought there was a contention here that the linear contact caused more pressure than elliptical.

No, what was questioned was the idea that a .7 mil conical tracking at 3 grams would cause no more wear than a small elliptical (0.2 mil tracing radius) tracking at 1.5 grams.

I finally found the original post in the other forum by a fellow named Klaus. These appear to be his synopses of the studies; I don't have the original research itself. http://www.audioasylum.com/audio/vinyl/messages/10141.html

Perhaps interesting to the OP is a 1978 study in which different stylus shapes were tested, all at low tracking forces. "Tests were carried out with the version IV cart with biradial, hyperbolic and hyperelliptical (25.4 x 38 microns) tips. As far as record wear is concerned, no difference between the tips was found, when playing with 1.25 grams." Since 1.25 grams is the recommended tracking force of the beloved M97xE, a more sophisticated stylus shape might not have any great advantage in preserving one's records.

luckydog
10-23-2011, 02:55 PM
Most styli´s footprint are to a rather great extent depending on vinyl compression. Personally I believe that instantly this compression is very small, and the contact is very similar regardless of shape, and in a little longer term the contact point is moving when playing.
Commonly explained footprints are very hard to visualize and believe.
gusten
Very insightful. I agree, this explanation actually fits dynamic physics and geometry involved. Not aware of any other that does. And I spent a long time looking for myself. Dynamic indentation can't happen to any extent, and instantaneous stylus contact location moves about within a 'contact region'. It's impossible to believe commonly accepted footprints, gusten is correct.

None of the papers in Klaus' summary above addresses dynamic (sliding with friction) indentation. It's very different from static. Davies at least acknowledges this. There are fundamental physics discrepancies unless dynamic indentation is small. And geometric discrepancies with commonly accepted footprints either way.

Instantaneous contact area doesn't change much between most stylus profiles, i agree.

jrtrent
10-24-2011, 06:06 AM
Commonly explained footprints are very hard to visualize and believe.

I don't know. Flavio81's description seems pretty easy to visualize:

since the groove deforms, it "hugs" the diamond 'sphere' in the case of a conical stylus. An elliptical is a conical stylus with one cut at the front and another at the back, so the sphere is 'truncated'. Thus, the vinyl groove has less sphere to "hug". Result is less contact area.

The theory predicts it and the experiments confirm it.

The experiments show that a .7 mil conical can track at heavier forces than a smaller conical or elliptical yet cause no greater wear. It seems logical for that to be accounted for by differences in contact area, and hence pressure per given area. Flavio81's observation that "the theory predicts it and the experiments confirm it" makes believing the commonly held footprints idea all the easier.

The OP asked if 2 grams is too heavy for his AT95E. Based on available research, 2 grams might be too heavy for a .2 X .7 mil elliptical, but maybe not too heavy for the .4 X .7 mil elliptical on the cartridge in question, since the theory would indicate that it has greater contact area.

Are there other theories extant to account for the observed differences in record wear vs. tracking force for various stylus shapes and sizes?

luckydog
10-24-2011, 06:52 AM
I don't know. Flavio81's description seems pretty easy to visualize:
Suggest try to draw a few. You'll see gusten is right. And what's more, common footprints would require indentation to become deeper for longer contact lengths, which is impossible.

I agree with Gusten, instantaneous contact area can't be much different between different stylus profiles. And in all cases, always smaller than the 'region' over which the instantaneous contact point moves on the stylus. In this way, 'stylus wear patch' might have the footprints as commonly accepted, but the instantaneous contact location is much smaller, and moves about within that patch or 'region'.

Seperately, if one looks at energy required in dynamically compressing vinyl, one can see for oneself that there's nowhere near enough available for it to happen to any notable extent.

So I doubt there is significant difference in groove wear between well made quality styli of various profiles. All things being equal. But I also doubt there is much groove wear anyways, at any reasonable VTF, when all is of good quality, and well set up.

jrtrent
10-24-2011, 08:09 AM
So I doubt there is significant difference in groove wear between well made quality styli of various profiles. All things being equal. But I also doubt there is much groove wear anyways, at any reasonable VTF, when all is of good quality, and well set up.

The available research doesn't seem to back up your suspicions, but perhaps your qualifiers of "all things being equal" and "at any reasonable VTF" would preclude the type of studies that would show differences.

luckydog
10-24-2011, 08:55 AM
I'm not aware of research that stands scrutiny, or addresses relevant dynamics, unfortunately. I've read quite widely on this topic.

One more thing one can do for oneself to demonstrate is to measure stylus/groove friction coefficient. You'll see it doesn't vary that much with stylus profile, but correlates more with 'quality' or reputation of manufacture. A factor of 2 covers pretty much all styli. It's not proof, but illustrative and supportive.

jrtrent
10-24-2011, 09:10 AM
I'm not aware of research that stands scrutiny, or addresses relevant dynamics, unfortunately. I've read quite widely on this topic.

I'm not even sure what "dynamics" is all about. What I'm interested in is the relationship between record wear, stylus size and shape, and tracking force. What studies have you read that contradicts the findings of the studies Klaus mentions? (gotta run out the door to work, but I'll check back later today)

flavio81
10-24-2011, 10:02 AM
Suggest try to draw a few. You'll see gusten is right. And what's more, common footprints would require indentation to become deeper for longer contact lengths, which is impossible.

He's referring to visualizing the stylus shapes, not the actual contact patch. I agree that this one would not be so easy to determine.


I agree with Gusten, instantaneous contact area can't be much different between different stylus profiles. And in all cases, always smaller than the 'region' over which the instantaneous contact point moves on the stylus. In this way, 'stylus wear patch' might have the footprints as commonly accepted, but the instantaneous contact location is much smaller, and moves about within that patch or 'region'.

Interesting!


Seperately, if one looks at energy required in dynamically compressing vinyl, one can see for oneself that there's nowhere near enough available for it to happen to any notable extent.

Umm?! Using the Namiki contact areas (example: 30 um^2) and the typical VTFs (example: 2g), the pressures are so high that (i guess) they should be compressing the vinyl in the elastic region (and highly likely that in the plastic region too).

The electron microscope pics of played grooves, and the wear studies, all point out that there's a wear mark left in the groove (take this as fact), i would guess that this is due to the vinyl entering the plastic region (this is not a fact). What you propose is that this 'mark' is due to the roughness of the diamond surface? (In other words, the 'wear' mark is due to abrasion)?

So I doubt there is significant difference in groove wear between well made quality styli of various profiles. All things being equal. But I also doubt there is much groove wear anyways, at any reasonable VTF, when all is of good quality, and well set up.


Agree with you. Use a perfect tracking cartridge, clean the records always, and forget about the wear.

flavio81
10-24-2011, 10:06 AM
Since 1.25 grams is the recommended tracking force of the beloved M97xE, a more sophisticated stylus shape might not have any great advantage in preserving one's records.

Maybe. The way i see it, the more 'sophisticated' stylus shapes are, for me, useful in:

1. Improving the sound on records that were slightly damaged by a previous stylus, by virtue of "reading" more of the groove wall. This is evident when playing a record that suffers from sibilance, using a MicroLine stylus (AT440MLa, anyone?) and comparing the vocal sibilants versus the audio obtained with a conical or elliptical.

The performance of the former is *dramatically* better in this specific case; and you see so many threads that start with "i can't get rid of the inner groove distortion no matter how many times i check alignment and try loefgren/baerwald/stevenson/nietszche/kant" and then somebody posts "i had that problem until i got the AT440MLa". In this case the record was previously damaged. A VERY COMMON scenario!

2. I have reasons to believe (but no strong evidence) that some advanced stylus shapes will give less distortions overall.

luckydog
10-24-2011, 10:11 AM
Dynamics is the difference between, say, a stationary bowling ball on a trampoline, and dragging one at high speed across the trampoline. At a speed, indentation of the moving ball will be tiny compared to the static case. You can see it's very relevant to stylus contact area, and none of those papers address this.

Gusten's points are good, because no indentation means commonly accepted footprints are impossible, and variation of instantaneous contact area (and so, by premise, wear), with stylus profile is far smaller than commonly accepted. I think I'd go further, and say that many footprints require impossible indentations anyway, anyone can verify by drawing.

Furthermore, imperical evidence for dynamic compression of vinyl/stylus is commonly taken to be harmonic distortion observations, and 'top resonance'. Both of which are indistinguishable from cantilever flex. Indentation isn't necessary to properly explain observations. Everybody just sleepwalked into accepting it, on the face of it.

Also, on a loose premise that groove wear is related to stylus/groove friction, no significant difference in friction = no significant difference in wear. Not proof, but supportive.

marcmorin
10-24-2011, 10:18 AM
Maybe. The way i see it, the more 'sophisticated' stylus shapes are, for me, useful in:

1. Improving the sound on records that were slightly damaged by a previous stylus, by virtue of "reading" more of the groove wall. This is evident when playing a record that suffers from sibilance, using a MicroLine stylus (AT440MLa, anyone?) and comparing the vocal sibilants versus the audio obtained with a conical or elliptical.


.

Provided any damage is indentation of the groove, and smaller than the contact patch of the diamond. Protrusion of damage in the groove wall would have to be read.

luckydog
10-24-2011, 10:43 AM
Umm?! Using the Namiki contact areas (example: 30 um^2) and the typical VTFs (example: 2g), the pressures are so high that (i guess) they should be compressing the vinyl in the elastic region (and highly likely that in the plastic region too).
That's statics though. Whereas dynamically, the groove surface to which force is applied is continuously changing, so there would have to be continually fresh compression. When one looks at how much energy that continuously requires, there's nowhere near enough available. It's provided by stylus drag (friction). The stylus slides over the vinyl surface, it doesn't compress, one can tell from the drag (or lack of).

The electron microscope pics of played grooves, and the wear studies, all point out that there's a wear mark left in the groove (take this as fact), i would guess that this is due to the vinyl entering the plastic region (this is not a fact). What you propose is that this 'mark' is due to the roughness of the diamond surface? (In other words, the 'wear' mark is due to abrasion)?
Think i'd entirely expect the molecular surface to be 'disturbed'. Like ski marks on a piste perhaps, bound to be some composite changes. Vinyl 'molecules' are pretty big, and IIRC the marking is not deep. Devil's in the detail !

Anyways, I was delighted to read Gusten's post, because it appears to converge with what I had concluded for myself. Despite the fact that it is obviously not the accepted view.

I can go back to sleep now !

91r100gs
10-24-2011, 10:56 AM
Presently I am running my Music Hall Tracker at 1.9 grams. It tracks great at this force, no IGD, and my albums seem to have a quieter background and delicate percussion instruments come closer to the forefront.

One album I play a lot is my 40 year old copy of Deep Purple "Machine Head". It has so much less IGD now than when it was put to rest, when I went digital. It was played during its infancy, and for years on a Realistic/BSR changer with a low end Shure/Realistic magnetic cartridge that was run up near 3 grams.

I'm guessing that the MH Tracker is running in a totally different part of the record groove, and is probably the reason for the improvement. IMO cleaning is more important than tracking force, when it comes to less record wear.

BrocLuno
10-24-2011, 11:11 AM
Wow, I see we have moved on to dynamic plastic deformation and standing wave fronts caused by the high loading pressures of tiny tips speeding along a plastic trough. I've often thought that it was the record that was magic, not the diamond. Sure, different tips generate different responses and detail. But imagine being that record surface. Here comes a ton of force in a tiny space and I'm supposed to do this over and over again? Ain't it wonderful that it works at all :)

aabottom
10-24-2011, 12:32 PM
Wow, I see we have moved on to dynamic plastic deformation and standing wave fronts caused by the high loading pressures of tiny tips speeding along a plastic trough. I've often thought that it was the record that was magic, not the diamond. Sure, different tips generate different responses and detail. But imagine being that record surface. Here comes a ton of force in a tiny space and I'm supposed to do this over and over again? Ain't it wonderful that it works at all :)
It is amazing that 64 year old technolgy still works so well.

luckydog
10-24-2011, 01:29 PM
Wow, I see we have moved on to dynamic plastic deformation and standing wave fronts caused by the high loading pressures of tiny tips speeding along a plastic trough. I've often thought that it was the record that was magic, not the diamond. Sure, different tips generate different responses and detail. But imagine being that record surface. Here comes a ton of force in a tiny space and I'm supposed to do this over and over again? Ain't it wonderful that it works at all :)
Well, dynamically, it's more like the stylus slides on the vinyl surface, and not very dramatic. And the image of high force/pressure comes from statics, which doesn't apply. Like in skiiing/surfing, its a surface phenomenum when it's going well, and need not be high force or involve much deformation/wake.

melofelo
10-24-2011, 04:13 PM
maybe the friction caused by the rotating groove in constant contact with the stylus tip also adds another factor...heat.:scratch2:
scroll to bottom of page..
http://www.micrographia.com/projec/projapps/viny/viny0200.htm

flavio81
10-24-2011, 05:44 PM
maybe the friction caused by the rotating groove in constant contact with the stylus tip also adds another factor...heat.:scratch2:
scroll to bottom of page..
http://www.micrographia.com/projec/projapps/viny/viny0200.htm

The "stylus melting the vinyl" myth has already been disproven.

luckydog
10-25-2011, 04:59 AM
Flavio81 is right about not melting. Or even getting hot enough to be interesting, for that matter.

And there's something quite bizarre going on in the photo in the link melofelo posted. It's a mono groove, which is damaged, and where the top groove width has increased on both groove walls. At several 'loud' spots, but not all. It doesn't look like wear to me, perhaps a damaged stylus, who knows ?

Friction, and heat such as there is, is not evenly divided between the groove walls. Because of the tracking offset angle, tonearm drag is significantly biased to act on the inner wall.

gusten
10-25-2011, 11:29 AM
I definitely share Luckydog´s conclusions regarding styli´s "footprints". Common footprints could make sense if they show the normal contact region where the contact points move when playing. As I see it this contact region could also be coupled with cantilever design and needle length.
gusten

markd51
10-25-2011, 01:16 PM
The "stylus melting the vinyl" myth has already been disproven.

This wasn't what LAST Laboratories once claimed, and probably still do. They claimed the groove reaches a temperature as high as 300F+.
Perhaps part of the problem is measuring such heat?

Common sense would dictate, that anytime two items would rub against one another and cause friction, heat would be a byproduct.

I would suspect a Stylus riding in a groove for any length of time will pick up some heat. How much, I have no personal idea, but if that Stylus does indeed become warm-hot, I would imagine that Stylus would be transferring heat back to the record groove. Mark

luckydog
10-25-2011, 02:02 PM
This wasn't what LAST Laboratories once claimed, and probably still do. They claimed the groove reaches a temperature as high as 300F+.

It's straightforward enough to show for oneself that's also impossible, as Flavio81 posted. Yes, there's heat, but not enough to make anything warm enough to be interesting.

markd51
10-25-2011, 03:41 PM
It's straightforward enough to show for oneself that's also impossible, as Flavio81 posted. Yes, there's heat, but not enough to make anything warm enough to be interesting.

Well, since it is "claimed by so many", that a Stylus does eventually wear out, friction then ideed must be present, correct?

I then conclude that LAST's "claim to fame" about the reduction of record, and stylus wear with their products, LAST Record Preservative, and LAST Stylast are all a bunch of hooey then?

I know for a fact that the LAST Factory did indeed once make such claims about heat at the groove-stylus interface, so, were they BS'ing the public with lies, and false claims, or did they indeed have laboratory research to back such claims up with scientific fact?

I will say this though, that I do have it on good authority from a Dealer who sells many high end Cartridge Brands, and that speaks to many of the manufacturers such as Benz Micro, and Dynavector, that these companies often get back cartridges for re-tipping, that have stylus' that are like brand new, no wear seen. Mark

luckydog
10-25-2011, 04:41 PM
so, were they BS'ing the public with lies, and false claims, or did they indeed have laboratory research to back such claims up with scientific fact?
That's exactly why we have to check for ourselves.

Ed in Tx
10-25-2011, 04:49 PM
these companies often get back cartridges for re-tipping, that have stylus' that are like brand new, no wear seen. Mark I can believe it. Do they notify the customer there's no visible wear and no re-tip is needed, and return it?

That picture of my Stanton 881S stylus in post #45, is a stylus with about 25 years of use, 5-20 hours a week, thousands of hours total. I could not see any wear flats or facets even at double the magnification of that image. Clean records and keeping dust away during play I think helps a lot, as well as low VTF 1.1 Grams is what I have always used on that one.

markd51
10-25-2011, 06:41 PM
I've read evidence myself, about Mr Van Den Hul stating that the Stylus can reach temperatures of 160C. That's 320F. Mr Van Den Hul is probably the most respected, and knowledgeable Cartridge maker on the planet.

As for not believing other's claims, with what methods, and equipment would you have knowledge, and access to, to proove VanDen Hul otherwise?

luckydog
10-26-2011, 05:26 AM
I'm a postgraduate physicist, since you ask. The heat story is something that circulates but doesn't stand scrutiny, no matter who espouses it ! It's a myth. One can measure for oneself how much energy is available (from stylus groove friction), and examine where it goes, and what (if anything) gets hot. The most common flaw is to overlook the fact that thermal conductivity of diamond is truly exceptional, and heat is readily conducted away from the diamond/vinyl friction interface by the stylus. Another common mistake is to ignore the fact that vinyl surface is continuallly changing, as the stylus passes, and any heat is left behind, it does not accumulate.

One can readily show for oneself there's not enough energy available to heat enough vinyl to any temperature that is remotely interesting. IIRC typically instantaneously just a few deg C rise at surface depth of 100nm. Which is also endorsed by common sense, because 320F would be damaging, and permanently change vinyl structure.

luckydog
10-26-2011, 07:39 AM
I definitely share Luckydog´s conclusions regarding styli´s "footprints". Common footprints could make sense if they show the normal contact region where the contact points move when playing.
Personally, Gusten's post is the enduring point of interest here. Because it has corollaries that challenge all manner of presumptions about benefits of different profile styli, including wear.

Heaviside
10-26-2011, 09:28 AM
Well, since it is "claimed by so many", that a Stylus does eventually wear out, friction then ideed must be present, correct?

I then conclude that LAST's "claim to fame" about the reduction of record, and stylus wear with their products, LAST Record Preservative, and LAST Stylast are all a bunch of hooey then?

I know for a fact that the LAST Factory did indeed once make such claims about heat at the groove-stylus interface, so, were they BS'ing the public with lies, and false claims, or did they indeed have laboratory research to back such claims up with scientific fact?

I will say this though, that I do have it on good authority from a Dealer who sells many high end Cartridge Brands, and that speaks to many of the manufacturers such as Benz Micro, and Dynavector, that these companies often get back cartridges for re-tipping, that have stylus' that are like brand new, no wear seen. Mark

Here's an interesting article from 1950. I was particularly impressed with the image of the diamond stylus after 2000 plays.

Dan
http://www.google.com/url?sa=t&rct=j&q=diamond%20stylus%20wear&source=web&cd=2&sqi=2&ved=0CD8QFjAB&url=http%3A%2F%2Fwww.aes.org%2Faeshc%2Fpdf%2Fhow.t he.aes.began%2Fmarcus_the-diamond-stylus.pdf&ei=lBSoToDlDMjl0QHco8WMDg&usg=AFQjCNGNV9S7nSBTD6Iz3iG0XDQ80uo5PA

Ed in Tx
10-26-2011, 09:59 AM
Here's an interesting article from 1950. I was particularly impressed with the image of the diamond stylus after 2000 plays.

Dan
And at 8 Grams.. nearly a 1/4 Oz. VTF.
Great article!

flavio81
10-26-2011, 12:01 PM
This wasn't what LAST Laboratories once claimed, and probably still do. They claimed the groove reaches a temperature as high as 300F+.

It is bull$h1t. It is a myth that is repetead even in books on the technical side of vinyl. LAST laboratories just believed it. Of course, that myth suits them perfectly.

flavio81
10-26-2011, 12:05 PM
I've read evidence myself, about Mr Van Den Hul stating that the Stylus can reach temperatures of 160C. That's 320F. Mr Van Den Hul is probably the most respected, and knowledgeable Cartridge maker on the planet.

Van den Hul is still spreading the lie. The lie started with a wrong observation by G. Alexandrovich (of Pickering/Stanton) on an AES paper called "the role of the scanning electron microscope in vinyl recordings" or something like that.

By the way, A.J. van Den Hul is one of those guys who wants you to purchase expensive audio cables so...

luckydog
10-26-2011, 02:47 PM
Flavio81 is right that it's just one of those bizarre urban folklore stories, the real origin of which is hard to trace, and has somehow become accepted as 'fact'. Despite contradicting common sense, and being straightforward to disprove.

Brett a
10-26-2011, 02:57 PM
Personally, I think it's amazing that music can be produced by dragging a rock glued to the end of a stick through plastic causing some magnets to wave around in proximity to a coiled up wire.

That could be worthy of an urban legend right there!

aabottom
10-26-2011, 03:13 PM
Personally, I think it's amazing that music can be produced by dragging a rock glued to the end of a stick through plastic causing some magnets to wave around in proximity to a coiled up wire.

That could be worthy of an urban legend right there!
Thanks Brett a, best post on this thread. Even better than my #60. :thmbsp:

gusten
10-26-2011, 03:39 PM
I feel a couple of questions are interesting. If using a softer needle than diamond, particles from that needle will become embedded in the vinyl and accelerate the wear, if playing the same record over and over.

What particles are the most abrasive, commonly on the record? Is the same phenomena happening when using a diamond, is it reasonable or irrelevant. If irrelevant will the surface mostly consist of Carbon and Plastizisers?
gusten

luckydog
10-26-2011, 05:47 PM
'Diamond dust' just can't be present in enough quantity to be an abrasive agent. Again, it's verifiable when one considers the totally tiny volume of stylus erroded over the course of 1000's of hours, left as a minute quantity of diamond spread over 1000's of km of groove.

No doubt there are abrasive agents that settle from air or are already present as impurities in the vinyl. But only a tiny fraction of household dust particles are small enough to get low enough in the groove to be interesting.

Just a guess, but perhaps most abrasive agents come from impurities already in the vinyl surface that become dislodged ?

markd51
10-26-2011, 06:43 PM
It is bull$h1t. It is a myth that is repetead even in books on the technical side of vinyl. LAST laboratories just believed it. Of course, that myth suits them perfectly.

I think it largely depends on what camp you have faith in, and who you believe?

markd51
10-26-2011, 06:45 PM
I feel a couple of questions are interesting. If using a softer needle than diamond, particles from that needle will become embedded in the vinyl and accelerate the wear, if playing the same record over and over.

What particles are the most abrasive, commonly on the record? Is the same phenomena happening when using a diamond, is it reasonable or irrelevant. If irrelevant will the surface mostly consist of Carbon and Plastizisers?
gusten

Probably the majority of dusts found on vinyl will be harder than the vinyl composition itself. Dusts can be many things, perhaps in the dusty New Mexico I live in, those dusts consist of minute rocks?

luckydog
10-27-2011, 05:08 AM
I think it largely depends on what camp you have faith in, and who you believe?

Again, that's exactly why one should always seek proof for oneself.

flavio81
10-27-2011, 11:05 AM
I think it largely depends on what camp you have faith in, and who you believe?

No. It's not about faith. It's about science. Science is not about beliefs. I don't need to "believe" that sin^2(x) + cos^2 (x) = 1, or that F=m*a, or that the earth's gravity acceleration is 9.81. There's a proof for it, be it theorical or be it based on actual measurement.
And now, the proof that there's not enough energy available to heat the stylus significantly, courtesy of Luckydog. LD, i'm pirating your post:

LUCKYDOG speaking here:

Decided to post my calcs on temp of stylus and vinyl in parts.

This is part 1, how much heat is generated. Source of heat is friction between groove and stylus.

From yosh's recspecs page citing JVC and other figures:

F = b*VTF

F is total friction force
b is coefficient of friction, 0.22 - 0.55 range
VTF is vertical tracking force

For typical b=0.4 and VTF=1.5gf, F=0.6gf=0.006N

For typical stylus velocity = 33cm/s =0.33m/s (inc rotation)

In one second, heat Q=0.006N*.0.33m=0.002 joules

Heat flow from stylus/groove friction P =0.002 joules per second = 2mW

Here's part 2 of my calcs on temperature of stylus and vinyl.

Conclusion from part 1 is that typical heat flow rate at stylus/vinyl contact is of the order of 2mW.

Part 2 is a discussion of physics of what happens to the heat generated at the contact area.

At the contact area, diamond and vinyl materials mesh and are essentially a composite material in the region where friction takes place, not necessarily very deep, but essentially one material. Heat is generated by making and tearing apart this composite material, as the stylus traverses the vinyl surface.

Diamond is an exceptionally good conductor of heat. It has a coefficient of thermal conduction in range 900-2000, one of the best materials around. Vinyl is a poor conductor of heat, coefficient of thermal conduction 0.4 - 0.8. This means that approx 99.95% of the heat generated in the contact region is conducted by the diamond, and the tiny remainder 0.05% is conducted by the vinyl.

Before addressing the math calulating contact region temperature in the next part, note that virtually all heat flow is conducted away from this region through the diamond. Whatever the temperaure of the contact region, some 2mW * 0.0005 = 1uW is conducted by the vinyl. This is a very small heat flow !

Here's part 3 of my calcs on temperature of stylus and vinyl.

Conclusion from part 1 is that typical heat flow rate at stylus/vinyl contact is of the order of 2mW. Conclusion of part 2 is that whatever the temperaure of the contact region, some 1uW is conducted into the vinyl, and this is effective heating power.

This is part 3 and looks at temperature rise of vinyl near the contact region.

Vinyl contact region continuously changes as record moves.

Assume contact region has a surface radius of 3um, stylus/vinyl velocity = 0.33m/s.

In one second, area swept by contact region A = 3um * 0.33*10E+6 um = 10E+6 um^2
From part 2, heat flow rate into vinyl from contact region P = 1uW
then heat flux into vinyl groove wall Y = P/A = 1uW/10E+6 um^2 = 10E-12 W per um
1um^2 = 10E-12 m^2
then Y = 1 W per square meter

For vinyl groove skin depth of 0.1um, volume swept by contact region in one second V

V= A * 0.1um = 10E+6 um^2 * 0.1 um = 10E+5 um^3
1 um^3 = 10E-18 m^3
V = 10E-13 m^3
Specific gravity of vinyl is close to 1 g/cm^3 = 10E6 g/m^3
Weight of vinyl occupied by volume W = V * 10E6 g/m^3
W = 10E-7 g = 0.1ug

In one second, heat flow = 1 uJ
Specific heat of vinyl is close to 1J/gK

Then average temperature rise T of vinyl groove wall skin to thickness of 0.1um

T = 1 uJ / 0.1ug = 10 deg K (celsius)

Obviously, convenient typical values were chosen to make the math plain, but these choices seem reasonable. Point is, there is not significant heating of the vinyl groove wall skin, not enough to melt or deform.


Flavio's comment: Even if we change some of the figures to go even more to the "safe side" this is a far cry of the über-hot melting tempeartures claimed elsewhere on the web. Part I is conclusive; and the friction coefficient of the vinyl record (used as a starting point) has been verified. There's only 2mW there, go heat a rapidly-running-away groove to more than 100ºC + using just 2mW of power !!

All in all, we should never forget that vinyl playback, at is core, it's governed by physics and physics can be perfectly understood using science. There's no need for relying in hearsay. This isn't quantum physics...

Pio1980
10-27-2011, 11:28 AM
Epoxy adhesives are heat sensitive compounds and if used for stylus tip mounting will soften with heat. I think Ortofon may use epoxy which is why they recommend avoiding alcohol cleaning. OEMs and Retippers know what they can use better that I so this is speculation..

gusten
10-27-2011, 11:46 AM
Epoxy adhesives are heat sensitive compounds and if used for stylus tip mounting will soften with heat. I think Ortofon may use epoxy which is why they recommend avoiding alcohol cleaning. OEMs and Retippers know what they can use better that I so this is speculation..

Epoxy compounds will not melt, if exposed to a higher temp than it was cured at, it will continue to cure. But when raising the temperature it will go through a Glass Transition state, and if the curing is of a low percentage, it will get soft for a short time. Epoxy is very resistant to Alcohols and heat, so maybe Ortofon is using some other compound.
gusten

Brett a
10-27-2011, 12:01 PM
No. It's not about faith. It's about science. [B]Science is not about beliefs..

Sure it is. Or often anyway. At some point, beliefs move in and take the place of science without the observer's knowing.

That point exists where one decides whether or not to believe that the scientific process has yielded the authoritative view of a subject.

The truly wise scientists (i think there are a few) know that we don't know the first tenth of one percent of anything. And are careful to steer clear of scientific dogma (or Scientism* as it is known).

A perfect example of this plays out here at AK every day. When it comes to the audible differences delivered by various cables, including AC cables, many people are quick to start thumping their proverbial bibles of science claiming with religious fervor that "it's not in the good book".

When obviously there are many who say the difference is there and science simply has not found a way to "validate" it by according to its own standards.

Which person are you? It has only to do with your beliefs.


Scientism

* Unlike the use of the scientific method as only one mode of reaching knowledge, scientism claims that science alone can render truth about the world and reality. Scientism's single-minded adherence to only the empirical, or testable, makes it a strictly scientifc worldview, in much the same way that a Protestant fundamentalism that rejects science can be seen as a strictly religious worldview. Scientism sees it necessary to do away with most, if not all, metaphysical, philosophical, and religious claims, as the truths they proclaim cannot be apprehended by the scientific method. In essence, scientism sees science as the absolute and only justifiable access to the truth.

Pio1980
10-27-2011, 12:32 PM
Epoxy compounds will not melt, if exposed to a higher temp than it was cured at, it will continue to cure. But when raising the temperature it will go through a Glass Transition state, and if the curing is of a low percentage, it will get soft for a short time. Epoxy is very resistant to Alcohols and heat, so maybe Ortofon is using some other compound.
gusten

I understand there are 2 fundamental forms of epoxy and one is particularly hydrophylic, thus susceptable to alcohol intrusion. My experiences with epoxies is that the household repair varieties tend to soften with an elevated temp, toward 100C F.I. My experience is quite limited and there are doubtless many specific variations that fall under "epoxy" definition unknown to me.

gusten
10-27-2011, 12:39 PM
A perfect example of this plays out here at AK every day. When it comes to the audible differences delivered by various cables, including AC cables, many people are quick to start thumping their proverbial bibles of science claiming with religious fervor that "it's not in the good book".

When obviously there are many who say the difference is there and science simply has not found a way to "validate" it by according to its own standards.


The problem is that these types of claims will always stay in the "belief" catagory, as the evidence will fail due to lack of proof. If the claims were to be proven, then they could fall in "fact" category.
gusten

avole
10-27-2011, 12:52 PM
I understand there are 2 fundamental forms of epoxy and one is particularly hydrophylic, thus susceptable to alcohol intrusion. My experiences with epoxies is that the household repair varieties tend to soften with an elevated temp, toward 100C F.I. My experience is quite limited and there are doubtless many specific variations that fall under "epoxy" definition unknown to me.Gusten has it right. I use epoxies in boat building and have yet to see an example of an epoxy melting, though it can take an age to set.

Good explanation here:
http://www.azom.com/article.aspx?ArticleID=986

Pio1980
10-27-2011, 01:08 PM
Back to title topic, the Matsushita/Panasonic strain guage cart family are in the 2g tracking class. They were originally entry level CD-4 four channel pick-ups for their plug-and-play four-channel ready turntable units.

Brett a
10-27-2011, 02:57 PM
The problem is that these types of claims will always stay in the "belief" catagory, as the evidence will fail due to lack of proof. If the claims were to be proven, then they could fall in "fact" category.
gusten
I think that's close, but missing my point slightly.

Until science proves the claims, it will remain in the category of "belief". The difference is the belief that science isn't done with cables yet. i believe it to be an eventuality that science will some day be able to measure the audible differences in cables that its missing presently.

I'd guess you believe differently.

gusten
10-27-2011, 03:10 PM
I think that's close, but missing my point slightly.

Until science proves the claims, it will remain in the category of "belief". The difference is the belief that science isn't done with cables yet. i believe it to be an eventuality that science will some day be able to measure the audible differences in cables that its missing presently.

I'd guess you believe differently.

I think I look at this a bit more pragmatically, the proof in this case will just be a controlled listening test, which as I see it always will fail.
gusten

Sorry for way off topic.

luckydog
10-27-2011, 03:53 PM
Gusten is right again. Pragmatism resolves such issues. A belief might as well be considered false if predictions based on it make no practical or useful difference. No difference in controlled listening tests, for example, would qualify.

Apols for off topic.

Brett a
10-27-2011, 04:37 PM
Yet the issue persists. Ya'll believe those tests are valid.

luckydog
10-27-2011, 05:22 PM
Apply the test of pragmatism to determine if they're valid.

Apols for off topic, again.

markd51
10-27-2011, 08:32 PM
Well gentlemen,
I do enjoy such friendly-amicable debates with you all, and here's some evident conclusions I come to about Stylus, and Record Groove heating, and the degree of such.

I seriously spent some good time over the past few days, looking for papers from A J Van Den Hul, and from others on the topic. Virtually nothing at all could be found.

Now Mr VDH supposedly claimed he devised a Thermocouple, somehow fitted to the Cartridge-Stylus, to measure heat. His claims were, due to Stylus Shape-Profile,there were differences in temperature measured. Well, I suppose I can believe that.

As for what temperatures were actually measured, and the fact if his methods were sound, and accurate, I myself have no idea?

And as well, the two camps about Diamond Stylus Wear itself, does it happen, or does it not?

I'm a believer of the other sort when it comes to Stylus wear, and I sort of believe mr VDH's one comment, that commonly, a Cartridge's suspension will often wear out before the Diamond Stylus itself will. Or, by an unnatural death, a mishap-accident.

That, and too many other variables of Vinyl playback, to ever out a solid figure on how long any given Stylus may last?

That one person may get 1000 hours from a Stylus, and another perhaps 5000?
I have little doubt still, that heat probably plays some influence, but not as great an influence as some has lead us to believe. Notice as well, LAST Labs no longer touts heat as a reason to use their products. Now it's "Shock Waves" lol

As I close this particular post, I would just like to offer my apologies to Mr Catman for taking his thread off onto some outerwordly tangent.

None the less, I have enjoyed this discussion with all you fine Akarma folks! Sometimes we all learn together. Mark

markd51
10-27-2011, 08:37 PM
Well gentlemen,
I do enjoy such friendly-amicable debates with you all, and here's some evident conclusions I come to about Stylus, and Record Groove heating, and the degree of such.

I seriously spent some good time over the past few days, looking for papers from A J Van Den Hul, and from others on the topic. Virtually nothing at all could be found.

Now Mr VDH supposedly claimed he devised a Thermocouple, somehow fitted to the Cartridge-Stylus, to measure heat. His claims were, due to Stylus Shape-Profile,there were differences in temperature measured. Well, I suppose I can believe that.

As for what temperatures were actually measured, and the fact if his methods were sound, and accurate, I myself have no idea?

And as well, the two camps about Diamond Stylus Wear itself, does it happen, or does it not?

I'm a believer of the other sort when it comes to Stylus wear, and I sort of believe mr VDH's one comment, that commonly, a Cartridge's suspension will often wear out before the Diamond Stylus itself will. Or, by an unnatural death, a mishap-accident.

That, and too many other variables of Vinyl playback, to ever put a solid figure on how long any given Stylus may last?

That one person may get 1000 hours from a Stylus, and another perhaps 5000?
I have little doubt still, that heat probably plays some influence, but not as great an influence as some has lead us to believe. Notice as well, LAST Labs no longer touts heat as a reason to use their products. Now it's "Shock Waves" lol

As I close this particular post, I would just like to offer my apologies to Mr Catman for taking his thread off onto some outerwordly tangent.

None the less, I have enjoyed this discussion with all you fine Akarma folks! Sometimes we all learn together. Mark

catman
10-27-2011, 09:52 PM
G'day all, no worries mate, it's been an interesting thread. In fact, I saw distinct parallels with my Amateur Radio work where quite differing views have been held by knowledgeable people, all pupporting to be telling the truth along with 'proof' to back up their various claims.

At various times I've found myself wondering what the 'real' truth is and whether such a thing actually exists. :scratch2: Regards, Felix aka catman.

luckydog
10-28-2011, 05:36 AM
At various times I've found myself wondering what the 'real' truth is and whether such a thing actually exists. :scratch2: Regards, Felix aka catman.
You know me, Felix, I'm no philosopher. But William James gave a series of lectures at the turn of the 20th Century, and defined Pragmatism. Which includes methods for determining truth in situations where more than one perspective version of it can, or is believed to, exist. It's worth knowing about, IMO, for rainy days and thread discussions such as this. It doesn't trump logic or reason, of course. But it's handy for resolving perspectives and beliefs, sometimes.

dlaloum
10-28-2011, 06:01 AM
And particularly useful for discussions with either A-Theists or Theists....

neobop
10-28-2011, 11:57 AM
Most styli´s footprint are to a rather great extent depending on vinyl compression. Personally I believe that instantaneously this compression is very small, and the contact is very similar regardless of shape, and in a little longer term the contact point is moving when playing.
Commonly explained footprints are very hard to visualize and believe.
gusten

That's interesting. Any supporting evidence that footprint is dependant on compression, or is that an assumption? Either way, there seems to be evidence to the contrary to similar contact conclusion.

Audio Technica vinyl stress photos show a great difference between elliptical and extended contact types. It doesn't take a great leap of faith to see a correlation between footprint and contact. Maybe I'm missing something.
http://www.vinylengine.com/library/audio-technica/cartridge-guide.shtml

Although I've never measured it, there see to be obvious frequency response differences with the same cart/cantilever and different stylus. With a narrower side profile, an extended contact tip would put more stress on the vinyl, not less, if there were similar contact.
neo

luckydog
10-28-2011, 01:02 PM
That's interesting. Any supporting evidence that footprint is dependant on compression, or is that an assumption? Either way, there seems to be evidence to the contrary to similar contact conclusion.
Anyone can draw it, and readily prove it for themselves, neo. I also posted a geometric proof over on VE.

Audio Technica vinyl stress photos show a great difference between elliptical and extended contact types. It doesn't take a great leap of faith to see a correlation between footprint and contact. Maybe I'm missing something. What is missing is any clue as to how on earth such a 'photograph' might be taken !? It is marketing material. NB it shows significantly worse stylus base clearance for the idealised line contact stylus ! NB the perfect groove base. NB the perfect lines and angles. NB incorrect groove height. It must be a sketch, and a concept one at that. It doesn't stand scrutiny.

neobop
10-28-2011, 03:07 PM
Anyone can draw it, and readily prove it for themselves, neo. I also posted a geometric proof over on VE.


A geometric proof that in actuality there is very little difference in contact area despite stylus profile?

That is interesting.

luckydog
10-28-2011, 04:48 PM
Well the proof is reductio ad absurdum that increased contact arc length=deeper indentation, which is impossible for any given VTF, of course. By extension it works for area too. Go check it out. But it's easy to prove just by drawing it yourself.

neobop
10-28-2011, 08:03 PM
Well the proof is reductio ad absurdum that increased contact arc length=deeper indentation, which is impossible for any given VTF, of course. By extension it works for area too. Go check it out. But it's easy to prove just by drawing it yourself.

Obviously I haven't read the long version. Conventional or accepted version would be that increased contact length = less indentation due to less force per unit of area. By indentation I assume you're referring to vinyl compression. Is indentation and contact synonymous? If that is the assumption your proof is based on, perhaps it is incorrect.

Maybe the AT pics are illustrations of actual research. Deeper indentation = less contact. How do you explain different sound and noise qualities attributed to different stylus shape, mass hallucination?

luckydog
10-29-2011, 04:38 AM
Is indentation and contact synonymous? Yes it is. Curved stylus surface must indent vinyl to contact at anything other than a point. This is easy to visualise, or to draw. What the proof shows is that increased contact line length, or area, requires increased indentation. Which is impossible for a given VTF, of course. In reality this is resolved because there is little indentation, and instantaneous contact area is far smaller than common published footprints, as gusten posted.

Maybe the AT pics are illustrations of actual research. Marketing research more like. They don't stand scrutiny for reasons already set out on this thread.

How do you explain different sound and noise qualities attributed to different stylus shape, mass hallucination?It's extremely rare to find two otherwise identical cartridges with just the tip changed. Always, there's a cantilever/suspension/generator change to accompany. So apples and apples are never compared. Besides, this argument does not affect distortion improvements from line contact styli. And surface noise difference is mostly simply associated with stylus base clearance. In that AT marketing sketch you can see they have overlooked this, and drawn the microline stylus with much reduced base clearance versus the eliptical !!! They have also sketched a perfect angle at the groove base, no radius, no crud. In reality, if the ML were really that profile, it would dredge the groove base and be disadvantaged as to surface noise, and the eliptical would be better. And that's why one has to be very careful before believing marketing material, neo !

gusten
10-29-2011, 06:11 AM
Another conclusion that might be drawn from this, is the footprint=contact region will be quite different if playing a silent groove, comparing with playing a normal cut one.
gusten

Edit: This is of course of no particular importance, unless if testing stylus´wear from a silent groove loop.

neobop
10-29-2011, 09:30 AM
Yes it is. Curved stylus surface must indent vinyl to contact at anything other than a point. This is easy to visualise, or to draw. What the proof shows is that increased contact line length, or area, requires increased indentation. Which is impossible for a given VTF, of course. In reality this is resolved because there is little indentation, and instantaneous contact area is far smaller than common published footprints, as gusten posted.

Marketing research more like. They don't stand scrutiny for reasons already set out on this thread.

It's extremely rare to find two otherwise identical cartridges with just the tip changed. Always, there's a cantilever/suspension/generator change to accompany. So apples and apples are never compared. Besides, this argument does not affect distortion improvements from line contact styli. And surface noise difference is mostly simply associated with stylus base clearance. In that AT marketing sketch you can see they have overlooked this, and drawn the microline stylus with much reduced base clearance versus the eliptical !!! They have also sketched a perfect angle at the groove base, no radius, no crud. In reality, if the ML were really that profile, it would dredge the groove base and be disadvantaged as to surface noise, and the eliptical would be better. And that's why one has to be very careful before believing marketing material, neo !

Right now on both ebay and audiogon NOS SAE-1000E and LT are for sale. These are identical except for the tip. They even share the same spec sheet. Users report a noticeable difference in sound. The line contact has a narrower profile which probably accounts for increased detail, especially in the high frequencies. I'm trying to look at this objectively, not make an argument.

I've done many stylus substitutions on AT bodies. Often there are differences in cantilevers/compliance, but sometimes not. Anyone can buy an AT-95E and substitute at least 4 or 5 different styli, all with the same cantilever and cu. They don't all sound the same, especially if you use a Clearaudio body. But once again, profile differences can account for much of it. But how do you explain music to noise ratios of extended contact tips? There is a noticeable reduction of noise with micro tips.

You provided no link to your indentation/contact theory. One must be careful when claiming proof of unverified data/assumptions. You seem confident that increased contact length = increased indentation, but the contact area of extended types has a much flatter side than the contact-curvature of an elliptical. I guess conventional claims would be based on increased contact = decreased indentation.

luckydog
10-29-2011, 12:15 PM
No-one on this thread made any claim that instantaneous contact area being smaller than published footprint in any way alters distortion advantages of fine minor radius styli. In fact, I explicitly posted otherwise. Instantaneous contact location simply moves about, and geometric advantages of small minor radius are preserved. At issue is the benefit of larger major radius, especially as to groove wear etc.

I already posted a plain summary common sense proof of the enigma, and it's pretty easy to draw for oneself. Plus, as I pointed out there's a properly set out geometric proof on VE. And, in any event, gusten originally posted exactly the same position on this thread. Actually, it's pretty compelling when you weigh it up, neo.

PS I have no idea if SAE-1000E and LT are absolutely identical except for the tip, BTW. I'd advise to accept only 1st hand inspection for such things, the devil's in the detail.

luckydog
10-29-2011, 01:27 PM
But how do you explain music to noise ratios of extended contact tips? There is a noticeable reduction of noise with micro tips.
Improved stylus base clearance seems the obvious one. Reduced sidewall clearance is another.

I don't think I have much to add to what's already posted here. Gusten's original post is a bit of a jewel, and hopefully I've been able to support that with a bit of common sense that anyone can explore for themselves with a pen and piece of paper. It should, at minimum, raise some tough questions. But it's still legal to disagree without reason, make the most of it whilst you can.

I'll go back to sleep now. Thanks for the thread, felix.

neobop
10-29-2011, 04:11 PM
No-one on this thread made any claim that instantaneous contact area being smaller than published footprint in any way alters distortion advantages of fine minor radius styli. In fact, I explicitly posted otherwise. Instantaneous contact location simply moves about, and geometric advantages of small minor radius are preserved. At issue is the benefit of larger major radius, especially as to groove wear etc.

I already posted a plain summary common sense proof of the enigma, and it's pretty easy to draw for oneself. Plus, as I pointed out there's a properly set out geometric proof on VE. And, in any event, gusten originally posted exactly the same position on this thread. Actually, it's pretty compelling when you weigh it up, neo.

PS I have no idea if SAE-1000E and LT are absolutely identical except for the tip, BTW. I'd advise to accept only 1st hand inspection for such things, the devil's in the detail.

LOL Lucky, I didn't say you or Gusten said anything contrary to advantage of smaller minor radius. I was suggesting it was a major reason for detail differences between two otherwise identical carts. It doesn't matter what you believe about the SAE. You choose to respond to what's convenient. Is an AT-95 identical to itself?

The vertical contact thing comes down to the question of compression and actual groove geometry. You say you have proof but fail to offer it. I think Gusten is right in saying that there is little compression. Until you prove otherwise, I'll assume you're wrong about vertical contact vs compression. Because micro styli mimic the shape of a cutterhead, it should have greater vertical contact.

Good idea, go back to sleep.

luckydog
10-29-2011, 05:15 PM
I see you conduct yourself as gracelessly as ever, neo !

As you agree with gusten (and I) that there is little compression/indentation, it inevitably follows that instantaneous contact area must be smaller than published footprints. So we all agree then. And it follows that difference in instantaneous contact area between various profiles is far smaller than difference between common footprints.

This needs no assumption, can be understood with common sense by anybody who's bothered to sketch it. If you wish to assume it's wrong, knock your socks off, neo, but you are effectively disagreeing with yourself now.......

And if you can't be bothered to find and read my VE content, you can make no credible assumption about it neo. In any event, it's irrelevant, the principle is self evident, and that is all that is being discussed here.

neobop
10-29-2011, 07:12 PM
I see you're as arrogant and condescending as always. You aren't gracious enough to even tell me the name of your thread. I don't browse the VE forum and I've lost interest in your "proof". It's only the compression-contact part I take issue with. Pragmatically, I am familiar with many stylus shapes and their sound. Don't underestimate their differences. BTW, some people own both versions of those SAE carts. They not only have the same specs, they're said to be identical except for the stylus. Seems like a good example.

luckydog
10-30-2011, 05:59 AM
It's only the compression-contact part I take issue with. That is not even debatable, small contact inevitably follows from small compression on a curved surface, the very thrust of gusten's original post......

To find my VE content, its very easy to use the search box. Of course, for this to be successful, you actually have to try.

The matter of whether various profile styli have sonic benefits is not in dispute here. You've misunderstood, neo. The matter at issue relates to the OP, VTF/wear etc etc.

gusten
10-30-2011, 08:08 AM
LOL Lucky, I didn't say you or Gusten said anything contrary to advantage of smaller minor radius. I was suggesting it was a major reason for detail differences between two otherwise identical carts. It doesn't matter what you believe about the SAE. You choose to respond to what's convenient. Is an AT-95 identical to itself?

The vertical contact thing comes down to the question of compression and actual groove geometry. You say you have proof but fail to offer it. I think Gusten is right in saying that there is little compression. Until you prove otherwise, I'll assume you're wrong about vertical contact vs compression. Because micro styli mimic the shape of a cutterhead, it should have greater vertical contact.


Hi neobop
I think I wrote that in my opinion the compression has to be "very small", meaning that indentation must also be very small. I find this believable and it makes sense, which to me these different "footprints" to a large extent don´t. Mainly because of the indentation contradictions.
gusten

neobop
10-30-2011, 09:22 AM
The amount of compression is conjecture not fact, despite what anyone guesses. That is, unless you've actually measured it. Perhaps wear patterns would be more telling. If you've proven that the amount of compression required for increased contact is impossible or severely limited, that would be interesting.

No, I don't misunderstand. Actual contact area should have a direct relationship on wear, all else being equal. That is my opinion. Because the side of an extended contact tip is sharper or thinner, if there is little or no extension it should have increased wear. I don't think that is the case. It also seems that micro tips exhibit less noise on worn records. I think less noise is due to increased vertical contact. While this is happening there is more information from a micro, not less. I don't doubt that actual vertical contact is less than claimed, but I think it's greater than what you're implying. Gusten said, "Personally I believe that instantaneously this compression is very small, and the contact is very similar regardless of shape, and in a little longer term the contact point is moving when playing." That was the post I questioned - very similar regardless of shape.

Edit: Gusten, our posts crossed. I was responding to Luckydog. I don't know about compression and this geometric "proof". My opinion is based on differences playing records. They seem undeniable and only explained by increased vertical contact.

luckydog
10-30-2011, 09:55 AM
The amount of compression is conjecture not fact, despite what anyone guesses. That is, unless you've actually measured it. I have measured it, indirectly, as anyone can. It shows up in tonearm drag. And there's nowhere near enough to support the amount of compression needed for commonly accepted footprints. What's more, those footprints would imply increased friction/drag for long contact styli, which does not happen.

Perhaps wear patterns would be more telling. As already posted, instantaneous stylus contact location moves about for a groove with programme material. It must. Within the nominal pattern of the footprint. So stylus wear pattern might well be expected to follow the footprint.

If you've proven that the amount of compression required for increased contact is impossible or severely limited, that would be interesting. I have, as already posted.

Actual contact area should have a direct relationship on wear, all else being equal. Agreed, but wear might well stil be very small in any event.

Because the side of an extended contact tip is sharper or thinner, if there is little or no extension it should have increased wear. Actually, things work out so that instantaneous contact area doesn't vary much with stylus profile, even with fine minor radius styli. Which mitigates what would otherwise be this exact issue.

It also seems that micro tips exhibit less noise on worn records. I agree, but that could just as readily be other factors, such as groove base clearance. There are a few specific non-line contact styli I use with exactly this benefit.

I don't know about compression and this geometric "proof". My opinion is based on differences playing records. They seem undeniable and only explained by increased vertical contact.
All can be better explained without increased simultaneous vertical contact. In fact, it removes contradictions.

flavio81
10-30-2011, 07:58 PM
Meanwhile i'm still using my SC35C cartridge at 4g, loving the great sound, and my records are still OK...

Bob_in_OKC
10-30-2011, 08:02 PM
I played my records with an Ortofon Concorde Pro S at 3g for a few years and I don't seem to have harmed any of them.

neobop
11-01-2011, 08:46 AM
Curiosity got the best of me and I saw the Lucky's proof at VE. I was right, it is interesting. In the drawing the groove wall is depicted as being flat, requiring a great deal of vinyl compression for extended vertical contact. Maybe this is exaggerated for effect, I didn't do any of the math. I guess that the groove wall would be concave, reflecting the shape of the cutterhead. It's hard to tell something like that with electron microscope photos I've seen.

I have measured it, indirectly, as anyone can. It shows up in tonearm drag. And there's nowhere near enough to support the amount of compression needed for commonly accepted footprints. What's more, those footprints would imply increased friction/drag for long contact styli, which does not happen.

As already posted, instantaneous stylus contact location moves about for a groove with programme material. It must. Within the nominal pattern of the footprint. So stylus wear pattern might well be expected to follow the footprint.

Actually, things work out so that instantaneous contact area doesn't vary much with stylus profile, even with fine minor radius styli. Which mitigates what would otherwise be this exact issue.


I also guess that a concave groove wall would would only increase vertical contact if the stylus actually stays at the same depth as the cutter. It should decrease with variation from concave area.

Stylus drag might be indicative of compression, but measuring drag does not quantify it. This seems a little vague. At any rate, AFAIK, most cart manufacturers now claim increased contact without specific amount. If a 30 yr old cart catalogue claims 10x the contact, maybe it's an exaggeration. If it claims up to 10x, maybe not. I really can't validate or refute this proof or theory. Without actual measurements comparing groove wall to stylus contact, it's a theory, not proof. I defer to experts who claim that extended contact is real.

gusten
11-02-2011, 06:46 AM
If I should make a guesstimate, I would say that for footprints and VTF to play any important role, the tangential vinyl velocity would have to be less than 10mm/s. The smallest velocity with 33rpm would be around 200mm/s.
Just my guessings.
gusten

LazySounds
11-02-2011, 07:34 AM
I have a number of records that I purchased from DJ friend, they have been played a LOT using an Ortofon Concorde Scratch.
That's a big fat spherical tracking at 4g'

They sound fine.

Vinyl appears to be reasonably tough so long as everything is clean and the stylus is not worn out.

Not that I know anything, just anecdotal evidence from heavy handed DJ friends, and my own primitive vinyl spinning efforts.

But I must admit I have found this thread and the theories within, quite fascinating. You guys clearly put a lot of thought in to your discussions.

neobop
11-02-2011, 08:35 AM
If I should make an guesstimate, I would say that for footprints and VTF to play any important role, the tangential vinyl velocity would have to be less than 10mm/s. The smallest velocity with 33rpm would be around 200mm/s.
Just my guessings.
gusten

How about linear arms, still compression?

Maybe drag is a direct measure but would difficult to translate to compression. Most of the time a pivoting arm isn't keeping the stylus tangent. Maybe compression isn't as necessary as previously stated. They used to think that vinyl got so hot it liquefied momentarily at contact point. Beyond compression!! LOL. It stands to reason that a stylus shaped like a cutterhead would have greater contact, but how much greater?

Maybe someone (not me) could put a carbon paper like substance on a groove of a white record, mark the drop point, and measure vertical contact. Anybody have an electron microscope?

One thing I can tell you is that micro tips are fragile and seem easily chipped or fractured. A micro line slipped out of my hand while I was aligning and fell on a metal platter. I checked and the tip was still there. I played some of a record and a long spiral of vinyl was stuck on the tip. It was a great Tommy Flanagan record too. Luckily I found another copy.
neo

flavio81
11-02-2011, 10:45 AM
If I should make a guesstimate, I would say that for footprints and VTF to play any important role, the tangential vinyl velocity would have to be less than 10mm/s. The smallest velocity with 33rpm would be around 200mm/s.
Just my guessings.
gusten

Care to explain why? (Pretty please)
Because vinyl doesn't have enough time to start deforming?

flavio81
11-02-2011, 10:46 AM
I have a number of records that I purchased from DJ friend, they have been played a LOT using an Ortofon Concorde Scratch.
That's a big fat spherical tracking at 4g'

They sound fine.

Vinyl appears to be reasonably tough so long as everything is clean and the stylus is not worn out.

My feelings too. I am now using the SC35C at 5 grams, still no ill effects, and yesterday i played the same record 2 or 3 times on a row, everything OK too.
Sounds pretty good and if you like you can read a review i wrote yesterday on it, at the "other" forum:
http://www.vinylengine.com/turntable_forum/viewtopic.php?f=19&t=41529

gusten
11-02-2011, 11:17 AM
Care to explain why? (Pretty please)
Because vinyl doesn't have enough time to start deforming?

I might be out on deep water, but yes I think so. To make an indentation in the vinyl Young´s modulus must be counted on. My guessing is a velocity between the vinyl and the needle less than 10mm/s, to have an indentation.. If using this low velocity I have seen a rapidly drop in output, like actually there is an indentation.
But I´m not sure, other factors could be involved. So a grain of salt is handy.
gusten

flavio81
11-02-2011, 11:35 AM
I might be out on deep water, but yes I think so. To make an indentation in the vinyl Young´s modulus must be counted on. My guessing is a velocity between the vinyl and the needle less than 10mm/s, to have an indentation.. If using this low velocity I have seen a rapidly drop in output, like actually there is an indentation.
But I´m not sure, other factors could be involved. So a grain of salt is handy.
gusten

Maybe this explains why back-cueing usually wears down the groove?

It would be interesting to do a wear test playing a record very slowly. Sadly my TT only goes down to 16RPM.

LazySounds
11-02-2011, 12:39 PM
My feelings too. I am now using the SC35C at 5 grams, still no ill effects, and yesterday i played the same record 2 or 3 times on a row, everything OK too.
Sounds pretty good and if you like you can read a review i wrote yesterday on it, at the "other" forum:
http://www.vinylengine.com/turntable_forum/viewtopic.php?f=19&t=41529

Interesting review, potentially heretical, conventional wisdom would lead one to believe that the use of a heavy tracking DJ cartridge will have side effects such as, but not confined to, blindness, insanity and death along with instantaneous destruction of ones records.http://www.audiokarma.org/forums/images/smilies/biggrin.gif

LazySounds
11-02-2011, 12:42 PM
I might be out on deep water, but yes I think so. To make an indentation in the vinyl Young´s modulus must be counted on. My guessing is a velocity between the vinyl and the needle less than 10mm/s, to have an indentation.. If using this low velocity I have seen a rapidly drop in output, like actually there is an indentation.
But I´m not sure, other factors could be involved. So a grain of salt is handy.
gusten

I'm enjoying this a great deal, I'm actually drawing pictures trying to get this straight in my head.

It is refreshing in any area of life to see people so passionately engaged in a subject.

Ed in Tx
11-02-2011, 12:56 PM
"The same tried and true formula of the late 50s, and of all broadcast studios."

Not necessarily so. The station I worked at in '70-71 used Stanton 500e cartridges on QRK turntables with Shure arms, and we set those up at 1.5 to 2 grams.

I have several records from there with no "cue burn" and all play great.


http://www.audiokarma.org/forums/attachment.php?attachmentid=278059&d=1306726882

(Note the vintage ash tray between the two 'tables :smoke:)

flavio81
11-02-2011, 02:44 PM
"The same tried and true formula of the late 50s, and of all broadcast studios."

Not necessarily so. The station I worked at in '70-71 used Stanton 500e cartridges on QRK turntables with Shure arms, and we set those up at 1.5 to 2 grams.

I have several records from there with no "cue burn" and all play great.


http://www.audiokarma.org/forums/attachment.php?attachmentid=278059&d=1306726882

(Note the vintage ash tray between the two 'tables :smoke:)

:thmbsp: Thanks for the pics! Well those Shure arms sure look light; i'd guess the correct match was a mid-high compliance cart. And Shure was one of the manufacturers that pushed for light VTFs.

On the VTF issue, there is an interesting article by famed audio-mathematician Michael Gerzon on the subject. According to him (and in concordance with VTF-wear papers by Walton of Shure), geometrically, applying 5g to a 0.7mil conical stylus is equivalent (wear-wise) to applying 1.2gm when using a 0.7x0.3mil elliptical, or 0.75g when using a 0.7x0.2mil elliptical.

Of course, this assumes that there is absolutely no dirt on the surfaces...

Ed in Tx
11-02-2011, 03:32 PM
Another picture I found online*, from the long-gone radio station 6 blocks from where I grew up (KBOX 1480) showing a couple of the turntables of the era (late '50s-early '60s, I think Gates). I have several old 45s from there that all have bad cue burn at the beginning. The plastic 45s were made from probably had something to do with their susceptibility to wear.

http://i125.photobucket.com/albums/p72/tblazed/kbox-prodrm.jpg

I used to ride my bicycle there and rummage through ther garbage cans for records.

*Thanks Mike Shannon and the knus99.com/KBOX1480 web site for the picture! Left and center are Homer and Jethro apparently promoting a record.

luckydog
11-02-2011, 05:43 PM
I guess that the groove wall would be concave, reflecting the shape of the cutterhead.
Bad guess, neo. Evidence, I don't think so, its BS. And doesn't that AT 'photograph' you linked (and consider true) show a dead straight groove wall ? Or have you overlooked or decided to ignore that now.......?

Stylus drag might be indicative of compression, but measuring drag does not quantify it. Er, yes it does.

I defer to experts who claim that extended contact is real. Thus ignoring blatently valid, and obvious, evidence otherwise. Without acknowledgement, or explanation. You'd better bring on the 'experts', neo. You've completely misunderstood again.

neobop
11-02-2011, 09:24 PM
Maybe the AT pics are illustrations of actual research.


Luckydog,
You're the one making claims, not me. Why don't you lighten up and show evidence of straight groove walls instead of all the nasty comments? Maybe you could explain or show why. It seems to me the groove walls would mirror the cutterhead. Look at the front of a micro line or micro ridge. They are like the cutter with curved sides. You're usually right, so what's the problem? I'm not convinced and I think the truth might lie somewhere in between. A proof requires verification of the assumptions.

dlaloum
11-02-2011, 10:50 PM
One thing I have not been able to find any info about...

Looking at FG styli - they are "cubist"-ish (thanks flavio for your thread on VE!) - the contact line looks linear and not curved.
But they are still specified with a "major radius".

So perhaps the major radius is more of an indicative estimate?

Given the varying methods of cutting and shaping LC styli - I question the assumption that the outside LC radius in fact matches the "major radius"

Although the "ride height" determined by the "major radius" might be equivalent to a true conical/spherical stylus of the major radius specified... the actual vertical geometry may in fact differ from that measure. - Is it more linear? more curved?, or does it in fact equal the major radius?

The last is the "obvious" answer - but the FG looks more like a line, and the shibata with its curved line is something else again.

On another conceptual approach to this - I look at the diagrams of a spherical, it reminds me of a "coracle" or round bottom boat sitting in water.

I look at the diagram of the LC - and it makes me think more of a hydrofoil, hyroplane or surfboard...

For the first case (round or v bottom boat) indentation when running and when static are pretty much the same - for the latter cases - hydrofoil/surfboards indentation at rest and indentation when running are very different. - I definitely understand that the physics at work in boats and on vinyl are very different... but I still feel that there is something about the "surfing the groove" analogy that may work well.

I vaguely recall Peter Lederman from soundsmith talking about designing his styli/cantilevers to reduce the "jitter" caused by the needle surfing across the top of the groove corrugations, and effectively microjumping (mistracking!!) from wave to wave, rather than following the wall precisely. - The type of mistracking he is discussing is at the very micro level, and would not be immediately apparent the way what we normally talk of as mistracking would be - hence his calling it "jitter". (Still the effect of even this sort of mistracking would be bad news for vinyl and stylus life....)

But then I may be mixing unrelated metaphors ....:scratch2:

bye for now

David

luckydog
11-03-2011, 04:58 AM
Luckydog,
You're the one making claims, not me. Why don't you lighten up and show evidence of straight groove walls instead of all the nasty comments? Maybe you could explain or show why. It seems to me the groove walls would mirror the cutterhead. Look at the front of a micro line or micro ridge. They are like the cutter with curved sides. You're usually right, so what's the problem? I'm not convinced and I think the truth might lie somewhere in between. A proof requires verification of the assumptions.
Just pointing out another self-contradiction in your posts on this thread, neo. That's not nasty, but it's hardly cause to congratulate you, is it ? You already posted what you consider to be 'AT research' photographs that clearly shows dead straight groove walls. And now you are claiming groove walls must be concave, despite that being contradicted by the 'expert' evidence you posted and hold to be true.

Seems to me like you're clutching at straws, having finally realised the geometric problem, and now refusing to acknowledge the obvious explanation, neo. Discussing moot guesses is a waste of time, you'll never agree anyway.

luckydog
11-03-2011, 05:25 AM
Looking at FG styli - they are "cubist"-ish (thanks flavio for your thread on VE!) - the contact line looks linear and not curved.
But they are still specified with a "major radius".

So perhaps the major radius is more of an indicative estimate?

Given the varying methods of cutting and shaping LC styli - I question the assumption that the outside LC radius in fact matches the "major radius"
Hmmm. What else can major radius mean in this context ? I doubt it. All 'line contact' styli are actually 'long major radius' styli AFAIK, perhaps to exactly avoid the 'chatter' issue of continuously shifting exact contact point due to imperfections in both groove wall and stylus otherwise ?

FG end up with a radius aspect ratio of about 15:1, which probably looks straight over a short arc.

Contact surfaces must be radiused to avoid actually being a cutter head, of course !

Although the "ride height" determined by the "major radius" might be equivalent to a true conical/spherical stylus of the major radius specified...
No, contact point seperation is only determined by major radius in a spherical/eliptical. For line contact type, the two contact surface major radii are not on the same axis.

I look at the diagram of the LC - and it makes me think more of a hydrofoil, hyroplane or surfboard... They all are exactly that, even sphericals. And the instantaneous 'working location' of the surfboard shifts about and ends up about the same size in all profiles, but the board is wider for line contact types.

...but I still feel that there is something about the "surfing the groove" analogy that may work well.
I think it is a good analogy. What we are interested in is the keel depth when its running, not static. And it equates to 'drag', that's the best way to measure it. When one measures this, for styli, the answer doesn't vary that much for different profiles. To me, most likely explanation is all stylus profiles instantaneously plane.

..hence his calling it "jitter". (Still the effect of even this sort of mistracking would be bad news for vinyl and stylus life....) One might imagine this being more of an issue for long major radius or true line contact profiles, where contact location might dart about.

neobop
11-03-2011, 05:40 AM
You already posted what you consider to be 'AT research' photographs that clearly shows dead straight groove walls. And now you are claiming groove walls must be concave, despite that being contradicted by the 'expert' evidence you posted and hold to be true.


I already agreed that those pics are probably illustrations. I'm not making claims and I'm not sure about any of this. I also posted that the 30 yr old cart catalogue might be an exaggeration regarding contact area.

Unless you show proof or strong evidence of straight groove walls, I'll assume you can't. I'll agree when you show why your assumption is true.

gusten
11-03-2011, 05:56 AM
Looking at FG styli - they are "cubist"-ish (thanks flavio for your thread on VE!) - the contact line looks linear and not curved.
But they are still specified with a "major radius".

So perhaps the major radius is more of an indicative estimate?

Given the varying methods of cutting and shaping LC styli - I question the assumption that the outside LC radius in fact matches the "major radius"
David

I don´t believe it to be a good idea to have the major radius too close to the cutterhead´s shape. Presumably this would cause an unpredictable and noisy output. As I see it the needle must be convex enough.
gusten

luckydog
11-03-2011, 06:45 AM
I already agreed that those pics are probably illustrations. But AT decided to illustrate the walls as straight, neo. You are, in fact, claiming groove walls are concave. There's no evidence for this, and unsurprisingly you aren't presenting any. Quite the opposite, what you have presented contradicts it. How many other guesses of yours will you ask me to 'disprove', is this some sort of game ?

Zodia
11-03-2011, 07:03 AM
Hu hummm

http://www.synthgear.com/2010/audio-gear/record-grooves-electron-microscope/

John

jrtrent
11-03-2011, 07:09 AM
On the VTF issue, there is an interesting article by famed audio-mathematician Michael Gerzon on the subject. According to him (and in concordance with VTF-wear papers by Walton of Shure), geometrically, applying 5g to a 0.7mil conical stylus is equivalent (wear-wise) to applying 1.2gm when using a 0.7x0.3mil elliptical, or 0.75g when using a 0.7x0.2mil elliptical.

In the VE thread, you mentioned that the article was available at VE. I didn't notice it under the "articles" heading there, and using the search box only brought up your cartridge review. Where do I need to look to find it?

You also wrote:
Some record sleeves say to use "10g or less" with a 1.0mil (mono) stylus, "5g or less" with a 0.7mil stylus or "3g or less" with a 0.5mil stylus. The L75 manual says exactly the same, and doesn't recommend using an elliptical at more than 1.5g. This is 100% consistent with the maths on Gerzon's article, which tells wear is equivalent in all the combinations i just listed.

I've seen the same or similar information on sleeves and in various articles and books. The reason, if addressed, for the difference in "safe" tracking forces with the different sizes has always been contact area, with smaller styli exerting more pressure per given area than larger styli. That explanation seems to be what is being challenged by many in this thread. What is the alternative to contact area as a theory for the differences in allowable tracking force limits?

Klaus's summary of record wear studies includes this tidbit from Anderson's 1978 study:
They further state that at that time, there was no measured evidence that the use of a long-contact-area stylus (van den Hul, fine line, micro line, microridge = 3.8 x 76 microns ) allowed to play with more than 1.5 grams without affecting record life.

This would seem counter to the contact area theory, since one of the supposed advantages of line contact styli is greater contact area to reduce record wear. If 1.5 grams remains the recommended maximum, the same as a small elliptical, then something other than contact area must be in effect. Maybe the tracing radius is more important than total contact area.

I've done much of my listening these past few years with .7 or .6 mil conical styli, tracking from 2 to 3.25 grams; I've experienced no undue record wear, and the heavier-tracking conicals seem to let me enjoy the music while suppressing the defects in my bargain-bin finds.

dlaloum
11-03-2011, 07:13 AM
Fantastic electron microscope pics!:thmbsp:

And it appears on these that the groove is indeed slightly curved.

if the groove is indeed curved, then the closer the radius of the LC curve to the radius of the groove curve, the larger the contact surface area will be...

dlaloum
11-03-2011, 07:38 AM
Shures technical seminar paper also from 1978, says that making conclusions about record wear is very difficult and refuses to draw a record wear conclusion.
(although some of the data presented appears to be indicative, the text conclusion states that this is only a small subset of the data and that overall a conclusion could not be drawn)

On the other hand, their study clearly shows that LC's have longer stylus life, and that lower VTF increases stylus life (as long as there is no mistracking).

I wonder where the high VTF = increased stylus wear idea started out and got its traction?

luckydog
11-03-2011, 07:54 AM
Hu hummm

http://www.synthgear.com/2010/audio-gear/record-grooves-electron-microscope/

John
Exactly. In the third picture down, there is clear image of of a dead straight groove wall in relief.

gusten
11-03-2011, 07:55 AM
Shures technical seminar paper also from 1978, says that making conclusions about record wear is very difficult and refuses to draw a record wear conclusion.
(although some of the data presented appears to be indicative, the text conclusion states that this is only a small subset of the data and that overall a conclusion could not be drawn)

On the other hand, their study clearly shows that LC's have longer stylus life, and that lower VTF increases stylus life (as long as there is no mistracking).

I wonder where the high VTF = increased stylus wear idea started out and got its traction?

Seems logical that LC´s would have longer life and also that VTF would affect stylus life.
gusten

dlaloum
11-03-2011, 08:06 AM
Exactly. In the third picture down, there is clear image of of a dead straight groove wall in relief.

I'm looking at the same picture - and my impression of most of the groove walls is of a slight vertical curve...

luckydog
11-03-2011, 08:13 AM
No, the groove walls are dead straight, with a bottom radius, as per spec. I'll try to post a mark up, but it is quite clear.

Hope this works :

http://www.audiokarma.org/forums/picture.php?albumid=1902&pictureid=12508

The optical illusion of wall curvature comes from the fact that the groove is laterally curved, of course. But, in relief, you can see the walls are vertically pretty much dead straight.

empirelvr
11-03-2011, 08:28 AM
I wonder where the high VTF = increased stylus wear idea started out and got its traction?

Simple, during the shellac days when steel tips were the norm.

For a 78, lower stylus pressures lessened the grinding action of the shellac on the steel or sapphire tip causing longer life for the styli.

The fact that softer vinyl microgroove records played back with a diamond stylus was an apple compared to a 78 shellac disc's orange wasn't considered. A pure case of "conventional wisdom" that stuck despite an obvious paradigm shift.

Plus, it was commerce as well. Fidelitone, Recoton and cartridge makers themselves had a keen interest in making sure people bought replacement styli on a regular basis.

Speaking of Fidelitone, I just came across an ad in the January 1960 issue of High Fidelity for something they called a "Pyramid Point" replacement stylus that sounds very much like a modern day LC/Shibata/FG etc. stlyus!

Excerpted copy from the full page ad:

"Shaped to follow the record grooves exactly....pick up ALL the recorded sound.

The Pyramid Point Diamond positively traces the centerline of the microgroove. Tracing distortion is reduced to the amount theoretically equivalent to a .2 mil contact radius. All harmonic distortion is reduced to impercertibile values."

Is this the first elliptical or something more extreme that didn't catch on?

I'll post a scan of this full page ad later tonight.

dlaloum
11-03-2011, 09:10 AM
Here is a pic of a Neumann record lathe "stylus"/Cutter

Very straight indeed...

luckydog
11-03-2011, 09:20 AM
Indeed, very straight. To view my mark-up above, it seems one has to be logged in, BTW. Then the image magically appears.

flavio81
11-03-2011, 12:15 PM
Luckydog,
You're the one making claims, not me. Why don't you lighten up and show evidence of straight groove walls instead of all the nasty comments? Maybe you could explain or show why. It seems to me the groove walls would mirror the cutterhead. Look at the front of a micro line or micro ridge. They are like the cutter with curved sides. You're usually right, so what's the problem? I'm not convinced and I think the truth might lie somewhere in between. A proof requires verification of the assumptions.

Come on Neobop... Cutting styli are totally a V, they were never ever curved, at least since 1948.
You could have googled the information instead of challenging us!!

flavio81
11-03-2011, 12:23 PM
In the VE thread, you mentioned that the article was available at VE. I didn't notice it under the "articles" heading there, and using the search box only brought up your cartridge review. Where do I need to look to find it?

Help yourself my friend:
http://www.vinylengine.com/turntable_forum/viewtopic.php?t=34155


This would seem counter to the contact area theory, since one of the supposed advantages of line contact styli is greater contact area to reduce record wear. If 1.5 grams remains the recommended maximum, the same as a small elliptical, then something other than contact area must be in effect. Maybe the tracing radius is more important than total contact area.

Yes, that gives food for thought. I'd say the groove is always deforming under pressure and this "equalizes" the contact areas. But the Shibatas (& friends) 'deform' it less so perhaps this enabled an advantage for correctly tracing the 38KHz+ frequencies (together with the major radius).

It is also of note that Lou Dorren (inventor of one of the first CD4 decoders) told at one forum that the CD-4 record compound was at one time tested (he was a direct witness) to withstand 500 plays at 5g with a portable record player -- afterwards the CD-4 carrier was still retained and the record played nice with a Shibata tip.

More food for thought.

I've done much of my listening these past few years with .7 or .6 mil conical styli, tracking from 2 to 3.25 grams; I've experienced no undue record wear, and the heavier-tracking conicals seem to let me enjoy the music while suppressing the defects in my bargain-bin finds.
:yes:
Check out the article i've linked.

luckydog
11-03-2011, 01:11 PM
For coherency, I prefer to discuss the Gerzon article over on VE. It's a topic that Flavio81 and I disagree about. He has quite an army, including the likes of Shibata on his side. I just have my rusty old maths and physics, but I'm still right :-)

There are two big problems with the Gerzon article, which invalidates its noble effort, and renders results and predictions misleading.

First is the constant k introduced in (2) is vanishingly small in practice. And this has major corollaries for all that follows it which is built on Hertzian indentation, which fails. Second is the extraction of necessary constants near (5) based on the assumption that the 'top resonance' is caused by a vinyl compression-spring/tip mass system. Whereas it can readily be shown to be caused by cantilever flex and self-resonance. This is where the Gerzon article really leaves the rails ! It has interesting methods, but after this point in proceedings, pretty much all numeric predictions it makes are useless, including the conclusions.

Practically, one can seperately validate that Gerzon's predictions can't be true. Dynamic indentation it predicts is impossible from energy considerations. Harmonic distortion is nowhere near as large as it should be if indentation were anything like so large.

So the Gerzon article doesn't stand scutiny, though it is self consistent. It is misleading, unfortunately. But it's in good company.

flavio81
11-03-2011, 02:25 PM
Post deleted -- let's discuss it on VE so we don't go off topic.

My "army" is on vacation right now, Luckydog!!

lini
11-03-2011, 10:06 PM
What I'd really like to see would be some comparative high-speed camera microscope movie clips for different tip shapes and also for several groove modulations (e.g. unmodulated vs. moderately vs. heavily modulated - and for the latter two maybe also once limited to some 12 to 15 kHz, once limited to around 20 kHz and once with some really high frequency content (e.g. a CD4 version of the 20-kHz-limited version with active rear channels) - 'cause I could very well imagine that the behaviour of the different tip shapes might depend on the actual modulation, too...) in order to see what actually happens. And that of course accompanied with pics of the possibly different wear patterns after certain numbers of plays (e.g. new vs. 10x vs. 50x vs. 100x played). Otherwise who knows which possibly significant side-effects there still might be?

Greetings from Munich!

Manfred / lini

dlaloum
11-03-2011, 10:10 PM
Me, I'd like my own pacific island with mansion and plane for easy access...

Which one do you think is more likely?

lini
11-04-2011, 12:56 AM
Not sure, David - what's your typical yearly income? And do you have any wealthy relatives or friends you'd expect ample sums from in the near future? ;)

Then again, maybe you could snag one of the previously nuked ones for cheap - and possibly even find an abandoned mansion and plane there? :D

Radiating grinnings from Munich!

Manfred / lini

dlaloum
11-04-2011, 01:11 AM
And that "glow in the dark" effect.... very very cool for parties!:D

luckydog
11-04-2011, 04:51 AM
What I'd really like to see would be some comparative high-speed camera microscope movie clips for different tip shapes and also for several groove modulations
It would make a great final year project for someone. And would settle some demons. Here's what I predict you'd see :

1. Significant vertical motion due to pinch effect, less for small minor radius styli.
2. Some small reduction in vertical motion for long lontact styli, but not much.

And here's some surprise predictions :

3. Cantilever quite flexible, and deflections moving quickly along it like waves or ripples
4. Stylus would twist or skew on its vertical axis, somewhat less for line contact.
5. Stylus would 'roll', again somewhat less for a line contact
(4 and 5 accomodated by cantilever twist)
6. Very small indentation of vinyl, no wake, for all stylus profiles.

Would need a camera perhaps 20,000 fps, but an order of magnitude either side would still be very interesting. And suitable optics/light, and a very stable jig. I hope somene has access, and motivation, to do it.

marcmorin
11-04-2011, 09:11 AM
It would make a great final year project for someone. And would settle some demons. Here's what I predict you'd see :

1. Significant vertical motion due to pinch effect, less for small minor radius styli.
2. Some small reduction in vertical motion for long lontact styli, but not much.

And here's some surprise predictions :

3. Cantilever quite flexible, and deflections moving quickly along it like waves or ripples
4. Stylus would twist or skew on its vertical axis, somewhat less for line contact.5. Stylus would 'roll', again somewhat less for a line contact
(4 and 5 accomodated by cantilever twist)6. Very small indentation of vinyl, no wake, for all stylus profiles.

Would need a camera perhaps 20,000 fps, but an order of magnitude either side would still be very interesting. And suitable optics/light, and a very stable jig. I hope somene has access, and motivation, to do it.

Which is what hasn't been discussed to this point, and raises the question of possible groove contact vs actuall groove contact.
The first bending mode in any pipe would be as you describe in #3, an up down flexing. The second and third modes of vibration in a pipe would be of the order of twist at the unterminated end. Are the styli cut slightly elipsoid to keep an accurate contact patch with the groove wall during second and third modes? (as well as trying to control the amplitude of the modes) If this is the case, the original cut doesn't actually contact more area in a static mode, but has the ability to have a longer region during its vibrational modes.
To keep a reasonable amount of contact area in the vinyl during the first vibrational mode a slight forward rake cut into the diamond such as found in the hyperbolic and shibata style diamond. The first vibrational mode of up/down bending should cause the stylus to slightly scrub.