[*Scotty*]

One thing the wire tie back on the end of the cantilever does is stop longitudinal movement of the cantilever when tracking a record groove. This stabilizes the stereo image compared to a cartridge that has the cantilever mounted in a rubber doughnut without a tie back. Compliance is also a function of the rubber doughnut's elasticity. Actual cartridge compliance would be determined by the tie back tension and the doughnut's modulus of elasticity.
 The cantilever is not intended to be a spring, if it flexes information is lost because the motion of the stylus in the groove was not directly translated into motion of the magnets.
 That is why so much R and D has gone into making a cantilever as ridgid as possible.
Here are a couple links to the referenced Ortofon MC200
MC200 cartridge cutaway.
http://www.ortofon.com/images/stories/cartridges/MC_200/Ortofon%20MC%20200%20p.2.pdf
Cantilever design discussed.
http://www.ortofon.com/images/stories/cartridges/MC_200/Ortofon%20MC%20200%20p.3.pdf
Scotty

[neobop]

David,
I think that view is incorrect.   If you remove the rubber donut completely the cart still retains compliance but loses damping.  How else could Ortofon play the MC200 without damping  in that phase paper?
"When you move from rubber doughnut to no doughnut (ie depend on the inherent springiness of the cantilever) - your resonant frequency will rise dramatically - it will be nowhere near the low frequency zone and may (should?) be well outside the audio range in the ultrasonic frequencies."
Have you done this?  Be specific please.  Some carts might use the rubber damper for compliance, especially those with no cantilever, but for most "conventional" carts I don't believe so.
 
Compliance isn't related to springiness, it is springiness.   What does cu x 10 6 cm/dyne mean? 
Dyne is a unit of force that is measured in centimeter per gram. This force is equal to the amount of force necessary to create the movement of one centimeter for each second, which is equal to one gram.  So we're talking about force necessary to create a small (x 10 6power) movement in a specific direction and measured at a specific freq.  In other words, flex. 
neo

One more thing to add to the above viewpoint.  The cart has a suspension, some kind of wire or supporting structure that is part of the cantilever system.  On an AT cart that suspension is directly behind and part of the top of the cantilever.    It is held in place by the compliance screw, misnamed or not. The MC200 suspension wire is as thick and longer than, the cantilever itself.

Sometimes the suspension in a cart will fail/collapse and the cart winds up sitting on the record.  This is not a rubber donut failure, it's a broken suspension.  The cantilever and the suspension primarily determine the compliance.  They are made to have varying degrees of springiness,  flexibility or movement for a given force.  The rubber damper primary function is well, damping.  Maybe it can be used as part of cantilever/suspension system, depending on design.
neo 

[dlaloum]

Well consider the ADC cartridges - no wire.
By design the cantilever is as rigid as possible so as to avoid all flex (other than as an imperfection) - so for our low frequency purposes in this discussion it is by definition non-springy.

The only thing providing "springiness" in these designs (along with damping) is the elastomer holding the cantilever in place.

In those designs there is also a pivot point, a hard point which is the fulcrum of the cantilever...

Could the compliance screws be the fulcrum point? or tightening of the fulcrum?

When I overtightened the screw on a berillium AT15ss stylus the boron cantilever snapped and dropped out...perhaps I should see if I can find that loose cantilever (I put it aside) and measure its length.

I am trying to put together the formulae required to calculate the flex of a boron cantilever... but I am pretty sure the result will be absolutely negligible for our purposes and at our frequencies. Aluminium cantilevers are more complex to calculate due to the tube/pipe hollow structure + anodising.... simple boron rods should be easier...

There are a number of reviewers and audiophiles who have claimed to be able to immediately hear the specific colourations introduced by tension wires...

In cartridges with a tension wire setup - the wire is part of the suspension and it does indeed flex - (and the level of tension/flex is of course related to compliance) - but the cantilever itself remains rigid.

bye for now

David

P.S. thanks for those links - That brochure is also available on VE and it has some good reference material in it...

[*Scotty*]

Here is a link to Audio Technica's "A Guide to Phono Cartridges".
http://www.audio-technica.com/cms/resource_library/literature/da2d70c7d46a2803/a_guide_to_phono_cartridges.pdf
This pdf DOC has a detailed drawing of the AT Paratoroidal Signal Generator showing the location of the compliance screw and the Radial Damping Ring.
http://www.audio-technica.com/cms/resource_library/literature/da2d70c7d46a2803/a_guide_to_phono_cartridges.pdf
Same DOC in color.
http://www.coolgales.com/brochures/AudioTechnicacartridgesbrochure.pdf
I will take the alleged colorations from a tension wire any day over the poor imaging that a cartridge without adequate control of the cantilever's longitudinal movement will exhibit.
Scotty

[dlaloum]

Ahh thank you...

so it is in fact a compliance screw - as it screws down it puts increased tension on the rear tensioning wire (for some reason I thought the AT styli didn't have a wire...  ) and therefore reduces compliance - but given that it is applying pressure directly to the tensioning system the whole setup is quite delicate....

Neo - formula for deflection from:
http://en.wikipedia.org/wiki/Deflection_(engineering)

Deflection in Radians = F*L*L / (2EI)

where F = force applied (VTF)
L = length of cantilever (7mm)
E = Young's modulus / modulus of elasticity (material spec for Boron  = 478GPa)
I = effective tip mass (area moment of inertia)

Resulting deflection in degrees is 9.78975E-17

Does it flex - yes
Is it relevant - no

to all intents and purposes 1g of static force does not cause a boron cantilever to flex.

The influence on the tension wire however would be quite different!

bye for now

David

[neobop]

David,
That's what I said in the first place.  You were looking at the rigidity of the cantilever alone.  It doesn't work that way.  The cantilever, suspension and damper comprise a system that determines compliance.  I'm not familiar with ADC system and lack of wire.  Maybe that's why the all seem to fail?  The cantilever has to be attached to something and doesn't act alone. 

You can see in the AT illustration that the suspension filament (wire) is contained within the cantilever attachment piece I was talking about.  Some older beryllium stylus had no housing around the filament.  It looked like a cantilever extension.  A 150MLX has a housing around the filament so there are or were some variations in design. 

BTW, some aluminum cantilevers flex considerably.  The amount is relative to other types and dimensions.  I think you'd agree that the difference in rigidity is audible.

P.S.  I noticed on another forum you said that CA carts are potted.   I wasn't aware of that.  Are you sure?

[dlaloum]

P.S.  I noticed on another forum you said that CA carts are potted.   I wasn't aware of that.  Are you sure?

Got me there - I am guessing... I cannot believe that they would simply rebadge cartridges and mark them up 400%+ even if they put a new mounting surround on them.... so I figure they must at least pot the damn things... ( I should do a proper investigation)

[neobop]

Far be it for me to defend CAs pricing, but it's not the same generator as the 95.   Beside the difference in resistance, the 95 is among the least expensive in build quality.  It doesn't even have OCC wire like the 100E, 110E, etc.  We don't know exactly what CA has or how it differs.  The separation spec for the 95 is 20dB at 1K.  The crosstalk spec for the Virtuoso V2 is better than 30dB at 1K.  Channel balance is 0.2dB.  Channel balance for the 95 is 2.0dB. 
It is interesting to note that the Concept seems to have identical numbers as the 95. 

Looking at the CA web site it seems like they keep revising the numbers.  Inductance was 420mH for all of them, now it's either 400 or the Maestro is 12:40H.  Maybe that's 412mH?  The V2 Maestro is listed at 3.6mV out.  When V2 first came out they were at 4.1 mV.  Ca seems to play with the specs quite a bit.  SPECIFICATIONS SUBJECT TO CHANGE.  They're looking more like the 95 all the time.  Maybe you're right and separation and balance is selected examples?  I wonder if I put a wood top on my potted 95 would it sound identical to the Virtuoso?
http://clearaudio.de/de/products/cartridges-mm-v2.php

neo 

[dlaloum]

Try it in a wooden headshell.

[*Scotty*]

Until someone actually measures CA's cartridges and generates cross-talk,channel balance and separation specs I won't believe the claimed numbers are real. CA's MM cartridges could certainly be selected AT cartridge bodies from a production run which have the specs they claim
for their cartridge models.
 As far the inductance claims go they could vary depending on the measurement procedure used and the spec is irrelevant to most prospective buyers.
 Scotty

[neobop]

Scotty,
Inductance is supposed to be a straightforward reading at 1K.  There was a question about home meter readings due to the resistance of the meter, but this shouldn't be a problem with a mfg.  The thing is, up until V2, all CA MM were supposed to be 420mH.  The 95 is 400mH.  95 impedance is 2800 and CA says 660 (questionable).  They seem to change some aspect of specifications a few times a year.

Output is supposed to be boosted on some top CA V2.  These specs linked to above, say it's virtually the same as before.  This is changed from when V2 first came out and I checked.  It's enough to make you dizzy trying to figure it out.  Maybe that's what they want.

I previously had the impression that CA played with the specs to make the bottom ones look worse.  It now looks like they're gradually going to 95 specs.  My Virtuoso seems to have higher end performance than the potted 95.  Could the wood top be responsible?  I didn't used to think so, but now I'm not so sure.   Have you read those raves about V2 Maestro?  I wonder if that could be wishful hearing, pride of ownership or if they just messed up the specs on their site.
neo 

[*Scotty*]

Inductance can also be measured at 10kHz. 420mH is within 5% of 400mH, this difference could easily be accounted for by production tolerances. The sound of the cartridge can be changed rather dramatically by how the cartridge body is damped. I used 4 layers of very small rectangles of 3M DAMPING SHEET from Music Direct on both sides of the cartridge body. This constrained layer damping transformed the sound of the cartridge. I would bet that the wood that the CA cartridge body is mounted in makes a similar improvement for the better.
 Spurious vibrations in the cartridge body and the stylus assembly are some of the biggest problems the stock AT cartridges have. The ATN-ML150/OCC and AT150MLX use a ceramic base to help suppress unwanted vibrations in the cartridge body. The Signet line actually attached the stylus assembly to the cartridge body with a screw, which is something I wish the entire AT lineup did. I super glued the stylus assembly on my AT 440ML to the cartridge to try to achieve the same result.
Scotty

[dlaloum]

The only Signets that I know of that had the stylus screwed to the body are the TK9 and TK10, which are the signet branded versions of the AT22/23/24/25 - which also had the stylus screwed to the body...

The rest of the Signet range did not have the body screws....

The other brands that I have seen screwed in styli with are Technics (EPC100, EPC-P205) and Nagaoka (MP30, MP50, MP300,MP500)

Any others?

bye for now

David

[*Scotty*]

Those were the ones I was thinking of, I mistakenly thought the entire line had this vital feature. Mind you I haven't seen a TK9 in the flesh in well over 20 years.
Scotty

[dlaloum]

On the Audiogon thread (the legendary one that Raul started)- there were a series of discussions and I recall it being mentioned a few times that the AT20ss sounded best in a wooden headshell.

There is also this thread on here: http://www.audiocircle.com/index.php?topic=33028.0

Basically using a thing layer (up to 3mm) of plasticine between cartridge and headshell.

This has been reported to work effectively for Grado's...

I would think that for best results the "plast-i-lator" should heave the plasticine constrained sideways, so it doesn't gradually get squeezed out over time - you need the plasticine slightly compressed for best damping results - and the cartridge screws not too tight (otherwise you are bypassing the plasicine and transmitting the energy via the screws) - I usually use nylon screws with the high compliance cartridges to reduce mass - they also don't screw on super tight (you strip the thread if you overtighten).

Some of the better headshells have a damping layer in or on the headshell itself - I have such examples from Denon and Audio Technica.

Yes - I am quite certain that most cartridges can be improved with some damping of the stylus/body/headshell/arm system. (talking about midrange frequencies here, not low frequency fluid damping type ...)

The Linn and post Linn school of arm design with the cartridges rigidly mounted to the arm - as tightly as possible - depends on the arm (and any internal damping fitted) to dissipate the energy...

The S-arms - well in an ideal world we can do some external damping with heatshrink, a little internal damping with cotton in the armtube, perhaps some damping dots (not sure about those), we can opt for headshells with twin pins top and bottom for a better connection to the arm, and then damp headshell and cartridge.... all of which adds mass so we end up having to carefully walk the tightrope between the right mass for the compliance and the damping it also needs...

The high compliance cartridges we play with need less damping than the lower compliance cartridges - so  exemplars like the AT150 and AT20 need less damping (the high compliance stylus suspension passes less energy through to the cartridge body) - the lower compliance examples such as AT95 and CA need more damping.... nature of the beasts.

I theorise that the best low priced option would be to use the AT92 upgrade styli (up to shibata) on the CA or AT95 bodies, and treat with damping mods.... the woodies might not need the damping mods, the AT95 and Aluminium bodied CA's probably would....

bye for now

David

[neobop]

Griff,
Before I get caught up in further discussion I want to say, helping to figure out your preamp manual was my pleasure.  The instructions are confusing.

You have a great accumulation of audio toys err gear, and your comments are interesting and most welcome.  Your brief description of the Decca sparked my interest again and your loan offer to David is very generous.  Please don't hesitate to join in the discussion, comment, or question.
neo

[dlaloum]

I've eyed off some elderly decca's a couple of times myself - I have a feeling they would work well in the JVC.... 
(I don't think they would suit the Revox AT ALL!!  )

So far I have resisted temptation - although my motto is "I can resist anything except temptation"

[Grbluen]

Neo,  I thought that I should at least acknowledge the fact that I may have been mistaken with regards to my preference of the ATN-440mla over the ATN-140LC. It obviously could be a case of my not having installed the cantilever correctly.  I will, in time,  give the 140LC another shot. I think the difficulty in sourcing the 140 makes the question moot.

[dlaloum]

The wording I have seen in a number of postings becomes admirably apt here....

It definitely becomes a mute point....

[neobop]

D_Grb,
I kind of doubt that, being mistaken that is.  Although I've never tried the ATN140LC on my 12E, it's similar to the ATN440MLa.  The LC is more compliant and tracks at 1.5g max if I remember correctly, and of course a nude ML vs nude LC.  That's about it - tip, cu and damper.  I loaded both with my 440 at 32K.  What is it about the sound of the cart with the MLa you'd like to change?  Can you put your finger on it?
neo

P.S. I have an ATN140LC with < 2 hrs on it.  If you'd like to transplant it maybe we could trade, but I think you might be barking up the wrong tree.