The importance of VTA, SRA and Azimuth - pics

[andromedaaudio]

Hai bblue great to read you tried , from what i can observe its probably tilted a couple degrees 1 or 2 forward on my table ( seen without microscope though) , the arm slightly raised at the back as on the picture at least with the supergold.
I prefer tube phono and skipping a step up transormer for purity .
great pics of the needle construction , dont be afraid of needle wear/record wear , ive never expirienced whatso ever and i have it now playing for more than a year
_DSC0003 by andromeda61, on Flickr

Being the eternal optimist, I keep hoping for some other explanation. I noticed in measurements the tip is very very close to 15 degrees. Coincidence? Or might there be something that you relate to differently in a cartridge that has no traditional cantilever?

I've started mounting and calibrating it on the TT and will try a couple of unimportant records to see what happens. In looking at how it is positioned, the tie-back string and the pictorials of the internal mechanism (which is minimal and simple component-wise) something really serious would have to have happened to get it moved incorrectly into this position. Very puzzling.

--Bill

 

[jcarr]

the variations Fremer found in the Lyra are a little frightening!

Bill: I should mention that some of the photos in the Stereophile article were mislabeled - for instance the 87-degree cartridge is not a Lyra but an Air Tight or Eminent (My Sonic Labs). Stereophile is supposed to issue a correction sooner or later.

BTW, Ralph Karsten of Atmasphere has recently rebuilt an LP cutting lathe and is starting to cut test lacquers. Ralph is gearing up to cut his own lacquer masters with his OTL amplifiers as the cutter drive amplifiers, and eventually, press his own LPs.

Here is what Ralph answered to a query in an Audiogon thread about what cutting angle he uses.

"what we have found about that pesky RTA (record tracking angle) is its not really a standard. The problem is variance in the cutting stylus. Under the scope they all look a little different, and to get them to behave you have to adjust the head up and down a little. But for the most part the stylus temperature seems to play a bigger role. We did shoot for about 2 degrees negative but you can't count on that to work with every single lacquer. Plus the stylus is only good for about 10 hours and during that time you have to compensate for its wear. So RTA is more of a thing to try for as long as everything *else* is working "

Given the incomplete state of understanding right now, I think that there is great value in measuring the SRA and CRA (cantilever rake angle, which is a more descriptive term for cartridges than VTA) at the position where a cartridge sounds best, and building up a solid database of measurements that includes record label, year of mastering, 33/45rpm, and perhaps even the cutting engineer (if known).

However, it may still be hasty to conclusively state that a single, specific angle is what all cantilevers or styli should be set to, on any and every LP.

Also, if you take photos of the same stylus and cantilever from slightly different camera positions, the SRA can appear to be different, so how the photos are taken is another issue that should be thought about and preferably standardized on before the data generated can be considered consistent and valid.

kind regards, jonathan carr

 

[jazdoc]

Jonathan --

Great information. Thanks.

 

[Bill Hart]

Jonathan- great of you to weigh in here, i did not mean to impugn the integrity of what you guys do- i think of you as a gold standard, so if there were departures from the norm, where does that leave the the great unwashed? Ironically, i am running an Airtight. or
The idea of having to make micro-adjustments beyond a simple twist of a 'vta' knob on a record by record basis would drive me insane. (alright, more insane). And I enjoy Ralph's contributions on the 'Gon where he is a generous contributor to various topics.
I still remember how much I enjoyed my Parnassus. Never did get to hear those Connoisseur preamps that Roy Gregory reviewed, though....

 

[MylesBAstor]

Bill: I should mention that some of the photos in the Stereophile article were mislabeled - for instance the 87-degree cartridge is not a Lyra but an Air Tight or Eminent (My Sonic Labs). Stereophile is supposed to issue a correction sooner or later.

BTW, Ralph Karsten of Atmasphere has recently rebuilt an LP cutting lathe and is starting to cut test lacquers. Ralph is gearing up to cut his own lacquer masters with his OTL amplifiers as the cutter drive amplifiers, and eventually, press his own LPs.

Here is what Ralph answered to a query in an Audiogon thread about what cutting angle he uses.

"what we have found about that pesky RTA (record tracking angle) is its not really a standard. The problem is variance in the cutting stylus. Under the scope they all look a little different, and to get them to behave you have to adjust the head up and down a little. But for the most part the stylus temperature seems to play a bigger role. We did shoot for about 2 degrees negative but you can't count on that to work with every single lacquer. Plus the stylus is only good for about 10 hours and during that time you have to compensate for its wear. So RTA is more of a thing to try for as long as everything *else* is working "

Given the incomplete state of understanding right now, I think that there is great value in measuring the SRA and CRA (cantilever rake angle, which is a more descriptive term for cartridges than VTA) at the position where a cartridge sounds best, and building up a solid database of measurements that includes record label, year of mastering, 33/45rpm, and perhaps even the cutting engineer (if known).

However, it may still be hasty to conclusively state that a single, specific angle is what all cantilevers or styli should be set to, on any and every LP.

Also, if you take photos of the same stylus and cantilever from slightly different camera positions, the SRA can appear to be different, so how the photos are taken is another issue that should be thought about and preferably standardized on before the data generated can be considered consistent and valid.

kind regards, jonathan carr

Interesting, Ralph did LPs a while back . Canto General comes to mind; not sure where my copy is

Now if only Ralph would release some R2R tapes!

 

[mep]

Interesting, Ralph did LPs a while back . Canto General comes to mind; not sure where my copy is

Now if only Ralph would release some R2R tapes!

But what does he have for source material?

 

[MylesBAstor]

But what does he have for source material?

Oh Ralph's been into R2R for ages. Would love to hear Canto General or his other recording (the name escapes me) on tape!

 

[bblue]

15 degrees is neither proper SRA nor VTA. I don't know what to make of it. You may want to ask them.

Actually, 15 degrees is a valid early VTA number used in carts. Actually indicated as 0-15 degrees, as that is the movement from at rest to full vertical modulation. It's gradually moved up since then. But that 15 degrees is the other direction from how this one seems to be pointing.

Not sure why London is sticking with the old number.

--Bill

 

[bblue]

Hai bblue great to read you tried , from what i can observe its probably tilted a couple degrees 1 or 2 forward on my table ( seen without microscope though) , the arm slightly raised at the back as on the picture at least with the supergold.

That is consistent with what I've been able to make out in other pictures from the net. 1-2 degrees is a lot different than 15 degrees, though. I'm not even sure, given that the angle is part of the cantilever (what there is of one), it could even produce an accurate indication of vertical movement.

I prefer tube phono and skipping a step up transormer for purity .

Do you mean in general? No need for an xformer with this cartridge at 5mv output.

great pics of the needle construction , dont be afraid of needle wear/record wear , ive never expirienced whatso ever and i have it now playing for more than a year

I'm sure you're right if the stylus/cantilever is at the proper angle.

--Bill

 

[bblue]

andromeda, I worked your image a bit so we can see the angle more clearly. It's a whole lot more than a couple of degrees forward, but I can't say that it is as far out as 15.

FYI.

 

[jcarr]

i did not mean to impugn the integrity of what you guys do

Hi Bill: No problem - your only source of information was what Stereophile printed. Nor is it Michael's fault, as I believe that it was someone else who got the photo captions wrong. Human errors can and do happen, and part of the price of being a well-known manufacturer is to roll with the punches from such errors (until corrections can be published).

Incidentally, the reason why we supplied Michael with a second Atlas was because there was a "perceived" low-rider issue with the first cartridge. Contrary to what has been surmised elsewhere, it was not because of an out-of-spec SRA.

My cantilever assembly drawings allow a +/- 2 degree stylus angle deviation (which is Ogura's highest specification), and I have yet to see any solid evidence that the review cartridges that we supplied were out-of-spec.

There are two components to SRA - one is the angle at which the stylus is affixed to the cantilever, and the other is the CRA (cantilever rake angle). Since the CRA is affected by the VTF as well as tonearm-pivot height, tight control over the CRA is a mandatory prerequisite for discussions of the SRA.

Although I have in my technical library Japanese articles which suggest that VTA will affect measured distortion as much as SRA (and the VTA depends on the vintage of the LP, with earlier ones being shallower), the precise CRA angle is perhaps not as important as having a consistent relationship between tonearm pivot height, VTF, and CRA.

After introducing "New Angle" technology on the Delos, and subsequently incorporating it into the Kleos and Atlas, I am fairly confident that Lyra has achieved a consistent relationship between tonearm pivot height, VTF, and CRA. Having done the R&D, I am also fairly sure that a v-e-r-y narrow VTF range is a necessary condition for achieving a consistent relationship between tonearm pivot height, VTF, and CRA. IME, even a +/-0.1g VTF range is is too broad. That's why our New Angle cartridges have an allowable VTF range of +/-0.05g.

Once a manufacturer has the CRA under control, it can afford to think about possible changes to the angle at which the stylus is affixed to cantilever. However, any change should not be a change simply because a single article in 1981 proclaimed that 92 degree is the magic number.

IMO, it would be very worthwhile if the What's Best community could be instrumental in creating a large database of user reports and perhaps IMD measurements.

The idea of having to make micro-adjustments beyond a simple twist of a 'vta' knob on a record by record basis would drive me insane.

Keep in mind that the geometry of most tonearms guarantees that altering the VTA will simultaneously affect the VTF. Ideally speaking, a tonearm should allow for the VTA to be altered without changing the tonearm pivot height (which should placed in the same horizontal plane as the LP playing surface). Unless you know that your tonearm has been designed in accordance with my previous sentence, you should double-check the VTF at the LP playing height once you have altered the VTA, and make subtle adjustments to the VTF if required.

Never did get to hear those Connoisseur preamps that Roy Gregory reviewed, though....

The 4-series has taken some audibly significant steps forward compared to the units that Roy has. I updated a 4-2 line preamp for Chris Thomas, and he was impressed with the improvements.

FWIW, I am working on a new discrete-semiconductor phono stage that introduces more sophisticated circuit concepts and topologies than the Lyra-Connoisseurs that Roy and Chris reviewed, but would hopefully retail for perhaps half of the previous Lyra-Connoisseur 4-series (thanks to a one-box structure rather than two-box, no air-dielectric etc.).

Target launch date is either within this year, or the beginning of 2013.

kind regards, jonathan carr

 

[MylesBAstor]

Hi Bill: No problem - your only source of information was what Stereophile printed. Nor is it Michael's fault, as I believe that it was someone else who got the photo captions wrong. Human errors can and do happen, and part of the price of being a well-known manufacturer is to roll with the punches from such errors (until corrections can be published).

Incidentally, the reason why we supplied Michael with a second Atlas was because there was a "perceived" low-rider issue with the first cartridge. Contrary to what has been surmised elsewhere, it was not because of an out-of-spec SRA.

My cantilever assembly drawings allow a +/- 2 degree stylus angle deviation (which is Ogura's highest specification), and I have yet to see any solid evidence that the review cartridges that we supplied were out-of-spec.

There are two components to SRA - one is the angle at which the stylus is affixed to the cantilever, and the other is the CRA (cantilever rake angle). Since the CRA is affected by the VTF as well as tonearm-pivot height, tight control over the CRA is a mandatory prerequisite for discussions of the SRA.

Although I have in my technical library Japanese articles which suggest that VTA will affect measured distortion as much as SRA (and the VTA depends on the vintage of the LP, with earlier ones being shallower), the precise CRA angle is perhaps not as important as having a consistent relationship between tonearm pivot height, VTF, and CRA.

After introducing "New Angle" technology on the Delos, and subsequently incorporating it into the Kleos and Atlas, I am fairly confident that Lyra has achieved a consistent relationship between tonearm pivot height, VTF, and CRA. Having done the R&D, I am also fairly sure that a v-e-r-y narrow VTF range is a necessary condition for achieving a consistent relationship between tonearm pivot height, VTF, and CRA. IME, even a +/-0.1g VTF range is is too broad. That's why our New Angle cartridges have an allowable VTF range of +/-0.05g.

Once a manufacturer has the CRA under control, it can afford to think about possible changes to the angle at which the stylus is affixed to cantilever. However, any change should not be a change simply because a single article in 1981 proclaimed that 92 degree is the magic number.

IMO, it would be very worthwhile if the What's Best community could be instrumental in creating a large database of user reports and perhaps IMD measurements.



Keep in mind that the geometry of most tonearms guarantees that altering the VTA will simultaneously affect the VTF. Ideally speaking, a tonearm should allow for the VTA to be altered without changing the tonearm pivot height (which should placed in the same horizontal plane as the LP playing surface). Unless you know that your tonearm has been designed in accordance with my previous sentence, you should double-check the VTF at the LP playing height once you have altered the VTA, and make subtle adjustments to the VTF if required.



The 4-series has taken some audibly significant steps forward compared to the units that Roy has. I updated a 4-2 line preamp for Chris Thomas, and he was impressed with the improvements.

FWIW, I am working on a new discrete-semiconductor phono stage that introduces more sophisticated circuit concepts and topologies than the Lyra-Connoisseurs that Roy and Chris reviewed, but would hopefully retail for perhaps half of the previous Lyra-Connoisseur 4-series (thanks to a one-box structure rather than two-box, no air-dielectric etc.).

Target launch date is either within this year, or the beginning of 2013.

kind regards, jonathan carr

Really valuable information! I don't think that all vinyl lovers realize adjusting tonearm height affects VTF. Kinda sucks but needs to be accounted for That's why I love Peter Lederman's Counter-Intuitive for the VPI arm. Allows for superfine adjustments in VTF almost on the fly (0-0.3 gm) without having to mess around with the counterweight. The Counter-Intuitive even allows for precise tuning of the VTF while listening eg. set the cartridge's VTF to the manufacturer's recommended value and then slide the ring back or forth. Very easy to get 0.005 to 0.01 gm adjustment (eg.more or less at the limit of reliability of most meters).

I'm waiting for Peter's new iPad app for setting up cartridges.

 

[Bill Hart]

Myles (and Jonathan)- how do you think this applies to the Airline (Kuzma)?

 

[MylesBAstor]

Myles (and Jonathan)- how do you think this applies to the Airline (Kuzma)?

http://www.sound-smith.com/cartright/index.html

As you can see, everything that would apply to a pivoted arm would apply to your Kuzma.

 

[andromedaaudio]

Its quite hard to see the angle without microscope , as the iron is bent and doesnt come out of the housing at 90 degrees , as one can see on the picture 3/4 down scroll of the cart technical build up sketch, but more importantly how does it sound ????



http://www.warrengregoire.com/hifi-stereo-phonocartridges.htm#LONDON DECCA

 

[Bill Hart]

http://www.sound-smith.com/cartright/index.html

As you can see, everything that would apply to a pivoted arm would apply to your Kuzma.

Right, makes sense, i was seizing on Jonathan's use of the word 'pivot' point in a horizontal, not vertical sense. But I guess what I'm trying to understand is this:
I get the need for critical set-up (and I am certainly no guru here, I have gotten those types in to help me in the past and Peter's device might even allow someone as unskilled as me to do a proper set-up), but.....

I change VTA on a record by record basis, by ear. And since, as Jonathan points out, that affects tracking force, that also means that I should be adjusting the latter each time I make a VTA change. That doesn't sound like something that's quick and easy to do on a constant basis, record after record, in a listening session. So, is the answer gross compromise? (I am aware that Peter makes that anti-counterweight, or whatever it is called, so perhaps that would allow quick adjustment, on the fly, as you suggested, when i change VTA?) Still sounds like a fair amount of fiddling for each record, no? Or is the Counter-Intuitive marked in such a way that you can do repeatable settings, like I do on the Airline for the VTA?
And, to Jonathan's point that in an ideal setting, the arm height wouldn't change when making a VTA change, how would that be accomplished other than at the headshell end of the arm?
I'm asking because I want to understand this, not busting chops here...
Does remind me of a guy i knew in the early 70's mounted a Vestigal arm wand on a Rabco 'linear' arm mechanism. Sorta like that joke about heaven and hell where the cooks are British, the Italians are the administrators, etc....{no offense to British cooking, that has improved; as to italian administration, well....}

 

[MylesBAstor]

Right, makes sense, i was seizing on Jonathan's use of the word 'pivot' point in a horizontal, not vertical sense. But I guess what I'm trying to understand is this:
I get the need for critical set-up (and I am certainly no guru here, I have gotten those types in to help me in the past and Peter's device might even allow someone as unskilled as me to do a proper set-up), but.....

I change VTA on a record by record basis, by ear. And since, as Jonathan points out, that affects tracking force, that also means that I should be adjusting the latter each time I make a VTA change. That doesn't sound like something that's quick and easy to do on a constant basis, record after record, in a listening session. So, is the answer gross compromise? (I am aware that Peter makes that anti-counterweight, or whatever it is called, so perhaps that would allow quick adjustment, on the fly, as you suggested, when i change VTA?)
And, to Jonathan's point that in an ideal setting, the arm height wouldn't change when making a VTA change, how would that be accomplished other than at the headshell end of the arm?
I'm asking because I want to understand this, not busting chops here...
Does remind me of a guy i knew in the early 70's mounted a Vestigal arm wand on a Rabco 'linear' arm mechanism. Sorta like that joke about heaven and hell where the cooks are British, the Italians are the administrators, etc....{no offense to British cooking, that has improved; as to italian administration, well....}

I would think that the Cartright could also eliminate the need for a microscope since it determines optimal azimuth, SRA, overhang based on lowest distortion.

 

[Bill Hart]

yep, but what about running changes in a listening session. I can't imagine whipping that thing out and doing set up checks everytime I change a record....

 

[MylesBAstor]

yep, but what about running changes in a listening session. I can't imagine whipping that thing out and doing set up checks everytime I change a record....

No but would eliminate a lot of confusion when initially setting the cartridge up. After that, it's much smaller changes. Theoretically, we're talking about improving the tracking ability too.

 

[ack]

I would think that the Cartright could also eliminate the need for a microscope since it determines optimal azimuth, SRA, overhang based on lowest distortion.

I am really looking forward to this device, actually the software-based version. Thanks for posting!