VTA method???

[mr_petit]

Exactly. Adjust for SRA, forget VTA.

You have to adjust VTA to adjust SRA. SRA is not a parameter you can adjust separately, unless you're going to retip.
The amount of vta you can adjust translates directly to the amount of SRA you're adjusting.
So there is no 'forget VTA'. (as in "10 degree deviation in VTA" is also automatically 10degree deviation in SRA.)

But that's all besides the point. My point was if anybody has actually adjusted VTA (or SRA whatever) within the range a normal tonearm has (so that +/-5mm) and actually measured or heard a difference and has the hands on measurements or sound files to back that up?

I mean that 10 degree that that jico stylus is off in your example from ASR...that is very very much a poor quality issue, and a good retipper should easily do a better job (just by eyeballing, let alone use a camera and some angle alignment software on his microscope). And if you look at that same graph, at that audio technica cartridge distortion line, its pretty much bang on (good quality control on that AT cart!), and adjusting it 1,3deg one or the other way (up or down, the scope of travel you basically have on a normal tonearm) doesn't make any difference. The maximum amount of adjustment on a tonearm is also even finer than what the test record gives in maximum resolution for the test tracks.

And these are measurements, not even sound files that should give the final word (the proof of the pudding is in the eating)

 

[Thomas_AA]

WHAT ON EARTH ARE YOU TALKING ABOUT?!?!?!
Just check the Specs there...

Ortofon specifies the cantilever angle to 23°. Since the VTA is measured from the stylus tip contact patch to pivot, you add ≈4°. Neither 23° or 27° is 20°.

 

[Thomas_AA]

You have to adjust VTA to adjust SRA. SRA is not a parameter you can adjust separately, unless you're going to retip.
The amount of vta you can adjust translates directly to the amount of SRA you're adjusting.
So there is no 'forget VTA'. (as in "10 degree deviation in VTA" is also automatically 10degree deviation in SRA.)

Look at the pictures in the post. The SRA is correct at current setting - no need to adjust; I've done the inspection of myJICO SAS as well. Correct SRA matches with the cartridge upper part parallell to the record at 1.45 g VTF. VTA is however higher than optimal, around 28° in my case.

 

[mr_petit]

Look at the pictures in the post. The SRA is correct at current setting - no need to adjust; I've done the inspection of myJICO SAS as well.

The measurements show that that Jico stylus is off by a minimum of 8 degrees. I don't see how you can ignore that.
The picture is not nearly as clear and magnified enough to judge or measure what the sra is imho.

 

[Thomas_AA]

The measurements show that that Jico stylus is off by a minimum of 8 degrees. I don't see how you can ignore that.
The picture is not nearly as clear and magnified enough to judge or measure what the sra is imho.

I can assure you that this looks as it should. I've had 4 JICO SAS/B, they all are the same. I get around 28° VTA at 92° SRA. They measure and sound excellent.

And what about the Ortofon replicant?

The Ortofon Replicant 100 geometry

In this thread post on down, we are discussing which side of the Replicant 100 stylus is relevant in calculating SRA off of vertical, and bblue said: I had always assumed the right side of the tip was the actual angle of concernand I had agreed. Here's my picture again, depicting vertical...

www.whatsbestforum.com

 

[Powertech]

Now for us mere mortals - Ortofon (I use a Super OM30) specify that the top of the cartridge must be parallel with the record both longitudinally and laterally. When this is the case, with the suggested optimal downforce - in this case 1.5 grammes - the stylus rake angle should be correct. This is listed as 20 degrees from vertical.

As I can only do this using visual cartridge gauges with the stylus sitting on a stationary record, I assume that the values given are for static measurement. This I presume gives a suitable starting point for any minor adjustments to be made to optimise the sound. Is this set-up good enough?

When the record is moving under the stylus with the the application of anti-skate force well, how much difference will the now dynamic conditions make significant difference to the stylus rake angle? If there is a difference, will it be enough to audibly affect the sound produced?

 

[mr_petit]

I can assure you that this looks as it should. I've had 4 JICO SAS/B, they all are the same. I get around 28° VTA at 92° SRA. They measure and sound excellent.

So is the cartridge shown in your example yours? If not I don't understand the relevance of your argument.
Because the one in your example from ASR doesn't measure excellent. It measures as if it is off by roughly 8deg, and the AT cartridge in that same graph measures as if it's spot on.
And the amount of correction that it needs falls way outside the range of adjustment normal tonearms give.

So what did you actually measure on your cartridges/how did you measure them to conclude that they measure excellent and can you reproduce those measurements here?

 

[catBot]

Ortofon specifies the cantilever angle to 23°. Since the VTA is measured from the stylus tip contact patch to pivot, you add ≈4°. Neither 23° or 27° is 20°.

No! It is you who adds ≈4° for no reason.
Check Fritz Gyger's documentation for their FG S. They do it in atleast two form factors:

• the groove-contacting lines ≈≈parallel to the longer crystall's axis (to be mounted on bent cantilevers)
• the groove-contacting lines at ≈≈VTA to the longer crystall's axis (to be mounted on stright cantilevers perpendicularly)

And they say it is possible to order any other orientation of the groove-contacting lines against the longer crystall's axis...

No matter what - the aim is the IMD minimum, not the "nice looking angle" of the cantilever... Use the proper test record and a spectroscope to achieve that minimum.

 

[Thomas_AA]

So is the cartridge shown in your example yours? If not I don't understand the relevance of your argument.
Because the one in your example from ASR doesn't measure excellent. It measures as if it is off by roughly 8deg, and the AT cartridge in that same graph measures as if it's spot on.
And the amount of correction that it needs falls way outside the range of adjustment normal tonearms give.

So what did you actually measure on your cartridges/how did you measure them to conclude that they measure excellent and can you reproduce those measurements here?

I just remeasured mine in static mode, normal LP thickness. 94° SRA, cantilever angle 25°; +4 degree for stylus = 29°. Setting SRA to 90° would give 25° effective VTA.

And yes it measures excellent, especially new.

Introducing the Phono Cartridge Measurement Library

This was our reference in the 1970s in a recording studio. We had an historic archive of concert performances cut to disc before tape. Our reference arms were the SAE 3000? large diameter disc curved on a large mass large diameter 16"? mains synced platter. At home at the time, I had a V15-IV on...

www.audiosciencereview.com

And sounds ok as well.

Dropbox

www.dropbox.com

 

[Thomas_AA]

No! It is you who adds ≈4° for no reason.
Check Fritz Gyger's documentation for their FG S. They do it in atleast two form factors:

• the groove-contacting lines ≈≈parallel to the longer crystall's axis (to be mounted on bent cantilevers)
• the groove-contacting lines at ≈≈VTA to the longer crystall's axis (to be mounted on stright cantilevers perpendicularly)

And they say it is possible to order any other orientation of the groove-contacting lines against the longer crystall's axis...

No matter what - the aim is the IMD minimum, not the "nice looking angle" of the cantilever... Use the proper test record and a spectroscope to achieve that minimum.

Of course VTA is measured from tip to pivot.

 

[mr_petit]

I just remeasured mine in static mode, normal LP thickness. 94° SRA, cantilever angle 25°; +4 degree for stylus = 29°. Setting SRA to 90° would give 25° effective VTA.

Is your cantilever angle 26 deg or is your vta 26 deg?
BTW your screenshot looks completely different from the stylus in your first example (especially how the tip is glued on). And the TA2 in your first example is 33 deg whereas yours is 26 deg. That's quite the difference (and the IMD measurements show that that stylus from your first example is out of wack, where the amount they're off in the imd measurements also corresponds with the angles in the photo's)
I assume that screenshot you posted in the post above with the TA1 and TA2 angle (dated 2011/06/17) is your actual stylus, the one you're talking about?

And yes it measures excellent, especially new.

Introducing the Phono Cartridge Measurement Library

This was our reference in the 1970s in a recording studio. We had an historic archive of concert performances cut to disc before tape. Our reference arms were the SAE 3000? large diameter disc curved on a large mass large diameter 16"? mains synced platter. At home at the time, I had a V15-IV on...

www.audiosciencereview.com

But this is an FFT measurement not an IMD measurement. there's also no difference shown in vta or sra

And sounds ok as well.

Dropbox

www.dropbox.com

this is just one file. how do we know how it sounds with a different VTA or SRA?
Remember, this topic is about one setting compared to another within same parameters. So 1 measurement or 1 soundfile can never conclude something. It's always the one measurement (or one soundfile) compared to the other.

 

[Thomas_AA]

Is your cantilever angle 26 deg or is your vta 26 deg?
BTW your screenshot looks completely different from the stylus in your first example (especially how the tip is glued on). And the TA2 in your first example is 33 deg whereas yours is 26 deg. That's quite the difference
At least, I assume that screenshot you posted in the post above with the TA1 and TA2 angle (dated 2011/06/17) is your actual stylus, the one you're talking about?

But this is an FFT measurement not an IMD measurement. there's also no difference shown in vta or sra

this is just one file. how do we know how it sounds with a different VTA or SRA?
Remember, this topic is about one setting compared to another within same parameters. So 1 measurement or 1 soundfile can never conclude something. It's always the one measurement (or one soundfile) compared to the other.

The picture relates to the Ortofon replicant, as an answer to the post I replied to. In that picture, SRA is 90° on a stationary record, and effective VTA around 26°.

The Shure V15Vx with JICO SAS/B that I have is a microline stylus, and has its SRA symmetric to the diamond. Static/stationary angles below of SRA and cantilever at 1.45 g, which is reduced by ≈1° during play.

With respect to music reproduction on LPs, low harmonic distortion is more important for good sound. IMD would be more problematic if records contained high level bass content that are vertically cut. But they don't; bass below 150 Hz or so is combined to mono.

 

[AvFan]

A few things from the 10,000' level to consider IMO:

• It is the cartridge manufacturer's responsibility to design and build their cartridges to meet predetermined performance goals. Choose a cartridge manufacturer who has a track record of doing so.
• Follow their instructions on how to set up the cartridge as those will meet the cartridge's performance goals. They don't expect their customers to have special test records or test equipment to properly use their products but by following their setup instructions the customer will get within an acceptable performance ellipse given their cartridge's parameters.
• Individual setup skills and tools will vary so be prepared to make minor adjustments by ear. If test equipment and records are available, sure, go ahead and use them but minor tweaks by ear are OK too.
• There is plenty of information available on how the SRA of various cart types should be set and that is done visually. If a USB microscope helps do that more easily that is just fine and it may reduce the size of the performance ellipse.
• I don't understand the insistence that SRA has to be set by using test equipment and a test record versus visually. Setting SRA visually is not perfect but keep in mind records are not perfect either so measuring with test equipment etc is giving a false sense of accuracy when playing music records versus test records.

OK, I'm off my soapbox. Merry Christmas to those who celebrate it.

 

[radiokom]

The picture relates to the Ortofon replicant, as an answer to the post I replied to. In that picture, SRA is 90° on a stationary record, and effective VTA around 26°.

The Shure V15Vx with JICO SAS/B that I have is a microline stylus, and has its SRA symmetric to the diamond. Static/stationary angles below of SRA and cantilever at 1.45 g, which is reduced by ≈1° during play.

With respect to music reproduction on LPs, low harmonic distortion is more important for good sound. IMD would be more problematic if records contained high level bass content that are vertically cut. But they don't; bass below 150 Hz or so is combined to mono.

Look at picture I posted above. And a line for VTA.

 

[AvFan]

The 25° line is meaningless.

Edit: And there is no way to know if the calculated 94° SRA actually runs through the contact patches of the stylus

 

[mr_petit]

The picture relates to the Ortofon replicant, as an answer to the post I replied to. In that picture, SRA is 90° on a stationary record, and effective VTA around 26°.

Ok, that clears things up for me

The Shure V15Vx with JICO SAS/B that I have is a microline stylus, and has its SRA symmetric to the diamond. Static/stationary angles below of SRA and cantilever at 1.45 g, which is reduced by ≈1° during play.

Ok, so that is in a whole other league than that Jico from your first example, judging by the photo. So that points to bad quality control at Jico if they permit the same needles with such a variation in SRA to be sold.

With respect to music reproduction on LPs, low harmonic distortion is more important for good sound. IMD would be more problematic if records contained high level bass content that are vertically cut. But they don't; bass below 150 Hz or so is combined to mono.

This is pure speculation without either measurements or soundfiles that display these exact differences.
Remember, this topic is not about what parameters are the most important for good music production, this topic is about how to set VTA or SRA to the optimal value and how to measure the differences, if there are any and in what range they fit.
Besides, IMD test files on test records use frequencies above 150Hz and still yield measurable diffences if deviation becomes high, shown in your own first example.
Why is harmonic distortion more important than intermodular distortion? Harmonic distortion is usually not that unpleasant to the ear, whereas distortion not related to harmonics can be extremely disturbing. For instance the IGD test track on the Tacet test record shows that IGD, which is not harmonic related, is extremely irritating.

 

[Thomas_AA]

Ok, that clears things up for me

Ok, so that is in a whole other league than that Jico from your first example, judging by the photo. So that points to bad quality control at Jico.

This is pure speculation without either measurements or soundfiles that display these exact differences.
Remember, this topic is not about what parameters are the most important for good music production, this topic is about how to set VTA or SRA to the optimal value and how to measure the differences, if there are any and in what range they fit.
Besides, IMD test files on test records use frequencies above 150Hz and still yield measurable diffences if deviation becomes high, shown in your own first example.
Why is harmonic distortion more important than intermodular distortion? Harmonic distortion is usually not that unpleasant to the ear, whereas distortion not related to harmonics can be extremely disturbing. For instance the IGD test track on the Tacet test record shows that IGD, which is not harmonic related, is extremely irritating.

JICO may or may not have a bad quality control - I can't say since there is no reference cartridge to compare to where several stylii have been measured that way. And I would not say it is in another league - I did comment on that other JICO where the SRA seemed closer to 95°. So my would be SRA 94° - cantilever ≈25°, while the other one SRA 95° - cantilever ≈27°. He also used 1.0 g VTF while I had 1.45 g, so I would expect a small difference. That said, cartridges and stylii are individuals, there is not one that measures exactly the same, all other things identical.

Regarding IMD and VTA, I refer to this page.

Vertical Tracking Distortion

Stereo Lab Vertical Tracking Distortion Vertical Tracking Error

pspatialaudio.com

Special attention to the cited phrases below, including the music samples with 12° (!) VTA error induced on the same page.

• The centre of attention (for example voice of solo instrument), as well bass and bass-drum (which induce the largest groove modulation) are usually panned centre, or near-centre, in a stereo mix in production and are thus unaffected by vertical tracking error.
• The distortion introduced by vertical tracking error is on the channel difference signal which is often considerably less modulated than the sum signal (for the reasons given above).
• The difference signal is highly correlated with the sum signal, so distortion the difference signal will often be masked by the Σ information.
• Most lathes include an Elliptical Equaliser which removes low frequencies (which would reveal the worst of the harmonic distortion) from the difference signal.

And I've long agreed with most things that Yosh written about VTA that I've linked to, and he have done some research:

Site Map

With respect to other distortion sources, such as highly modulated inner grooves with HF content, I agree they are much more audible than an increase from 1 to 2 percent VTA IMD for special test signals that rarely occur on music records. When it comes to harmonic distortion, it is clearly audible in higher frequencies (3-4 kHz and up) and higher modulations. A low THD and headroom for dynamic peaks just sounds cleaner.

This will close my session in this thread. There is really nothing more I can add.

 

[mr_petit]

JICO may or may not have a bad quality control - I can't say since there is no reference cartridge to compare to where several stylii have been measured that way. And I would not say it is in another league - I did comment on that other JICO where the SRA seemed closer to 95°. So my would be SRA 94° - cantilever ≈25°, while the other one SRA 95° - cantilever ≈27°. He also used 1.0 g VTF while I had 1.45 g, so I would expect a small difference. That said, cartridges and stylii are individuals, there is not one that measures exactly the same, all other things identical.

But again you're ignoring the measurements. You can clearly see that the optimum for the lowest IM distortion in that example lies somewhere around 30 degrees. Whereas the optimum for that AT cartridge that followed the same testing procedure, it'somewhere around 20-22 degrees (translates to a 0 to -2 deg SRA from perpendicular), the value usually used on cutting lathes. How to you explain that 8deg difference? This is not a matter of measuring 'exactly' the same, this is a matter of not being in the same ballpark at all.

Regarding IMD and VTA, I refer to this page.

Vertical Tracking Distortion

Stereo Lab Vertical Tracking Distortion Vertical Tracking Error

pspatialaudio.com

That site says exactly nothing about IMD or how irritating it is. Harmonic distoriton and intermodulation distortion are 2 completely different things.
Also there is a statement that lateral tracking error and vertical tracking error "are so similar" but any substantiation or any explanation why....is not present.

 

[Thomas_AA]

But again you're ignoring the measurements. You can clearly see that the optimum for the lowest IM distortion in that example lies somewhere around 30 degrees.


That site says exactly nothing about IMD or how irritating it is. Harmonic distoriton and intermodulation distortion are 2 completely different things.
Also there is a statement that lateral tracking error and vertical tracking error "are so similar" but any substantiation or any explanation why....is not present.

No, I am not ignoring the measurements. I just find that the VTA IMD distortion in the range we are talking about, 0.5 to 1.5 % increase for a special test signal, is not anything that I bother about when playing music content (also for the reasons mentioned above). Also, one should ask why e.g. Ortofon have chosen to use the replicant stylus that gives SRA/effective VTA of around 90°/26°. Perhaps the 6 ° VTA error is of no concern, all other playback errors included?

The site talks about VTA IMD and how it applies to music and syantethic signals; cite "The listening tests reported are not authoritative (they were not double blind and the panel was extremely small). Nonetheless the results are interesting. Its author (Richard Tollerton) reported that a vertical tracking error of just 2° was perceptible on synthetic test tones, but the figure rose to nearly 12° on music programme."

What I am most interested in is whether JICO have been conservative for their recommended VTF (1.0-1.5 g) and is reason for SRA to be a bit on the high side (I use 1.45 g brush down). In theory, lowering SRA and cantilever angle with 4° (to 90°/21°) would end up with an effective VTA ≈25°, but I would not do it with changing tonearm height much but rather with VTF. There is a way to test optimal VTF, but I have not dared to pass the higher limit.

 

[mr_petit]

No, I am not ignoring the measurements. I just find that the VTA IMD distortion in the range we are talking about, 0.5 to 1.5 % increase for a special test signal, is not anything that I bother about when playing music content

Ok, but what you're bothered about or not is not relevant and not an objective argument. Lots of people aren't bothered about many things at all, but this topic is about how to set the ideal VTA/SRA, how to measure it or it's consequences and potentially how it affects sound.

Also, one should ask why e.g. Ortofon have chosen to use the replicant stylus that gives SRA/effective VTA of around 90°/26°. Perhaps the 6 ° VTA error is of no concern, all other playback errors included?

You're concluding that VTA number from that picture with the measurements, not from the patent. The patent states that the sra should be 90 deg:

The angle of the front side facet surface to the upper surface of the record should be the customary 90°

and the vta of the cantilever should be ca. 20deg, so that is not really a set value. Their main claim is on the SRA. What VTA comes with that depends on how the tip is glued in.

The site talks about VTA IMD and how it applies to music and syantethic signals; cite "The listening tests reported are not authoritative (they were not double blind and the panel was extremely small). Nonetheless the results are interesting. Its author (Richard Tollerton) reported that a vertical tracking error of just 2° was perceptible on synthetic test tones, but the figure rose to nearly 12° on music programme."

Without actual music files we'll never know. Besides which type of music files is always very very important in these. Inner grooves? outer grooves? amount of modulation?
I see it like IGD. Lots of people claim it doesn't exist or doesn't occur on their setup. That is a consequence of either not having music where IGD occurs, or they don't know what to listen for, or are just plain deaf. It's easy to make a setup sound beautiful. It's not so easy to make a setup sound beautiful everywhere on every record.
I'm mainly interested in where things start to sound noticeably worse.

What I am most interested in is whether JICO have been conservative for their recommended VTF (1.0-1.5 g) and is reason for SRA to be a bit on the high side (I use 1.45 g brush down). In theory, lowering SRA and cantilever angle with 4° (to 90°/21°) would end up with an effective VTA ≈25°, but I would not do it with changing tonearm height much but rather with VTF. There is a way to test optimal VTF, but I have not dared to pass the higher limit.

You have that stylus. I don't. So you have to do the measurements whether or not VTF is set correctly on their recommendation. Lots of manufacturers are often dead wrong.
What's the dynamic compliance of that stylus? (without brush)
1.0-1.5 with a brush down is very very low. You'd expect a compliance of well over 35.
Whether or not more VTF brings you within your desired SRA range....depends on your static compliance.
However I doubt playing with the VTF would bring that stylus in your first example with that 8degree SRA error (according to the measurements) into the right ballpark.
The original v15IV is rated at 25mm/N, so that means adding 1g extra VTF (wich of course is a huge amount), only ads 0,25mm extra sagging of the stylus. That would result in a lowering of only 2 degrees on the VTA if the cantilever (tip to fulcrum distance) is 8mm long (pretty standard). Certainly not enough for the stylus from your first example.
And that's for 1g extra VTF. Adding half a gram or even less won't really do anything. Or that jico stylus must have an insane high static compliance of like 75mm/N or more, but that's unlikely.
But I assume you haven't done such calculations yet?