Fun with vinyl measurements

[JP]

Yes, sorry, you are producing so many apps now.I think the results with the Groove geometry app are in the ballpark when comparing to the Sperling record for the Groove Geometry.. Tracing distortion goes from about 0.25 to 1 % for a 1 kHz signal, at ≈2.5 cm/s. Below.

I am sure how I use the LF mechanics without numbers. I get the resonance in the ballpark (9-10 Hz) but I can't really say anything about amplitude without spec of the cartridge.

View attachment 524420

Well, I haven't put out an app for at least three days now.

For the tonearm mechanics calculator the only options are to measure it or find a way to infer it based on other data. That's not surefire; it's just directional.

 

[Balle Clorin]

I was not able to post the result of the suspension rejuvenation with Liqui Moly "power steering leak stopper" ( rubber softener) in time, so here are the results of 24 hr
treatment, I gave both ends of the "insert" a drop with several hours interval

Before in blue, RED after Liqui Moly, a quite pronounced positive effect, Left channel compared.
@Jimi Floyd gave me the tip, I found 2 other posts on the subject here.

I wish I had known this before I broke my Shure V15-VMR such was hard as a rock

and here both channels, treated to the right

 

[mackat]

I'm trying to understand something here.

This is a Dynavector 17D2 MKII that has a clearly audible channel imbalance towards the left channel.

The cantilever is skewed, it rides pretty low, and crosstalk is bad.

Why isn't the imbalance showing up at all in the graph? Here is a screenshot of the Audacity waveform, where you can see the imbalance:

Here is the WAV file: https://www.dropbox.com/scl/fi/2tnw...ey=ip6h41zsbayssa4jjt4tj5dig&st=qbrsjedv&dl=0

 

[JP]

~2.6dB difference the pilot tones, but that difference is not in the sweeps.

 

[mackat]

~2.6dB difference the pilot tones, but that difference is not in the sweeps.

Thanks, very interesting. I wonder what phenomenon would cause that. Perhaps the crosstalk issue?

 

[Thomas_A]

Thanks, very interesting. I wonder what phenomenon would cause that. Perhaps the crosstalk issue?

Skewed cantilever. Aligned with cantilever or body?

 

[mackat]

Skewed cantilever. Aligned with cantilever or body?

Aligned with body

 

[Thomas_A]

Aligned with body

You could try shift a bit to see effect. But it might not work....

 

[Balle Clorin]

I was not able to post the result of the suspension rejuvenation with Liqui Moly "power steering leak stopper" ( rubber softener) in time, so here are the results of 24 hr
treatment, I gave both ends of the "insert" a drop with several hours interval

Before in blue, RED after Liqui Moly, a quite pronounced positive effect, Left channel compared.
@Jimi Floyd gave me the tip, I found 2 other posts on the subject here.

I wish I had known this before I broke my Shure V15-VMR such was hard as a rock

View attachment 524489

and here both channels, treated to the right
View attachment 524484

An update, the effect on frequency response wears off after a week, or so still better than before, and it now track 100um, before it barely did 60um at 2.5gram

Spoiler: untreated

 

[Thomas_A]

My new JICO stylus for the Shure V15V. 1.25 gf and 11% antiskate. With 6° VTA shim. It needs readjustment of zenith. And the usual flip flop of crosstalk of test records...

 

[Balle Clorin]

you were lucky with that one!! Flat with no tricks.
I have a V15 V needing a stylus... hmm interesting. I believe i have seen that SASb for V15 may vary quite a bit in response.. thet has held me back form buying so far

 

[Thomas_A]

you were lucky with that one!! Flat with no tricks.
I have a V15 V needing a stylus... hmm interesting. I believe i have seen that SASb for V15 may vary quite a bit in response.. thet has held me back form buying so far

My "old" stylus is from June last year, so it is quite new. Differences between the stylii and the CA-TRS1007 and Ortofon are clear:

Introducing the Phono Cartridge Measurement Library

Posting in the proper place now :) Goldring 1042 I've been curious about this cartridge for a while, but hadn't been able to find any measurements online. This is a truly low compliance MM cartridge (16 mm/N vertical) fitted with an advanced stylus cut, something fairly rare these days. It...

www.audiosciencereview.com

Both stylii were shimmed ≈ 6 degrees. I will try visualise both stylii and measure VTA.

 

[Thomas_A]

After 2 hours and four attempts I got the zenith reasonably correct. Next was to check azimuth of this new stylus. Merolemez showed me it was basically symmetric BUT now was the minima at 48°. Now, is that VTA again giving me trouble? Should be shimmed differently this one?

 

[Balle Clorin]

The notes following Merolemez states that symmetric minimum is the goal , and that deviation from 45 is OK as a read it.
But I would like to understand what is going on geometrically.. I got 47 after realigning my gyro/SME V, before it was 46..

Spoiler: all data

 

[Thomas_A]

Yes I am also curious. This is the last frontier that will perhaps explain why we see differences between the test records as well. I can only think of one right now, VTA/VMA. I mean if it is the suspension, how would that work? The stylus is shifted by one groove and rides up and down on the other. If it would be suspension compression it must mis-track to go another angle. If the groove is 45° I can only see it move that way, unless if the groove is differently angled vs. the stylus/cantilever; VTA/VMA mismatch can cause this. Don't know if the be something electrical mismatch in the armature vs. coils as well.

 

[Balle Clorin]

I used 2 pieces of paper , one folded 90 degrees to create a groove… the other papers corner goes into the groove like a stylus tip. Play with it and you will see that if the flat paper corner goes 90 degrees down into the groove the groove a paper will fit. 45 degrees matches , but if you tilt the paper going inside the groove the groove angle at 45 do no longer align with the other papers edge, so the groove angle must be different to match the stylus/paper edge. Sorry I han not enough hands to make a proper photo.

But I think this indicates that deviation between VMA and VTA(SRA) cause the the minimum crosstalk to be 45+X degrees. Where X is a function of VTA/SRA mismatch with the modulation angle. What does not fit is the fact that the side of my paper groove have to get wider, “less” degrees from the horizontal- when I tilt the “stylus” paper. But if the merlomez angles are defined as degrees from the vertical it fits the VTA/VMA mismatch theory. So I think the same as you

If this is the case changing VTA shim angle should shift the Merolemez symmetry of minimum crosstalk.

 

[Thomas_A]

Yes, but in that case the stylus is a bit rounded so it should touch the groove. The problem is rather that the angle of movement will not match if the cantilever does not move in the same angle as the inclined groove. You get an in-phase crosstalk. If you take that V-paper and move a pen straight up the groove, it will move 45° - VMA/VTA is matched - zero crosstalk. Now move the pen in another direction up the hill, and it will not be 45° movement.

Fun with vinyl measurements

@ElectricWarrior, If I may, I’d like to posit the idea that not only is there a sliding friction for the stylus on vinyl but, the stylus/vinyl interface also exhibits sticktion. Stylus sticktion would account for at least some of the difference seen between the two videos. In the second video...

www.audiosciencereview.com

I think the Ortofon record 1 kHz signal is cut at a different VMA than the CA-TRS1007. Going closer to 45° on the Merolemez will give better values of the Ortofon, while if you get lower or higher, the crosstalk will worsen. Then I think the CA-TRS1007 is optimum at ≈48° on the Merolemez.

What to do about it? I think I need to go trough the exhaustive shimming again with this new stylus and do measurements using the Merolemez and Ortofon test record.

 

[Balle Clorin]

You probably know this , but In phase cross talk or out of phase crosstalk just depend of the azimuth error direction, I posted a figure on this from Pramantik article in Audio

 

[Thomas_A]

You probably know this , but In phase cross talk or out of phase crosstalk just depend of the azimuth error direction, I posted a figure on this from Pramantik article in Audio

Yes I know that relation. You cannot get better azimuth correction when e.g. the Merolemez result is symmetric. But it seems crosstalk is also dependent on the VTA/VMA match but it is only the absolute values. If the Merolemez is cut at 20° and you have VTA 20° you will get the lowest crosstalk at 45° if also azimuth is correct. This also explains the varying crosstalk between different records, which will have different cut inclination angle/VMA. The closer you have VTA and VMA, the lower crosstalk you get in both channels. Since my latest stylus is quite different from my previous with respect to Merolemez results, I will try shimming in steps 0-6°, even if it is a lot of work. I would like my new stylus to be perfectly aligned and not change alignment after wear has started.

If it is related to e.g. suspension compression, I need to figure out how that is possible. I have not yet found it. It also may contradict the visual cantilever angle measurements, so more experiments are needed.

 

[Balle Clorin]

And then there is Zenith . I cannot get a good curve shape that crosses zero at the null points.. I get zero crossing at the wrong shape or a nice shape that has zero crossing at the wrong place..
Even when AnalogMagik tells me I have lowest IMD at 121 mm radius.

I start to wonder if this is caused by stylus diamond not having the correct alignment with cantilever . Hard to make a photo but my diamond is not as bad as the Sperling results suggest.

I thing it is mayme more important to have the cantilever horizontal angle correct than angling the cantilever to have the diamond groove contact at zero error( at the nulls)
Since it is the cantilever movement that generates the signal..