Fun with vinyl measurements

[Balle Clorin]

Your File looks correct, I get:

Band	VTA L [°]	VTA R [°]
2B+6dB	23,3	25
2B+9dB	22,9	24,9
2B+12dB	22,8	23,8

But what is wrong with the Python Script? I don't know, as I am not in Python...

Super , very happy, I think I love you!!!

 

[Balle Clorin]

This is Dynavector 20X2Low, frequency response..from 2013 YouTube.
One the few places I have seen a proper curve for this one.. Some German plots on a forum but that was using a poor test record, Stereoplay 7 inch
I measures a friends one that had a problem/ damage .for that reason I did not post it
This one looks very nice

Here is the plot from a 7 inch freebie Stereoplay test record

 

[Balle Clorin]

A better zenith/horisontal tracking angle script on the way...

Can you share one of your good alignments @Thomas_A? So I can test a good alignment file

 

[Thomas_A]

You have to explain more...!

One file, newest JICO stylus:

Dropbox

www.dropbox.com

Moerch geometry:
Effective length 230 mm
Offset angle 24°
Pivot to spindle: 212 mm
Stylus overhang: 18 mm
Outer null point: 121.754 mm
Inner null point: 65.345 mm

 

[Balle Clorin]

here you go.. I did not replace SME alignment in Orange. NOTE degrees is true angular error ,not phase difference and vs radius mm

This is how you used to the the date in time vs phase difference

I still do not know why my cartridge never can get close to the zero line like you..

 

[Thomas_A]

Have not followed this - been busy. The tracking error should be converted to theoretical inter-channel phase difference (first of the lower three curves). If the curve shape is very close the difference will be the record zenith error (approx 1°). That is what I interpret it as. If alignment is wrong, curve shape will be wrong. A good analysis would be to create a correlation curve (=linear correlation, with highest correlation coefficient) between theoretical phase shift and experimental values. A fixed shift is then the error of the record (where the linear cross the x or y axis). Noise should not affect correlation coefficient too much, I think (just more points in the curve).

About your results, have not looked into it but if you show your curve again as the three other lower ones like the three below, what is the correlation between curves?

 

[Balle Clorin]

@Thomas_A ,For manual conversion/evaluation from R-L phase difference to angular error consider this when using Sperling record for alignment.
My revised script does this automatically, and plot both ways, Phase difference between channels and angular error. It could do zenith error by comparing theoretical and measured curves, but I choose not too, better to judge visually ..( script would be confused if you do not have perfect alignment)

 

[Thomas_A]

@Thomas_A ,For manual conversion/evaluation from R-L phase difference to angular error consider this when using Sperling record for alignment.
My revised script does this automatically, and plot both ways, Phase difference between channels and angular error. It could do zenith error by comparing theoretical and measured curves, but I choose not too, better to judge visually ..( script would be confused if you do not have perfect alignment)

View attachment 530969

Ok,

this is an improvement to have the theoretical curve. With respect to alignment, both overhang and twist change the shape and absolute values. If one assumes that the record has a 1° error you should be able to get similar response as I have - but it is a pain to do the adjustments. I don't think our records have different errors.

 

[Balle Clorin]

Yes.Thanks, I have that curve, and also Play with the Vinylengine alignment calulator and Excel sheet. It does not take much adjustment to see an effect in reality.
When I recover from my recent operation I will try more experiments with my AT540ML on the Fisher player, doing it on the SME with fixed headshell and ackward access is a pain, even if the pivot-spindle adjustment on SME is a nice feature, I obviously struggle with the angle. Maybe the OC9 has a problem too.

The other thing is that now the IMD on AnalogMagic show close to perfect alignment, Sperling not, so I think the records differ.I am beginning to think visual alignment of cantilever combined with correct overhang is the best approach.

 

[Thomas_A]

Yes.Thanks, I have that curve, and also Play with the Vinylengine alignment calulator and Excel sheet. It does not take much adjustment to see an effect in reality.
When I recover from my recent operation I will try more experiments with my AT540ML on the Fisher player, doing it on the SME with fixed headshell and ackward access is a pain, even if the pivot-spindle adjustment on SME is a nice feature, I obviously struggle with the angle. Maybe the OC9 has a problem too.

The other thing is that now the IMD on AnalogMagic show close to perfect alignment, Sperling not, so I think the records differ.I am beginning to think visual alignment of cantilever combined with correct overhang is the best approach.

I think one has to validate test records with some laser measurements. Records deviate in one or several aspects which makes it impossible to make any good conclusions. The Sperling 1 kHz can very well have a 1° fixed zenith error. It would be nice if the script could simulate fixed record errors as well.

Recover well!

 

[Balle Clorin]

A guy at Whatsbestforum has A laser pickup and say he gets the same results as me, same IMD, same channel balance on AM Tracks so som of the results are probebly embedded in the record. I hope he checks his laser PU on the Sperling too
Different record for setting Azimuth affect IMD on AnalogMagik
Post in thread 'Analog Magik'
https://www.whatsbestforum.com/threads/analog-magik.25735/post-1117726

 

[Thomas_A]

A guy at Whatsbestforum has A laser pickup and say he gets the same results as me, same IMD, same channel balance on AM Tracks so som of the results are probebly embedded in the record. I hope he checks his laser PU on the Sperling too

I wonder when Boisclair will publish his results. Been waiting for a while now.

 

[Balle Clorin]

Some collection of crosstalk data I placed in the wrong thread..
Post in thread 'Frequency Response Test Records'
https://www.audiosciencereview.com/...ency-response-test-records.30210/post-2592587

If the Zenith data vary as much as crosstalk it may be Difficult to reach a conclusion for Bosclair too.

 

[Balle Clorin]

Quite happy with my VTA script here now.. Jico is known to ebe around 30 degrees VTA so shimming is the smart thing to do

Effect on VTF on MC is less.

here is another cartridge 33PTGii

and AT OC9MLii

REV6 improved version,very close to spec /visual now

 

[Thomas_A]

Those records are rare. How do they match with visual measure? Other than that vertical modulated 1 kHz is more available. AP record.

 

[Balle Clorin]

AP ULtimate analog Test record in not vertical modulated and useless,udated wirj a Photo. probably 1.75g VTF, estimate 23 degree

 

[Thomas_A]

AP ULtimate analog Test record in not vertical modulated and useless

I know. I was thinking 1 kHz vertical. There is a minimum 2nd HD where VTA match VMA.

 

[Thomas_A]

Test of a Linn Aliexpress belt. Looks and fells ok after some conditioning. A bit more tension vs. the original Linn belt. So how did it fare?

Original Linn Neoprene belt (now changed to the 3 year old one):

Looks really as it did in the past. Quite good with low 1.0 Hz peaks.

The Aliexpress belt:

Horrible 1.0 Hz peaking (as well as 0.5 Hz).

Verdict: Poor

 

[Balle Clorin]

Reminds me of some High end TT I have measured...
Well that proves that belts matter a lot. Somtimes I wonder what is the point of building/buting an oilrig of a Turntable, just to fail completely on speed since proper belts are unobtainium.. Better to buy a Rega then

I write this since I have measured TTs costing 150k-100k$ thae fails completely on speed stability due to poor belts, if a manufacturer cannot source a very good belt the TT is doomed to be mediocre

 

[morillon]

Reminds me of some High end TT I have measured...
Well that proves that belts matter a lot. Somtimes I wonder what is the point of building/buting an oilrig of a Turntable, just to fail completely on speed since proper belts are unobtainium.. Better to buy a Rega then

I write this since I have measured TTs costing 150k-100k$ thae fails completely on speed stability due to poor belts, if a manufacturer cannot source a very good belt the TT is doomed to be mediocre

Yes, it's indeed a huge, but not new, issue...

but it also ties in with all the observations about the "very relative" nature of vinyl production, even our test records... which leads us to put all our efforts at "high-end" settings into perspective, etc.