Fun with vinyl measurements

[JP]

Yes, I don't think there are any surprises here. The platter runout was less than I expected, though I'd think the unit variation could be a bit large, thought not meaningful.

 

[morillon]

Yes, I don't think there are any surprises here. The platter runout was less than I expected, though I'd think the unit variation could be a bit large, thought not meaningful.

new capacitors...torlon bearing thrust cap...removing the brake...what to do.. ;-)

 

[JP]

Wouldn't make any difference for runout. And removing the brake is load of BS fueled by FUD.

 

[morillon]

Wouldn't make any difference for runout. And removing the brake is load of BS fueled by FUD.

I was just listing classics that can be done on this machine.. ;-)
( and new quartz and control the electronic)

 

[Balle Clorin]

Fud?

 

[JP]

Fear, uncertainty, doubt.

 

[JP]

This is typical for a direct drive.

It is called pole cogging. I'm not sure whether it is a 4 or 8 pole motor.

Here is one measured with a gyroscope (16-pole?):
View attachment 313588

It's actually not remotely common for a DD, especially a PLL controlled one. This is what we call "broken".

 

[morillon]

Fear, uncertainty, doubt.

this is to ensure that the "flexible" strip is not in contact when it is not engaged- under tension.

 

[JP]

I've only seen it contact if someone has messed with it, and it's a rather easy adjustment if so. However, the usual claim is that it vibrates, which during normal use, it doesn't.

 

[morillon]

I've only seen it contact if someone has messed with it, and it's a rather easy adjustment if so. However, the usual claim is that it vibrates, which during normal use, it doesn't.

I know..
the idea is that can possibly lead to some doubts when it is no longer in tension and contact while that no real use in non-pro use..that's all..explain the practice of withdrawal

 

[Balle Clorin]

It's actually not remotely common for a DD, especially a PLL controlled one. This is what we call "broken".

Broken? I have not seen any present TT that achieve anything below 0,05% on 2-sigma, and 90% are above 0.1 This broken unit is 0,03? Vinyl is BACK, but it is not because it has improved

 

[morillon]

Cassé? Je n'ai vu aucun TT actuel atteignant quelque chose en dessous de 0,05 % sur 2-sigma, et 90 % sont au-dessus de 0,1. Cette unité cassée est de 0,03 ? Le vinyle est de RETOUR, mais ce n’est pas parce qu’il s’est amélioré

?
it is still the interest of a little serious dd in good electronic and mechanical condition to go below 0.05% in sigma2..and if you come across it at more than 0.1%, problems, or trash...

 

[JP]

Broken? I have not seen any present TT that achieve anything below 0,05% on 2-sigma, and 90% are above 0.1 This broken unit is 0,03? Vinyl is BACK, but it is not because it has improved

I'm looking at the spectrum and polar. I don't find W&F as a single number to be all that useful outside of being a gross indicator.

 

[morillon]

I'm looking at the spectrum and polar. I don't find W&F as a single number to be all that useful outside of being a gross indicator.

if a global measurement unlike you I find it significant and fits well with the listening observations.... for those who listen to the piano etc.
(already that it is an accumulation of the wf of the recorder if the temp of the real/real and not digital the defects of vinyl pressing..etc it quickly adds up to a lot)

 

[JP]

That's pretty much how gross measurements work.

 

[USER]

I just realized that this is a better thread for this question:

Why are these crosstalk results on a CBS STR-100 seemingly correct (accounting for phantom center result at 1kHz) across the range here? I have 25+ other measurements with this record and those results are limited to about -20 dB with the exception of one or two barely getting to -25 dB.

 

[aaaakkkk]

I just realized that this is a better thread for this question:

Why are these crosstalk results on a CBS STR-100 seemingly correct (accounting for phantom center result at 1kHz) across the range here? I have 25+ other measurements with this record and those results are limited to about -20 dB with the exception of one or two barely getting to -25 dB.

View attachment 316686

You can experiment with SRA + -5*,
on a cartridge that shows separation exactly greater than 30 dB.

.

 

[Balle Clorin]

I have seen the same om CA TRS-1007, suddenly I get 30 on one cartridge ( Technics EPC-270Cii ) stands out better than the rest. And if I remount it I may loose the good results. Sometimes is seem related to Zenith/Azimuth/VTA , other times I cannot get it back good whatever I do. The 1khz results can be corrupted by sub 100hz noise so I filter at 400hz to be sure

 

[Thomas_A]

I just realized that this is a better thread for this question:

Why are these crosstalk results on a CBS STR-100 seemingly correct (accounting for phantom center result at 1kHz) across the range here? I have 25+ other measurements with this record and those results are limited to about -20 dB with the exception of one or two barely getting to -25 dB.

View attachment 316686

Are these result from a different test record? Test records may differ depending on pressing and master. They should be numbered/dated for reference, IMO.

 

[Thomas_A]

I have seen the same om CA TRS-1007, suddenly I get 30 on one cartridge ( Technics EPC-270Cii ) stands out better than the rest. And if I remount it I may loose the good results. Sometimes is seem related to Zenith/Azimuth/VTA , other times I cannot get it back good whatever I do. The 1khz results can be corrupted by sub 100hz noise so I filter at 400hz to be sure

Do you have any systematic investigation, e.g. changing SRA/VTA on crosstalk? The two main factors on crosstalk of cartridge should in theory be:

- Azimuth
- Vertical tracking force

Both factors affect the centering of the stylus magnet or coil between the coils/magnets.

Other factors may be (but not really studied?)
- Stylus suspension (should be symmetric)
- Lateral tracking angle
- SRA/VTA