Fun with vinyl measurements

[Balle Clorin]

I do not get as good results as you two on my Tacet copy, so I use my B&K QR2010

First some old Shakenspin results on Sony PS-212

Then NAK T-100, Polar and Audacity, all in one page

 

[Thomas_A]

I suspect the QR2010 has 2.22 and 4.44 wow peaks. From where comes the Shaknspin peaks?

 

[Balle Clorin]

From the DD drive I guess

 

[Thomas_A]

From the DD drive I guess

The record polar plot wavy pattern is around 8 peaks, about 4 Hz. Is that seen also for the Denon and gyro? i don’t remember.

 

[stereoplay]

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?):

 

[Thomas_A]

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

Thanks,

one question regarding your numbers. Is DIN Weighted = Quasi-Peak/weighted peak? WRMS is the weighted RMS according to JIS, as I get it.

 

[stereoplay]

Weighting (in the frequency domain) means:

and unweighted:

Quasipeak in the time domain means:

A fast attack time (e.g. 31ms) and slow decay time (e.g 1000ms) is used to emphasize the peaks. Nowadays the 2sigma method is recommended (all newer standards refer to that).

 

[Balle Clorin]

The record polar plot wavy pattern is around 8 peaks, about 4 Hz. Is that seen also for the Denon and gyro? i don’t remember. Gyro

The Gyro does not have the 4.4Hz but other Hz, the same 4.4 occurs on Clearaudio and B&K and Tacet test on the denon 51F

Fun with vinyl measurements

Must be very hard to oberve where to push the record, I cannot manage that I think..

audiosciencereview.com

I could not get good sentering/results with Tacet..

 

[USER]

Also something to consider for the Sony PS-212 results: a tale of repair misadventure.

You can see the effects of cleaning and quick adjustment of a spare Denon DP-35F. I then tried adjusting the trim pots for motor adjustment according to the manual. I didn't realize that my cheap Hantek oscilloscope was not reading the amplitude setting correctly. So there was no 1:1 correspondence to the 15V lissajous figure I should have seen.

The file names describe the steps. But the 5th shows the effects of misadjustment. As I can't measure the amplitude correctly, the 6th is adjustment was made by eye. The lissajous figure doesn't reach 15V. I need to figure out a solution to my problem. I realize this is likely the most amateur fail anyone can have, lol. Could what you are seeing on the Sony be related to a trim pot setting being off?

Just in case: would a 50ohm BNC to BNC adapter for my probe interface help?

 

[stereoplay]

Just in case: would a 50ohm BNC to BNC adapter for my probe interface help?

Not at all. It only match the input impedance for HF-measurements.

 

[Thomas_A]

Weighting (in the frequency domain) means:
View attachment 313599

and unweighted:


View attachment 313600

Quasipeak in the time domain means:

A fast attack time (e.g. 31ms) and slow decay time (e.g 1000ms) is used to emphasize the peaks. Nowadays the 2sigma method is recommended (all newer standards refer to that).

Yes, I think I get that.But what confuses me is that quasi-peak also is called weighted-peak as DIN standard says. So what is your DIN figures? Quasi-peak with and without the weight curves? "DIN linear" give me clues as it is just peak and not quasi-peak.

 

[Balle Clorin]

I ran Restorer -Jons calibarion files on the T-100. could not set the level xcactly on 0db, but close.
https://audiosciencereview.com/foru...nweighted-jis-din-ccir-and-nab-help-me.10737/

 

[stereoplay]

DIN measurements are quasi peak.
One with the weighting curve with a peak at 4Hz and the other with 0,2...200Hz (-3dB) (linear)

 

[Thomas_A]

DIN measurements are quasi peak.
One with the weighting curve with a peak at 4Hz and the other with 0,2...200Hz (-3dB) (linear)

Thanks! So the it is so that DIN quasi peak (linear) usually is a bit higher than 2sigma.

 

[Balle Clorin]

The file names describe the steps. But the 5th shows the effects of misadjustment. As I can't measure the amplitude correctly, the 6th is adjustment was made by eye. The lissajous figure doesn't reach 15V. I need to figure out a solution to my problem. I realize this is likely the most amateur fail anyone can have, lol. Could what you are seeing on the Sony be related to a trim pot setting being off?

Sony PS-212. Thanks, I only adjusted the internal 45rpm and 33rpm trimmers to get the front panel trimmer within normal range, and strobes stationary in center position.
I have not found the complete manual , so I am not sur how to do the proper adjustments

The file names describe the steps.

All the text seem to be the same to me---?

 

[USER]

Hi everyone, I have begun updating the "understanding, troubleshooting, and adjusting with measurements" section of the cartridge measurements library thread.

Introducing the Phono Cartridge Measurement Library

After years of development we are finally launching our phono cartridge measurement library. These measurements were created using the brilliant cartridge response python script written by @scott wurcer and @JP. Information about its origins can be found in the following threads...

audiosciencereview.com

Please let me know if you have any comments, suggestions, or if I got something wrong. Thanks.

 

[JP]

During my unanticipated forced downtime that afforded me the window to write the script to facilitate these measurements and plots. These are laser displacement measurements of an SP-10MKII platter, taken from about 1cm in from the platter lip, spinning under its own power. This is an early unit that I imported from Japan 2-3 years ago. It shows signs of being stored in a slightly unfavorable environment. The motor is untouched.

The max deviation is 0.07623mm / 0.0030" over four revolutions. It's 0.09152mm / 0.00360" over 200 revolutions. Time permitting I'll measure it with a cartridge on a cut-down record, and repeat all measurement after servicing the motor. And, of course, measure a few more units.

For giggles, the second plot superimposes four revolutions of what I'd consider a rather flat record. Max deviation is 0.33559mm / 0.01321". Platter and record measurement are not indexed.

 

[USER]

During my unanticipated forced downtime that afforded me the window to write the script to facilitate these measurements and plots. These are laser displacement measurements of an SP-10MKII platter, taken from about 1cm in from the platter lip, spinning under its own power. This is an early unit that I imported from Japan 2-3 years ago. It shows signs of being stored in a slightly unfavorable environment. The motor is untouched.

The max deviation is 0.07623mm / 0.0030" over four revolutions. It's 0.09152mm / 0.00360" over 200 revolutions. Time permitting I'll measure it with a cartridge on a cut-down record, and repeat all measurement after servicing the motor. And, of course, measure a few more units.

For giggles, the second plot superimposes four revolutions of what I'd consider a rather flat record. Max deviation is 0.33559mm / 0.01321". Platter and record measurement are not indexed.

View attachment 314456
View attachment 314457

You should zhuzh up the post Korf style and talk about how this is audible.

Anyways, this is super cool. Can't wait to see the results post restoration. In the meantime let's see your MKIII!

 

[JP]

Ha. I’ll skip doing it Korf-style.

Three thousandths is really good, so I don’t expect servicing to make that better. I am curious if the orbit behavior changes.

 

[Balle Clorin]

Seems like the record is the problem not the platter….