Fun with vinyl measurements

[Aero]

What is the point of these to anyone aside from you?

The meaning is, for example, as follows:
I am thinking about buying a resonance damping system

KAB TD-1000™ TONEARM FLUID DAMPER FORTechnics SL1000R / 1200-1210 GAE, G, & GR, 100C, 1500C & MK7
They have been selling this system for several years, but I can't find any measurements of how the effect of damping resonance in the range of up to 20 Hz gives the use of this system.
There are only descriptions, users, or the manufacturer and great properties of using this system, such adventure literature.
There are various other systems of damping resonance to 20 Hz, in turntables e.g. Denon Sony, JVC, etc.

I think it would be worth measuring what effect all these systems have on limiting resonance in the range of up to 20 Hz.

I measured the Ortofon Jubilee and AT-95E, using the Technics 1200GR2 turntable, and it shows that the level of unwanted but unavoidable resonance, despite the vastly different quality of both cartridges, is almost identical. Another user measured the Shure cartridge with damping and a damping tonearm, and the level of resonance is incomparably lower, the difference is very, very big.

 

[Aero]

That doesn't explain why you think it has any relevance to anyone else. You're showing the resonance with your arm, and you're using a flawed tool to do it.

When I find some free time, I will mount the same cartridge on an arm with electronic, adjustable level of unwanted resonance suppression and use your tool to measure the frequency response at 5 different levels of unwanted resonance suppression. I will see what effect reducing, increasing the amplitude of unwanted resonance will have on the frequency response of the cartridge.
In addition to sounds in the 20Hz - 20 kHz band, every cartridge generates, always generates a high amplitude signal in the range up to 20 Hz. Always.

 

[JP]

When I find some free time, I will mount the same cartridge on an arm with electronic, adjustable level of unwanted resonance suppression and use your tool to measure the frequency response at 5 different levels of unwanted resonance suppression. I will see what effect reducing, increasing the amplitude of unwanted resonance will have on the frequency response of the cartridge.

"My" tool would be poorly suited for that. It takes fs/100 slices of the signal and gives the amplitude of the largest bin at the instantaneous frequency at the step size. This means the signal exciting a resonance needs to be at the same frequency as the then present sweep fundamental, or always present such as the arm/cart resonance. As a consequence it's the response below ~50Hz where this shows up, and the behavior is well known.

In addition to sounds in the 20Hz - 20 kHz band, every cartridge generates, always generates a high amplitude signal in the range up to 20 Hz. Always.

It's the resonance of the system, not the cartridge, that does this. Dynamic compliance of the cartridge vs. the effective mass of the arm. The cartridge doesn't generate anything on its own.

 

[Aero]

"My" tool would be poorly suited for that. It takes fs/100 slices of the signal and gives the amplitude of the largest bin at the instantaneous frequency at the step size. This means the signal exciting a resonance needs to be at the same frequency as the then present sweep fundamental, or always present such as the arm/cart resonance. As a consequence it's the response below ~50Hz where this shows up, and the behavior is well known.



It's the resonance of the system, not the cartridge, that does this. Dynamic compliance of the cartridge vs. the effective mass of the arm. The cartridge doesn't generate anything on its own.

Of course you are right that a gramophone cartridge does not generate high amplitude resonance in the range of up to 20Hz.

You know it, I know it, but not everyone knows that in addition to playing the signal recorded on the record, a signal from the range of 0-20 Hz is added to it, with a fairly high amplitude, because the records are uneven, because the tonearm has a poor design, because the gramophone cartridge has a poor damping system, etc.

The lower the amplitude of this resonance, the better. In fact, the entire history of gramophone development is a constant struggle with this undesirable phenomenon.

I did not have a test record at the time, so I used the same recording.

Denon DP-67 turntable

Resonance damping off

Resonance damping set to maximum value

Does reducing the amplitude level of the undesirable resonance affect the frequency response of the gramophone cartridge? I do not know.
You have to check it.

The manufacturer of this turntable wrote:

"This tonearm inherits the fully electronic damping mechanism of the DP-100M tonearm. Generally, the horizontal Q dump mechanism is normal in this class, but the dynamic servo is also equipped with a vertical Q dump mechanism, which dampens the vibration of the tonearm caused by too much low-frequency Q resonance. It effectively controls, prevents abnormal increases at low output frequencies and increased crosstalk, eliminates the causes of modulation distortion and ensures music reproduction with higher purity."


Another manufacturer, KAB-1000, wrote this about its system that it offers for Technics 1200 series turntables:

1. Attenuates peak amplitude at resonance.

2. Actually reduces the stress the cantiliver sees riding up and down a warp.

3. Eliminates que skipping at the beginning of the disc.

4. Reduces the sensitivity of the tonearm to external vibration.

5. Subjectively increases detail retrieval
The question is, do these systems improve anything and how does this affect the sound quality?

 

[Balle Clorin]

My Denon 51f has electronically damping it works well , but the thin arm has some serious resonance at 80hz and some above 100hz too, I cannot hear it but it is visible on some pink noise tracks FR. Damping does not work at these hz . It is easy to do sound comparison , I cannot hear the effect , do you?

 

[Aero]

My Denon 51f has electronically damping it works well , but the thin arm has some serious resonance at 80hz and some above 100hz too, I cannot hear it but it is visible on some pink noise tracks FR. Damping does not work at these hz . It is easy to do sound comparison , I cannot hear the effect , do you?

I am interested in what effect limiting the amplitude of unwanted resonance in the 0-20Hz range has on the frequency response of the phonograph cartridge

Why in the 0-20Hz range? Because in this range the amplitude of unwanted resonance is the greatest.

I am also interested in whether if I lower or increase the frequency * at which the resonance peak occurs, will it affect the frequency response of the phonograph cartridge or not?

* For example, I will increase or decrease the effective mass.

 

[Thomas_A]

There is one test signal on the Hifi News record, 1 kHz together with a LF signal causing IMD flutter. Now, check the spectrum of that one.

 

[Balle Clorin]

I am interested in what effect limiting the amplitude of unwanted resonance in the 0-20Hz range has on the frequency response of the phonograph cartridge

Why in the 0-20Hz range? Because in this range the amplitude of unwanted resonance is the greatest.

I am also interested in whether if I lower or increase the frequency * at which the resonance peak occurs, will it affect the frequency response of the phonograph cartridge or not?

* For example, I will increase or decrease the effective mass.

Start measuring properly using REW instead of Audacity and you can investigate frequency response properly, use the calibration I gave above to make pink noise response flat.

 

[Aero]

There is one test signal on the Hifi News record, 1 kHz together with a LF signal causing IMD flutter. Now, check the spectrum of that one.

I checked the Denon with a full-band sweep signal, Side B Track 7, HiFi News.

I believe that the frequency response signal used on this forum is equally good for checking the resonance amplitude level in the range up to 20Hz

Could you, at your leisure, check the Shure with the brush down, and without using the brush, and, the arm with the attenuation off and the attenuation on?

 

[Thomas_A]

I checked the Denon with a full-band sweep signal, Side B Track 7, HiFi News.

I believe that the frequency response signal used on this forum is equally good for checking the resonance amplitude level in the range up to 20Hz

Could you, at your leisure, check the Shure with the brush down, and without using the brush, and, the arm with the attenuation off and the attenuation on?

My tonearm has fixed damping. Have tested with Shure brush up and down as well, but at the moment, doing other checks; there are plots around with Shure brush up and down.

(I just wanted to tell that the resonance test on the HiFi News test record is designed check the resonant frequency with an audible warbling 1 kHz signal.)

 

[Aero]

Start measuring properly using REW......

When I retire (it will be soon) and have enough time to thoroughly explore this program, I will start using it.

 

[Balle Clorin]

The 5-20hz resonance causes intermodulation distortion, not deviation in the frequency response, according to theory and my own measurements, on the Hifinews record one can visually see the resonance , not only hear it. IMD can be seen as sidebands by the single tones but may be obscured by TT and record speed variation WF

 

[undeakyetonde]

I am interested in what effect limiting the amplitude of unwanted resonance in the 0-20Hz range has on the frequency response of the phonograph cartridge

No effect. To my best knowledge, this unwanted resonance is already in the frequency response of the 'cartridge + tonearm' system.

I read that this resonance introduces some AM and FM modulation in audible frequency region. Which is non-linear distortion and can't be described by means of a frequency response

 

[Balle Clorin]

@Balle Clorin

can you share your "fricatives" files from the Shure and AT?

I can't get better than this at ≈1.45 g (Shure V15Vx/SAS/B):

Dropbox

www.dropbox.com

you have mail with link to files

 

[Thomas_A]

you have mail with link to files

Thanks,

it sounds a hint less with the AT, but the distortion is still there. Mostly it goes into the right channel so I wonder how (i) lateral tracking angle error and (ii) antiskate force would affect this.

 

[Aero]

On the outer part of the plate, the needle usually has a large setting error, which results from the geometry.

A large part of the tips is glued crooked.

All this affects the result of the frequency response measurement.

 

[Balle Clorin]

I have been trying to get the zenith correct forever… not finished
In my speakers the AT is way better than the Shure..no contest The Shure gives a wide horisontal splash when it hits the sibilants. The AT is much more controlled.

 

[Thomas_A]

I have been trying to get the zenith correct forever… not finished
In my speakers the AT is way better than the Shure..no contest

Did you swap/test the Shure on the SME as well?

 

[Balle Clorin]

No too much work

 

[Thomas_A]

No too much work

I understand.