Considerations in turntable development

[RalfAM]

In another thread we came to the question of what considerations and experiments are made in the development of a turntable. Specifically, it was about the design of platters. In order not to deviate from the topic there, I was asked to open a new thread. Therefore, I would like to describe my point of view here and get your opinion.

Decisive for the sound quality of a platter is its vibration behavior. The less it vibrates, the less it disturbs the music reproduction. Of course, it is not possible to completely avoid vibrations. Therefore, the question for the developer is, which and how many vibrations do I allow. He has to decide which sound signature he gives to the platter and how many costs he causes.
The vibration behavior is determined by the parameters mass, damping and stiffness. From mass and stiffness results the natural frequency and the amplitude. The damping determines the period of oscillation. It would be ideal to achieve a very high stiffness for a small amplitude and a high damping for a low period of oscillation. But this is not so simple.
In most solutions, these two goals oppose each other. For example, if you want to improve the damping by using appropriate materials like soft rubber, you reduce the stiffness at the same time.

Here I do not yet want to explain how the corresponding choices affect the sound. I look forward to hearing your experiences.
Attached you will find a text I wrote for our dealers on this subject. Please do not mind that it sounds like advertising.

 

[AMR / iFi audio]

In another thread we came to the question of what considerations and experiments are made in the development of a turntable. Specifically, it was about the design of platters. In order not to deviate from the topic there, I was asked to open a new thread. Therefore, I would like to describe my point of view here and get your opinion.

Decisive for the sound quality of a platter is its vibration behavior. The less it vibrates, the less it disturbs the music reproduction. Of course, it is not possible to completely avoid vibrations. Therefore, the question for the developer is, which and how many vibrations do I allow. He has to decide which sound signature he gives to the platter and how many costs he causes.
The vibration behavior is determined by the parameters mass, damping and stiffness. From mass and stiffness results the natural frequency and the amplitude. The damping determines the period of oscillation. It would be ideal to achieve a very high stiffness for a small amplitude and a high damping for a low period of oscillation. But this is not so simple.
In most solutions, these two goals oppose each other. For example, if you want to improve the damping by using appropriate materials like soft rubber, you reduce the stiffness at the same time.

Here I do not yet want to explain how the corresponding choices affect the sound. I look forward to hearing your experiences.
Attached you will find a text I wrote for our dealers on this subject. Please do not mind that it sounds like advertising.

Good post, I appreciate it. It is very hard to balance those two aspects. Great, that you were able to introduce the concept in a simple way, so people here can get a better understanding of vibrations in audio. Cheers!

 

[PeterA]

Ralph, Thank you for starting this thread. It is an interesting topic. Could you tell us more about the rest of your turntable?

 

[RalfAM]

Ralph, Thank you for starting this thread. It is an interesting topic. Could you tell us more about the rest of your turntable?

Sorry that my answer comes so late. Attached you will find a file showing the most important innovations on the M1 turntable. The text in the attachment is in German. Please pay attention to the drawing. Here is the translation of the text for you:

Platter:
The parts of the turntable are screwed with a certain tightening torque.
By this solution the stiffness and at the same time the internal damping of the platter can be increased to a maximum.
This results in a significant reduction of spurious vibrations.
Therefore, the turntable of the M1 has the most neutral sound possible.

Platter bearing
The platter bearing has all the advantages of an inverted bearing.
However, our innovative design avoids the disadvantage of an inverted bearing. The oil does not run out of the bearing.
In addition, we have provided the bearing with a non-contact seal.
This measure and materials such as high-performance ceramics and graphite ensure a long service life.

Record weight Ars M1
We developed the record weight together with the University of Bayreuth.
The invention is a new method for vibration damping.
We are the first to use very fine powder for vibration damping.
Due to the friction between the many particles, a great deal of vibration energy is rendered harmless.
The use of tungsten powder increases this effect to the maximum possible.