I consider a turntable as one big resonant machine, it has resonances from everywhere, somewhere more resonance, and somewhere less.
It is from the combinations of different resonances that this or that sound signature of the player is formed and it is almost impossible for us to predict it, we can only theorize a little.
OK, you have two dimensions, can you tell which resonance you have better, the oboe sounds more natural
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It is from the combinations of different resonances that this or that sound signature of the player is formed and it is almost impossible for us to predict it, we can only theorize a little.
OK, you have two dimensions, can you tell which resonance you have better, the oboe sounds more natural
?I am not certain i understand the question fully but let's try this answer.I consider a turntable as one big resonant machine, it has resonances from everywhere, somewhere more resonance, and somewhere less.
It is from the combinations of different resonances that this or that sound signature of the player is formed and it is almost impossible for us to predict it, we can only theorize a little.
OK, you have two dimensions, can you tell which resonance you have better, the oboe sounds more natural
The whole assembly has resonances, vibrations etc etc, but our aim is to let the cartridge generate an output as accurate as possible to the recorded signal. If something is disturbing the cartridge it will disturb that to a greater or lesser extent.
For sure, adding any resonance with the replay equipment is not what we aim to do!
In terms of what I have measured, other people are better qualified to discern what causes things you can see on the plot, but for certain i have never experienced the occasion when the measurement looks better than before but the sound is worse, but I have experienced when the sound seems better but the measurement is worse, that tells me that something has been added to the recorded signal and it sounds pleasant but is not accurate to the record.
I find most often i hear a small part of some music which had previously been obscured, and then also the whole thing sounds more open etc, possibly also an oboe sounds more natural, but other times improvements are heard elsewhere. Everytime you can see it on the measurement.
An interesting arm, real fresh water thinking.
With an air bearing friction is virtually zero. The addition of a silicone damping trough adds resistance to carriage movement that increases with velocity. The faster the carriage moves the high the resistance.
With a purely mechanical bearing the resistance to movement will be constant regardless of carriage velocity and no additional damping is required. (ignoring stiction)
By floating the carriage in water the load on the bearings will be reduced which will reduce bearing friction. Water has a much lower viscosity than the silicone fluid used with an air bearing, typically several thousand times lower. The contact area between the paddle and silicone fluid is normally very small. The contact area between the float and the water will be much higher. The resistance to movement offered by the water is likely to be not that different from that of the silicone fluid. The exact amount will be dependant on the shape and surface texture of the float.
A point that Mike made that I would like to back up is regarding the use of PTFE for making the wheels. As the wheels are designed to roll and not slide on the rail the coefficient of friction between the wheels and rail is not important. What is important is the rolling resistance. PTFE, being very soft will have a very high rolling resistance. Making the wheels out of a very hard material such as stainless steel will dramatically reduce rolling resistance. Think of a push bike tyre that is pumped up really hard, it rolls more easily than a soft tyre. The hard tyre still has high friction with road but still rolls.
The increase in the mass of the wheels using steel compared to PTFE will be negligible when taking the entire mass of the carriage into account. A harder material should have better mechanical coupling as a bonus. I would recommend making the bearing yoke as a more rigid structure linking the armtube to the wheels with the float as a separate structure.
One question. How do you prevent mold growing in the water. If this grows on the rail and wheels it will coat them with a soft layer that will increase rolling resistance.
Niffy
With an air bearing friction is virtually zero. The addition of a silicone damping trough adds resistance to carriage movement that increases with velocity. The faster the carriage moves the high the resistance.
With a purely mechanical bearing the resistance to movement will be constant regardless of carriage velocity and no additional damping is required. (ignoring stiction)
By floating the carriage in water the load on the bearings will be reduced which will reduce bearing friction. Water has a much lower viscosity than the silicone fluid used with an air bearing, typically several thousand times lower. The contact area between the paddle and silicone fluid is normally very small. The contact area between the float and the water will be much higher. The resistance to movement offered by the water is likely to be not that different from that of the silicone fluid. The exact amount will be dependant on the shape and surface texture of the float.
A point that Mike made that I would like to back up is regarding the use of PTFE for making the wheels. As the wheels are designed to roll and not slide on the rail the coefficient of friction between the wheels and rail is not important. What is important is the rolling resistance. PTFE, being very soft will have a very high rolling resistance. Making the wheels out of a very hard material such as stainless steel will dramatically reduce rolling resistance. Think of a push bike tyre that is pumped up really hard, it rolls more easily than a soft tyre. The hard tyre still has high friction with road but still rolls.
The increase in the mass of the wheels using steel compared to PTFE will be negligible when taking the entire mass of the carriage into account. A harder material should have better mechanical coupling as a bonus. I would recommend making the bearing yoke as a more rigid structure linking the armtube to the wheels with the float as a separate structure.
One question. How do you prevent mold growing in the water. If this grows on the rail and wheels it will coat them with a soft layer that will increase rolling resistance.
Niffy
Since a vinyl player is a resonant machine, it is clear that it will be as you described - with one pronounced resonance, one instrument or group of instruments will sound better, and with another pronounced resonance ...
But in any case, everything will look like - put the head on - the tail fell, put the tail on - the head fell.
It goes without saying that the tonearm should not go beyond some given framework in its construction, namely mechanical construction, as well as in the choice of materials and their own resonances.
And everything that is smaller is the games of little boys, one likes one thing, and another another.
For example, I already fell out of love with the air tonearm, but I fell in love with the aqua tonearm and found it the best at the moment. The music plays with it right now when I write the message. It plays lively, freshly and accurately.
PTFE wheels have a very small load in order to push through like a tire on a bicycle, so this comparison is completely incomparable.
They roll on glass in exactly the same way as steel, but the sliding material of the PTFE allows you to slide very well on the stainless steel axles.
Also, fluoroplastic does not oxidize and does not rust in water, nothing happens to it at all. The same tonearm worked for me for about a year, that was 9 years ago.
The room is very dry, but I still thought about a couple of silver coins in the water for my aqua tonearm. Well, in order to avoid mold, although ... I think I'm more likely to get moldy than the water in the aquarium.
Off in a different direction now Havun!! if you configured the carriage like an air bearing but instead immersed it in a bath like your aqua and pumped incompressible water (a fish tank pump?) would you get the best of both types?
M
Maybe I didn’t quite understand the Google translation, but it seemed to me that it was better for you to do the experiment with fountain water on the tonearm
.Google translate has a lot to answer for!Maybe I didn’t quite understand the Google translation, but it seemed to me that it was better for you to do the experiment with fountain water on the tonearm
I believe incompressible liquids have some benefits. i expect that is what you have found with your aqua.
The configuration of the air bearing is appealing in that one apparatus resolves the requirements of lateral movement and all other location. The only problem being the compressible nature of the air.
If you had the same arrangement as an air bearing but it was an aqua bearing i feel you would get a good result.
M
Interesting Havun, i wonder what major events have been created by misunderstandings from Google translate!?
Please try to imagine the air bearing but instead of pumping air it pumps water and to avoid everything getting wet the bearing sits in a bath.
I don't think air acts as a spring inside the air bearing. For my style of the air-bearing arm, the air-bearing can load 42 lbs. Such air bearings have been used in precision machinery. If the air acts as a spring, it will not maintain the accuracy of the machinery. The air inside the air bearing can't and won't act as a spring at all.
Another objection to air-bearing arms is that the air-bearing arms are not grounded mechanically. The air bearing has no mechanical contact with its base, but it doesn't mean it can't dampen the vibrations from the cartridge. The air film inside the air bearing can act as effective damping. I have no proof that why my air bearing is so dark in the background. But I believe it has something to do with the air film.
Great to see some healthy and interesting debate again here!
I think it's all a question of degree. I feel sure (although always open to persuasion or better knowledge) that in comparison to something solid the air acts as a spring. The question may be whether this matters or not?
Mechanical grounding, likewise, if you have great performance with that arrangement then something is obviously working well! - even without mechanical grounding.
My experience has led me to believe that damping is best applied only as far away from the stylus as possible, down in whatever the base of the plinth is, elsewhere I find it often leads to quiet backgrounds but is coupled with dull and lifeless in the arrangement I have, stiffness has always been better in my experience to limit vibrations in the parts close to the stylus, small and light components there are a benefit as well.
This would only be necessary if the pulling force of the 2 gram vinyl groove would be greater than the mass of the tonearm resting on the flat float and would overturn the float.
But this is fortunately not the case, so the float lies on the surface of the water and does not even think about changing its location.
I think this is a legit argument. However, I am still not convinced yet. Further investigation is needed.
Here is a diagram to illustrate my viewpoint when I said that the accuracy of the wheels and the wall of the water container is problematic. From the diagram, you can see there is a gap between the wall of the water container and the wheels. Once the record moves, as in your video, the eccentricity of the record will pull or push the arm sideways. It will cause tracking errors. There is also a dilemma. If the gap is too small or nonexistent, the effects of record eccentricity will put all the effects on the cantilever. The cantilever will be bent unless there is very small friction between the wall and the wheels. If the gap is too large, it will produce large tracking errors.Knife wheels have a very small area of contact with the ideal glass surface, they are also attached to thin stainless steel axles, in the working position they are moistened with water, so they work out the eccentricity fabulously, it's nice just to look at it (I'll shoot a video
I am not convinced either. Further investigation is needed, too.
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