I would worry more if a air hose breaks or pops of.
If power goes, propulsions from the motor will stop too, and the platter lowers itself gradually.
The American Sound Turntable- Beyond's Minimalist!
- Thread starter ddk
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If power goes, propulsions from the motor will stop too, and the platter lowers itself gradually.This is what made me nervous about my TechDAS and CSPort. There can be damage if you lose power. I believe both mfg state that in the manuals. Somehow I live in a city rated in the top places to live with the highest % of educated people yet the power is highly unstable. With the Audio Tekne table it’s impossible to damage anything with air/power loss because there is no bearing at all.
When I was a level 27 Audiophile I wielded the Infinity Turntable, which spun forever at exactly the right speed by the force of my audiophile greatness!Audio is a combination of science and witchcraft , easy to see the warlocks from the wizards ..!
with the CS Port 'damage' is a relative thing.
yes; the platter will settle on the granite plinth surface with a power outage. could be a very slight marring of the surface as the spinning platter settles. but it would have to happen many, many dozens of times to effect the 'true' of either surface to effect performance. so the risk is much more operator error over a long period of time turning power off on the back instead of hitting 'stop' and then slowly slowing down the platter with your hand before you power down the air pressure........than power outages. as power outages are relatively rare and the table is not running all the time.
i get my share of power outages living in the mountains with extreme weather; but in 6 years now.........once......i shut the power off wrong, and have never had an outage when my CS Port was spinning. and i do leave the CS Port running for hours on my 'vinyl' days.
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"No bearing at all" is not correct, there will always be a film of air that suspends the platter, if that disappears the part being kept apart will touch, if this happens during rotation the parts can sustain damage, unless they are so hard they can't scratch. Alternatively a porous carbon air bearing will slowly stop rotating even from high rpms (thousands) if air flow gets interrupted, this type bearing requires a higher air pressure and very clean air. I am not sure if any TT manufacturers use this type bearing, they are costly, maybe Kuzma ?
I use a tool compressor, it is noisy as hell, but has a 50 liter expansion tank, i keep it in the attic i cannot hear it at all. It starts up every 40 minutes and runs for about 40 seconds to a pressure of 10 bar. If my power goes the platter will stop long before the air bearing has lost its pressure. This type of operation gives very little condensation of. I never see any traces of water on air arm or bearing. A few drops i empty from the expansion tank after many hour of operation.
There is no traditional type bearing. There is a structure under the platter that is ~10” wide with a flat top (basically an inverse of the platter). If you lose air it will gently lower onto this. This was one of my main concerns when buying and Imai said no damage can happen.
I spoke with the CSPort engineers directly and they were concerned that even the slightest marring of the granite would cause issues. They said there is a 5 micron accuracy to the top flatness which needs to be maintained.
The problem with air bearings is that if you make the emergency running surfaces too large, a dead air volume is created there. There is no air pressure there. This can cause the record platter to tip over and lose its centering. To make matters worse, incorrect belt tension on a heavy platter, for example, can make the problem even worse. We are talking about micrometers here, you can't see it with your eyes. The second problem is that the contact between the two surfaces (roughening) creates air turbulence, which increases the dead air volume. You don't hear it, but the life is shortened. If used correctly and with clean, oil-free air, they are long-lasting.
P.S
an air bearing is usually concave in shape where air escapes, a damage will rarely occur
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Yes , wanted something properly engineered…And then you settled for a DD Yamaha as you matured !
I am not really sure, but here is a guess: I imagine the platter drops 1/1000th of an inch, or some such tiny distance, and two completely flat surfaces would rub against each other very briefly until the platter stops spinning. It would be an abrupt instant. I do not think there would be any damage, but I am not absolutely certain.
If this air bearing collapse issue is real, I think two possible solutions would solve the problem of damage were there contact. Easiest is to have a very light, thin coating of lube on one or both surfaces that could make contact. An alternative would be to have a thin teflon ring between them. Maybe I’m missing something.
I am very interested in turntables with airbearings. While I am no engineer, as far as I understand there are two major types of airbearing used in turntables. The first one is what I called half or partial airbearing, with which the platter floats on a cushion of air in the vertical plane, but still having somewhat conventional bushings in the horizontal plane. Micro Seikis, and maybe the Airforce and CS Port models, employ this kind of arrangement.
The second one is what I called a full airbearing, with which there are air cushioning in both the vertical and horizontal planes. Turntables employed this kind of arrangement include the Versa Dynamics, Rockport Sirius II and III, Kuzma XL Air, and maybe others.
I am using an industrial compressor with a 25 litre surge tanks for my Rockport Sirius II. So, in case of a power outage, the air supply will not be interrupted.
I am also very interested to learn what kind of airbearing is used in the AS!
The second one is what I called a full airbearing, with which there are air cushioning in both the vertical and horizontal planes. Turntables employed this kind of arrangement include the Versa Dynamics, Rockport Sirius II and III, Kuzma XL Air, and maybe others.
I am using an industrial compressor with a 25 litre surge tanks for my Rockport Sirius II. So, in case of a power outage, the air supply will not be interrupted.
I am also very interested to learn what kind of airbearing is used in the AS!
I just confirmed with DDK. He says I am correct. Zero damage with power outage. Only outer edge of platter would come into contact with the base. Both are very flat and solid stainless steel. There is no contact anywhere near the bearing area. If the pump is turned off accidentally, there are safeguards in place. The pump remains on until platter stops spinning, them air supply stops and platter lowers onto base. He seems to have thought of scenarios.
That’s exactly what I thought the CSport should have. Some sort of recessed ring so it’s flush with the stone surface but a soft landing pad just in case. You wouldn’t even see it since the platter barely rises under air pressure.
... such a simple obvious solution that reflects the thoroughness of thinking that went into this design.
Not really possible, as the distance between the surfaces are so small, when a airbearing engages it does not lift the platter much. Oil or lubricant would blow of over time. A hard coating or hardening of the metal on potential rub surfaces is possible , but not on CSport i guess .
The ring would be flush with the plinth surface. Raising height would be no issue.
That makes no sense, to have any saving effect, the ring would have to be higher than the bearing surfaces, that are very close themselves, the platter has to rotate without touching the ring.
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