Oh sure air can impose its own sound - air transmits sound, to begin with; but ddk should try the Herzan at least. I just don't believe there is a "perfect" system.
One Amigo Visits Utah To Hear 5 Reference Turntables-My Step Beyond
- Thread starter Steve williams
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I'll let David comment but we did talk a good deal about the Herzan and similar devices. David makes no bones about it that the sound must be "natural" and he feels that a lot of ambience in the record is removed thus taking away from the "natural" sound he seeks. Perhaps it might work for the American Sound but I know he wasn't keen on putting one under his TechDas. Hopefully he will comment about this
That is interesting. I am very curious about David's thoughts of putting an active isolation platform like the Herzan under the TechDas.
The American Sound TT at 550 lbs or something may be too heavy for such a platform.
I do find it interesting that most of David's tables are belt drive. I think the EMT tables are idler and there do not seem to be any direct drive turntables. David, what method do you use to verify the accuracy of the speed on your tables?
Quite to the contrary...greater ambient space and clearer resolution is achieved using the Herzan under the AF1...sounds more real, natural. The good thing about Herzan, it's a no risk proposition. They will send out a demo unit. If you don't like the results you pay for shipping. A $12,000 investment is well worth it on a system of that level. The only issue I see is fitting the af1 on the TS-140 isolation table. You must have the TechDAS HRS platform under the TT as it has recessed feet that will fit of the TS-140. The AF1 is too wide to fit on the table by itself. Here is another option....that would not require the HRS...The AVI series. They even have models that support over 1000lbs...perfect the the American Rock of Gibraltar table...
http://www.herzan.com/products/active-vibration-control/avi-series.html
you'll have to discuss it with David as I have no opinion one way or the other but he did comment about the loss of ambient sound under a Herzan
Thanks Christian. I just looked up that link. I wonder if anyone has tried those 400 models under an entire rack full of components. I'm just speculating, but I can see how draining internal vibrations out of the components into a solid rack using spikes or Stillpoints and then isolating the rack from floor-borne vibrations by placing in on one of these devices. The only issue then is air-borne vibrations hitting the components and rack from the air waves launched from the speakers. Placing the rack on these isolators in an adjacent room could be the ultimate solution.
the EMT is an idler. I think David uses a strobe s well as a regenerator. He has found the exact voltage that maintains the correct table speed and has the regenerator set for those voltages for each table
Basic mechanical engineering - air bearings are very stiff, therefore they will transmit high frq noise (vibration) right through them. Although cool in concept, they are really not ideal for turntable/arm bearing. That is why the other tables David have sounds better than the new AFO table (not because they are old).
That also explain why you would want to have a very good isolating platform under that table, if you must have it.
That also explain why you would want to have a very good isolating platform under that table, if you must have it.
What do you mean ? since airbearingtables are suspended tables , with an airpocket between the platter and the spindle iirc?
Micronozzle
The advantages of the micro-nozzle air bearing technology include:
efficient use of the air cushion (close to the physical limit) through a uniform pressure within the whole gap;
perfect combination of static and dynamic properties;
highest-possible flexibility of the air bearing properties: with a particular gap height, it is possible to optimize the air bearing such that it has, for example, a maximum load, stiffness, tilt stiffness, damping, or a minimum air consumption (respectively also in combination with others);
multi-approved highest precision of all air bearings, e.g. in the measurement technology due to slightest movements (<< 2 nanometer) through physical, lowest-possible self-excited vibrations;
considerably higher tilt stiffness than conventional air bearings such that the air within the gap flows through canals from the loaded to the unloaded areas away;
vibration-free within the entire operating range even with high air pressure supply (actually even much more than 10 bar are possible);
highest reliability due to the large number of nozzles: clogging of nozzles by particles is out of question (no failure in operation) because their diameters are much higher than the gap height;
possibility to adjust bearing properties for deformation and tolerances of the bearing and opposite surface;
proven usability for many bearing
Conventional airbearings
With conventional single nozzle air bearings, the compressed air flows through a few relatively large nozzles (diameter 0.1 – 0.5 mm) into the bearing gap. The air consumption thus allows only some flexibility such that the bearing’s features (force, moments, bearing surface, bearing gap height, damping) can be adjusted only insufficiently. However, in order to allow a uniform air pressure even with only some nozzles, air bearing manufacturers take constructive techniques. In doing so, these air bearings cause dead volumes (non-compressible and thus weak air volume). In effect, this dead volume is very harmful for the air bearing’s dynamic and causes self-excited vibrations.[
Micronozzle
The advantages of the micro-nozzle air bearing technology include:
efficient use of the air cushion (close to the physical limit) through a uniform pressure within the whole gap;
perfect combination of static and dynamic properties;
highest-possible flexibility of the air bearing properties: with a particular gap height, it is possible to optimize the air bearing such that it has, for example, a maximum load, stiffness, tilt stiffness, damping, or a minimum air consumption (respectively also in combination with others);
multi-approved highest precision of all air bearings, e.g. in the measurement technology due to slightest movements (<< 2 nanometer) through physical, lowest-possible self-excited vibrations;
considerably higher tilt stiffness than conventional air bearings such that the air within the gap flows through canals from the loaded to the unloaded areas away;
vibration-free within the entire operating range even with high air pressure supply (actually even much more than 10 bar are possible);
highest reliability due to the large number of nozzles: clogging of nozzles by particles is out of question (no failure in operation) because their diameters are much higher than the gap height;
possibility to adjust bearing properties for deformation and tolerances of the bearing and opposite surface;
proven usability for many bearing
Conventional airbearings
With conventional single nozzle air bearings, the compressed air flows through a few relatively large nozzles (diameter 0.1 – 0.5 mm) into the bearing gap. The air consumption thus allows only some flexibility such that the bearing’s features (force, moments, bearing surface, bearing gap height, damping) can be adjusted only insufficiently. However, in order to allow a uniform air pressure even with only some nozzles, air bearing manufacturers take constructive techniques. In doing so, these air bearings cause dead volumes (non-compressible and thus weak air volume). In effect, this dead volume is very harmful for the air bearing’s dynamic and causes self-excited vibrations.[
A volume of air trapped in a volume creates an elastic system. In the case of air bearing systems, the air flow can create turbulence - the preassure should be optimized. Also sometimes bearings must have a critical drag for best sound, its not only a minimization affair.
Although active platforms are excellent isolators, they also preclude energy flow from the turntable to ground. It is why there are no definitive rules and we need our ears.
TechDas, Micro Seiki and AS aren't air bearings, they have high mass platters that float on a very small volume of air, no negative sonic effects that I can audibly detect and no bearings to consider. An air bearing is a different thing altogether, the only one I know with one is the Continuum table. Anyway conjecture about the advantages and disadvantages of different bearings is totally moot as the designers already identified the best type for their application. As they say the proof is in the pudding and they've all fulfilled their promise using various technologies.
Air Suspension, active & passive- I'm a firm believer of mass coupling and resonance control, preferably together. These are high mass, suspension less tables so YMMV with other types. My platform of choice is Kinetic Systems lab tables with their steel tops, very heavy, very solid and their steel tops have great control over resonance. I did a lot of experiments using the air isolation of these tables and came away not liking it. Air has a voice and you can hear it, can be pleasant but its also a coloration. What I heard was that not enough air in the foundation resulted in a muddy sound, adding enough air to bring back or enhance the focus, changed the character of the sound. The low bass became too tight, unnatural imo, in the context of these particular tables! There was also a halo, additional body if you want in the upper bass and low mid sections. Depending on the tt, system, the type of music you listen to and personal preferences all this might be a positive too, but not for me. I prefer a more natural sound allowing for the differences among instruments, music and the artists to come through rather than an ideal one. The other issue with air is that even with active setups the sound will change as you lose and add air. Passive ones are even worse because they required diligence and never ending manual maintenance.
Active Electronic Suspension- I haven't been convinced to try them for several reasons, including their low mass. Reading their materials these products were designed to isolate a static machine from floor born vibrations, i.e., bottom up, by wiggling around. In this case, the tt isn't a static object and its the source of continuos vibration, now this platform has to adapt to vibration coming from top which it wasn't designed for, and that coming from the floor. I respect the view point of those who like them, it all depends on what they used prior to their the active platforms and if they actually went back & forth a couple of times before settling on it. I know from experience that given the hassle of setup and inconvenience of mass the back & forth part isn't easy with these turntables, so I wonder… Even if it improved performance it can't change the basic nature of the table, like no amount of tuning will ever turn a Porsche into a Ferrari. Personally, I find placing a light weight wiggly platform under a high mass table, specially one dependent on high inertia counter intuitive.
david
Air Suspension, active & passive- I'm a firm believer of mass coupling and resonance control, preferably together. These are high mass, suspension less tables so YMMV with other types. My platform of choice is Kinetic Systems lab tables with their steel tops, very heavy, very solid and their steel tops have great control over resonance. I did a lot of experiments using the air isolation of these tables and came away not liking it. Air has a voice and you can hear it, can be pleasant but its also a coloration. What I heard was that not enough air in the foundation resulted in a muddy sound, adding enough air to bring back or enhance the focus, changed the character of the sound. The low bass became too tight, unnatural imo, in the context of these particular tables! There was also a halo, additional body if you want in the upper bass and low mid sections. Depending on the tt, system, the type of music you listen to and personal preferences all this might be a positive too, but not for me. I prefer a more natural sound allowing for the differences among instruments, music and the artists to come through rather than an ideal one. The other issue with air is that even with active setups the sound will change as you lose and add air. Passive ones are even worse because they required diligence and never ending manual maintenance.
Active Electronic Suspension- I haven't been convinced to try them for several reasons, including their low mass. Reading their materials these products were designed to isolate a static machine from floor born vibrations, i.e., bottom up, by wiggling around. In this case, the tt isn't a static object and its the source of continuos vibration, now this platform has to adapt to vibration coming from top which it wasn't designed for, and that coming from the floor. I respect the view point of those who like them, it all depends on what they used prior to their the active platforms and if they actually went back & forth a couple of times before settling on it. I know from experience that given the hassle of setup and inconvenience of mass the back & forth part isn't easy with these turntables, so I wonder… Even if it improved performance it can't change the basic nature of the table, like no amount of tuning will ever turn a Porsche into a Ferrari. Personally, I find placing a light weight wiggly platform under a high mass table, specially one dependent on high inertia counter intuitive.
david
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Steve, I'm just curious. From the pictures you showed it seems that the AS table and the AF1 had different cartridges on them. (The AS had and EMT plus something else, while I could not identify the cartridge on the AF1). So when you made the comparison, was the turntable the only variable? Seems like if that was not the case, a true comparison was not made. ( I am also assuming the wiring was identical.)
Marty,
Both cartridges are Neumanns of the same vintage and both verified NOS when purchased, the difference is only in the color of the shell but otherwise sonically they're near identical. The arms are also the same modified SME 3012-R with exactly the same tonearm cable. There are big differences among all these tables, hence the desire to keep them all. They're a real bitch but when setup right I find the Neumann cartridge operating on a level apart from anything else I ever heard. The difference in sq between these tables won't be as pronounced using other cartridges, but its still there, and known; only Steve heard them at their most extreme...
david
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Marty
I asked the same question when we were going to a/b the AF1 and the AS as I wanted to be certain that the cartridges were the same. It is an easy comparison. A good as the AF1 is the AS to my ears had more meat around the bone and at that time David was using the stainless steel platter on the AF1
I asked the same question when we were going to a/b the AF1 and the AS as I wanted to be certain that the cartridges were the same. It is an easy comparison. A good as the AF1 is the AS to my ears had more meat around the bone and at that time David was using the stainless steel platter on the AF1
The EMT cartridges are only on the EMT 927 turntable. At the time, AF-1 had/has an Ortofon MC-20 Super with associated SUT for daily listening and Neumann for VIPs like Steve! Neumann on the AS is also reserved for very special occasions. For now daily listening is with a vintage Ortofon ST-15 and associated SUT. Decca FFSS mono or stereo cartridges on the 3rd arm and various mono or stereo Ortofon SPU cartridges on the 4th arm, but they'll get swapped out again in due coarse.
david
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