Dear @lewm : You are right but marketing for the sellers is the name of their " game ". Always exist misinformation, everywhere.
Regards and enjoy the music,
R.
Regards and enjoy the music,
R.
Best platter mat, especially for DD turntables
Hi lewm, Thank you for your clarification on the DD motor to spindle connection. You are correct that the rotor is just the magnet and is part of the motor only and by itself is inert. In fact for the SP10MK3 (and only the MK3, the MK2 is different), the magnet rotor is huge and around the outside of the coil stator and connects to the platter directly. So, in the case of the SP10MK3, there is no part of the motor that attaches to the spindle and in this respect, resembles a belt drive. However, for most other DDs (including the SP10mk2), the magnet rotor connects to the spindle directly. And while the rotor itself is inert, force is applied to the rotor and hence spindle in order to create motion. This is unlike belt drives and the SP10, whereby force is applied to the platter in order to create motion. And the argument here (commonly made by belt drive aficionados) is that the platter has a higher mass than the spindle and provides more damping properties. But we're splitting hairs. Nevertheless, the whole point of the SDP and the Japanese wooden platters (from sampsa55's link) is to completely isolate both the platter and spindle bearing from the vinyl. And while the Japanese designs rely on mass and the damping properties of wood; SDP relies on its material, POM (which closely matches vinyl characteristics), mass and gel absorption packs between platter and SDP. But I'm now thinking that Acoustical Systems probably got the concept from Japanese, after seeing the links from sampsa55. For my SP10, I ordered the SDP height to just cover the original spindle because I do not need additional platter mass to help with speed stability (thanks to the wonderful speed stability of the SP10mk3) unlike belt drives. BTW, I'm not pitching for Acoustical Systems. I'm just a satisfied user and offering this solution to those who are seeking to go beyond the normal mat/clamp fine-tuning and try to address one area that affects both DD and belt drives which is spindle bearing vibrations. OTOH, I suppose air bearing spindles do not have mechanical contact and friction also. Hmm, maybe the SDP may be seeking to get the benefits of air bearing spindles in this respect? |
Dear @ddriveman : Look, maybe what happened with your AT666 is that in order those rubber rings can makes the LP hold down must be on certain " position " and with precise " stretch " characteristics. For do that AT surrounded the rubber rings ( at the midle of its mounting in the At platter. ) with a nylon thread that puts the eaxact pressure in the rubber for vaccum can happen. That nylon thread ( time to time. ) it brokes and with out it there is no vaccum so you need to build by your self that thread and put on place. Because that kind of behavior is more or less often what I did it with was instead of nylon I used a thing guitar metalic chord and wroks with out problem. This task must be do it with care because the metalic chord if we put so much tension around the rubber ring we can broke the rubber and then there is no way to fix it. In the other side, what you posted about the Goldmund is the same with the SOTA when you install it you can't take out again but you can use the SOTA/GOLDMUND mat in removable way: with out take away the protector in the bottom plate of those mats. Btw, good to know that the Essential is still " Essential " in your great audio system. If you can I appreciate that email me: [email protected] Regards and enjoy the music, R. |
Ddrive, I am sorry to hassle you, but you are incorrect in drawing any distinction between the SP10 Mk3 and the Mk2 (each of which I either own [Mk3] or have owned [Mk2]), when it comes to motor "noise". The distinction you make between the two in terms of how the rotor is mounted to the platter/spindle is correct, but you are drawing the wrong conclusion. Think about it. The rotor is NOT a source of mechanical noise, no matter what, because it is acted upon only by an alternating magnetic field. Whether torque ( or "force", as you put it) is thus applied to the platter or to the spindle does not make any difference. Further, in a belt drive turntable the belt itself is a way in which motor noise or vibration CAN in fact be transmitted to the rim of the platter. This is an issue germane to belt drive technology. In a way, you've got it backwards. If you think more about this, I predict you will come to see my point. |