2. analog
  3. 126170-7436

Best platter mat, especially for DD turntables

There has been quite a bit of posts about platter mats and I wanted to add my experiences. I have posted this on the vintage DD thread but have been requested to move this into a new discussion, so here it is.

For my Technics SP10mk3 (Krebs 2 mod), I have tried Boston Mat 1, Micro Seiki CU180 and the TTM Mat with Matching Oil filled clamp (http://www.usaudiomart.com/details/649203862-ttm-mat-2-and-oil-damped-stabilizerweight-combo/). Among these 3 mats, the TTM was the best and after I introduced it to Albert Porter, he too thinks it's the best for the Sp10mk3. However, I have found an even better platter mat that I would like to share with the group. It's Acoustical Systems SDP (http://www.arche-headshell.de/accessoires/sdp-the-sonically-most-effective-upgrade-for-every-turntable/). SDP stands for Special Decoupled Platter. This is not just a mat but an additional platter that decouples and isolates the bearing and spindle from the stylus. While most mats offer some isolation and decoupling of the platter, this is the only mat I know that also decouples the spindle. It stands head and shoulders above all the other mats. In fact, for me, the improvement it brought to my SP10Mk3 was greater than the Kreb mods. It's expensive and requires the arm-boards to be raised but it's worth the trouble IMHO. Especially for DD turntables where you have  the motor directly connected to the spindle (in most designs though there a few that are decoupled), it makes sense to decouple not only the platter but the spindle from the LP. Hence, SDP probably makes more improvements for DD turntables than Belt drive turntables. 
Here is how the SDP is different from other mats. What is not obvious form the pictures is that the SDP mat is thicker than the original spindle height. Hence it sits over the original spindle completely and has its own precision spindle to guide the LP and clamp/s onto the SDP. In other words, the original spindle is buried inside the SDP. Underneath the SDP are soft vibration absorbing gel packs which interfaces between original platter and SDP. This allows the SDP to absorb vibrations from the original platter. The mass of the SDP also acts as a damper for any vibrations from the original spindle. 

The net effect is that the noise floor drops further and I can hear more detail, resolution, separation and space. Very startling improvements.  FWIW. 
ddriveman
ddriveman OP
129 posts
 
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?
Ag insider logo xs@2x
rauliruegas
9,123 posts
 
Dear @halcro : I agree on your post to inna other than that " fine tunning " refereing to that acrylic " mat " that in reality is not a mat but a TT platter that's way diferent because a mat is a way of system fine tunning but a TT platter is a  change in the design.

Regards and enjoy the music,
R.


Ag insider logo xs@2x
rauliruegas
9,123 posts
 
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: rauliruegas@hotmail.com

Regards and enjoy the music,
R.
lewm
6,770 posts
 
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.
ddriveman OP
129 posts
 
Hi lewm,

I see our point (I think).
The DD motor generates motion via magnetic force and hence there is no mechanical contact (although one can argue that the force generated by magnetic field in a way provides "stiffness" between rotor an stator and may still transmit some vibrations, but certainly much less than physical contact).
But in belt drives, there is physical mechanical contact and you actually need friction between pulley/belt and belt/platter and that is a bigger source/risk of vibrations being transmitted!! Am I correct?
I guess I was still touting the typical thoughts of belt vs DD in my earlier post. The British audio press via Linn Sondek did "pollute" our minds about belt drives and shape so much of the vinyl world that we know today.
And no worries about hassling me, especially if you're polite about it, which you are. It's the great part and fun of audio forums and learning.
More to discover