Ddrive, I beg to differ with your premise: "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." This is a common misconception usually propagated by belt-drive enthusiasts. The motor is NOT directly connected to the spindle in a direct drive turntable; only the rotor part of the motor is coupled and usually to the platter, rather than to the spindle. The rotor per se is incapable of making any noise; it's just an inert magnet, usually, that is made to rotate by the action of the stationary stator via an alternating magnetic field. The issues with DD are mostly EMI emanating from the proximity of the totality of the motor. Otherwise, the only source of noise is the bearing, a problem with any and all types of turntables. Other than that, I will refrain from arguing here about turntable mats; what a can of worms!
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.
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.