Vintage DD turntables. Are we living dangerously?

Agree and concur with numerous posters above, the Technics Sp10Mk2/Mk2A bearing structural architecture indeed can safely support the additional weight of a Micro Seiki CU-180 or the rarer CU-500 series Gunmetal Copper alloy platter mat provided the spindle's thrust pad is in good order, of course, thrust pads can also be changed and improved, if desired.  Clients have mentioned over the years rumors of Pass Labs using a Stainless Steel based replacement platter with reported success directly in place of factory Sp10Mk2 platters although I have yet to personally listen to one or actually examine one myself.  I believe it was roughly 2.5 - 3 years ago when we sat down and designed, prototyped then began to manufacture a suitable direct oem replacement Copper and Magnesium/Aluminum alloy based platter for the Technics Sp10Mk2/Mk2A models.  This is the same platter found on the AF Sp10Mk2 NG model.  If anyone is curious as to how it performs in comparison to a stock setup, please feel free to PM me directly for further insight.  As many are aware, the Sp10Mk2 design incorporates an electronic braking system, in addition to the mechanical brake belt facilities, which will tolerate the added weight of a heavy platter mat or higher mass replacement platter but the subsequent braking affect is slightly diminished in stock form.  When it comes to actual platter-to-record interfaces, naturally, each individual users system to a degree will react uniquely through difference playback characteristics, this applies when changing Sp10Mk2 platters entirely and/or platter mats and the reality is with all things high end audio related, no "one size fits all" solution exists.  This is the subjective and sometimes perplexing nature of the hobby and something I for one believe makes things all the more interesting in our niche world.   

Just for kicks, below are some additional weight specifications gathered over the years.

- Technics Sp10Mk2 Factory platter weight - 2.9kgs  = 6.4 Lbs.
- Technics Sp10Mk2 Factory Rubber Mat - .54kg = 1.2lbs
- Misc. Outer platter periphery rings - (Various manufacturers measured over the years) ranges - .5kgs - 1.4kgs / 1.1 lbs. - 3.2lbs. 
- Oyaide MJ-12 Aluminum record mat - .68 kg = 1.5lbs. 
- Artisan Fidelity Copper/Magnesium/Aluminum alloy replacement Technics Sp10Mk2/Mk2A platter - 5.4kgs = 12lbs. (designed to be used without a record mat)
- Record Clamps - too many to list - typically ranging from 6oz - 4lbs.+  

I'll have my MK3 back on the bench in a week or two, time permitting.  If someone wants to lend a heavy platter mat to the cause, I can perform some measurements to try and determine the impact to motor performance. 

My intuition says it's less about PLL alignment, and more about drive gain. 

Yep.  Drive gain. 

Ddriveman,

The DP80 is a very nice machine especially when retrofitted into a GrooveMaster plinth, which can easily be customized to accommodate two arms, it'll be a large machine especially if you want to use 2 ea.  12" arms.  Because of the size of the platter I'd recommend at least 10" arms, the DP6000 and the DP80 have larger platters than the DP3000 and DP2000, which is why I supply the DP6 and the DP8 with 10" arms and the DP3 and the DP2 with 9" arms.

As far as a comparison between the Technics SP10 Mk2 compared to the DP80 I would state they are about even as far as performance, the SP10MK3 is in a different league altogether.  Now if I could just get a hold of a DP100 :-)  

I did a full restore of the Denon DN308 a number of years ago - that was a fantastic machine but rather large, below a link to a picture of this machine. The motor for comparison is about the size of a gallon paint can. 

http://audiokarma.org/forums/index.php?threads/one-mother-of-a-turntable.180085/

This now resides with a fellow audiophile, kftool, whom has his system listed here on Audiogon. 

https://systems.audiogon.com/systems/723

Good Listening


Peter

When I owned "only" the SP10 Mk2A and the Denon DP80, both in very similar slate plinths, I gave a slight edge to the DP80 and eventually sold the Mk2A.  But I agree, the Mk3 surpasses both by a considerable margin.  Prior to applying the Krebs mod to my Mk3, I would have said that the L07D was slightly preferred, not that I could hear anything wrong with the Mk3. The two were just different flavors of goodness. The Krebs mod seems to make the Mk3 sound as fluid and open as the L07D with slightly more "drive" than the L07D.

JP, can you amplify on your cryptic comment about the effect of a heavy platter mat? "Drive gain"?  I was thinking last night that I wished I could modify my statement that a heavy mat might mess up the servo mechanism. Obviously it's also about the motor and its torque.  I thought that the original designers had to match platter inertia with torque and servo action, a triumvirate of factors.

Also, you guys, my concern about a heavy platter mat was not about bearing wear.  It was about the possible effect of a very heavy mat on speed accuracy and constancy. See above.  I'd give the CU-180 a try on the TT101, based on Halcro's comment, but pigskin too.