Vintage DD turntables. Are we living dangerously?

Lew, re: metal mats

Some time ago I believe it was Raul who recommended the Audio Technica AT666.  That is a metal mat with vacuum hold down.  His preference was simply as an added mat, ignoring the vacuum.  I looked that up and it weighs 1.4 kg, still pretty heavy but within the range listed in the SP-10 MK 2 manual.

lewm
03-14-2016 5:54pm
2.7 kg!!!!!! (...) Perhaps Peter and JP can chime in on this subject.

If you go to a show where Pass Labs have their source setup, you'll likely see a MKII with an ~8kg stainless steel platter.  My understanding is their 'tables have been setup this way for years without issue.  Stainless platters for the MKII show up on Yahoo every once in a while.

I had one (a platter) here for a bit on one of my MKII.  Takes a little longer to start and stop, but I didn't notice any ill effects.  I didn't measure any circuit parameters while running it - having a MK3, it was doubtful I'd even keep a MKII around.  W&F was about the same as the stock platter.

You'll see stainless platters show up on Yahoo every once in a while.  

I'd monitor the thrust pad a bit more often.  

I have run a micro seiki CU mat on my MK2 for months - to me it sounds much better that way.  I would state that the bearing in the MK2 can easily handle this load, its a thrust plate and a ball bearing.

Below is a seller on eBay that sells replica of it weighing in at 3KG!!!!!

http://www.ebay.com/itm/MICRO-SEIKI-COPPER-MAT-CU-500-REPLICA-WORLD-BEST-LOOKS-FANTASTIC-BRAND-NEW-/...

And a thinner one weighing in at "only"1.86kg

http://www.ebay.com/itm/MICRO-SEIKI-COPPER-MAT-CU-180-REPLICA-WORLD-BEST-LOOKS-FANTASTIC-BRAND-NEW-S...


Good Listening


Peter

@lewm cu-500 on my sp10mk2 only improved the sound quality to another level of performance. One of the best upgrade i have ever made. 

Ok. If you guys sanction the use of platter mats that are way heavier than the original mat, some even as heavy as the platter upon which they sit, I must be off base. I was given to believe from reading on this subject that the servo action was tuned to the rotational mass of the "platter", which must of course include the mat. As an aside, it is gratifying to know that Nelson Pass is into vintage DD turntables enough to use one at an audio show.

For clarification, when you say that Pass uses an 8kg stainless steel platter, do you mean that he puts an 8kg ss mat on top of an 8.8-lb platter on an SP10 Mk2? (Because 8.8 lbs is the weight of a Mk2 platter, IIRC.) So, here you’re going from probably around 10 lbs total (accounting for the weight of the OEM platter + OEM rubber mat) to a total weight of more than 28 lbs (OEM platter + 19.4-lb ss mat). Is that what you meant, JP? I think at that point what must happen is that rotational inertia takes the place of servo action much of the time.

This has nothing to do with wearing out the bearing, by the way. I am wondering how it affects the servo.

By the way, I have no doubt that metal mats can sound great; I just think that the Boston Audio Mat2 sounded more neutral than any metal mat I have tried, albeit none of them weighed 19 lbs.

And finally, here I am talking about a TT101.  Someone said he tried a heavy metal mat on his TT101 and was not enthused.  Has anyone else got an opinion?  I think Halcro has a copper mat on his TT101. One potential advantage of the copper mat on TT101 is that it would act as a shield to block EMI coming up from the motor.  I made a shield for my L07D out of TI Shield placed under the platter "sheet" (as Kenwood calls the stainless steel mat), and it seemed to remove a coloration that was not noticeable until it was expunged. Lots of L07D owners do something like that. The coreless motor stator and rotor in both the L07D and the TT101 are oriented such that there would be a possible field projected upward toward the platter surface.  Does this make sense, JP?