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Record mats, VTA, clamps and my ears

Hi-
I've got a Thorens TD 316 with ClearAudio Arum Beta+. I've been experimenting with the original mat, a slightly thicker Audioquest Sorbothane mat, and a thinner Ringmat. I have dutifully ignored reading too much about VTA because my 'table doesn't support adjusting VTA.

The Sorbothane sounds better than the stock. Highs are the same, but the bass is less muddy. The Ringmat has a similar improvement in the bass, but there is more high end air. There is also very slightly more high frequency tics. But the problem is that some recordings sound thin. Airy, sure. But thin.

The turntable was set up using the original mat by a respected area tech. Not the very best high end guy--I would have been out another $200 had I used him. (The joys of the big city). Still, I'm confident my tech did a creditable job.

So I'm wondering how much of the differences I'm hearing are due to the change in angle of the stylus in the groove due to the different mat heights, and how much is due to the quality of the interaction between the 'table and the mat.
Are my findings consistent with advanced stylus angle theory? Should I have been paying attention in class when Sam T. told us everything I should already know?

Also, being The CheapSkate, I have a "The Original Pod Disclamp." Got it for twenny bucks on eBay. Anybody ever heard of this animal? Alas, I have questions. The Pod Disclamp worked best with the original mat insofar as the original mat is the stiffest. This is important as there is a depression around the spindle, so it physically possible to push the center of the record near the spindle down far enough so that the perimeter of the record raises up. No matter--even with the needle going up and down, things SOUND better that way! Arrgh! What does this mean? Must I now pay $2000 for a Final Tool just so I can own a 'table that follows the basic laws of physics?

Anyway, I try to apply just enough clamping force so the record is somewhat damped, yet not contorted.

The clamps effectiveness is reduced with the corresponding lack of stiffness of the mat. At least that's what my wife keeps telling me. So the clamp works best with the original mat, second best with the Audioquest Sorbothane, and third best (but still an improvement) with the Ringmat.

Hopefully, my confusion hasn't dulled your enthusiasm over providing me with my much lacked and sorely needed guidance.

I remain--

The Cheapskate
brtritch
sean
6,229 posts
 
No problem Dave. I'm glad that you found something that worked for you and gave you the results that you were looking for. I had tried the Ringmat on one of my previous tables with a pivoted arm and did not like the results. As such, i have never given them second thoughts and had moved on.

Is it possible that the added mass of the clamp that you were using or the manner in which the clamp was applied could have contributed a negative aspect to the TT being used ? I have never used a VPI but have seen the internals of one courtesy of United Package Smashers ( UPS ). To me, the table was of lighter construction and lacking mass, therefore making it more susceptible to both air-borne and floor-borne vibration. On top of this, the suspsension did not appear well suited to adding much additional mass to the platter. If the springs were already soft / and or not properly adjusted and you added additional mass to the platter, you might have increased the coupling from the TT chassis to the platter. If that were the case, going to a lower mass platter mat and removing the clamp might make all the difference in the world. Keep in mind that i am not critiquing your choice in gear or how it was set up, only commenting on the possible reasons why we might have observed such different results.

Obviously, others may have different points of view and experiences and i'd be glad to hear from them also. Sean
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dopogue
1,767 posts
 
No, the VPI TNT is a very heavy TT (the platter alone must weigh 10 lbs) and is not "supposed " to benefit from a Ringmat. That's why I was so surprised.
sean
6,229 posts
 
Dave, i can see what you mean about these tables being pretty heavy. Thanks for helping me to realize that. I checked things out at Audio Advisor after reading your post and all of the VPI's there appear to be pretty stout. I'll have to ask my friend what model VPI it was that UPS obliterated. Sean
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bob_bundus
1,834 posts
 
VPI's platters at the upper end of the product line are at least 20 pounds or more (acrylic / lead / cork combo) & yes I've been told that they are reported to work best with the record very closely coupled to the platter. Mine (a MK4 with a TNT bearing & platter) is supposedly that way. I'm not going to claim firsthand experience here, but the guy that I bought it from has. He had experimented extensively with mats & clamps, ending up with a paper thin "analog survival kit" mat & the Black Diamond clamp. Not wanting to 'reinvent the wheel' I've never tried anything else, but after the above read-through I'm tempted to begin experimenting all over again. Not that I'm unhappy with the rig as-is, in fact quite the contrary. Sometimes, ignorance really is bliss.
viridian's avatar
viridian
4,184 posts
 
Do not ever use The Pod disc clamp. It requires you to put downward pressure onto the spindle and can damage the main bearing. The three feet can also cause a degree of deformation of the vinyl, but this is less severe than the former problem. Modern clamps such as the SOTA, Michell, etc. avoid both of these problems in various ways. Don't cheap out when your precious vinyl and turntable are at stake! The real theoretical advantage of using the Ringmat is that bearing noise and platter/plinth borne vibrations are not easily transferred to the disc itself. The drawbacks have already been mentioned.
Marty
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