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

Showing 1 response by brtritch

Thank you all for your comments. It's so nice to find like minded individuals that write extremely graphically explicit technically confusing sentences that need to be read a half dozen times!

An interesting side note: I had been using a tweaked out Fisher 800C receiver (1960's top of the line, best all tube receiver ever made) until two days ago, when I subbed a CJ PV-5 tube Preamp into the system (still using the Fishers 32 RMS per amp section.)

The most profound differences were in gain and bass response, which in turn wrecked havoc with my turntable. I had had 2 five-pound lead weights on two corners of the chassis. They were a desirable tweak, until the newfound gain and bass response caused impending subwoofer meltdown. I’m sure most of you can imagine the cycle: a little rumble causes unwanted bass response, which causes vibrations, which in turn cause more rumble.

Removing the weights, I experimented with the three different mats and clamping and unclamping, adjusting to produce the loudest bass I could play without overload using B. B. King’s “You’re Mean” off the “Completely Well” album. The sorbothane mat with clamp won.

I experimented with cones up, down, rubber, and sorbothane hemispheres in various combinations on my Target turntable rack. The best combination occurred with a Vibrapod shaped piece of rubber (marketed to be used to mount machinery for vibration control) directly on the Target MDF, with a Black Diamond cone pointing upward on top of it, with the Thorens mounted on top of three of those rubber/cone doohickeys. I’m not done tweaking (could God build a system so good that even he couldn’t tweak it?), but at 106 dB I think the stabilization is mostly taken care of.

With regards to the writer that wrote that the Pod DisClamp should never be used, I’m a big guy—6-3—with big hands. The trick is to support the platter with the fingertips while using the thumbs to engage the clamp. A trip to the hardware store suggested by another writer produced an assortment of washers, including a very flat one just smaller than a record label that I glued some felt to that compensates very well for the otherwise relatively uneven downward force cause by the three prongs of the clamp.

The Cheapskate loved how the 69cent Vibrapod shaped piece of rubber outperformed the $60 Audioquest Sorbothane hemispheres, as well as the assortment of washers I got for 82 cents.

Keep those cards and letters coming,
The CheapSkate