Thoughts On Turntable Clamps And Weights

I had the local machine shop make a weight for me out of a scrap piece of round bar brass, it weighed around 300 grams, and another out of a new hockey puck, he made it perfectly round and center drilled, both with the same old slip mat remains glued to the bottom. I still have them, but now use the Pro-ject Clamp It when I feel the need, seldom with the beefy 50's 60's, and some 70's mostly mono records I now favor. When I use a weight, or the clamp, it's mostly for those thin flexi thin discs to give them a little body. Warped discs get replaced unless there's a special value. The Clamp It fits all my turn tables (one dedicated stereo, one mono for each system), some better than others. I don't use them for every disc (my ritual is long enough as is) and I haven't noticed any unusual wear during servicing. Nice to have around, but when I'm upstairs the clamp is down....

You don’t need a threaded spindle to use a clamp. The well regarded SOTA clamp is a simple reflex clamp that clamps the spindle and pulls itself against the label as you flip the clamping lever.  It’s been around for decades. I’ve use it with 5 different TTs, none of which have a threaded spindle.

I thought we were talking about the sonic benefits of weights or clamps, not their use to flatten warps. That’s an entirely different subject.

Using a clamp seems to stifle a lively sounding recording.  I know not everyone will be in my corner on this, but I prefer the livelier unclamped sound. I don't use mine anymore.

Not all weights and clamps are created equal. The contact surface with the record also matters.

As the stylus moves in the groove, it causes the record to vibrate slightly. This is enough to cause detectable distortion. Therefore this vibration should be sunk into the platter and the weight. Unfortunately, all materials reflect that vibration to some extent.

The factor that determines reflection or absorption of vibration is the speed of sound in mating materials. If the SoS is close, transmission is high, if dissimilar then transmission is low. Two materials which are very close to, or within, the range of SoS of vinyl records, are graphite and Delrin. So an interface of these is best.

I use one of each.

I should also note that an intimate contact of iron (steel) and graphite or Delrin renders the pair dead to vibration. Other metals, I don't know..