Screw-down reflex clamps vs. record weights


Recently we have seen more and more 'record weights' on the market. These are normally lightweight(300-400gr)and simply sit on the record. They do not appear to give priority to bonding the record to the platter.
Two outstanding record weights of this type are the Kuzma Ebony Record Weight and the HiFi Tuning VRO ('vinyl resonance optimiser') - there is a review of this(for those who read German) at www.fairaudio.de.
It appears that these clamps, rather than channelling disc resonances away through the spindle and main bearing and/or optimising contact between the record and the platter surface, seek to absorb them directly (i.e. into the clamp itself).
The Kuzma Ebony is a particularly interesting case since it has been introduced by a company that supplies screw-down reflex clamps as standard on its high-end turntables.
My question is: has anybody had any experience of these clamps - probably 'vinyl resonance tuners' is a more appropriate term - on their turntables as replacements for screw-down reflex clamps? Clearly as a way of dealing with warped or dished records they will not be of much use, but it may be that they do a better job of damping the disc.
I would be particularly interested to hear of experiences involving SME turntables (whose platters incidentally are covered with a bonded layer of 'Isodamp' damping material).
Thanks,
Peter
pgtaylor
Perhaps the price of entry,for these "tuners" is prohibitive. I think I saw $700 for one of them which claimed to have Platinum as part of its makeup.
Peter, this may be too simplistic for the type of response you are looking for. Based upon years of playing vinyl and using both weights and screw-down clamps, here are my observations.

Weights - faster and easier to use. Main concern is for any affect of the added weight on the spindle bearing, depending on the mass of the weight.

Clamps - ability to adjust pressure when considered for flattening a warped or dished record. I've experienced times when over-tightening a clamp can cause the outer edge of the record to lift up, thus requiring a reduction in pressure.

I can't say I've heard sonic differences between these types of hold downs, so long as they result in appropriate pressure to produce full contact of the record with the mat.

As a practical matter, the profile of either type of hold down can endanger some cartridges when they are allowed to move to the end of the run-out groove. The screw down clamp with my Kuzma Stabi was designed to minimize this concern.
Screw-down clamps is an evidence of how fool hobbyists can go. To me It's not pleasant to screw and unscrew clamp all the time I want to change record. I have lots of 45's and singles. No screw-down clamp for me plz.
I have been experimenting with the Stillpoints LP1 on my Kuzma XL, which is normally supplied with a heavy screw-down clamp. It definitely changes the sound in the following ways: the overall loudness of the system is lower; there is less apparent 'propulsiveness,' particularly in the upper bass; the midrange does seem more 'pacific.' I retuned my system to accomodate these changes, largely by fiddling with the crossover point and gain of the woofer on my Avantgardes, and adjusting the overall level of the system (i.e., I play it at a higher setting on the line stage). I spoke with Franc re using it in place of the factory clamp and he did recommend his ebony weight. So, in essence, there is no reason, according to the turntable manufacturer, why I have to use a screw down clamp.
I'm liking what the Stillpoint is doing. But I also changed out line stages recently, and that's made a dramatic increase in bass articulation. So, I readjusted everything again. And it sounds terrific. Right now, I'm sticking with the Stillpoints, but that isn't an across the board endorsement for you to go out and buy one.