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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
atmasphere's avatar
atmasphere
11,577 posts
 
I've had excellent results with the Basis clamp. However the patter design on any 'table is crucial for optimal results. Plus the LP itself plays a role. Sometimes you are better off using an O-ring on the spindle to help dish the LP, other times that does not work so well.

If the platter pad does not have damping qualities of its own you may not get the same results... thus without the platter/turntable information included with comments about the clamp or weight the results will be unreliable.

I've been playing with the Stillpionts recently. It has its own sound and is better than nothing at all, but I've not been able to get it into the same realm as the Basis clamp so far.

I use our own Atma-Sphere 'table.
tonywinsc
583 posts
 
For clarification, I want to point out that the washer used with the Sota Reflex Clamp is made of felt. When I bought my Sota tt and clamp many years ago, it came with two or three of these felt washers. As mentioned, the washer makes a big difference in coupling the record to the platter with the reflex clamp. As far as I can tell my platter is flat, except for the slight relief near the spindle that is about the same diameter as the record label. The Sota reflex clamp flattens the record out to the outer edge with the felt washer under the record. Without the felt washer, I think the record would dish when applying the reflex clamp.
I have a couple of records with funny warps that make the outer edge roll up on one side when I clamp them down, but they are coupled to the platter the rest of the way in. I experimented years ago with and without the clamp. I don't remember hearing a big difference, but I use it everytime because many records will not lay perfectly flat on the platter without it.
whart's avatar
whart
2,968 posts
 
My Kuzma XL and factory clamp does use a spindle washer but I am not using it with the Stillpoints weight. I am continuing to experiment, but lost power most of last week due to the hurricane. We are now back up and running.
peterayer
1,382 posts
 
I wonder if a noisy bearing transmitting chatter or resonance up the shaft and
spindle into the platter and then the LP is the reason that some people report
better results without the use of a weight or clamp. The LP is thus less coupled
to the noisy platter. Clamping this LP would transfer more noise to the stylus
and thus out through the system.

It seems that the goal is to minimize resonances at the LP/stylus interface. That
means draining energy and resonances out through the arm and also down
through the platter/bearing. If resonances are entering the system from the
bearing then the use of a record weight or clamp could make the situation worse
by coupling the LP to the resonance transmitting platter.

I would think the ideal is a silent bearing supporting a heavy, damped platter
coupled closely to a flat LP. This would introduce minimum resonance/noise
and drain away energy from the stylus.
pgtaylor OP
32 posts
 
Peterayer - interesting hypothesis of yours that when people report an improvement on changing from a screw-down clamp to a record weight (of the type we are discussing) this may actually be due to some sort of 'decoupling effect', i.e. the record weight, precisely because it does not optimise transmission of resonances through the spindle/main bearing channel, may in fact help to stop bearing noise being transmitted upwards through the splindle into the disc.
You conjecture that, the noisier the main bearing, the more likely it is that a record weight (as opposed to a clamp) will have a beneficial effect.
Of course, it is true that some turntables have noisier main bearings than others, but surely practically all main bearings produce some degree of resonance or vibration. So even our SME turntables (mine a Model 30/2) - with their fantastic main bearings - are still producing some noise, albeit to a degree that we would normally consider negligible.
So I wanted to ask: as a long-term SME user, have you ever tried a record weight as an alternative to the SME reflex clamp on either of your SME tables? Have you ever tried either of your turntables with no clamp at all (i.e. leaving the SME clamp off)?
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