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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

Showing 2 responses by peterayer

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.
peterayer
1,382 posts
 
Hello Pgtaylor, I have not tried any alternative clamping/weight systems to what is supplied with my SME tables. I did try listening to my SME Model 10 without the clamp and spindle washer. I thought the sound became a bit less clear and dull, but that was a long time ago and I can not recall the specifics.

Prompted by this thread, I did some more extensive listening on my SME 30/12 with and without the SME clamp and washer system. The results in general seem to be about the same as with my Model 10 but as this system is more resolving, the difference seems more pronounced.

I listened to selected tracks on three LPs in A-B-A or B-A-B order:
1. Vivaldi, Les Concertos Pour Mandolines
2. Ellington/Brown, This Ones for Blanton
3. Johnny Harman, Once in Every Life

The Vivaldi is very difficult to reproduce well because of the complex harmonics of the mandolines and harpsichord. Sure enough, without the washer and clamping system, dynamics were dulled, leading edges were not as crisp and harmonics were rolled off and blurred. On the Blandon and Harman, bass, piano and voice had less weight. Overall tonal density was diminished slightly. I'd say the sound was less vivid.

The differences were not huge, but I was very pleased to get the old sound back with the washer and clamp. Interestingly, I also tried one cut with the washer and no clamp. This raised the LP off the platter surface and the result was terrible. The LP slowed down so much with stylus drag, that is sounded almost like a 45 played at 33 and speed shifted with more or less stylus friction. It makes me wonder about playing an LP on a hard platter surface like brass or copper with no clamp, but many people do this with reportedly good results and hear more "air".

So, at least with my SME tables, the washer/clamp system seems to flatten the LP against the platter and improve the LP/platter interface for improved sonics. Whether this helps to drain energy from the cartridge away from the LP into the damped platter or isolate the LP from bearing noise, I don't know, but I much prefer listening as recommended by SME.
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