Screw-down reflex clamps vs. record weights

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.

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.

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 - 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)?

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.