Thoughts On Turntable Clamps And Weights

@lewm 'Darkness' makes me think of an absence of treble - yet some of the most musical of TT, IMO, can also be described this way. Like the Nottingham Analogue Dais.

Every time I've made a big improvement to my system, it's involved a loss of high frequency hash. The sound just becomes smoother and more natural, less 'hifi'.

So I'm wondering about your use of the term 'darkens'. Could it be that the Kenwood ring reduces HF distortion? Or are you using the term differently?

FWIW, Kenwood made a peripheral ring back in the early 80s for the L07D. If you use it, there’s a special setting on the power supply/motor control module so the servo then compensates for the added inertial mass. Yet the ring seems to slightly downgrade the SQ of the turntable. Darkens or closes in the sonics, slightly.

@terry9 I have read your posts in the past and you show out as having a mind for the engineering side.

To get a idea of where my endeavours are going, the SP10 Thread on DIY Audio throughout the latter of last year and into this year covers a range of the platter designs to be used.

The designs for the bearing are coming from different places in Aus' and the UK, there is not as much work believed to be needed to create the measured run off's that are quite attractive.

I discovered the benefits of improving a generic type bearing design more that 20 years ago on a Garrard 401. Owned TT's since, that are in regular use, have all had a treatment in this area.

My interest in the Lenco GL 75 has enabled myself to meet quite a few who have done very successful work with this bearing type.

I am a vociferous advocate and encourager of carrying out this type of modification, meeting with a trusted support is the hurdle to be overcome.

My friend who has worked extensively on GL 75's, has gone to the extremes of having a Lenco Bearing Produced with a two part composite Spindle, Metal Spindle > Delrin Bushes in the New Machined bearing housing. The spindle to platter interface is using a material attached to the metal part of the spindle, where the material can be Natural, Thermoplastic, Metal or even a Composite.

When experiencing this in use as a Ebony Wood > Stacked Platter, the improvements was very very noticeable and quite outstanding as a functioning part when compared to other bearing modifications immediately available to try. 

This is a Spindle Mod', I am in discussion about for the alternative bearing design referred to earlier, Panzerholz would be my wood of choice. 

There is a more complicated bearing design in the making, I can't discuss it too much as it is not my work.

I have struggled to get a discussion going on a Air Bearing design. I have in my thoughts a design for one. I have to wait to see if it can be adopted into the design for this new complicated bearing design, seeing the dimensions of the New Bearing Housing and working with them, to offer the Air Bearing the optimised set up will be the challenge.                 

My LP turntable is a VPI TNT VI on a Townshend Seismic Sink (with super platter, VPI power controller, highly modified SME IV arm, Zesto Allesso SUT, etc). I tried VPI and an all copper exterior ring (latter used for a few very warped LPs) and VPI heavy center weight. They both negatively affected the sound with darkening the overall presentation. I play my LPs without a ring or center weight. I have heard on a higher end analog set-up a special wood many $1000s center weight that improved the sound. All my friends play LPs the same way, no rings or center weights. Same reason.  I think the platter is Delrin.  LP sounds neutral and dynamic just sitting on it.

I also got a 1mm cork mat to replace the felt.  If nothing else the dust and static problems are gone.  I tossed the felt and did not do a "with" and "without" test on them.

@pindac  Suggest that you rest the record directly on the Delrin, as Delrin and vinyl couple very well (speed of sound is essentially the same). Also, you might do better with thinner Delrin, as thick pieces can be heterogenous.

Also, consider an air bearing. More trouble, but lots less noise. Best is air in all dimensions, like a thrust bushing from New Way.

Balancing is important, and easily done by machining an oversize cylinder. Thing is, it's easy to find an approximate centre of a cylindrical billet, so turn around that approximate centre, and shave off the excess to give you a perfect centre. Keep the cylinder on the lathe chuck and let it settle. Mark that point, and rotate it to the top. If it stays there, your cylinder is balanced. If not, remove a little material from the bottom, until the cylinder stays in any position. Then you have a static balance. 33 RPM is not enough to require a dynamic balance IMO.

This requires the lathe to have low stiction bearings. Also, be very careful to fit the spindle in the exact centre identified above. Repeat the balancing procedure with the spindle in place, if possible. This works with a massive platter. If the platter is light enough, go directly to turning and balancing on the spindle.

BUT - your machinist may have better ideas. It's his profession, after all, and I'n just an amateur.

My TTW Gem V2 came with a 1kg weight. It makes a noticeable improvement.

I have VPI HW-40 turntable which is direct drive. It came with a very nice weight and peripheral ring. I prefer to use the Stillpoints LPI weight. It is heavy at 848grams. The HW-40 is a beast and I seem no issue with this heavy weight. I have never used the ring FWIW.

@jrcotner Excellent report on your early experiences.

There is more to come if you work with the Platter Mat.

I digested all of your information and bought a lightweight clamp.  It arrived yesterday and I did the "with" and "without" test on a few albums and noticed improved sound quality on all of them.  Instrument separation improved, lower frequency sounds became fuller and highs were clearer.  And some of the background muzziness went away. 

In the evening I played a few more albums and my wife, who is a passive bordering on indifferent listener, even noticed the improvement with the clamp.  She said she could hear each instrument more clearly. 

So the clamp was money well spent.  Thank you for your advice and observations.

I would not get too hung up on weight being a concern.

Multiple Bearings Assemblies are produced using almost identical designs, which also share identical / almost identical materials. 

These designs are seen to support in some cases Platters that have a substantial weight, and some of these platters with Substantial Weight are transferring the weight as a point loading onto a materials such as Sapphire that has a concerning fragility, especially as a material shattering is a risk that has to be calculated for.

I have a improved design bearing in use and a new design bearing to be put in place on a owned TT.

The New Design Bearing has Sapphire included for the certain roles, the Engineer who is to produce the design has made known that it is transportation of the TT, that poses the concerning risks not the typical usage. As I take equipment to other abodes or events, flagging up the concern about transportation is relevant to my own circumstances.

To be used in conjunction on a TT with the Original Bearing, Improved Bearing Design and New Design Bearing are a variety of Platters.

There is the Original Platter, a Phosphor Bronze Platter ( produced for another TT, but with a modification that makes it compatible for use on this TT), a machined replica of the Original Platter in Stainless Steel. The two non-original Platter are both close to be 3 x increased in weight over the original.

Additionally to be used are Machined Delrin Top Plates of a 20mm and 40mm thickness, which are to be mechanically fastened to all three platter types.

The friend who has the Stock Delrin and a CNC Machine is also to produce a part to be used for the extension Spindle. This might be a made from differing materials, being homogenous, as is the Platters and Delrin Top Plates. It is most likely to be used as a composite such a Panzerholz as well.

The point of interest to me is to see how the experienced individuals go through the motion to balance these assemblies.

I also use Spindle Weights where the Maximum Weight used belongs to a composite spindle weight @ 1Kg.  

These additional loadings on the differing bearing assemblies are of no concern to the Engineer who is to produce the New Bearing Design, their own historical investigations on the subject and their own trials undertaken leave them with no concerns about the weights being proposed to be added.

The above is a version of a work already pioneered by another, this is a revisit to the work already done on a different Continent. If the Mountain is not coming to Mohammed, then there is foot work to be done. 

The above is a uncommon approach, and a extension of other experiences been created, it is made known to show the OP that added weight is not to be concerned about.

More in alignment with the OP, I have used multiple Weights on Platters, I have even used a Stacked Platter.

These variants are able to impact on a sonic to the point there is a noticeable change.

I class this type of investigation as seeking out a interface that best creates a environment that is most suited to the Styli/Armature. When a optimised interface is discovered, a systems produced sound can sound quite attractive and is wanted to be maintained.   

I agree with @mulveling that weights in general can be quite subtle in how they impact on a produced sonic, but when investigating and attempting to fine tune a interface, these subtle changes can be the ones that produce the sonic that is most attractive to the end user, even if just limited to how a Bass Line is perceived to decay.

The place where there are real-world changes to be found, using my experiences, is through the exchanges of a Platter Mat.

Trying out different materials and thickness of a material can really effect the sonic. The broadening of experiences with differing materials as a platter mat can end up with there not being a ubiquitous mat for a system.

I have as a result of my investigations four 'go to' mats, that are produced from four different types of materials.

Tenuto Phosphor Bronze (Lean in Sonic),  AT-677 Duralumin ( Tint of Richness) , AT-600 Ceramic ( Perceived Richness),  5mm Forex Foam - this is a very cheap to purchase material ( competes equally with the former three mats, where the preservation of detail, dynamics and envelope are compared, it is Rich in Tone compared to all the others), Forex Foam as a 3mm thickness was a not to my liking.

Different weights in use can tweak the sonic a little when used in conjunction with the above mats, but I am most contented with the 1Kg composite weight (main weight Stainless Steel) adorning the Album.  

           

 

@boxcarman Agreed. No weight, no clamp, (no mat even!)

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 use the Analog Disk Light from HRS. It has nothing to do with flattening records though, but it sound betters with it on to my ears on my Clearaudio Performance DC TT.

Screw on clamp, light weight and it can be attached with variable tightness.  I always use the oem clamp on my VPI Hw19 mk4 just enough to flatten the record.

I too have a VPI Scoutmaster Signature with a Dynavector DRT XV1s. After about a year of use, I applied a small portion of black permagum to the cartridge shell and adjusted the counter balance accordingly. It gives the tone arm more mass and sounds great. All of my albums are flat and it’s a toss up whether I use a clamp or not. The lp sits on a cork platter cover, so there’s no slip. Tone arm weight is set to 2 grams. The platter is aluminum-not composite   

Ok, so I neglected to mention the washer. Sue me. I don’t use it with flat LPs, and again I thought the discussion was about sonic effects of weights and clamps, not record warps. But inevitably it seems headed that way. There’s only about a dozen other threads on that subject. Carry on.

Mijostin…pita for you but not for me. Never dropped it simply flattens the record. The option is to use it or not. I have used it for years

@stringreen , IMHO periphery clamps are a Pita and an accident waiting to happen. They are totally unnecessary if you get a reflex clamp like the SOTA. 

@lewm , @terry9 

Wow, hold on now. Lew, there is supposed to be a firm rubber washer about 0.5 to 1mm thick and 1/2 to 3/4" in diameter over the spindle, under the record. The Sota REFEX clamp contacts the label only at its very edge. When you tighten the clamp down the edge of the label is forced down into the label rebate flexing the record into the platter/mat. This will remove small warps and flatten dished records. It is way better than just a record weight. SME, Avid, Oracle, Kuzma and Dohmann use this method. It is not as good as vacuum clamping but a bunch less complicated and it will work everytime. Vacuum clamping will fail if the record is badly dished or too warped. 

 

I contacted Pro-Ject regarding clamps and weights but did not receive a response.   

My VPI has a periphery clamp and weight.....works very well, but it was designed for its use.

This leaves out a crucial part of what happens when one placing a floppy disc of vinyl on a surface. There will be a cavity below that shift from center to front of the disc when adding a clamp.

Tap the disc with your nail and you clearly hear the hollow space below. Thinking any cartridge will not "hear" and reproduce this cavity is denying the acoustics of that environment.

Me thinks, a vacuum is the only way to couple disc and platter into one acoustic unit. Tap that sandwich and you will only hear the sound of your nail striking the record, nothing more.

I would not consider any turntable, in any price range without a proper vacuum hold.

It is as basic an issue as firm speed stability and lack of bearing noise.

The flywheel effect attained by a weighty clamp might be worth the price of admission by further stabilizing rotational speed.

The coolest record clamp I ever saw on Youtube was vacuum with a flexible seal on the perimeter which pulled the record completely flat without the use of weights.

Bergman Galder Vacuum Clamp

True, but under the label is vinyl. That too is important, or so I suspect.

We know, but weights and clamps typically contact only the label. What they otherwise do is push the LP into closer contact with the platter or the mat, and that’s where ideally you want delrin or graphite.

@lewm 1++ 

For turntables that are not supplied with a reflex clamp the Sota is the best. It must be used with a firm mat and a thin rubber washer over the spindle. It the mat is too soft the edges of the record will curl up. 
 

The issue here is keeping the record flat and dampened. Even small variations in pitch will ruin the effect of feeling you are at a live performance. As record elevation changes the pitch changes. Very few records are perfectly flat.

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..

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.

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.

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.

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....

I live in Austria and recently purchased a Pro-Ject X8 from a local dealer. I also purchased a Pro-Ject " Clamp It" that was recommended by the dealer, and I have been using it on the X8. The Clamp weighs 120 g, has a leather contact surface, and the contact pressure is adjustable. A very clever design. Although none of my records are badly warped, I have noticed that some slightly warped records are more flattened on the platter with the Clamp It. Does it make an audible difference? On a first order, no. However I need to do more careful listening tests under ideal conditions (I live in a flat, so that can be challenging) to determine if there are more subtle sonic benefits. The Clamp It is a Pro-Ject product, so it would work nicely on you X2-B. For the cost (88 EUR here) it might be worth the investment.

As for weights, price has zero to do with any perceived sound change. Weight is weight (until it gets too heavy) and anyone who tells you otherwise is trying to sell you something you don't need or believes in things that don't exist.

A weight does NOT necessarily raise the outer edge of the record. A properly designed reflex clamp is a well-known engineering solution to this problem.

I use a very thin Delrin shim of about 75 mm diameter and a 2+Kg steel weight with a Delrin ring around the bottom. The result is a shim that forces the label up and a weight around the edge of the label which forces everything else down.

Benefits are improved flatness, obviously, and also an extremely good marriage between record and the 1" graphite mat, resulting in increased clarity and dynamics.

This approach is not suitable unless the thrust bearing of your turntable is sufficient for the task. My air bearing is..

I have a VPI Classic and I use the same TT weight plus their outer ring. Done this for the last 10 years, no issues. BUT I also had a project carbon TT and called them about using a heavy weight on it, they said no can do.

On my VPI Scoutmaster Signature, which includes a clamp provided by the manufacturer, I find I prefer a weight. I tried a brass weight by TT Weights, it’s fairly heavy, and the sound of my records played using the weight does sound better than with the stock screw down clamp. The sound with the weight is more vibrant.. more lively. The clamp makes the music sound a bit more dull and bland. So I’ve just stuck with the weight. I’ve noticed no excessive wear on the motor or bearing. I’ve been using this combo for ~15 years. Ymmv

CAUTION!

Whether you are using a clamp or any kind of weight, it will often rise up the edges of the vinyl. Therefore you also need an outer clamp. That's what I ALWAYS do. Welcome to the world of vinyl. Totally worth it but highly demanding. And then came streaming... I do that too, when I feel lazy, or old :)

I would contact Pro-Ject and ask them to make a recommendation. That a clamping device wasn’t included with the turntable suggests it sounds best without one. You will need a threaded spindle to use a clamp. It can flatten a warped record  somewhat but don’t expect miracles.

I prefer a weight. My turntable sounds better with one and once the platter (it’s heavy) is spinning, I don’t have to turn it on and off to change a record versus a clamp.

I’ve found the sonic distinctions between various weights & clamps to be subtle at best. That said, over time I’ve settled on Stillpoints LPI as favorite.

The real value of a center weight comes when used in conjunction with a ring clamp to effect whole-record clamping. There’s only so much clamping you can do from JUST the label area.

Also of importance are ergonomics and thoughtful design features like: if an end groove fails, does this weight help or hurt my stlyus’ chances of survival? The thick pucks (like Stillpoints) are helpful because they’ll block the headshell / body well before a cantilever gets near a clipping edge.

I also remember an early version of Clearaudio's Twister clamp where the metal twist knob would pop off surprisingly easily; might as well have been a cartridge & record wrecking ball at that point. Wtf! Fortunately later versions fixed this.

I've been using a DIY 8 ounce weight (Thorens TD125 MkII) for 20 years without any noticeable decline in sound quality (the deck/bearing seem to be fine).

I tried a few heavier (some much heavier) commercial weights, but did not care for the sound (decline in harmonics/reverb), but mine is a "sprung" deck.

Give a light weight/weight a try.

For my taste I prefer the contact between the weight/record to be hard/solid (no leather, felt or other soft interfaces).

I suspect that I might be satisfied with an even lighter weight, but never got around to experimenting.

My DIY weight is a small Mapleshade brass cone mounted to a Thorens 45 rpm adapter (oddly the diameter of the cone and the adapter are the same).

 

DeKay

 

These are only opinions, but yes.  You need to listen for yourself.  In some cases, I can imagine that one might prefer no weight or clamp.

Thank you for the interesting and thoughtful responses.  From what I gather, locking the vinyl to the platter, with either a weight or clamp, is helpful to a point.  But more force does not necessarily equal improved performance. 

Depends upon the TT drive system, whether there is potential to damage the bearing or drag on the motor. Some use what I view as ridiculously heavy weights, 500g and much more. I would stay at or below 250g, as an arbitrary rule of thumb. Clamps can be very light, because their effect depends upon a physical push provided by a threaded mount or a clamp mount, and certainly a well made clamp is putting no strain on the motor or bearing; it’s pushing the LP against the platter mat and platter. If you believe that your platter mat is an important component for dissipating energy generated at the stylus/vinyl interface (and I do), then the use of a moderate weight or clamp is justified. Very expensive, sometimes very heavy, weights made of exotic materials that make magical claims for improving sound quality, beyond any improvement one may perceive from a "sensible" weight or clamp are a manifestation of audiophilia nervosa, in my opinion. For example, Shun Mook.

FWIW, weights and clamps should be used to solve extant problems. I don't believe that their arbitrary use has any real promise of improvement in TT performance. If I were to use one I would use the lightest one possible to solve the problem, i.e. a clamp to help flatten a disc used only when necessary. I'm not so sure you can conclude that the use of a heavy weight doesn't affect performance on longevity of the bearing, less so the motor, but I'd be more concerned that a heavy weight might affect the torque. KISS applies. Don't fix what ain't broken. :-)

@bigtwin

Any strain on the motor is almost negligible.

Look at the physics. 

Possibly slight additional wear on the thrust bearing.

Thanks for the info.  I was wondering about the use of weights regarding motor and bearing strain as well.

The vast majority of my vinyl is very flat to start with.  Does adding a weight not add unnecessary strain on the TT motor?   

There’s a difference between a clamp and a weight, both in weight and function.

The most important thing to avoid is dropping the blasted weight on a record on the turntable.

If you can manage that, I think they do assist if they clamp down tightly. The weights on my SME tables screw down and flatten all but the most stubborn records (and then we're in Vinyl Flat territory). Long ago I had a J A Michell clamp on an RP3, that didn't really do anything. Waste of time and money.