Groovetracer subplatter and P3-24 a Home Run!

I founds its actually easier to change records on the fly with the groovetracer sub-platter. Its spindle is polished and bright. As I place the record over the spindle area and lower it the polished spindle is a cinch to see. No hunting needed. The stock Rega spindle was dark so I had to hunt for it (without letting it touch the paper labels). A bit harder.

As for sound improvements the groovetracer delivered....nicely.

 

the low slung counter weight lowers the center of gravity. sort of like a porsche flat six versus a v or staight 6. this should improve the tracking of the arm and quiet chatter a bit. in ideal circimstances the cog should be at the record surface but the designer can't know how high future cartridges will be.

 

It won't have a major effect on the way that you play records unless a few fit too tightly on the spindle. Just by the spindle being a bit taller and a straight cylinder rather than having a tapered tip, it might slow the placement and removal of records down just a hair. That's not why most people buy such items, rather they expect some sort of sonic improvement.

You might consider buying just a ceramic ball bearing for much less than a full subplatter. You'll save a bunch of money and also get a similar if not identically tighter tolerance/lower noise interface, minus the jewelry. Not everyone likes the change but most will say that it does effect the sound. OTOH, if you've got the extra change, try out a GT and see if you like it.
-Bill

 

Counterweights can change the sound. Almost anything that you do to a table or arm will change the sound. That does not mean it'll be an improvement. That point seems to be overlooked a lot by the marketers of products.

The RB301 with its stainless stubshaft and concentric counterweight is about as good as it gets for a Rega arm. The only thing that would be an actual improvement would be the tungsten counterweight as it is a smaller diameter and keeps the weight closer to the pivot point. A Rega heavy weight would also by moving the weight more forward but it doesn't have the same diameter advantages and it changes the mass of the arm a bit. Even these higher quality weights are only subtly better than the stock unit.

The underslung counterweight designs are for marketing not for improved performance. They increase the reaction time of the arm in one direction and effect the vertical plane of movement more than the lateral, lowering resolution. What the overall effect is is a fatter sounding bass response. This is because the pivot point of the arm was not designed to be controlled from a lower point. Some confusion is apparent because there are some arms that in fact are designed to use a lowered counterweight point and these also lower the pivot point so that the cartridge, pivot, and weight are all in-line with the arm tube acting only as a connecting structure. This still focuses the weight and inertia around the pivot point. The SME V is such a design.

On a Rega and most other arms, the weight is designed to be placed near to and in the center line of the arm tube. The counterweight is actually balancing the sum of the arm tube and the cartridge, not just the cartridge and the majority of the mass is in the arm itself. This allows the arm tube to move as freely in any direction as the weight is centered around it rather than having more mass below the pivot point and creating more inertia than normal in the vertical plane. So unless an arm is designed from the ground up with the intention of having a lowered pivot point as well as a counterweight which is just the right shape to match the arm tube and cartridge profile to form a separate plane of balance, it is best left in a concentric fashion around the bearing.
-Bill

 

XYYY, I've got a spare Groovetracer counterweight. How about I send it to you, give it a try and report back to the group what you're experience was? PM me with your address if you are interested. All I ask is that you send it back in a couple of weeks.

 

I have the exact same turntable and cartridge and bought a Reference subplatter. I haven't had any problems changing records on the fly with the longer spindle.

 

http://forum.audiogon.com/cgi-bin/frr.pl?ranlg&1130145670&&&/Groovetracer-Counterweight-for-Rega-Turn
some user reviews of the counterweight. similar products from Kerry F2 and Expressimo which were favorably reviewed by Mikey.

 

You should be ashamed of making statements that are as incredibly inaccurate as this. Inventing facts then passing them off as fact is reprehensible.

 

So a tighter spec bearing will not result in a lower noise floor?
-Bill

 

All ball bearings are manufactured to a specific standard and given grades to differentiate them. For example, the bearing balls I use are within 10 millionths of an inch in regards to roundness or sphericity. The stock Rega steel ball is probably Grade 25 which is still within 25 millionths of an inch in sphericity. You can see that the "spec." is plenty tight.

The tolerance of the bearing has little or no effect on the noise floor, however the density could have much greater impact. The problem with the steel ball is that it's coefficient of friction is much higher than any ceramic bearing which is extremely important given the amount of pressure generated at the thrust point.

A more important matter is the steel shaft thrust point which is on the bottom of the Rega subplatter that wears over time because it is not hardened. The only part of the shaft that is hard is the outside diameter which is "case hardened", not through hardened as one would see in tool steel. Case hardening only penetrates the outside diameter of the shaft by about 0.030" leaving the core of the shaft soft and subject to wear.

The point being, friction at the thrust point of the stock unit will increase with every play and because of this, more noise or vibration is created. The noise floor suffers greatly when this happens. You will see a small dimple on the bottom of the stock unit if you want a visual on this.

I use sapphire as a thrust plate material that is second only to diamond in terms of hardness. It is also extremely efficient in terms of friction, much better than steel.
This is something you completely overlook every time you post negative comments in regards to my product.

The thrust point between the zirconia ball and sapphire thrust plate does not wear over time (like the stock unit) and gives the turntable an extremely stable foundation to produce a low noise floor. The fact that it rotates concentrically doesn't hurt either.
The two main points of the subplatter are to provide a rotating mass that creates as little friction as possible and turn concentrically to minimize speed fluctuation.
I hope this helps answer questions to anyone actually interested in how the subplatter assembly works.

 

Thank you for the kind words Stephen.

 

I have to disagree. The Groovetracer Reference is designed as a system, and the sapphire-jeweled business end of the superior-engineered thrust bearing really is a key part of the functionality provided by this system in lowering the noise floor. The lowering of the friction of this system, particularly when the bearing has 4-5 months to run-in, is just ridiculous. This significanlty lowers the noise floor, and when you do that, you increase the S/N ratio, and you can hear more of the music from the LP.

The quality of the R&D and engineering in this product is absolutely of the highest level; bespoke Formula 1/aerospace level build quality. I've been to VinylAddict's shop when I bought mine, and I've seen the quality of his work, and it's off the charts with respect to the quality of the engineering specification.There's an impressive level of R&D in this deceptively simple-appearing product, but if you saw first hand how it is put together, you would know. It reminds me of the level of engineering of the Ohlins shocks on my sport bikes.

 

You're welcome, Frank. They were intended to be as accurate, as well. You manufacture a superb product, and as someone who teaches Design for Six Sigma to engineers and scientists, I know a superb piece of engineering when I see or use one. The way your subplatter is manufactured reminds me of Leitz microscopes.

 

The OP is looking for input from users of the Groovetracer subplatter. Have you ever actually used one?

 

To correct some points here that might effect what people think of the stock Rega quality and just how the bearings actually work, I'll elaborate. Ball bearings are graded, I don't need to be educated there. Ceramic ball bearings are always ground to a finer tolerance than steel bearing and this tolerance is in fact the only reason that they would be selected for this application. So by simply buying a better ball bearing, you will lower the noise floor. The question becomes, will you hear it as the noise floor is below that of any vinyl record surface/cartridge interface. That doesn't mean that it will not help, it just points to how small of a change that you might expect from it. The bearings can be bought very inexpensively. They can be a pain to remove if you don't like what you hear however as they cannot be fished with a magnet like the steel bearing.

There is also the oil bath that comes into play and Rega uses a heavy oil, as does Linn. The oil provides a hydraulic interface between the metal halves of the bearing and coats the ball bearing as well. The viscosity is specific for the bearing as it keeps the noise floor and the speed in check, with parts which are farther apart. If the tolerances were much tighter, a lighter oil could be used, however I'd be wary of doing so without replacing the entire bearing system, not merely half of it. In a true high spec, jeweled bearing assembly, no lubrication would be needed. Of course the cost is very high and the benefits are not as great as with investments in other areas such as tonearm quality.

The last item is the statement about the hardness, tool steel and other rambling as it is not relevant and should not be construed as such. Indeed, Rega uses a hardened steel bearing shaft and mates it to a hardened steel ball, so wear is lessened in that area. The heavy oil also helps create a greater film layer on the parts. The bearing well however is brass and this is the softest material, so if we were concerned about making a better bearing and hardness was actually a major issue, that is the item that should be addressed first. The fact is that it is also partly responsible for the great sound of the stock tables. Rega has been famous for making very high performance products at very affordable prices and has made very good materials choices in the designs. The main point being, the cup shape that you would see on the bottom of the spindle/bearing shaft (if you were foolish enough to remove your subplatter just to examine it) is machined into the shaft and is normal, it does not indicate wear. It provides a properly shaped seat for the shaft to run on the ball bearing below it.
-Bill

 

No idea why you posted this. Bearing grades are simple to understand, no need to add confusion to the matter. As I stated previously, the "density" of the ball will have more to do with sonic improvement. Do you really think that the difference in sphericity/surface finish between (Grade 5) 5 millionths of an inch and (Grade 25) 25 millionths of an inch will make a sonic improvement?

A lot of applications feature jeweled bearings where lubrication cannot be used. This does not mean lubrication cannot be used in applications that allow it so please don't post absolutes when it only leads to confusion. FYI, there are other turntable manufacturers who use jeweled bearings, just not Rega.

I choose to manufacture this type of bearing because it is a sound design and works very well on the Rega turntable. It deserves a better bearing and now there is one available for anyone interested.

Once again, you call my informative post "rambling". and you post paragraphs of confusing information to let people think you know what you're talking about.
You really don't understand metal properties and tolerances at all. I explained that the shaft is case hardened to let folks know that only the outer surface of the shaft is treated for hardness. Case hardening is a process used to treat steel that has low carbon content. Tool steel has a very high carbon content and therefore is able to be "through hardened." Case hardening only allows a shallow penetration of hardening.

To repeat, The center part or thrust point of the shaft is dead soft so the part of the shaft that is touching the ball bearing will most definitely wear over time. This is a simple fact and has absolutely nothing to do with the profile machined into the brass bearing housing, which by the way is not a cup, merely a profile created by a drill point. There is always a dimple worn into the bottom of the shaft and it is easily seen when the subplatter is removed. BTW, This is comon knowledge.

Anyway, the fact remains that the area where the 2 surfaces touch grows with continued use and creates more friction and induces more noise/vibration over time.
One final note, one of the main reasons the outer core of the shaft is hardened is to prevent galling. It is a bad idea to have a "soft" steel shaft rotating in a brass sleeve.

 

Records sound better on my P3 since I modded to Groovetracer.
The re-wired tone arm was a big improvement too
Peace-
Norm/t5

 

I thought you run a hifi shop. Frank is a machinist who works for the aerospace industry.

I think he's a little more qualified to discuss this subject than you are....

The original post was for "User input..."

We've this discussion/argument many times now. You haven't heard the product, yet you never miss a chance to bash it and "explain it" to us. You're not a machinist or an engineer, you really aren't qualified to discuss the subject. Not only has everyone who's tried it like it, everyone who's bought one has heard the same change in sound quality. One of the first things any scientist will tell you is that solid science and engineering produces repeatable results.

Yet, you just don't stop harping about this, trying to convince us all that a product you have ZERO experience with can't and doesn't work.

I'm sure you'd be equally offended if there were a group of people that had never visited your hifi store constantly claim that you were a bad person to buy hifi from.

 

Bull-puckey. The improvement is not only audible, it's significant. Your statement makes me think that you have no actual, direct, first-hand experience with a GT Reference subplatter.

 

I'm not bashing Frank's product. I am clarifying some things that Frank said about Rega products. I always get a chuckle when you "bash" me personally.
-Bill

 

Of course you have. You are vague when it suits your purpose and you are absolute when it fits your purpose. Yet you say that I should not speak in absolute terms. Let's just say that you go out of your way to try and create a need for your product by trying to bring doubt upon Rega's. I want your product to sell on its own merit, not because anyone is led to believe that there is something wrong with their Rega products. Your characterization of "wear" on the parts is silly. We are talking about hardened steel parts that are subject to only a few pounds of weight and very low rpm. If you were talking about a high speed bearing, it would be a valid point.

You choose to say that it's a great thing when your product has a few thousandth tighter tolerance when it suits you and yet you then choose to say that another product, a less expensive alternative to yours, is no great shakes when it has equal or better tolerance. You speak in absolutes about wear when it has nothing to do with the actual application.

I don't need an education on tolerances of bearings, hardness, or the chemistry of metal wear as I have studied those points with engineers over the years in past jobs. I used to sell these parts to machinists and engineers in industry and government. Let's just call your tidbits "common knowledge" amongst ourselves. I don't expect you to speak in a way that would trivialize your interests but I'll be available to make sure that others don't misinterpret the input as being purely scientific and instead understand that it is directed at marketing your products.
-Bill

 

it appears some education would help. A tolerance is a the permitted variation in some measurement or other characteristic of an object or workpiece; in essence, a window of acceptable or nominal performance of a component that enables or supports acceptable performance. It is not an attribute like sphericiity, which is a physical measure of the properties of an object. Tolerances are determined by the customer's need for acceptable variation. Bearing grades are not tolerances, they are the attributes and standard deviations of a target mean for a specific quality, e.g. sphericity, hardness, etc.

 

My goodness, you don't get it, and it's twice that you have impolitely called my posts both "rambling" and "silly".
The bottom of the shaft is not hardened. I tried to make it clear in two posts earlier. The Rega shaft is actually cut from a much longer length of shaft, let's use a 3 foot length for example. That longer piece is case hardened and ground. This means that the outer "case" or surface of only about 0.030" is actually hardened during the process.
Following that process, the long shaft is cut into smaller lengths to be used as a bearing shaft. This exposes the shaft ends as being soft because remember that case hardening only hardens the outside diameter of the shaft. Is that clear now? I've tried to makie it so.

 

You corrected nothing. You post on a subject which you clearly have no experience, knowledge, or formal education about. You are not a mechanical engineer, a tool / die maker, or a journeyman machinist or anything close to those - the fact that you worked with people in these trades (as you claim) does not equate to you being any sort of expert in the subjects. Stick to something you actually know. Your jumbling of information here calls into question whatever else you may have to say about turntables.

So you 'studied' the "chemistry of metal wear"....and the "tolerances of bearings."

Obviously those weren't 'engineers' you were studying with!

 

OK, so now you're selling audio gear and guitars.
Somehow your expertise in selling parts to machinists was no longer required. I can understand why.