Strange Tonearm Tweak. Long


As you all know, I am a little different. I like to read and study stuff like tonearm technology. I noticed that some of the better unipivot designs have employed "outrigger" style outboard weighting systems on their arms, that work like a tightrope-walker's balance pole. This not only balances azimuth, but also gives the arm better stability to lateral deflections from the cartridge suspension, so the arm is not moved when the stylus is pushed laterally by the groove information. I began to think on this, and I wondered why no gimbal-bearing arm makers are doing this. Surely since the vertical plane rides on a vertical axis bearing, there is still some chance for the arm to be laterally deflected by the stylus, when the stylus should be doing all of the moving, not the arm. I think that this is why they use heavy arms, but a heavy arm in the vertical movement plane is not good for tracking. A heavy arm in the horizontal movement plane is good for resisting sideways deflection that would impair pickup function.

So I decided to try increasing the mass of my tonearm in the lateral plane, while keeping it light in the vertical plane, by the use of "outrigger" weights, just like a unipivot does.

I bought lead fishing weights that looked like long rifle bullets(just the lead part) They were about an inch long and about 3/8" diameter, and weighed 12 grams each. I drilled into the bases about 1/4" and press-fitted them onto the nuts that hold the arm into the bearing yoke, so they stuck out straight sideways, like sideways spikes. This put the weight out pretty far to the sides as outriggers, and kept the weight centered exactly around the bearing pivot axis so it did not increase the vertical mass significantly, but it did very slightly. It did not influence the tracking force at all.

So now the arm had outrigger stabilizers on it in the horizontal plane of motion.

I put on a record and sat down to listen. Let me tell you, fellas, this was a mind blower. I have never heard this much information come out of a cartridge before. I heard sounds on records that I had listened to for 30 years, and never knew those sounds were on the record! And I have had some pretty good analog gear in my time. And what I didn't own, I heard at the audio store I worked at. This is the most astounding mod I have ever heard on a tonearm. And it cost me $1.49 for the fishing weights, and I got 3 extras.

The only slightly negative thing about it, is that it increases the anti-skating force, so you have to cut that back a little, and if you have some marginal scratches that might skip, they are more likely to skip with this mod, due to the resistance to sideways movement provided by the outriggers. I had this happen once last night, but I didn't consider it a problem.

But the increase in dynamics, and detail and overall sound quality is astronomical. It blew me away.

I have a DL103, which is a very stiff cartridge, and it may be that this is not needed for a higher compliance cart. But, I think that it would be good for anything that is medium or lower in compliance.

The key to it, is that it only increases the resistance to sideways movement, without interfering with the effective mass of the arm, or the vertical swing movement that needs to stay light to track warps. I played some warped records with this mod, and they played just as well as without the mod, except they sounded better.

I have a pretty good analog setup now, but I can say without reservation, that this mod made my rig sound better than any analog rig that I have ever heard in my life. I have never heard a Rockport.

Stabilizing the arm against unwanted lateral deflection increases the information retrieval and dynamics by a very large percentage. If your arm is not set up like a Rega style arm, then you can glue a 1 ounce long rod across the top of the bearing housing(sideways) like a tightrope-walker's balance pole. Use lead if you can, it won't ring. You don't have to do any permanent changes to your arm that might wreck its resale value to try this out. If it has anywhere near the effect on your system as it had on mine, you won't be taking it off.

It may come close to the movement of your cueing lever, so make sure you have clearance to use it. Mine was close, and I have to come in from the side now to use the lever, at the end of a record. That is fine with me! This was a major, major improvement in the sound of my rig. It is staying permanently. As in "forever".

If you are a little tweak-oriented, and not afraid to do stuff like this. You should try it. It will knock you over.
twl
I am always up for a good way to lose money. If I produced these, would anybody buy them? What would you be willing to pay for an easy mod that improved your analog rig? Considering for the RB250, I would have to get new bearing dust covers, and the weights, and affix/screw them together, paint, package, and market. And hopefully make a few dollars. :^) Sounds like around $49.95 retail to me. What do you think?
Zaikesman, the damping I was refering to is fluid damping and besides sound its effect on the cartridge is this; when the arm is put into motion, lets say to the left, the weight of the arm resist the motion, and then goes into motion to the left, pulled by the cantilever. when the cantilever then goes back to the right, the arm is still going left, and so the inertia arm of the puts additional stress on the cantilever.
How much stress is put on the cantilever is affected by how heavy the arm is. (actually not the weight, but the inertia, which is affected by weight).The higher the complience, the more the cantilever flexes to a given amount of weight, and if the cantilever can flex enough, and the arm is heavy enough, the arm can be put in motion.
The real idea is to keep the cantilever centered, not having to much resistance to movement so the arm follows the cantilever, but enough resistance to keep it from overshooting.To achieve this, a fluid of a certain viscosity is used, the viscosity permits slow movement with little resistance while faster movement is resisted. So you can see that the tuning of the viscosity, and amount, could achieve this.
Here's where it gets complicated-damping with fluid can have similar effects to adding weight, as the fluid restricts movement. Fluid can have positive effects on sound. How much is attributed to keeping the coils centered or the restriction of movement, or the adding of the solidity and resistance to vibrations is one question in my head. the other is that as weight is added, and fluid is not, this makes the arm more prone to going in motion.
Fluid can have negative effects as well. Besides the cantilever to be less centered by not having it tuned properly, or causing more stress than intended, to much damping kills the sound quality. In my experience, Adding damping cleans up the sound and widens the stages, and tightens aand focuses the bass. After a certian point, then the sound starts to get dulled in the high end, then becomes veiled and then more diffused past the point it was before it was added. There have been some instances where adding any at all caused this.
So there is the object of my curiousity, one or two of them, among others.
The damping you are refering to, Zaikesman, is damping the armtube for ringing, and it is always a good idea. I have always had good results, no matter how good or bad the arm, no matter how good the match of arm and cartidge. One of my favorites-a drinking straw, of slightly smaller diameter than the inside of the armtube, and stuff the space between the straw and the inside of the armtube. This provides a pretty good surface/dialectric for the wire as well. (seems better then having it smushed against the armtube). I want to try cat hair, but my doner cat moved on. My theory is that cats seem to absorbe sound,and they are always sneeking up on stuff. In the wild, they have to be sound absorbant, so there may be something evolutionary to that.
Twl, fifty bucks, that would be a bargain. Seems like a hard way to make money, as I don't see much profit there. I think a lot of people would be into it though.
$49.95 in normal retail = about $79.95 in audiophile retail. What do those dropped counterweight mods sell for? You'll be doing two weights instead of one, so yours should be a bit more.
Basement, I have some cats, with plenty of hair. People some times ask me if I own anything without cat hair on it. I would have to say no. Maybe my entire house is well-damped. Just kidding, but I do have some cats.

Regarding your thoughts on damping, the arm should always remain centered over the groove. The arm should never move by stylus deflection. If it does, you lose bass information, possibly other information, and dynamics. The stiffer a cartridge's suspension(compliance)is, the more likely it is to deflect the arm during play. If the arm has sufficient mass in the horizontal plane, the cart cannot deflect it, as the horizontal moment of inertia(of the arm) is higher than the cartridge can overcome. This is the ideal relationship for maximum information retrieval from the groove. However, the arm must be free to traverse the record from start to finish, unimpeded by friction. The high moment of inertia in the horizontal plane, does not increase friction, but merely resists momentary, microscopic "wagging" that would otherwise impede correct pickup function. The fluid damping strives to duplicate this function by applying "shock absorber" type damping, against this "wagging" tendency. Neither of these methods should have a deleterious effect on the integrity of the cantilever, since the cantilever is supposed to be designed to move the distances involved with the velocities involved. Merely stabilizing the tonearm should have no destructive result on the cantilever. To the contrary, it should provide better functioning of the cantilever/stylus to do their intended tasks of groove tracing. Arm wagging has always been a bugaboo for analog rigs. The single minded desire for light weight arms, disregarding the need for lateral stabilization has allowed this modification of mine to become possible. The funny thing is that unipivot designers achieved some of this by striving to keep the azimuth level, but also got some of the benefit of lateral stabilization in the bargain. I think that this is responsible for alot of the improved sound of the high end unipivots recently, espectially the Graham. Gimbal arm designers totally ignored this because their arms were already stable, and didn't think of the lateral stabilization need, with the exception of Dynavector. Unfortunately for them, they did some other things at the same time that caused other problems to surface, and their arm never really caught on. And many people thought it was just a heavy arm, in a world of light arms that were all the rage.

It is interesting that this lateral stabilization is at the heart of turntable design, with aerospace tolerance bearings and heavy platters, and belt drive, being used to ensure that the groove does not wiggle sideways under the stylus. But the same thought escapes tonearm designers who allow their arms to be easily moved around in the groove by the very information that they try to retrieve. So all of this effort by the TT makers to keep that groove stable, is largely lost by the arm moving around. The perfect relationship of arm to platter is perfectly rigid and non moving with respect to the lateral plane. It should only follow the spiral. The bearings are highly-spec'd and tubes are built with great care to reduce vibration, and all kinds of technology is used to make them do everything else. But, still they let the headshell end of the wand get shoved all over the place by the cartridge. Isn't that wierd? Now to be fair, alot of cartridges are high-compliance and don't have much "push" to them, and alot of arms have enough lateral mass to stay fairly well in place. So for many applications they are ok. For the low-compliance crowd, things are not ok. If you have a Koetsu, or a Lyra, or a Shelter, or a DL103, or alot of other really good high end carts, then your arm is very likely not up to the task of getting the best from them. And the more you try to go to a lighter arm, the worse things get. And all these makers are trying to use featherweight materials like titanium and carbon fiber to make things even lighter! And here comes ol' TWL, that wierd-o from outer space, saying that we need to increase mass in the magnitude of ounces, not grams! But only in the horizontal plane, and in the right place. No wonder his TT sounds good. His arm stays in place.
Where do I send the money for this mod, and what cool name do you associate with it?