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  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  (System | Reviews | Threads | Answers | This Thread)

09-14-02
  Responses (1-50 of 269)
Click title to read one, or click date to read all below it.

09-14-02   In my first paragraph, i meant to say that the "horizon ...   Twl

09-14-02   Good show twl. the idea is to get the most mass below the pi ...   Viridian

09-14-02   Just another thought, twl, that it could be a combination of ...   Tsouthworth

09-14-02   Twl: from your description is seems (to me) that you are ad ...   Dekay

09-14-02   Viridian - i already use the expressimo heavyweight, and fou ...   Twl

09-14-02   Twl: very interesting, though i cannot see an "easy&qu ...   Dekay

09-15-02   Very interesting approach twl, but the analogy between stabi ...   Zaikesman

09-15-02   Quote: "for my decidedly non-audiophile-approved techni ...   Psychicanimal

09-15-02   Geez, psychica, didn't take long for my post to pull you out ...   Zaikesman

09-15-02   Yes guys, this mod is similar to a damping trough mod, with ...   Twl

09-15-02   Twl can you post a picture of this tweak? jim   Jvr

09-15-02   Quote: "you mean after all this time you didn't 'get' t ...   Psychicanimal

09-15-02   Twl - i'll try to post here about what i find when i try the ...   Zaikesman

09-15-02   Zaikes, the dynavector 507 was addressing this idea, and tha ...   Twl

09-15-02   That "fritz geyger mirror-polished stylus" is the ...   Psychicanimal

09-15-02   after reading this, i was compelled to put my table on the ...   Basement

09-16-02   Basement, all tonearms already incorporate a greater vertica ...   Zaikesman

09-16-02   Zaikesman, i think you are on the right track for calculatin ...   Twl

09-16-02   Basement, what zaikesman said about the vertical tracking fo ...   Twl

09-16-02   Twl, what you figured out is what i was actually attempting ...   Zaikesman

09-17-02   I went to the dynavector web page, and read the info on the ...   Twl

09-18-02   The problems with the design of the dynavector tonearm are t ...   Viridian

09-18-02   Viridian, i agree. they were onto something, but the executi ...   Twl

09-18-02   Twl, your inquisitive and experimental interest in the hobby ...   Viridian

09-18-02   Thanks very much, marty. i enjoy all of my time here with yo ...   Twl

09-18-02   Yeah twl, next thing your going to tell us is you built your ...   Albertporter

09-19-02   Yeah, viridian, i had wondered before about the angle issue ...   Zaikesman

09-19-02   i just had a scary thought-might want to put some of that t ...   Basement

09-19-02   Basement, cantilever damage is more likely with higher compl ...   Twl

09-19-02   Zaikesman, your observation is on the money, however realize ...   Viridian

09-19-02   Yes v., i realize that. still think you'd hear the warp bef ...   Zaikesman

09-19-02   I think that the dyanavector 507 reduced vertical mass is go ...   Twl

09-19-02   Well twl, then you know what the next step is - design and m ...   Zaikesman

09-19-02   Cool stuff z and t; an even quicker way to lose money than t ...   Viridian

09-20-02   I am always up for a good way to lose money. if i produced t ...   Twl

09-20-02   zaikesman, the damping i was refering to is fluid damping a ...   Basement

09-20-02   $49.95 in normal retail = about $79.95 in audiophile retail. ...   Zaikesman

09-20-02   Basement, i have some cats, with plenty of hair. people some ...   Twl

09-20-02   Where do i send the money for this mod, and what cool name d ...   Nrchy

09-20-02   I would add to basement's and twl's comments about viscous f ...   Zaikesman

09-20-02   Zaikesman, agreed. no cause for more weight than necessary f ...   Twl

09-21-02   we have two ideals here, maybe three. as far as tracking go ...   Basement

09-21-02   Basement, i don't understand most of the first half of your ...   Twl

09-21-02: Basement
It took me a long time to understand as well. Now I'm grappelling with mass and it's relationship with damping. If you are like me, you think about this stuff all the time, and things come to you, (obviously, look at whats come back at us).
This part I think you might be missing- you mention that all (most) your records are not off center. While there are quite a few that are obviously off center, what we are talking about here within the cantilever/coils is microscopic. All records are off center, evan if just a fraction of a groove width, they aren't manufactured to the kind of tolerences we are striving for. If you dismiss this, then you shoot for the arm staying put at the cartridge. Really, what we want (in theory) is the arm to stay put directly over the cantilever. The key to this, with fluid damping, as stated by Z above, is the viscosity. Control the resistance selectively at selective speeds (traditionally, the speed being the frequency of the warp/wow). To see it, you definitely need to get in and look at the cantilever at the cartridge to see how much it is moving in relation to the cartridge. to measure it, you definetly need test records and the like. ( I don't have these resources, maybe you do).
There is more to controlling frequencies then just keeping the coils centered, though. There are, I believe and suspect, differences and simularities between fluid damping and mass. We are not done with this yet.
Last night, I put my immedia back on to test some of this. I drained some fluid out until the arm could tilt easily to one side but come back without overshoot. Then I weighed some pennies, came up with 5 pennies on each side to be about 12 grams with electrical tape, and slung them out with a paper clip. They are about 1.75" out on each side, just below the record height, slung out at the same angle as the cartridge, and just taped on the top with a piece of electrical tape, over the center of the bearing, and they swivel front to back because of the tape. archaic, but they increase the horizontal mass considerably with minimum effect on any other parameter.
What I thought I heard was a wider soundfeild with more separation between intruments. But the induvidual instruments seemed more truncated, less air and detail around them. The high end seemed more recessed with a loss in detail. I didn't adjust damping at all between the two. I did notice more movement of the cantilever, at least I thought I did. Sounded similar to adding to much damping, and of coarse this experiment is extreme, I didn't play with it any further.
One resource I don't have lately is too much time. I am currantly getting more enjoyment in the tweak factor by hearing your results.
The immedia has damping, and it is easy to control and adjust/change, but it is also much heavier than the rega, I plan on starting another thread if you don't to see if anyone has tried fluid damping with the rega, and if any is readily available.
This is a new tonearm you are designing, isn't it? You are changing the parameters of the design. Seems to me you are somewhere roughly as far from the rb-series as the ol 750 is.

Basement  (Threads | Answers | This Thread)


09-21-02   Basement - have to say that i too, either do not understand ...   Zaikesman

09-21-02   Zaikesman, i used poor terminology in my last post regarding ...   Twl

09-21-02   Basement please clarify your points, we need to know more ac ...   Twl

09-22-02   keep in mind i am still trying to grasp a lot of this mysel ...   Basement

09-22-02   I will respond to some of your points if i can, basement. f ...   Zaikesman

09-22-02   Ok, we have a couple of suppositions here, and i will try to ...   Twl


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