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
Gadfly,
I'm very pleased that my tweak has been instrumental in helping you get more enjoyment out of your analog system.

Thank you.
Well, I bought a modified RB250 from a member who asked if I tried the TWL hifi mod. I said no but read the whole 23 pages printed out on this thread... I went & got some Blu tack (its called Fun Tack in Canada & sold by Lepage).
But I could not find the bullet weights. Today, looking at some tiny metal cones I bought many years ago, I simply got out the tack and stuck a metal cone (about 1/2 onz weight) on each side.They are actually about 1/2 in dameter and again 1/2 high before developping a cone at the end.
The difference is night and day! So much more information, so much more dynamics, detail and soundstage. But the sound!! Before I tought the sound was a bit flat and confined to the speakers. After this modification the instruments came really alive and I can hear so much more detail. Even my son comming down the stairs noted that the music really sounded wonderfull. All this comming off a Grado cart with a signature 10 needle. Would you beleive I get this from a Technics SL 1210 turntable with an acrylic platter and Maplewood brass heavy feet!
I suggets you run , not walk to the store & get the $5 stuff - you will never take it off! Never mind reasoning it out or fear the bearing cant take the 1/2 onz load. I suggets you just try it....
Many years ago, people questionned big speaker wires; they reasoned this and that with very scientific measurements. They also questionned pointed feet for audio and speaker; they reasoned that one also...
Just try it - you will never reason this mod again...
Twl,
I would be interested in knowing your thoughts on the groove tracer type design counterweight which appears to be a more mechanical amplification of the tecnoweight. Is it more beneficial for a low compliance suspension? Is it logical that the farther back from the bearing axis the side dampening effect is multiplied? Mmm.......

Where might farther semi ridgid outboard weighting have diminishing returns.....is there a sweet spot or compliance ratio perhaps related to balanced off axis weighting related to dialing in suspension tuning? .... also any other currently avalible rega style counter weights that might be worth considering.
Thanks in advance
Jon
Hi Twl and all other major contributers in this thread. I'm about to buy a OL Silver MKII, and during my research I stumpled across this thread. It seems like you have a brilliant mod on your hands Twl.

I was wandering if you guys have experimented with different material for the weights? I googled "bullet weights" and noticed that you can get them in many different materials such as led, brass, steel, tungsten etc.

Initially I though that tungsten would be preferreble, as you don't have to handle the not so health frinedly led, but the tungsten weights are about half the size of the led weights because of the increased density. Now I'm thinking that this might affect the mod, as the weights would be shorter and not stick out as far. Any comments on this would be greatly appreciated.

I recommend you try and search for "bullet weights" and "worm weights" on the Bass Pro website (http://www.basspro.com), that will give you a lot of options. You can even get some in funky red colors :)

Thank you in advance.
Anders
have an RB300 mounted on a Townshend Rock Mk. III. This turntable incorporates a damping trough at the cartridge. The trough is filled with a viscous silicone solution. An outrigger assembly is mounted at the headshell that has a paddle that runs through the viscous solution . The RB300 came from Townshend. It came with the tungsten CW w/ an additional weight epoxied to it to offset the added mass of the outrigger. The diameter of the hole on the additional weight is larger than the shaft. Its weight is being supported by the tungsten cw.

I am using the latest Shelter 501.

I applied the TWL mod last night with great anticipation only to find VERY minor appreciable effect. Perhaps a VERY SMALL increase in bass definition and weight.

I am wondering if the trough of the Townshend is providing similar stability to that of the mod?

Any thoughts would be appreciated.