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
Have not read through every thread here...but... I used to own a unipivot Lurne arm from France that had this arrangement built into a hollow tube that was fitted perpindicular to the arm tube toward the rear. The tube contained two weights that you would push through and position to stabilize the arm just like a tight rope walker...worked great.
Hi Twl, and thanks for your reply. I'm still frankly astonished. Thankyou again. I posted a new thread of suitible superlatives in your name because i think you deserve it for this, but the moderators seem to have disallowed it. hence the new post on this thread. Congratulations again for your "mod" which i actually think is more a wonderful inovation in the field of tonearm design, even if others have tried to impliment such ideas independantly at other times. I am amazed when something like this isnt taken up by huge numbers of audiogonners, magazines and manufacturers. It is no joke to say that it has raised my Rb300 to my OLSIlver level, and even surpassed it slightly, probably helped by the 4 feet cardas rewire that obviated any joins to other wire before the phono stage. I shall rave on for a while about this one!
Hello my name is sean thorpe of Blackpool England, I would just like to inform you that your site is a google whack. If you do not already know, this means that when you enter the two words 'jazz' and 'occilascope' it is only your site that appears on google!!!!

congratulations!!!

Sean Thorpe.
Hi Twl,
Gilbodavid pointed me to this thread after reading my post on the "lenco thread". I'm glad he did, because I was unaware of it and I'm very much interested, but, reading through it, I realised that, maybe, it's not suitable in my case as I have an ortofon 530 MM cartridge which has a compliance of 25(?), and as you point, it probably isn't enough to move the arm.
What do you think?
It would look cool, though...