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 just installed Tom's Hi-Fi mod, and it made a significant improvement to the sound. I hear way better bass - much tighter, more defined. Also, the trebble is more refined - I had been experiencing some sibilence on some slight high pitched vocals, but that's gone now. Finally, there is more detail - I'm hearing things I didn't hear before. Thanks Tom for a terrific mod!! (My vinyl rig is Teres 135/OL Silver/Shelter 501MKII).
Hey TWL are you still checking this thread? When you say you drilled into the bases are you talking about the lead weights? I would like to try this on my RB300. When you attached them did you just glue yhem on with super glue?
Colitas, yes, I drilled the bases of the lead weights to fit the cap-nuts on the bearing axle. You have to use a 1/4" drill to do the depth of the rounded part of the cap nut, and 5/16" to fit over the flats of the nut. It is really 23/32", but if you use 5/16" and ream it a little bit, then it fits over nicely. I recommend super glue because it sets fast, but if you want to make it easily removeable, you can use clear silicone seal. It takes overnight to dry with silicone seal, so you need to make sure that you have the weights securely positioned during the glue-drying process.
For those that have been following this thread, I have just conducted a listening comparison with the OL Encounter against my HiFi Modded Silver arm. Basically, the Encounter has about the same effect as having the HiFi added to the Silver arm. The Encounter had an improved wiring loom, and has some other things like a tapered arm tube, that may have contributed to a slightly more refined presentation than my modded Silver arm. The Encounter sounded just a touch better overall. But the HiFi mod brings the Silver up to about even with the Encounter, with only very small difference in the refinement areas. That's the latest information available at this time. If you like the Encounter but can't afford it, then the modded Silver is a very good substitute for alot less money.
FYI- I found an alternative to lead which greatly simplifies adding weight. It's called "the original Sticky Weight" which is made of tungsten and claims to be 30% heavier (by volume) than lead. It is a consistency that is thicker than modeling clay and can be molded and stuck directly to just about anything. Found it at "Bass Pro Shops", one ounce for $5. Apparently, fishermen use it to quickly add weight to fishing line.

Regards
Jim