2. analog
  3. 1032024188

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
twl OP
3,251 posts
 
Basement, cantilever damage is more likely with higher compliance cartridges than lower ones. Since they flex so much easier, they are more likely to get flexed beyond their limits and break off. The low compliance ones are much stiffer and have a stiff suspension, so that is less likely. Of course you can break off any cantilever if you try hard enough. Lyra carts are relatively low compliance.

Regarding damping, silicone fluid damping for this application is troublesome, because of 2 reasons. The level of the stuff in the trough is critical, and nobody can really say how full to make it for best results. You have to "tune" it to your cartridge compliance, and that is a little "iffy". but it can be done. Second, the viscosity of the damping silicone changes viscosity over time, so the damping will change also. If you are not paying attention, or, don't change the silicone, you may lose the damping. The inertial weight system is a one-time deal that stays the same, once you install it. It could also need tuning to the cart, but once you are higher than the needed level, being somewhat heavier is no big deal. So my way of thinking is to tune it to a real stiff cart, like a DL103, and then it will be more than sufficient for any more compliant cart(which is all of them - the DL103 is the stiffest cart made).
Post removed 
zaikesman
3,017 posts
 
Yes V., I realize that. Still think you'd hear the warp before the change, though, and besides, any heightened tracking ability would tend to make up for this shortcoming in my estimation, but I guess the best solution is not to have warped records! (Which would rule out many of mine...)

Basement, are you refering to a tomearm wrap? I have one of these from Music Direct installed on the integral arm of my Technics SL-1200, just on general principle. It's a ribbon made of very thin, very stretchy black rubbery stuff that sticks to itself, which you wind around the arm in an overlapping spiral fashion. Couldn't vouch for what exactly it does, though. It's been on too long, and too many other things in my system have changed since it was installed (including TT items such as cartridge, mat, and support). Trying to remove it and reinstall it later would probably compromise it physically, it seems to me, so there it remains. I can tell you that the arm does seem well-damped by it (in the sense of not ringing), and that it adds negligable mass. It also stays put quite nicely, and looks quite ugly.
twl OP
3,251 posts
 
I think that the Dyanavector 507 reduced vertical mass is good for tracking warped records, but it requires that the cartridge be matched to the lower mass for proper resonance function. I also don't really like the short radius arm for the same reasons you guys are talking about, VTA/SRA changes of large magnitude on warps. I believe that this outrigger mod supercedes the Dynavector approach.
zaikesman
3,017 posts
 
Well Twl, then you know what the next step is - design and market the commercial version of it! Let me see how it's coming along during the prototype stages if you're going to be looking for investors...

(Come to think of it, if you weren't thinking about designing a whole new arm around this idea, maybe you could just make a retrofit mod kit for Rega arms...shouldn't be too killer, market's there and waiting...)
More to discover