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
Jim, the hanging counterweight is good on my arm, but I don't know how it will affect the Well-Tempered. If the turntable doesn't bounce around much, it may be ok. It is not too good on Linns and tables that have springy suspensions. Also, if you are going to try it, I'd recommend using a rubber O-ring slid onto your end-stub at the correct place, and using that to stop the string from sliding backwards when you cue the tonearm. I found that without the O-ring as a "stop", the string wants to ride backward on the tonearm when you cue it, and then you lose your VTF setting, and it is a pain in the butt. The O-ring placed behind the string, at the correct point for the proper VTF setting, keeps the string from sliding and will retain your VTF setting, and is much more pleasant to use.

It is worth a try to use the hanging counterweight. It's cheap and easy to fabricate. If it doesn't do well in your application, it's no big loss. You can always go back to adding weight to your existing counterweight, like you were going to do.

The main idea is to hang it like a swing, with the string going across the arm tube, and holding the counterweight cross-wise, so it doesn't rotate around. Just hook the string to both ends of the lead bar. This works in my application, and the rubber O-ring keeps it in place on the end stub. It takes a little fiddling to find the exact place on the end-stub for the O-ring to be, but a few minutes with the VTF scale, and some very fine placement adjustment of the ring, will give you the proper spot. Once this is done, you can even totally remove the counterweight, and then replace it with the string against the front edge of the O-ring, and you have the same VTF setting. It is like a place holder. It just stops the string from sliding backwards. It isn't a clamp for the string, just a slide-stop.

Make the lead bar the same, or slightly heavier than your existing counterweight. Make the string the right length, so that when you hang the weight on your end-stub, the lead bar is about at the same level as the platter surface. Then slide the O-ring onto the end-stub, adjust the position until you get correct VTF with the string right up against the front edge of the O-ring. That's it.

Hopefully, there will be no parts of the tonearm housing that will be in the way of this during use. If there is, then you have to modify, or go back to Plan A.
Thanks for the tips, Tom. BTW, the WT is an unsuspended table, so no worries of weight on the string bouncing around. Any ideas on vibration damping?
The arm. I thought that perhaps there would be some significant gains there, but don't know much about it.

Thanks
The Well-Tempered Arm is already pretty well damped. There is sand in the arm tube, and a big glob of silicone under the bottom of the stabilization disc. If anything, it may even be over damped. I strongly doubt that you are getting any ringing from that arm.

Perhaps as Basement states, you might get some benefit from doing something to the support housing for the arm. I don't know about that. I never tried doing any Well-Tempered mods.