a wonderful thread.. i've learned a lot. thanks twl for this post!!
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.
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.
269 responses Add your response
Back to the Tensegrity subject for a sec: Visited Frank Lloyd Wright's Taliesin West in Phoenix recently, and there was an obviously handmade Tensegrity sphere (composed from wooden rods with some kind of natural fiber cord and about a foot in diameter) diplayed sitting atop one of the living room tables and looking fairly old. Unfortunately, our tour guide knew nothing about the object or its provenence, but it seemed solely decorative in purpose. Could FLW himself have toyed with this construction, and also come to the conclusion that fascinating as it was, its only practical application is purely asthetic? |
Zaikesman, yes I think that is possible. I have tried to build several tensegrity constructions, and they all have problems with rigidity. It seems that the wires that I used always had some amount of stretch to them, and this always resulted in flex of the structure. Very disappointing. But it is a very cool concept. |
Tom et al- After considering all that has been brought up on this thread and how I could apply it to a Well Tempered table, I've come up with a simple method that might work, but I'd like thoughts/opinions from the group on it before proceeding. Here it is (You may have to look at the WT website to picture the Record Player arm)- Quite simply, mount "X(?)" amount of the aforementioned lead tape to the the left and right side of the counterweight, but below the level of the arm tube. This would provide the stability of the "teardrop" shaped counterweight (and possibly some resonance control) and maybe a little more lateral than vertical damping. (Yes, I know it would be better to have the weight at the pivot point, but the WT arm's pivot point is unusual.) I don't think there should be a concern about bearing wear except that the string just needs to be able to support the additional weight. (It's 12 lb test fishing line) The only problem I foresee is being able to fine-tune the tracking force as, with the additional weight, a little movement will create alot of tracking force change. I guess it would be possible to add a fine-tuning counterweight of some sort. Anybody care to weigh in with suggestions? Thanks Jim |
Jimbo, you can do what you are proposing, and it will improve the sound to some degree. The improvements, however, will come from the lowering of the center of gravity of the counterweight, and not from increasing the horizontal mass component of the tonearm. This is because when you increase the mass of the counterweight by adding the lead tape, you will have to move the counterweight closer to the pivot in order to balance the cartridge. As such, the mass components as the cartridge sees them, will remain the same, or at least very similar. But lowering the center of gravity of the counterweight by adding the lead tape will improve the tracking of the cartridge and I suspect the improvement will be audible. Due to the things I mentioned above, I think that adding the lead tape at the very bottom of the counterweight would be the most productive place to put it, in terms of making the most sonic improvements. If you have to make several layers on top of each other, to get the desired effect, then that is what you should do. Bringing the majority of the counterweight mass down near the level of the platter is known to improve the tracking performance. However, I don't think that it will do anything for increasing the horizontal mass component. But hey, any improvement is worth doing, right? It's innovative, and cool to do your own tonearm mods. |
Tom- In your tweek, the effective mass of the arm doesn't change. Doing what I propose on the WT would change the effective mass in the same way as the heavy teardrop counterweight would- correct? If so, would there be any downside? (I suppose that the length of the arm is sufficient leverage to handle an extra ounce of counterweight, though.) Thanks for your comments. Regards Jim |
Jim, there would be no problems, as long as you don't make the mass of the counterweight so high as to not be able to move it close enough to the pivot to allow counterbalancing of the cartridge. The heavier you make the counterweight, the closer it must be positioned to the pivot, in order to balance the arm. At some point, you can make it so heavy that you run out of room to move it forward on the arm, because you run into the bearing housing. That's the limit. Put the additional weight at the bottom where it will do the most good for lowering the center of mass. |
YEAH!! I dig tweaking. It sounds like your ideas should work real well for a # of reasons, so here is my pre-feedback on your proposal- I have had great success adding lead to the couterweights of all the arms I have tried it with. My origoinal goal was to increase the mass of the arm (If I recall correctly, it was because I read that this was a tweak applied to the well tempered arm, replacing the counterwieght with a heavier one). When considering this keep in mind that there is a difference between what is referred to as effective mass and mass. Effective mass is the 'effect' that the mass has on the inertia of the arm. As twl states, increasing the mass of the counterwieght and moving it closer is a perfect example of increasing mass without changing the effective mass. Twl's mod is an example of the opposite- the mass applied at the pivot changes the effect in the vertical plane very little, while the effect on the horizontal is increased disproportionally. So, if you were to consider a graham arm with adjustable sidewieghts, and spread the sidewieghts out from the pivot equally, the mass does not incease, but the horizontal effective mass increases because it then takes more force to effect movement in that plane. The vertical effective mass remains unchanged because the weight remains at the same point relative to vertical movement. The reason I go into this so much is because if you see a picture of the newest version of the immedia arm, you will notice that mr. perkins has moved to a scheme that has the counterwieghts extended out to the sides. He has increased the effective mass in the plane that effects azimuth. The immedia is a unipivot, so stability in this area is important, and the well tempered is also a unipivot, with a very similar damping scheme. The rb-series is not a unipivot, so the azimuth is fixed, and while the aftermarket counterwieghts do move the mass of the arm lower, I wonder how much of the improvement is because the mass is lower, or because the properties of energy absorbtion. With a counterwieght that is perfectly round with it's energy transfer dead center, the energy would be reflected back equally and at the same time, and if the point of energy transfer is off center, this may serve to be an effective way of breaking this up. As evidence I would point out the reported success of mods that change the tension of the rear stub of the rb-type arms and they're success relative to these droppoed counterwieghts. And also, regarding mass for benifits of energy absorbtion, One of the best tweaks for the well tempered arm was arm wrap on the base, and also, the immedia arm first had a base that was very similar to the base of the well tempered arm, until it was changed to the heavy stainless piece it is now, and the success the graham 2.0 has because of it's heavier base over the 1.5. I am looking foward to hearing about your results. |
Basement, regarding your thoughts on counterweight mass and absorbing vibrations, I have developed a new hanging counterweight for my arm that totally de-couples the mass from the arm, and the only thing that contacts the end-stub is a short length of fishing line. The counterweight is a lead bar that hangs under the end-stub like a swing, at the height of the platter surface. I have found that this beats the holy hell out of the Expressimo Heavyweight on my arm, and I am using it exclusively now. The sound is way more open and unencumbered, and really kicks ass. In my case, I found that getting the mass of the counterweight off the tonearm shaft entirely, really opened up the sound. With this counterweight and the HiFi mod, I am really in the top league with this tonearm now. |
Tom- Would I be better off hanging a lead weight off the end stub than attaching lead to the bottom of the counterweight on the WT? Thought that lead on the counterweight would also serve to dampen vibration, something that decoupling would not achieve. I would suppose that, if using a hanging weight, the shortest string possible would be better to keep it from swinging? |
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. |
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. |
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). |
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 |
I haven't given this subject thought for a while, but Jimbo3's new development prompts me to wonder whether it will be problematic in any way to add the weight unevenly (or maybe 'in a statically unbalanced fashion' would be a more accurate description) about the vertical axis (i.e., in the horizontal plane). With the Rega 'arm, the added weight (at least with the lead fishing-weight method) will necessarily be kept concentric with the vertical-bearing axis, since it will be attached to extensions of the axle itself, and the two weights will be added in symmetric, statically-balanced (180-degree opposition) distribution between the two bearing-ends. If I remember correctly, one reason I never tried this tweak with my SL-1200 tonearm (besides me already having added the KAB dynamic fluid damper, and also not being sure that the bearing-end configuration would be amenable to hosting a fishing-weight attachment anyway) was that the 'arm suspension design features a left-hand horizontal-bearing tower that would preclude adding weight to that side, due to there being no clearance available. In other words, I knew that even if I could get a fishing-weight attached to the bearing-axle end, the only place I could do so would be on the right-hand (one) side, leaving the added weight unevenly distributed about the vertical axis. But now, thinking about how one would go about adding the maleable 'plastic' weight Jimbo tells us about, and still keep things perfectly symmetrical, has made me reevaluate the importance of this concern. And I seem not to be able to think of a reason why, with a gimballed 'arm, this would be a big deal. After all, I highly doubt that my S-shaped tonearm is statically balanced in the horizontal plane, but dynamically, this doesn't matter. So it would seem that if I use this product to glom-on some additional weight anywhere I can get it stuck onto the vertical-bearing carriage - statically 'balanced' or not (i.e., without concern for symmetric distribution) - it would produce the desired effect of increasing rotating mass in the horizontal plane only. And indeed, it would be very easy for me to add mass this way with the stuff Jimbo used. Anybody agree/disagree with this conclusion? |
Zaikes, I'm not familiar with the design of your arm, but wouldn't weighting one side significantly more than the other torque the bearings and potentially cause uneven wear? Tom, I received the HiFi yesterday, thanks for the quick shipment. One question about installation: how far onto the axle nuts should they go? OOTB they cover about half the nut. Should I ream them out so they slip on further? I assume they should NOT go on so far as to touch the bearing surfaces, right? Doug |
Doug, they can go on halfway, and that is the normal position. But they can go on all the way by reaming them a little deeper, if you like the look better that way. I sent you an email about it. I hope you got it. You're right, they shouldn't touch the bearings at all, if you seat them deeper. So be careful. |
Thanks Tom, Our first couple of days with the HiFi Mod have been positive and informative. Bass is much tighter. It is considerably more impactful at the front of the note, with less overhang or bloat on the trailing end. Cello and string bass lines are much clearer and more tuneful. Heavily scored orchestral passages are more transparent, more individual instruments and less mishmash. Quite good results. The bass is sometimes almost too impactful, we literally feel airwaves. That's great when it's a bass drum or cathedral organ, but should I feel this from the mechanical action of a harpsichord? I'm not kidding, we do. Have you ever been thumped in the chest by a harpsichord note? It's not just about the bass. All notes are affected in the exact same way: there's more impact and body at the front and middle of the note and less overhang. In our system this change is audible even for VERY high notes like cymbals, triangles, harpshichord, etc. For harpsichord this is not so good, it reduces the last bit of bloom and color. We're going to play with VTF and try different mounting schemes before gluing the weights on. I'd like to retain most of the bass-mids benefits while allowing the extreme HF's to stay a little more relaxed. It's possible keeping the weights from damping the bearings may do the trick, so I may try mounting them on a bar straddling the bearing yoke. YMMV of course, stay tuned. |
Followup review of our HiFi Mod: I'm a bit embarrassed. After two more listening sessions, it appears the odd effects I reported above are entirely due to problems with individual recordings. Like any high end component, TWL's mod reveals more clearly what's on a record. On good recordings the effects are good, while the flaws of poor recordings are more easily heard. In the 'Case of the Dark and Thumping Harpsichord', it seems this recording was made in a cathedral basement, in a small room with stone walls, floor and ceiling. To tone things down they covered every surface with blankets. This over-damped the HF's but was insufficient to control echoes from the bass and the action, which remain heavily reverberent. Even worse, the weather during the sessions was hot, humid and heavy. A recording made in those conditions SHOULD sound dark, heavy and thumpy. The HiFi Mod helps accurately portray the unfortunate truth. Of course on good recordings this closer adherence to the truth is brilliantly successful. The HiFi Mod is a keeper and a winner. Another A+ review! |
Thanks Doug. I thought it would come around to that. Since the mod simply stablizes the arm laterally and cannot add anything, the cartridge will have excursion only to the extent that the recording modulates it. I knew the anomalies were in the recording. I'm very glad that you are enjoying it. Of course, on your rig everything will show, and if there was something bad, you'd know it immediately. Nothing is totally perfect, but for $20, this has to be one of the world's best bang for the buck things ever. As the inventor I may be biased about it, but it does kick some major butt. The voting is still unanimous. Every single person that ever used the HiFi Mod is very well pleased with the results. |
Tom,I must say that I hear a dramatic difference in the bass,its seems to sound more solid and deeper,also,the overall clarity seems to be richer,like the sound has moved up to the front edge of the speakers,I'm very happy with this mod,and agree with you and everyone else that it is weell worth the cost....thanks for all your help Tom...greatly appreciate it...255/501/silver250....Bill |
Bill, thanks for your impressions. I was wondering if you had the chance to install it yet. Really glad that it is performing well in your system. Now you and the others are really getting the max out of your arms. It makes a difference to get all the performance the arm can do, instead of just some of it. The thing I like about it is that it doesn't really change the arm, it just lets the arm do what it can in a better way. You hear all of it instead of a portion. And of course, it also does the same thing for the cartridge because the arm's job is to hold it stable so it can pick up the maximum information. Thanks for your kind words also. I feel very happy to have been able to help all of you with the sound quality of your analog rigs for such a reasonable price. I never really made any money off this mod because by the time I went and bought the stuff and worked on it and drove to the post office, it was a wash for me. But my reward was in the satisfaction that I got from helping all of you. That is why I was always so concerned about whether you got the desired results. It was worth the effort just to read the emails and posts from happy audiophiles. There is no price that can be placed on that. Those responses were worth more to me than any money. It made me feel good, and always brought a smile to my face. Money comes and goes, but happy experiences and friendship will give a lifetime of good memories. Money can't buy that. I thank each and every one of you HiFi Mod users for your faith in getting my mod. There probably won't be many more now that they have changed the OL arm to the new type. But this has been a great experience for me, and it has truly been my pleasure to have met(by email) and worked with each of you. Keep in touch. Tom |
The HiFi Mod still lives! A couple of weeks ago I referred someone to this thread from AA. Next thing you know, he's made a mod for his Empire arm! You have to check this out! SCEvan's AA post about his homemade HiFi Mod… http://db.audioasylum.com/cgi/m.pl?forum=vinyl&n=247585&highlight=scevans&r=&session= And a photo… http://db.audioasylum.com/cgi/m.pl?forum=vinyl&n=247586&highlight=scevans&r=&session= And some followup discussion… http://db.audioasylum.com/cgi/m.pl?forum=vinyl&n=247607&highlight=scevans&session= Genious knows no bounds, and Tom has a new market he can expand into. You gotta love it! |
Doug, I got an email from him today, showing the pics of his mod. Pretty inventive! I think that he could do away with the clamp, and just glue the things onto the side of the housing, and that would pretty it up a bit. I'm very flattered that my idea is still breathing. I guess you just never know where something will end up, when you start a ball rolling. I'm glad he got good results, and it just shows how universal the need is for something like this on many tonearms. I went for the Rega type arms, since there are so many of them out there. But except for 2 guys, they all went onto Origin Live Silver arms. I suppose the Rega guys just aren't interested. Too bad. It can really improve their arms. |
OK! I'm finnaly getting around to upgrading my REGA tonearm. In short I have a P3 with the RB300. I just purchased a new RB250 brand new from 2juki. I wanted to get rid of the spring and the tracking force dial. I do have an expressimo heavyweight,already. I have on order, another VTA riser(cat must have gotten the other one to play with), and the hex-treme tonearm end stub. I am going to upgrade the wiring too(another thread?) Ihave chosen to to do the work myself to keep cocts down. Anyway, any suggestions on what kind of weights to attach to the RB250? The bearing housing(I beleive that's what it is) is round, not flat! The classified ad is still in under tonearms here on the 'Gon for a picture, for those that want a reference.Any ideas on what to attach and with what(epoxy, I beleive was recommended) |
Yes, just glue the weights to the caps for the RB250. Make sure that they are nicely centered, and also be sure that the shape of the weights you get don't interfere with the operation of the cueing lever. I found that the long tapered bullet shaped sinkers work best. You can use up to 7/16 ounce weights on each side. For higher compliance cartridges, use less weight. |
Well........ I finally got hold of some lead bullet fishing weights (the ones that weigh 11.42 gms) & drilled into them 1/4", as TWL himself did. Since I use a Benz L2 (static compliance 15um/mN) I chopped off the tips of these weights & brought the weight down to 9gms. I press fitted the weights using Blu-tack. Had to adjust VTF & backed down anti-skating a bit too. Indeed, TWL, the addition of these lateral weights is a minor revelation! Bass is much deeper & tighter. Dynamics are more explosive, for sure! It appears to be the equivalent of the stylus tracking deeper in the groove 'cuz the info retrieval is much greater. The OL Silver 250 Mk1 was a great tonearm in its stock form but these outrigger weights take it to another higher level. The only annoyance is that it interfers w/ the cueing mechanism & like you I too have to come in from the side. My old habit of going straight for the lever is dying a hard death!! ;-) |
Bombaywalla, thanks for your report on your HiFi mod. Another satisfied user. This also works just as well on any Rega tonearm. Where are all you Rega guys? After 2 years of testing on dozens of tonearms of various types, and various cartridges, with no bad results, I'd have to say that this HiFi mod is an unqualified success. I really think that the people who haven't tried this mod, are not fully aware of just how much better things sound, when the HiFi mod is installed. Most people who tried it were amazed at the amount of improvement. |
Bombaywalla, glad you finally got a chance to try them. We demoed our OL Silver both with and without the weights before glueing them on permanently. It was no contest. You probably did the right thing using a little less weight for the Benz. Twl will have to come out with HIFI MkII for cartridge swappers. How about threaded weights that can be moved in or out for fine-tuning? The magic continues! |
Alc777, the Graham weights have two functions. The primary reason for them is control of azimuth-rocking on warps. Stabilizing lateral inertia was a secondary benefit AFAIK. On a gimballed Rega or OL Silver no azimuth control is needed, so the primary (only) effect of Twl's weights is the increase in lateral effective mass. |
Johnnantais, I think you will like it. This mod is just like the types of things you like to do: cheap, easy, and effective. I like those kinds of mods too! I made the mods for my tonearm and a DL103 cartridge with 12gram weights on each side, for a total of 24gram increase in lateral mass. For cartridges with a more normal medium compliance, less mass is needed. With Grado or other high compliance cartridges(including Cartridge Man Music Maker II), it may not be needed at all, and could cause the "dreaded Grado Wobble" when playing. NOTE: The mass MUST be equal on both sides of the pivot. I figure that this mod on your Lenco/Rega setup should send you directly into audio Nirvana! I really do think you will be surprised at how much better it sounds after modding. Have fun!!!!!!!! |
Zaikesman, because if it is not, it will cause the tonearm to have a lateral force applied in the direction of the heavier weight, like an anti-skating adjustment. I have read arguments from others that this is impossible and physics dictate that it is impossible. I counter that argument by having done experiments that show it is not only possible, but predictable. I have done leveling and every other precaution, but it happens. One person who bought the mod got so anxious to listen that he tried to play with only one weight installed, and the tonearm skated all the way across the record from just a slight bump! So, no matter what some may say in theory, in practice this is an issue that must be dealt with. Perhaps it is simply because ideal theoretical conditions cannot be met in practice, in this application, and the bearings are smooth enough to allow the drift. Small variation of unequal weight may be dealt with by adjustment of the anti-skate mechanism on the tonearm. Whatever the reason, it is important to have a reasonably close match of the weights that are used for this purpose. I'm not saying that it is necessary to take this down to the 1/10000 of a gram, or anything. Just make them pretty close, and that should do it. When I make them, I just eyeball them for the same length, and use weights from the same package that were pre-weighed before I cut the depressions in the ends. That has been close enough for all my previous work. Also, it should be noted that the length is important, because the force applied increases by the square of the distance from the pivot. Since this is a geometrical increase, the length of the weight(which creates the distance of the center of mass of that weight from the pivot) is pretty important also. I made the weights about an inch long, because I am using that geometrical force increaser to assist the desired effect, while keeping the actual mass that I'm using to a minimum for the application required. |
Interesting. It does seem somewhat counterintuitive (in the case of a gimbal 'arm only). Obviously, the situation cannot be totally analogous to an anti-skate hanging weight arrangement, since in that case the connecting piece of line and bracket over which it hangs work together to apply the gravitational force in a lateral vector. Your experiments seem persuasive though, so it would be educational to find out the reason for the observed behavior. I would suppose that to someone with the requisite knowledge of basic dynamics and the fundamentals of the application at hand, this would be a "D'oh!" question, but judging by your own uncertainty, and the certainty of some of your (presumably well-versed) correspondents apparently being at odds with experimentation, perhaps not. As I mentioned above, I don't think that an S-shaped 'arm (such as my own 1200) would be statically balanced in its lateral mass distribution, and the argument could be made that uneven mass distributions as seemingly innocuous as headshell offset or a headshell finger-rest, operating at the distance from the pivot point which they are, should then be almost as disruptive even on a straight 'arm (or could those two factors cancel each other out?). As far as the TT leveling necessity goes, this is of course true anyway - extra weights or no - since the unbalanced (due to the applied VTF) mass of the 'arm/cart is always in play. |
Zaikesman, I believe I can explain this phenomena, and it is interesting because it relates to the effectiveness of this mod. You are correct in your visualization in that in a pivoted arm, movement is restricted because of the fixed position of the bearings, and wieght placement will not alter what the bearings allow, but it can, and does, shift the forces on the bearings and the amount, and this affects the direction of the forces and the resistance to force. picture a straight rod with a pivot in the center and equal wieghts on each end. if you bend the rod at the center so that one side is down and the other is level, the other side will then wnat to come down as well, evan though you haven't changed the weight on each side of the pivot. now picture the same straight rod with a lot of weight on one end. the location of the pivot has to change to make them balance. now flip this stuff sideways and consider the pull of the cartridge on the pivot of a tonearm. to shift the mass in relation to the pivot will shift the force on the pivot, just as changing the location of the pivot change the balance of the arm. in the case of the lateral force, or the anti skate, it would shift to one side of the bearing. if you were to remove the arm from the table and hold the arm so it hangs toward the floor, it would not hang straight down if you had more weight on one side than the other. with the arm on the turntable, there is no force on the bearing until the record spins and pulls the stylas away from the pivot. with a change in wieght distribution, you change the amount of force required to pull the cartridge from one side to the other. the nature of the hifi mod is to increase the lateral mass as to increase the resistance to sideways movement. to add a weight on only one side will still increase resistance in both directions, but will increase it more in one direction than the other. |
I'll jump in here for a sec. to add that I've used Twl's "HI-FI" tweak on a vintage Empire 598 table w/ 598 tonearm, employing a heavier and longer lateral weight on the "right" or outside of the arm yoke to generate anti-skate (the inside weight is quite small). It doesn't take much in the way of high-tech testing to verify the outcome of setting my arm up this way. All one has to do is closely eyeball the cantilever as it touches down on spinning vinyl: without the offset HI-FI tweak the arm "wants" to move "in" towards the platter spindle and the cantilever bends "outward" away from the spindle in response; with the tweak installed the cantilever remains straight upon touching spinning vinyl, and remains so. My vintage arm used an A/S spring tucked inside the yoke that created resonance issues, now gone entirely since I chucked the spring and discovered the A/S effect with help from Twl. A while back I engaged a lengthy argument on the Vinyl Asylum regarding such A/S effect and it turned ugly, personal and stupid; the gist of it was "me" saying "it actually works!" and "them" saying "but it's not physically/mathematically possible...so you're an idiot, etc." No more arguing for me - it flat works. It "has" to work, in the sense that the fact of the A/S effect only validates the basic concept of the *concentric* HI-FI tweak...beneficial effect of which has now been verified via user reportage again and again. Personally, I think it's just about the coolest thing I've learned since taking an interest in vinyl. BTW, I fiddled with the left-right balance (length and weight) of the offset HI-FI tweak by ear, the aim being to get a centered stereo image. |