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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
dougdeacon
3,338 posts
 
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.
dougdeacon
3,338 posts
 
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!
twl OP
3,251 posts
 
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.
phillykid
35 posts
 
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
twl OP
3,251 posts
 
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
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