A friend sent me these scans of a DIY tonearm project from Japan.
Pictures here
Looks like he's hoping to eliminate tracking error. Lot of parts, though.
Anyone here understand Japanese?
Pictures here
Looks like he's hoping to eliminate tracking error. Lot of parts, though.
Anyone here understand Japanese?
Garrard 100 Zero tonearm...
basically it looks like a better quality version of the Garrard tonearm. Said to have tracking error in the same range as a 5' (yup that's feet) tonearm.
The issues are mainly the requirement to pivot the headshell, and to do it while retaining zero play.
The Garrard arm's main weakness was the unequal (when compared) length to the actual tonearm "main" arm. I know I have one.
I think the concept has a lot of merit. Unfortunately I am not sure it can be realized without too many comprimises. I may try to modify my arm to improve the pivot bearing.
stew
basically it looks like a better quality version of the Garrard tonearm. Said to have tracking error in the same range as a 5' (yup that's feet) tonearm.
The issues are mainly the requirement to pivot the headshell, and to do it while retaining zero play.
The Garrard arm's main weakness was the unequal (when compared) length to the actual tonearm "main" arm. I know I have one.
I think the concept has a lot of merit. Unfortunately I am not sure it can be realized without too many comprimises. I may try to modify my arm to improve the pivot bearing.
stew
Hi there,
now this is really great. The pseudo-tangential arms like those from alan william say (implemented on Garrard zero) or its original (?) the Burne-Jones arm. They just deserve to be copied. That means DIY or commercial! How come none of the k€ tonearm companies even try. It must be way easier to sell 'simple' designs for big complex sums
And of course such a complex design CAN be executed really nice, also with regards to the pivots. Have a closer look at the impressive tangential (but passive and therefore silent) design from Micha Huber:
http://www.tonarm.ch/home_e.html
COOL, but costly. So DIY. I just wish I had studied some japanese. Untill then, I'll have to wait for someone real nice who will translate the article.
enjoy your favourite albums!
Mark
now this is really great. The pseudo-tangential arms like those from alan william say (implemented on Garrard zero) or its original (?) the Burne-Jones arm. They just deserve to be copied. That means DIY or commercial! How come none of the k€ tonearm companies even try. It must be way easier to sell 'simple' designs for big complex sums
And of course such a complex design CAN be executed really nice, also with regards to the pivots. Have a closer look at the impressive tangential (but passive and therefore silent) design from Micha Huber:http://www.tonarm.ch/home_e.html
COOL, but costly. So DIY. I just wish I had studied some japanese. Untill then, I'll have to wait for someone real nice who will translate the article.
enjoy your favourite albums!
Mark
oshifis said:
Yes. absolutely.
Just because an arm has no tracing error doesn't mean it's a linear tracking arm.
The huge difference is that a true linear tracker has the stylus forces always acting straght down the arm tube, fed into the bearing at right angles. Result, no bias forces and no changes with dynamic loading.
These arms will still both exhibit all of the bias (antiskate) problems of an ordinary arm because they still have (varying) offsets. Given that they introduce a lot of extra parts, joints, friction and mass into the equation I suspect the performance would be much worse in that respect than a normal pivoted arm.
Hi there,
sorry for me being a believer, but I don't see why "the design solved one problem, but introduced several others". I think it's the other way around, actually
And for the era concerned, the zero arm was, concidering the asking price, plenty good: Very short, stiff arm; Made of Berrylium (OOOOHH): strong and extremely light so that any rotational inertia objections are simply not valid. Further the design sports a very, very low tracking error. The patent describing the design (e.g. DE2121398A1) mentions an a tracking error of -64 arcseconds at the inner grooveradius. This is really low! And IF one gets all the pivots to work nicely (i.e. truely silent
) it can work true wonders.
Now, if anyone out there can make such a long arm, rigidly and with less than 25 g effective mass, please give me a buzz. I am pretty sure a source of unobtainium would have been discovered in case anyone indeed could....
kind regards,
Mark
sorry for me being a believer, but I don't see why "the design solved one problem, but introduced several others". I think it's the other way around, actually
And for the era concerned, the zero arm was, concidering the asking price, plenty good: Very short, stiff arm; Made of Berrylium (OOOOHH): strong and extremely light so that any rotational inertia objections are simply not valid. Further the design sports a very, very low tracking error. The patent describing the design (e.g. DE2121398A1) mentions an a tracking error of -64 arcseconds at the inner grooveradius. This is really low! And IF one gets all the pivots to work nicely (i.e. truely silent
) it can work true wonders. Well, Nanook, you are too humble. An error of -64 arcseconds at the inner useable radius (DIN norm just 57.5 mm at that time) would require a "conventional" (Baerwald protracted) tonearm having an effective length of 15.1 meters (SI). The romans (possibly some chinooks as well) would speak of 49.5 foot. Anyway, Nanook, your source lost one order of magnitude somewhere along the the line
Now, if anyone out there can make such a long arm, rigidly and with less than 25 g effective mass, please give me a buzz. I am pretty sure a source of unobtainium would have been discovered in case anyone indeed could....kind regards,
Mark
The more I study the battle of forces applied to a cantilever, the lower my opinion of offset pivoted arms. IMHO, tracking error is only part of the problem, and maybe not as large an issue as commonly believed. As Jeff says, the introduction of offset is what causes skating force. The Zero 100 arm is a pivoted arm with offset, so it's just not in the same category as a linear tracking arm. It's clever and neat, but it also introduces a lot of complication for what it accomplishes.
Hi Conrad, I believe you are thinking the same way that I am. How is that linear arm project going?
My big concern with these arms is that all of the energy needed to move the extra joints, pulleys, string(!) and the six extra bearings ( ) in that Burne-Jones design is being supplied by side force on the poor little cantilever.
Personally, I wouldn't want to trade a bit of tracing error for a huge increase in mass and friction.
My big concern with these arms is that all of the energy needed to move the extra joints, pulleys, string(!) and the six extra bearings (
) in that Burne-Jones design is being supplied by side force on the poor little cantilever. Personally, I wouldn't want to trade a bit of tracing error for a huge increase in mass and friction.
When the weather gets warm I'm going to start cutting metal and experimenting, but I'm a bit frustrated. Like everyone who's come before, I can't solve all the problems in any one design. Arms are a nasty trade-off! I also find, in spite of any protestations to the contrary, I'm swayed by aesthetics. If a design looks "bad", I have trouble considering it, even if the math says it's the greatest thing since sliced bread. BTW, the things on your web site are brilliant! I'm surprised you don't already have a linear arm up there.
Conrad Hoffman said:I'm surprised you don't already have a linear arm up there.
.....too damned hard! But it does get rather tempting when you keep posting those air bearing ideas. I'm very familiar with Len Gregory's "conductor" arm and it really does sound superb, though very fiddly to use and, IMO, a bit ugly.
I'm proud to say that my arms contain absolutely NO new ideas, they are all shamelessly pinched from much better qualified people than me
You are right, there is an engineering aesthetic: things that work right usually look right - the Forth bridge, the Hawker Hunter etc.
Do keep posting the progress on the arm, I'm running out of ideas to steal.
Hi Jeff, and all others out there,
I can understand your concerns that you submitted:
Still, in the much more advanced, near or truly tangential designs (linear included!), one has to pay attention to the extra pivots, or sliding friction and/or pumps induced noise. But if you do, you end up at so much lower distortion levels that no debate remains really. The point you made on extra pivots, is not as grave as you may think. The minimum number of contact points in the ball bearings for a gimbal design (e.g. RB250) is 8. A Burne Jones can be done with just 6 contact points! Executing the pivots cleanly, like in the Thales, one of the best, if not THE best tonearm in the world can be made. Just listen. Makes all beliefs and arguments superfluous.
regards, and enjoy your albums!
Mark
I can understand your concerns that you submitted:
one should realise though that inertia and not mass per se is important when evaluating a tonearm design. Therefore the counterweight on a pivoted conventional tonearm should preferably be heavy(!). Increasing the counterweight density decreases the effective arm mass at the tip. With an air-bearing linear tracker (e.g. forsell or kuzma) the lateral inertia (important for a not perfectly centered record) is the complete mass of the sliding arm!! In general this will be WAY bigger then on nearly ALL pivoted tonearms (conventional or pseudo-tangential, except dynavector DV507). How come generally audiophiles prefer a linear tracker nonetheless? Or, for that sake, prefer in general the 'sound' of a 12" arm over that of a 9" one? Could the reason be the 0.65% peak distortion (minimum mind you!) for a nine inch arm? I am, by the way, not willing to call 0.65 % distortion "a bit of tracing error."jeff spall said:
My big concern with these arms is that all of the energy needed to move the extra joints, pulleys, string(!) and the six extra bearings (
Personally, I wouldn't want to trade a bit of tracing error for a huge increase in mass and friction.
Still, in the much more advanced, near or truly tangential designs (linear included!), one has to pay attention to the extra pivots, or sliding friction and/or pumps induced noise. But if you do, you end up at so much lower distortion levels that no debate remains really. The point you made on extra pivots, is not as grave as you may think. The minimum number of contact points in the ball bearings for a gimbal design (e.g. RB250) is 8. A Burne Jones can be done with just 6 contact points! Executing the pivots cleanly, like in the Thales, one of the best, if not THE best tonearm in the world can be made. Just listen. Makes all beliefs and arguments superfluous.
regards, and enjoy your albums!
Mark
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