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Hello, I have read claims that an S tonearm has a lesser tracking error than a straight tone arm. That contradicts my rudimentary understanding of geometryI tried to research it, but did not find anything in terms of comparisons.
What are the advantages of an s-shape tone arm? Just a better dealing with resonances (rotational, instead of shear torque)?
Follow Ups:
A lot of DJ turntables nowadays use straight tonearms, but *no offset angle* at the headshell. This apparently improves skip resistance considerably, at the expense of 10-20 degrees of tracking angle error.Obviously, the sound quality suffers, and all audiophile-oriented straight arms angle the headshell.
Think I'm making this up? Look at the Stanon STR8 series.
The best alignment for that type of tonearm would be a single null-point at 79-mm. This requires an underhang rather than an overhang. ;-)
I have one of those, I might measure it to see if it is underhung.No, I'm not a DJ, I bought it so I could make some measurements on the drive electronics, I'll sell it on Ebay when I'm finished.
Say you are a radio station and you have ham handed dj's....having universal replaceable headshells allows you to set up multiple cartridges so you can accomplish nearly instantaneous swaps to keep your tables running.Or imagine you are a mono 78 nut with good stereo LP's -- the S shaped tonearm allows you to set up a variety of cartridges on universal headshells. I was using a variety of headshells on mine that allowed for the best sound reproduction for each cartridge I owned. I consider the straight forward replaceable headshell this designs most helpful feature.
The advantage of a straight tonearm is mass reduction and being able to redistribute this mass as a means of improving sound reproduction.
The disadvantage of a straight tonearm is that you are likely to be married to a manufacturer's proprietary headshell in order to accomplish quick changes as described above. If you have such a tonearm buy these while you can!
I find it fascinating that I can mount a variety of tonearms and hear completely different quality of sound reproduction. In some cases tonearm changes will lead to greater sonic difference than cartridge changes.
For instance my Denon DL103R sounded pretty plain jane to me until I mounted it in an Empire 980 tonearm with a very heavy headshell. Then it sounded lush and full like real live music. So having the right combination is often more important than just the shape of the tonearm.
My favorite tonearm is a screwy looking unipivot designed by Magnepan. Thank You Win for letting me taste the fruit of genius.
This thing digs out inner detail better than most any tonearm I have owned or sold. It is a straight tonearm, carbon graphite design with the most impressively engineered counterweight system I have ever seen. The goal of a tonearm is to plant the stylus right there in the groove. The counterweight design shows the cartridge to function as if it has infinite mass at the stylus and allows the vertical tracking to respond as if it were light mass. It gives you the best of both worlds. I know of no other manufacturer that offers a better designed counterweight.
I guess the goes around in a circle and ends up saying that there are many more factors than the shape of the tonearm wand that go into making an excellent sounding tonearm.
Tonearms work as a system to help the cartridge function ideally. This is one very complex system to nail perfectly.
I believe the S arm was designed to allow proper offset angle while accommodating interchangeable headshells mounted straight to the end of the arm tube. When concern for a lower mass arm developed to match high compliance cartridges back in the 70s, someone realized a fixed headshell could reduce mass. Once the fixed design gained popularity, designers realized they could utilize a straight arm tube, further lowering mass, with the fixed headshell itself being offset. Now that high compliance cartridges are not so common, medium mass arms can offer interchangeable headshells once again. Cartridge compliance matching with arm mass for best resonant frequency is more important that arm shape, in and of itself.The other consideration is arm bearing angle as discussed by BK.
Hi,Regarding alignment of a cartridge, the tracking error is the same for an s-shaped tonearm as it is for a straight tonearm with an offset headshell (not a straight tonearm like those popular on Vestax DJ turntables which do not have an offset headshell). Tracking error is determined by tonearm effective length, the mounting distance and the offset angle. The shape of the the tonearm between the stylus and the pivot has no effect on tracking error.
From a design point-of-view, the differences between a straight tonearm and an s-shaped are subtle. An s-shaped tonearm can have vertical bearings that are aligned with the cartridge even when the vertical pivot axis is perpendicular to the tonearm tube, whereas this is not possible for a straight tonearm.
For a straight tonearm to have vertical bearings that are aligned with the cartridge, the vertical pivot axis must be offset by an angle of about 20 degrees from perpendicular.
Best regards,
sounds like your post gives the nod to S-shaped arms in terms of having the vertical bearing aligned with the cartridge (which is a good thing).for a given effective length, is an S-shaped arm 'longer" (=more material to resonate)?
for every "pro", is there a "con"?
I think Brian's point is that it's simpler to make a vertical bearing which is perpendicular to the axis of the arm through the pivot (as required for an "S" arm) rather than one which has an offset angle (as required for a straight arm). For a given level of machining tolerance the simpler job will turn out better but the difference is, as he noted, subtle.For a given tube size a straight arm will always be stiffer. From there on you are on your own, my opinions on stiffness and tonearm resonance differ wildly from the accepted wisdom so we won't open that particular can of worms.
nt
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