I am very strongly in the tangential arm camp. I also think they sound better. Furthermore, the symmetrical wear pattern results in a stylus that can withstand more use before it must be replaced. This is good.
I used a Rabco SL-8 (1st model) from 1971 to about 1984 (and still have it). Great performance and stylus life, as you say, but I eventually began hearing faint motor electrical noise in the headphones, whenever the arm was being driven. It sounded like worn or dirty rotor brushes to me. I checked grounding and shielding, and rerouted the signal wires inside the SL-8, but to no avail. I was never able to eliminate/isolate the noise from the signal.
At the time, replacing the motor seemed like it would be costly and nearly impossible to find. It's a highly precision swiss-made motor with built-in gear reduction. It was a marvel of miniature engineering at that time, and probably a by-product of the space race. The motor was certainly the most expensive part of the SL-8, which otherwise looked like something I might build in the shop using off-hand parts--not that that's a bad thing. It made it pretty easy to work on, and besides, it did look pretty cool.
The Rabco had other issues. The platinum whisker contacts would sometimes foul mid-record, causing the horizontal tracking angle to increase until the reject contact was reached. Then the arm would pop up before the end of the side. In order to minimize the electrical noise within the tonearm, The votages were all under 1.3 volts DC, which is the underlying cause of the problem. Not enough EMF to overcome contact resistance.
This problem manifested itself all too often when I had a roommate who smoked. Swabbing the platinum cat-whiskers with alcohol was a major nuisance and I always feared damaging/deforming those delicate whisker wire contacts in the process. Using a spray cleaner like freon (all we had then) or today's Dioxit would have been messy and potentially damaging. Not good on a Thorens TD125 with a walnut arm-board and plinth.
The SL-8 arm/wand did not permit quick and easy changing of the cartridge, and I prefer to play worn and noisy records with a cheap .7 mil ball tip, to spare the wear on my more expensive styli. I now have a half dozen carts mounted in universal headshells, and love the flexibility and fun that these provide with my offset arm.
A Rabco arm modified to use the universal shells would seem to be the best of both worlds, but one must bear in mind that tangentials are more complicated and prone to problems of their own, as my SL-8 demonstrated. The newer straight-line tracking turntables all tend to develop problems, and tend to be very hard to service. Remember the KISS principle.*
Karma16, You are entirely correct about stylus wear, anti-skate bias, and the microscope as a diagnostic tool. And I concur that it's not possible to perfectly compensate for skating. The skating force is significantly affected by groove modulation (loud-soft), vinyl formulation (soft-hard), stylus geometry, degree of stylus polish and wear, and the changing speed of the disc as seen by the stylus, at any point on its radius. The friction of the offset arm's horizontal bearing complicates matters even further and there are still other forces at play such as resonance, which nobody fully understands, and which render bias correction little more than a guessing game. Nonetheless, the offset arm is capable of making very sweet music. It may not be perfect, but as most of us know, a good arm on a good deck can outperform CDs.
Using a blank disc or blank band to set the bias is not very effective. One quick check is to tap on the top of the deck while a record is being played. If the stylus skips to the next groove in, apply more correction, if it skips backward, apply less. With some decks, a sledgehammer blow may be needed, but I don't recommend it. :nono:
A better method is to play a mono disc that exhibits tracing distortion. Play it in stereo mode and listen for distortion in one channel or the other, and adjust so the arm leans more toward the distorted channel (on a stereo disc, the left channel is encoded on the inner groove wall). Bias correction is optimal (at least at that instant) when the distortion is least or exhibits the same intensity in both channels. High quality headphones and an experienced ear are a must however, and without them, the blank band method offers at least a reasonable first approximation.
The more contact the stylus maintains with the groove wall, the harder it becomes to determine the amount of skating compensation needed. But generally, the line-contact and hyperbolic styli generate less skating at a given VTF, and so require less compensation. The skating force generated by such a stylus tends to increase as the diamond wears, and may eventually exceed the skating of a new elliptical. This is actually true of any stylus. When the wear becomes really egregious, the skating force may even promote groove skipping.
My last use of a stylus microscope (at an audio salon) to examine my own numerous styli indicated that I tend to overcompensate for skating. So, now I try to use less compensation than before. Without the microscope, I'd never have known. How much will it help? Perhaps not a lot, but no harm in trying.
I seem to hear stylus wear within a hundred hours of installing a new stylus. It's slight and not often present at first, but it's there. I've also read that the major record labels would change diamond styli on their QA equipment every 40 hours or so to ensure they were hearing a worn stamper, rather than a worn stylus. When one considers that the typical stylus is still not fully broken in by that point, it seems that one can never have ideal vinyl playback. It's not a perfect world, so we live with it.
I have a lot of retired styli that have seen only two or three hundred hours play. And contrary to what I've heard on the forums, line contact styli (SAS, micro-ridge, hyper-elliptical, et al.) wear just as fast as ellipticals, despite their lower pressure on the groove wall. I suspect it takes less actual wear of the exotic's diamond side wall before it becomes noticeable/objectionable. This may be in part because of the extremely revealing nature of such styli, but also because it simply takes less diamond wear for the exotic profile to become deformed enough to cause mistracing. And let's keep in mind that as more groove area comes in contact with the stylus, the more impurities and anomalies the stylus will be subjected to, which often results in more noise, although there may be some averaging going on.
Regardless, it seems that the more extreme the geometry, the more susceptible it becomes to wear, which is mitigated by the reduced friction at the larger area of contact, thus the stylus life does seem to be about the same duration or maybe just a little longer for the exotics, but not a lot longer.
So much for those costly styli being more economical. I don't find them so in the real world. I don't have deep pockets, so I save my best styli for the cleanest and finest pressings in my collection. Run-of-the-mill discs get played with the ellipticals and anything with a scratch or grit gets a cheapo spherical.
Don't dismiss spherical/conical tips. A .6 mil ball can sound almost as good as an ovoid on discs with moderate recording velocities, and are more forgiving on a worn or noisy disc. What's more, the spherical tip will be easy on the vinyl, even at a VTF of 2 grams, at which correct anti-skating becomes much less significant.
The cost of a Jico SAS will buy a dozen ball tips. The Ed Saunders "Red Ed" cart made by Audio-Technica, is a very nice spherical cart which at this time is available for a measly $16. Replacement .6 mil ball tips for it are $9.95, a 3-mil 78 tip is $12.95 and the elliptical tip for it is just $19.95. It's a decent cart for your not-so-perfect pressings. See it here:
http://www.edsaunders.com/reded.htm
And an extensive review here:
http://www.edsaunders.com/rededreview.htm
Alas, I fear this post is way too long. Ciao.
*KISS: keep it simple, stupid.
