Linear tracking arms

Tobias, when a linear arm is cued, as the canteliver and stylus drop onto the lead-in groove; if the arm is not level or there is undue friction on the shaft, the canteliver will take the sudden shock of a side load from the leverage of the lead-in groove. this "jolting" action will eventually disable the canteliver attachment assembly. if there is very little or no friction (a properly designed air bearing) and the arm shaft is level, then the Jolt will be minimal and no problem will develop. the other issue is the mass of the arm assembly, which if too great will make this issue more probable. a unipivot arm has some "slop" and a very slight deflection angle (whereas the deflection angle on the linear arm is direct) to absorb the jolt so this is essentially a non-issue with them.....but, of course, this slop (and the geometry) is the design limitation of the unipivot.

this might sound like all the trouble isn't worth it......but i assure you it absolutely is. the only trouble is checking the shaft level about every 2 or 3 months and sliding the shaft back and forth once before playing to remove any dust from the shaft. with such a high-mass turntable nothing really affects the set-up.

Mikelavigne : ouch, what a graphic description of the shock of the stylus landing on the record ! I got a good feel for the leverage effect from the groove. Thanks very much for a very clear explanation of the issues involved in linear tracking arm design as they affect cartridge wear.

I certainly believe you when you say the trouble can be worth it. UHF magazine, for example, swear by their Pierre Lurné-designed linear tracking arm and Audioméca TT. I mentally place this setup, yours and a few others in the very select group of successful linear trackers. At the other end of the spectrum, I also note the regular appearance of used Rabcos on eBay...

Tobias, do you refer to the Pierre Lurne's SL5? If so, I can confirm that I have been using it with no problems for 11 years, and the only problem I had recently (you might have seen my post) was due to my leaving the dust accumulate, and not keeping the arm clean, only God knows for how long. The "problem" was then sovled in 5 minutes. However, recently somebody said to me that because the SL5 also has a pivot of some kind, it is was not truly linear. But who cares, the tracking is and remains linear, as far as I can tell, with all the advantages of linear! And this for only a fraction of the price for one of the big names, not to mention the hassle of pumps, etc.

Inna,

Agree with all the above. I had an inexpensive linear arm (HK/Rabco ST-8) and now have a mid-price pivoting arm (OL Silver). The linear tracker was cool, and I didn't have to fuss with antiskating or worry (much) about tracking error. Nevertheless, the OL arm plays circles around it. Even with the same cartridge, the pivoting OL tracks better and handles antiskate test tracks better. It even plays music better.

Mikelavigne's graphic description of scary cueing is right on. I played a record the other day for the first time with my new arm. While cueing I noticed a terrifying series of gouges in the lead-in area from a previous rough cueing. It looked like someone had used a jackhammer on the poor thing. (Mike, have you been sneaking into my LP collection? I'm pretty sure your records don't look like this!)

Leep--hi, yes I meant the SL5. It's in UHF's Alpha reference system, see

http://www.uhfmag.com/reference.html

Thanks very much for the benefit of your experience with it.

Toby