Unipivot vs Linear Tracking

Btw,forgot to mention,the "pivoting arm" I alude to IS a unipivot!

Sorry for not being more specific

Spl, are you asking about Unipivots or pivoted arms in general? Assuming the latter...

I have to admit being in the camp of true believers around linear tracking arms. I largely agree with Sirspeedy about the magic they can deliver if properly designed, executed and set up, and I've always used a linear tracking arm in my own system. At the same time, I've heard linear arms that easily are outperformed by any number of pivoted arms (anyone remember the Rabco linear?)

Over the years, my listening with well setup pivoted arms convinces me that "it's all in the execution." The sound quality from any of the top arms, whether pivoted or linear, can be stunning when properly set up, and the sound can be indifferent to atrocious when care and attention has not been given. As always, the magic is in the details (as Lloyd Walker is fond of pointing out).

As to setup, linear tracking arms do eliminate having to make a choice about tangency -- its either exactly correct along the entire tracking line or it's exactly wrong everywhere. A pivoted arms will always be correct in at least two points across the record, even if always off everywhere other than those two points. :-) I wouldn't say that either is easier to set up correctly than the other.

We moved a year or so ago, and I had to transport and then re-assemble my Walker Proscenium turntable with its linear tracking arm. I easily spent 10 hours over severaly days finetuning the setup of the arm and cartridge until I was satisfied. (Lloyd and Fred can do it in an hour or so.) I suspect I would have spent the same time with a Graham or Triplanar or VPI or Scheu.
.

i must agree with Sirspeedy when he says...

Yet,and yet....IMO,once you hear a "superb system" that employs an "elite" linear tracking arm(preferrably air bearing)the experience is akin to "what is assumed" regarding being exposed to something like crack cocaine.

YOU ARE INSTANTLY HOOKED!!(also assuming you have been listening to LP's for a really long time,and know "their" signatures)

From my experiences,and taking my way of listening "into" a great set-up(which my friend "has" in spades),the linear/air bearing arm is simply an amazing instrument!

it's not right to label my system as 'superb'.....that is for others to say.....but i could not describe the emotional reaction i get to my Rockport Sirius III with an air bearing linear tracking arm better than 'the Speedy one' has done.

there is a fundamental 'grounding' of the music; if you take the advantages of a 12" arm over a standard length.....and increase that effect by a few (many?) degrees. it is difficult to separate my particular arm from the whole of my particular tt, as it has been designed as a whole system.

Rockport did make a couple of linear tracking arms which could be purchased separately, the 6000 and 7000; but they are not at the level of the Sirius 3 arm.

linear tracking arms come in many different levels and degrees of quality. you will find many opinions on their relative performance. early ones were driven by motors, the arm would 'crab' across the record. some non-air bearing linear tracking arms have trouble with keeping the rail properly clean and are particularly troublesome to keep optimal.

it's is said by some that air bearing linear tracking arms are bass-shy due to the lack of a direct contact hard bearing. again; it is a matter of execution. no one who has heard bass from the Rockport in my room would say that.

i cannot speak to other linear tracking arms regarding the need for maintenance or tweaking. my arm is amazingly self sufficient; i can switch a cartridge in about 15 minutes including dynamically adjusting VTA. there is a groove in the platter which makes overhang a snap.....just line it up. once set it 'never' needs adjusting. when i'm in the mood i can easily adjust VTA for each record thickness, takes 5 seconds. my compressor (upstairs in the attic) has never needed any attention.

at the top of the food chain a pivoting arm and linear tracking arm are both great choices. there are many more great pivoting arm choices. if you get the right linear tracking arm and it's optimized for your turntable; it is very easy to live with. but that's not cheap and there are not many choices.

added note; regarding which is easier to set up. i have not seen an arm easier to set up than mine. the reason is that there are simply less varibles. you have no overhang question, no real azimuth question (in theory you do but not really). no anti-skating. the only issues are VTF and VTA. VTF is simple. i set VTA by ear dynamically; listen for 5 minutes, make minor adjustment and i'm done.

there is fluid filled trough for resonance control but it needs no attention at all.....the record is always perfectly flat and the isolation of this tt is pretty good.

all the pivoting arms i have used require about 4 times the effort to get you pretty close; then a few hours of small tweaking to get things right.

Great responses by all above. Of course it's important to note they're all talking about arms that cost far more than most pivoted arms (more than most complete vinyl rigs actually).

I haven't had the pleasure of working with a top level linear tracker, but I did own two of those Rabcos back in the day. Even those, crude as they were, were ridiculously easy to set up. Sonically they were at least the equal of similarly priced pivoting arms I had. Unlike everyone else on the planet, I never had a lick of trouble with either of them. I still have the ST-8 and it works fine.

My (pivoting) TriPlanar arm costs more than those Rabcos, the tables they were mounted on and all the cartridges I ever used with them put together. Is it better? Well, of course. In fact it's phenomenally better since, as noted above, any arm requires good execution and setup. But even with this marvelously adjustable device and plenty of experience, I can't dial in a strange cartridge in much less than 25 minutes, and a really good setup takes longer.

Linear trackers are based on the theory that tangency is the most important feature of the arm and that the linear tracking arm perfectly mimics the geometry of the cutting head of the master, whereas pivoted arms inherently display tracking distortion. However, the cutting head of the master is applying great force with a blade while a linear tracking tonearm is "dragging" the whole arm assembly across the record with a few grams of down force, quite a different situation. You could say that linear trackers are triumph of execution over practicality if they are done correctly.
I spent some time playing with one of John Elison's spreadsheets from vinyl asylum, plugging in values for tracking error for pivoted arms. I find it difficult to believe that a properly set up pivoted arm, even a 9 inch arm, has enough error to significantly "hear" the tracking error unless the arm is not set up correctly. I tend to think the audiophile imagination "knows" there is some tracking error and runs rampant to fill in the blanks to believe that 12 inch arm and linear trackers are audibly superior "because" of the geometry advantages. If somebody states they can "hear" the superior qualities of a linear tracker vs. a properly set up pivoted arm, I would be very skeptical.
I tend to believe that if linear trackers and 12 inchers sound better, it would be for reasons other than the geometry, either superior overall execution of the arm or better cartridge matching or higher effective mass etc. It is hard for me to believe that the "fumble factor" involved in a linear tracker would make it a better choice in every instance. The linear tracker seems to have many design disadvantages and pitfalls compared to a good pivoted arm. I hate to invoke the dreaded DBT, but that is one that I would like to see the results of.