Unipivot vs Linear Tracking

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.

Cjfrbw,

you make some very good points. why a particular product sounds the way it does is always complicated. how would one elimiate all differencs between any two designs other than a pivot and linear tracking. the answer is not likely to ever occur. so you could never get to a point where you have sufficently isolated the issues to use DBT to prove it. even then, i don't personally believe DBT proves better....at best proves differences were proved to a particular person under specific conditions at a particular moment.

so we are left to assign characterisitics based on experience.....imperfect as that might be.

my personal perceptions about linear tracking on my tt may be as much as result of the eddy current direct drive motor, and the air bearing on that motor and the 60 pound platter. it may be the vaccuum hold down, or the 250 pound plinth. it may simply be the quality of build, and not linear tracking.

my opinion is that when you do go to the trouble to do 100% of all the things that can be done to make a tt perform optimally; one of those things is linear tracking.

i have recently purchased three additional tunrtables, a Technics SP-10 Mk2, an SP-10 Mk3 and a Garrard 301. this is not any commentary on my Rockport; it is a matter of curiosity about all the excitment people are having with these vintage dd tt's when they install them in a modern plinth and add a state-of-the-art arm. i also want to have my other cartridges mounted and ready to play. i am currently contemplating which arms i will use; in any case each arm will be pivoted.

once they are all up an running i may not keep all three (rather the wife may not allow me to).....but i want to hear them for myself.

my agenda was not the linear tracking verses pivoted arm question; and clearly the Rockport and these other tt's will have fundamental differences.....but it should shed more light on the question of this thread too.

personally; i am much more a direct drive (or rim drive) guy than a linear tracking guy and think that properly applied it has more fundamental effect on the music than the arm approach. music fundamentaly is about timing. this comment is not to hijack this thread but more to put it in a bit of context.