What defines a good tonearm


I'm in the market for a very good tonearm as an upgrade from an SME 345 (309). Most of the tonearms I have used in the past are fixed bearing except for my Grace 704 unipivot. I dont have a problem with the "wobble" of a unipivot, and they seem the simplest to build, so if they are generally at least as good as a fixed pivot, why wouldnt everyone use a unipivot and put their efforts into developing easier vta, azimuth and vtf adjustments, and better arm materials. Or is there some inherent benefit to fixed pivot that makes them worth the extra effort to design and manufacture
manitunc
Now that you mention it my wife and my tonearm have a lot in common. Both take a lot of maintenance and are fiddly to get just right but the results are well worth it. A great deal of synergy but adjustability and ease of set up? Not so much.
For a serious answer I have found that the execution of the particular arm is more important than the design principal chosen. Conventional arms, unipiviot arms, linear tracking arms, etc can all sound great [ or not!]. Every design principal has strengths and weaknesses and great designers can maximize the first and minimize the second. If one design principal were clearly better then we would not still see the variety of arms we do. Unless of course audiophiles were just mindlessly searching for novelty and the latest thing regardless of sound quality; what a ridiculous thought!
Stanwal,
And I guess thats my point. I mean, there are DIY unipivot arms on the web using knitting needles with material costs under $5.00 that are being touted as being more than acceptable, so how much more does it cost to make a great unipivot that is priced at $5,000.00. I know they are beautiful, and the workmanship is superb, and they have adjustability and all that, but if unipivot is the answer, why bother with the difficulty of building a fixed bearing design. Or is there some deficiency in unipivots that the fixed bearing is trying to fix.
I remember using a Pickering table that had a unipiviot arm consisting of a large steel needle which fit into the bottom of a plastic cup on the tonearm. Did it work? Sure. Did it sound like modern arms? Hell no! The question is , what do YOU find acceptable! Just because it is a unipiviot does not mean that it the equal of a GOOD unipiviot. My Graham arm is a unipiviot and cost considerably more then $5, as do the VPIs that I am a dealer for. If you cannot hear the difference between arms then get the cheapest one you can. If you can get the best you can afford. No one can prove to you using logic that a good tonearm is a necessity, only your ears can tell you the answer. I am constantly amazed by what SOME of the DIYers think is acceptable; others are among the most sophisticated of audiophiles. Many of the expensive arms on the market were designed by individuals who were dissatisfied with the commercially available ones, starting with SME and on through Graham, Basis, etc. I am a great believer in saving money but an even greater believer in good sound; just like in every other sphere in life, while money is no guarantee of quality, good costs more than bad when everything is taken into consideration.