There are several different arm types available, and they can all be good. They may have some different strengths and weaknesses, and some are good enough to have mostly overcome any "categorical" weaknesses that may be attributed to the basic design concepts of the arm category they belong to.
Basic unipivot - A single point bearing system, which generally is quite unstable when cueing, but becomes much more stable when playing the record. There may still be some level of instability present when faced with low compliance cartridges. Main advantage is typically a liquid sounding midrange and effortless sounding presentation. Bass is sometimes weak sounding.
Improved unipivot - Some unipivots provide "outriggers" or other forms of stabilizers to counter the inherent instability of the basic unipivot design. These can be top quality sounding arms, and may handle low compliance cartridges satisfactorily. Advantages are as above like the basic unipivot, but with less or none of the disadvantages, depending upon the design. Graham 2.2 is probably the best known and respected of this type. This type is currently quite popular in sales.
Gimbal bearing - Uses a dual axis bearing system employing precision adjusted bearings such as ball races. Has much higher inherent stability than a basic unipivot, but may suffer from bearing chatter in the lower quality or lower price models. Advantages include good overall stability when using lower compliance cartridges. Bass response is usually good. Sometimes they may sound more mechanical or less effortless than a good unipivot, and less liquid in the mids. SME V is probably one of the best known of these types.
Linear tracking - Uses an air bearing or mechanical system to allow the tonearm to track tangentially to the record groove. Has alot of potential for excellent sound quality because of this. However, the expense and complexity of certain designs may make them very expensive. The lower priced models may suffer from maladies that make them sound less good than lower priced pivot arms. Sound quality can be effortless and liquid like the best unipivots, and have the stability and the bass response of the best gimbal bearing arms. The most expensive and highly regarded arms in the world are typically linear tracking air bearing type arms. Eminent Technology ET2.5, Walker,AirTangent, and Rockport are well known arms of this type.
There are some other types such as knife-edge bearing, and dual pivot, and hanging tonearms. These are relatively rare types of arms, but they can be good if designed well. SME 3012 is a knife edge, Morch DP-6 is a dual pivot, and Schroder and Well-Tempered are hanging types of arms. These arms are well regarded, so they can be considered among the better or best arms, even though they use some less conventional designs.
These descriptions are quite general, and may be more or less applicable to any given brand of arm. I do not intend to disparage or hype any one type of technology, but just want to give some basic ideas of the major categories and their typical strengths and limitations.
The best arms in all these categories can transcend the basic limitations of the simple designs, and can be world class arms. Many other things play into this equation, such as materials resonance, construction quality, rigidity, wiring, geometry, etc.
The best thing to do is audition the arms with good reputations in their price ranges that you can afford, and consider the synergy of the table and cartridge that you plan to use. The arm is not working alone, and needs to be considered in a system context with the appropriate table and appropriate cartridges. This is the only way you can get proper results from your package.
Basic unipivot - A single point bearing system, which generally is quite unstable when cueing, but becomes much more stable when playing the record. There may still be some level of instability present when faced with low compliance cartridges. Main advantage is typically a liquid sounding midrange and effortless sounding presentation. Bass is sometimes weak sounding.
Improved unipivot - Some unipivots provide "outriggers" or other forms of stabilizers to counter the inherent instability of the basic unipivot design. These can be top quality sounding arms, and may handle low compliance cartridges satisfactorily. Advantages are as above like the basic unipivot, but with less or none of the disadvantages, depending upon the design. Graham 2.2 is probably the best known and respected of this type. This type is currently quite popular in sales.
Gimbal bearing - Uses a dual axis bearing system employing precision adjusted bearings such as ball races. Has much higher inherent stability than a basic unipivot, but may suffer from bearing chatter in the lower quality or lower price models. Advantages include good overall stability when using lower compliance cartridges. Bass response is usually good. Sometimes they may sound more mechanical or less effortless than a good unipivot, and less liquid in the mids. SME V is probably one of the best known of these types.
Linear tracking - Uses an air bearing or mechanical system to allow the tonearm to track tangentially to the record groove. Has alot of potential for excellent sound quality because of this. However, the expense and complexity of certain designs may make them very expensive. The lower priced models may suffer from maladies that make them sound less good than lower priced pivot arms. Sound quality can be effortless and liquid like the best unipivots, and have the stability and the bass response of the best gimbal bearing arms. The most expensive and highly regarded arms in the world are typically linear tracking air bearing type arms. Eminent Technology ET2.5, Walker,AirTangent, and Rockport are well known arms of this type.
There are some other types such as knife-edge bearing, and dual pivot, and hanging tonearms. These are relatively rare types of arms, but they can be good if designed well. SME 3012 is a knife edge, Morch DP-6 is a dual pivot, and Schroder and Well-Tempered are hanging types of arms. These arms are well regarded, so they can be considered among the better or best arms, even though they use some less conventional designs.
These descriptions are quite general, and may be more or less applicable to any given brand of arm. I do not intend to disparage or hype any one type of technology, but just want to give some basic ideas of the major categories and their typical strengths and limitations.
The best arms in all these categories can transcend the basic limitations of the simple designs, and can be world class arms. Many other things play into this equation, such as materials resonance, construction quality, rigidity, wiring, geometry, etc.
The best thing to do is audition the arms with good reputations in their price ranges that you can afford, and consider the synergy of the table and cartridge that you plan to use. The arm is not working alone, and needs to be considered in a system context with the appropriate table and appropriate cartridges. This is the only way you can get proper results from your package.