What makes a good tonearm?

I'm entering the world of decent analog and believe I understand why the turntable design is critical (e.g., vibration isolation, balance and speed stability) but am scratching my head a little about tonearms. What makes a good tonearm good and a great tonearm great? The resulting sound is always the key, but what design characteristics contribute to that sound? Tonearms are a big investment and can be tough to change later so I'd like to understand more about them before I buy anything. Thanks in advance.

Showing 3 responses by dougdeacon

The OL Silver is a great arm for the money, especially if modded with Twl's HIFI Mod. Not quite world class of course, but hugely impresive for the money. It mates well with some extraordinarily good cartridges like Shelters and Koetsu's. (The Shelters are also extraordinary performers for the money, as everyone on this thread probably knows.)

There are two articles worth reading on the Basis website. Good info if you can translate dorky engineering-speak. The Basis Vector is one of the three or four best pivoting arms in the world by all reports, as it should be for 3x the cost of a Silver.

What do the Resolution + RB900 go for? I could offer some of my usual opinionated recommendations if I knew that. I'm guessing there are tables that will be considerably punchier.
Speaking in generalities, a non-suspended table will tend to sound "punchier" than a suspended one. For much the same reasons, a gimballed arm will tend to sound punchier than a unipivot. A more stable base for the record and cartridge will allow maximum energy transfer from groove modulation to cantilever, with less loss of energy to suspsion or arm movement. If transient speed and dynamics are your goal, keep those aspects in mind.