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.
ozfly

Showing 3 responses by buscis2

Ozfly, You've been doing your homework haven't you? I own an Origin Silver, full mods, including slotted armtube/revised bearings.

For what's it's worth, I'll give you my spin?.....

My present arm of choice is, and has been, a modified RB900. Some interesting notes:

One step in the Origin upgrade includes glass beading and shot peening the armtube. These procesees actually alter (increase) the armtube surface hardness and surface texture. The surface hardness then becomes almost equivalent to the surface hardness of the "FACTORY" RB900 armtube. Get it?
(Origin won't tell you this but...) this process alters the resonance frequency of the armtube and actually INDUCES ringing in an more audible frequency range.

Their solution? Cut a slot in the armtube. It absolutely works. In fact it reduces the actual ringing to a lesser degree of magnitude than the standard RB900 arm. It also alters ANY resonances to a more desirable area of the frequency spectrum. Also, the arm is now hand assembled using the same "abec" spec'd bearings used in the "FACTORY" RB900. Get it?

Sound good right? It is. To an extent.

Throughout this whole concept, we MUST keep in mind that the coatings applied to the outside of the factory armtubes is not just "Krylon" or "RustOleum" spray paint. These coatings are specially formulated to provide very specific finish mil thicknesses, surface hardnesses, and vibration DAMPENING characteristics. Application procedures, fluid application viscosities, and deposition thicknesses are held to extremely close tolerances.

This is REGA'S way of doing things. As you can see, these are two different approaches to ultimately achieving similar results.

Kinda.

The info I just provided you is the fact. Now I'll provide you the opinion part. Personally? I feel that the Origin, although wonderfully detailed, open, airy, and all those other stupid adjectives, don't sound like music. After the mods? The weight disappeared. To Me? It sounds "clinical/critical". I hear the music being dissected, not played.

Some people may like that sound. Not me. I really enjoy the music that the RB900 makes. The 900 has been rewired w/ Cardas Litz, an adjustable Heavyweight and VTA. That's it.

It allows a Fender Precision to sound like a Fender Precision. Not an Alembic. Double 30" bass drums, sound like 30"s, not 26"s. A cathedral pipe organ has BALLS and tends not to sound "compressed". The 900 arm fools you into thinking it's not there. The Origin is audible, present, pronounced.

Please don't misread this. You will be very hard pressed to find a tonearm in the sub $2-$3000 price point that has all of the wonderful qualities of the Origin sound. But, that's just the point. The origin HAS a sound. It HAS a sonic signature. I don't want to hear ANY of my components. I also would have to question why a company modifies a tonearm (RB250/300) to closely replicate the specs of an already EXISTING (RB900) tonearm. Is it because that (EXISTING) tonearm is being used as the standard? Is it the benchmark? The pinnacle? Hmmm.

IMHO. Food for thought.

Regards, ED

Ozfly, There are so many good AND bad tonearms, and tonearm designs. It will all come down to which compromises you are willing to contend with. Every tonearm design available ie: linear tracking, gimballed, unipivot, or laser have issues.

I'm providing you with a link to very good primer on essential design parameters and considerations from the theoretical aspect. It is basic, but provides the fundamentals of established design criteria and execution.

Details and complications such as fixed effective length affecting overhang, linear offset, and feeble attempts to attaining null radii, (in essence, trying to defeat the laws of physics and geometry), constantly fluctuating centers of gravity and azimuth alignments in unipivot designs, ultimately inducing resonances (which somehow need to be dampened), and having to tolerate the eccentricities of linear designed arms who's systems begin to become so complex, that these complexities begin to introduce an almost insurmountable amount of variables to the equation.

Anyway, try this for a starter:

http://www.tnt-audio.com/sorgenti/armdesign_e.html


Hope you enjoy, Ed.
Ozfly, if in your studies of gimballed arms, you find a tonearm that will outperform an RB250, fully modified, with Cardas Litz (or equiv.) wire, stainless end stub, adjustable Heavyweight and VTA adjuster, under $500, even under $1000, make me the first to know, would you?

Over $1000? Other options are available. But you will be surprised at how few with an equivalent price/performance ratio.

IMHO.

Happy Listening, Ed.