9", 10" or 12" tonearms

This thread runs the risk of rehashing everything we've talked about over the past few years. With that in mind, I encourage the original poster to use the search facility on both this forum, Audio Asylum, DIY Hi-fi, etc.

For the purpose of this thread however, let's start with some simple stuff - a few guiding principles in audio component design. With that in mind (and in no particular order) here is Mackris' incomplete list of design axioms. Feel free to add others:

1. Designing any audio component is all about engineering and the art of compromise

2. You need keep the sound of real music in your consciousness, and if you play an instrument or are involved in its production or recording, you will be guided in profound ways

3. Measurements are a key starting point to any component aspiring to greatness, but they are ONLY a STARTING POINT (see #2)

4. If you attempt to optimize one design parameter at the expense of all others, you will fail miserably (see #1)

5. If you start to compare your component against other components, you will fail miserably (see #2).

There are all too many audiophiles who obsess about parameters, measurements, and numbers. Re-read #1 & #3 and get over it.

A bit of tough love ... a metaphor:

Imagine the music "lover" who approaches his music appreciation the way many tortured audiophiles do - in a decompositional manner. One day, he begins reading about tuning methods (just, well tempered, Pythagorean, equal tempered, etc.) It dawns on him that all fixed interval instruments (fretted instruments, keyboards, African thumb pianos, etc.) are inherently flawed. From that point onward, he refuses to listen to any of these instruments.

Does this remind you of anyone? Let the healing begin ...

Tonearm length is an attribute that raises its ugly head every few months. If you search this and other forums, you'll find posts by Frank Schroeder and Bob Graham on this topic. They can both address this better than I can. This is, after all, their own specialized part of this audio world and both have argued that a shorter arm better balances all parameters (see#1).

As far as Frank is concerned, he'll make any arm length your heart desires, but his personal arms are (in general) 9" arms.

Let's assume you set out to design a long tonearm, because you consider minimizing tracing distortion to be of paramount importance. Let's further assume that you want the arm to be compatible with a range of commonly available cartridges (Benz, Ortofon, Dynavector, Lyra, etc.). This means that you'll need to keep the effective mass down to the 10-12 gram range.

How do you accomplish this? Thinner walls in the arm tube (as compared with a 9" design)? Thinner, lightweight headshell (as compared with a 9" design)? Remember, that effective mass is an inertial moment, so weight at the headshell side of the arm has a greater influence on your effective mass.

How to you keep this lightened arm from rattling like a bucket of bolts when your Mahler 9th starts rocking and rolling? Things to think about ...

The bottom line is, that there is no easy answer to this. Both Frank S, and Bob G. consider that all parameters can best be balanced in a shorter (9") tonearm.

Now, if you want to design a dreadnought to run with a low compliance cartridge, you may not face as many compromises. You get my drift. There is no simple answer.

Those of you who were fortunate enough to see/hear the world debut of the Durand Talea tonearm in my room at this year's Audiofest will note that we have yet another great arm that centers around the 10" length (266mm, or 10.47" to be precise).

Joel did not set out to design a mid-length arm any more (I'm sure) than Herb Papier did with the Tri-Planar. As a matter of fact, Joel's earliest efforts were on the long side of 12".

Now ... don't go out and quote me as saying that 10" is the ideal length because I love both the Durand (266mm) and Tri-Planar (250mm). The point here, is that their material exploration and design process brought them to these lengths. I know this in the case of Joel, and strongly suspect it in the case of Herb Papier and the Tri-Planar.

Bob Graham and Frank Schroeder landed more in the 9" camp. The point is that all 4 of these arms are great tonearms. There are some great 12" tonearms as well but to ascribe any of these arms' greatness to their length would be drawing an erroneous conclusion.

Cheers,
Thom @ Galibier

Thom
As usual, your posts are clear, articulate and to the point. We "audiophiles" love to talk about what we think or believe but often this is based on feelings and not facts. As we also know, cost or price is not always a reflection of quality but also reflects available supply.

It is true, the discussion about tonearm length comes back every few weeks and all is said or written about. A good made 9“ Arm is superior to an average 12“ Arm.
Just my personal opinion about it.
A top 10“ or 12“ or longer Arm will give some results which can be interesting for one or the other.
When the customer wants to learn, he has to learn by himself. The typical audiophile is lazy, he looks for someone who „knows“ more than he does and will follow.
Can be ok, but you know the sentence „Ask 5 audiophiles and you will get 6 opinions“?
Best way is to visit other systems and to listen, after a while you will get impressions which will - or can - be a step forward.
Today we have internet and the times are modern, means, in High End - specially in analog - „Products“ came into the „market“ which are made from amateurs, supported from DIY groups, Internet support, Hype, good pricing when writing positive, top margins etc.
I don‘t care about, it is the way it is and everyone can burn his money the way he prefers. Everyone who has to live from „this“ has to defend his opinion and it does not make much sense to support old designs which are no longer available.
But let‘s go back to real life.
A customer can do his own comparisons, he has not to live from it and when the system is good enough to show the differences, he will hear the differences.
I did that, I think, I bought or loaned about 15 Arms and I had (or have) good/average 9“Arms (both expensive), I had 10“ Arm (expensive), same with 12“ Arms and after all those years I think, I do not prefer Arm length, I prefer the brain from the designer, some are better than others. And I prefer science and precision.
It is not a religion, I know some audiophiles who listen with Tables or Arms or Cartridges. I would refuse to listen to any longer than 5 minutes, because it is colored, limited...They are happy with it and don‘t want to know it any better (not everyone is interested in real top performance, a real top review is ok, too)
High End means „High“, not average, not hype(d), it means a better preformance... today and tomorrow we will see the change, average units will become „The Standard“ and when more and more believe in that, it will be „The Standard“.
When you don‘t believe in „The Standard of today“ you‘ll have to work on your own.
Sad, but true.
It is a long journey...

Lets not forget the fact, that the majority of all plinth turntables can NOT accommodate tonearms with an effective length greater than 10" (even the VPI 12.x and Kuzma 4Point tonearms do use a 9-10" mounting distance with off-center bearing location to move around this fact).
Thus any tonearm designer with a remote interest in sales will think twice ( and set aside the whole idea... ) about launching a 12" tonearm.
And it was that way ever since.
Custom audio born tonearms in 12" were always introduced as "off-springs" of their older 9-10" brothers.
All exceptions worth mention were broadcast-clones.
Aside from the points you mentioned - which most circle around less stiffness and increased dynamic moving mass (effective...) - this is one paramount "practical no-go" for 12" tonearms.
But I guess we all can agree, that in terms of geometry the 12" have a natural advantage in terms of tracking arc aspects. The increased mass is no question - well maybe one day we will see the re-rise of low compliance cartridges. Isamu Ikeda just revised his cartridges to lower the compliance......
Yes - in tonearm design it is all about careful choosing and weighting the needed compromises against each other.
The fact that we see many cartridges today with quite heavy body weight but quite high compliance ( certainly NOT a good mixture... it considerably increases the effective mass of ANY pivot tonearm ) doesn't make the game any less demanding ....

All great posts. My simplistic approach: I love the sound of my TT with a Graham Phantom Mkii and contacted my dealer and Bob Graham. Bob and my dealer took care of me and put me in a 10" Phantom Mkii because of clearance issues with my TT - a VPI TNT with Super Platter and Ring Clamp.

Find the equipment that gives you a musical experience you love and the rest will take care of itself.