looking at upgrading my tonearm from a triplanar

Tim Paravicini chose the Helius Omega for his EAR table. I'm guessing it's pretty good!

Ralph, your mention of the hardness of the bearings in the Triplanar brings to mind a couple of questions for me. Could you give us your design engineer's perspective on the following?

- What is the significance of the hardness of a tonearm's bearings? At the tonearm weights involved, that alone wouldn't seem to be important.

- On the other hand, beside the bearing design itself, two bearing characteristics would seem, at least conceptually, to matter a great deal:

1- The bearing's ability to transfer mechanical energy out of the arm tube and into the mass of the turntable
2- The smoothness of the surface of the bearing material, for lowest friction.

Geoffrey Owens, the designer of the Helius arms, states that how an arm handles the mechanical energy created by the cartridge is his number one priority in designing an arm! Further, that the bearing assembly should optimally transfer that energy out of both sides of the horizontal bearings at the same time. If it doesn't (and I assume he will tell you very few do), there will be a faint echo created by the arm, because of the mechanical phase differential between the two. Wow.

Helius arms are offered with either Tungsten or Ruby bearings. Goeffrey acknowledges the potential for damage to the Rubies, but feels their surface smoothness is sufficiently superior to ANY metal as to make the risk a worthwhile trade-off. Viewed under a high-powered microscope (Geoffrey's other profession has been in Laser Optics), even the highest spec metal bearings have a very irregular surface. That, of course, creates sticktion.

As in everything else in Hi-Fi, tonearm design is a matter of conflicting design elements, requiring a choice on the part of both designer and consumer.

Some of Geoffrey's other business is involved with NASA-level space exploration. There is actually a superior alternative material already employed in the bearings contained in the Voyager spacecraft, I believe it is, but I don't feel entitled to repeat what was told me a few weeks ago regarding upcoming Helius products. I will just say that if I were looking into State-Of-The-Art tonearms, I would not buy one before next year. You heard it here first!

Is the Mk.VII Triplanar a significant improvement over the Mk.VI, or merely incremental?

I hear ya, brother! According to ARC, every Mk.2 version of every ARC product is a huge, dramatic transformation of the now unlistenable original. Some SP-10 owners probably traded in their pre-amp for the new SP-11 without thinking twice, soon thereafter regretting it.

I'm sure the Mk.VII Triplanar improves on the Mk.VI (the change was made long ago), but by how much and in what way(s)? A Mk.VI can be had for around $2k, making it look like an easy choice over any new arm at that price.

For anyone finding atmasphere's discussion of the bearings used in the Triplanar important in their consideration of tone arm design, or even just interesting, let me direct you to the Wikipedia entry (I don't know how to attach a link---I gotta learn how to do that!) on Silicon Nitride. One section in the entry is specifically about it's use in the making of bearings. NASA chose Silicon Nitride bearings for the main engines of the Space Shuttle for several reasons, one of them being that they are much harder than bearings made of ANY metal, no matter the hardness rating.

Geoffrey Owen of Helius Designs will be using them in his new TOTL tone arm being readied for introduction next year, but is also offering them as an upgrade on the current Omega arm. The standard Omega has Tungsten bearings, the Silver Ruby Omega, duh, Ruby ones, which as Ralph pointed out are easily damaged. Geoffrey used them because they are so much smoother than any metal (look at even the hardest grade of any metal bearing under a high-power microscope---it has quite a rough surface, no matter the grade; part of Geoffrey's business is in laser optics for use in space exploration telescopes), with far lower friction and, as Geoffrey told me, noise, the level of which is a major design criteria of his in making tone arms.